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Immunology Exam 1 Part 2. Created by: Laura Wilson. Where are lymphoid stem cells produced in older fetuses and neonates?. Bone marrow . In mammals, where do T cells mature?. Thymus. In mammals, where do B lymphocytes mature?. Bone marrow.

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immunology exam 1 part 2

Immunology Exam 1Part 2

Created by:

Laura Wilson

the classification of lymphoid organs and tissues is based on
The classification of lymphoid organs and tissues is based on:
  • The level to which they participate in the maturation of lymphocytes
  • Provision of a suitable environment for the interaction between foreign antigen and antigen-sensitive T and B lymphocytes
what makes up the central primary or generative lymphoid organs and tissues
What makes up the central (primary or generative) lymphoid organs and tissues?
  • Thymus
  • Bone marrow (mammals)
  • Bursa of Fabricius (avian)
what are the functions of the central lymphoid organs and tissues
What are the functions of the central lymphoid organs and tissues?
  • Regulate production and maturation of lymphocytes, ie, generate lymphocytes that are individually different, the concept being “one cell, one specificity”
slide8
T/F
  • All of the central lymphoid organs regress with age
false
False
  • All but bone marrow regress with age
slide10

Mature lymphocytes acquire __ __ __ and other ___ ____ and learn to discriminate btwn self antigens, which are tolerated, and foreign antigens, which, generally are not

  • Specific antigen receptors
  • Phenotypic characteristics
maturation and differentiation of lymphocytes occur
Maturation and differentiation of lymphocytes occur:
  • Independent of foreign antigenic stimulation
what happens with removal of the central lymphoid organs early in life
What happens with removal of the central lymphoid organs early in life?
  • Loss of lymphocytes
  • Loss of immune responsiveness
where is the thymus found
Where is the thymus found?
  • Anterior mediastinal space
  • In horses, pigs, sheep, cattle, and chickens, it also extends up the neck as far as the thyroid gland
slide15
Part of the thymus that contains about 85% of the total thymocytes, cells here are relatively immature and divide rapidly
  • Cortex (outer thymic zone)
slide17
T/F
  • Thymic epithelial cells are found throughout the thymus
slide19
T/F
  • Interdigitating dendritic cells (IDCs) and macrophages are found in the thymic lobules
slide20
True
  • Particularly where?
  • At the coricomedullary junction
where are interdigitating dendritic cells idcs and macrophages derived from
Where are interdigitating dendritic cells (IDCs) and macrophages derived from?
  • Bone marrow
where does thymic involution begin
Where does thymic involution begin?
  • Within the cortex which may disappear completely, whereas medullary remnants persist.
what is corical atrophy related to
What is corical atrophy related to?
  • Corticosteroid sensitivity [lysis] of the immature cortical thymocytes
what occurs following neonatal thymectomy of day old mice
What occurs following neonatal thymectomy of day-old mice?
  • Total loss of cell-mediated immune response
  • B cell response to protein antigens is significantly impaired
when stem cells migrate to the thymus they acquire
When stem cells migrate to the thymus, they acquire:
  • Antigen receptors (TCRs) and other functional and phenotypic characteristics of mature T cells
what causes the functional and phenotypic changes in t cell maturation
What causes the functional and phenotypic changes in T cell maturation?
  • The influence of cytokines and thymic hormones
slide28
The phenotypic markers appear on the developing T cell membrane as _____ at different stages of differentiation in the thymus
  • Proteins
maturation of stem cells begins in the and as thymocytes mature they migrate toward the
Maturation of stem cells begins in the ____, and as thymocytes mature, they migrate toward the ______.
  • Cortex
  • Medulla
slide30
T/F
  • Only mature T cells exit the thymus and enter the blood and peripheral lymphoid tissues
positive and negative cell selection of thymocytes is a function of
Positive and negative cell selection of thymocytes is a function of:
  • Thymic epithelial cells
  • IDCs
  • macrophages
which thymocytes undergo positive selection
Which thymocytes undergo positive selection?
  • Thymocytes that express functional CD4 or CD8 molecules, ie, recognize self MHC I and II molecules
  • Thymocytes that express TCRs that have weak affinity for self-peptides
which thymocytes undergo negative selection
Which thymocytes undergo negative selection?
  • Thymocytes that DO NOT express CD4 or CD8 molecules
  • Thymocytes that DO NOT express TCRs or express TCRs that cannot bind weakly to self peptides
  • Thymocytes that express TCRs that have strong affinity for self-peptides
  • (Cell death may occur via neglect or by apoptosis)
slide35

The process of + and – selection effectively eliminates most T cells in the thymus, to the extent that >__% of the developing T cells die in the thymus

  • 90
definition
Definition:
  • Lymphoepithelial organ found in birds but not in mammals; observed as a sac-like structure dorsal to the cloaca
when does the bf reach maximum size
When does the BF reach maximum size?
  • 1-2 weeks after hatching (followed by gradual involution)
by the time the bird reaches age only atrophied vestiges remain of the bf and thymus
By the time the bird reaches _____ age, only atrophied vestiges remain of the BF and thymus.
  • 6 months (sexual maturity)
what occurs following a bursectomy of day old chicks
What occurs following a bursectomy of day-old chicks?
  • Only a slight drop in the numbers of circulating lymphocytes
  • Dramatic decline in Ab immune response
  • Slight to no effect on cell-mediated immunity
slide42
T/F
  • Peripheral (secondary) lymphoid organs arise late in fetal life and persist through adulthood
slide44
T/F
  • Removal of any of the peripheral lymphoid organs significantly reduces an individual or animal’s immune capacity
false45
False
  • It does not significantly reduce it
the sites where mature lymphocytes response to foreign antigens are initiated and develop
The sites where mature lymphocytes response to foreign antigens are initiated and develop.
  • Peripheral Lymphoid Organs
slide47
Adaptive immune responses to antigens entering the body via the skin and mucosa, or from parenchymal organs and CTs are initiated in the:
  • Lymph nodes
slide48
T/F
  • The majority of B cells die through apoptosis
slide49
True
  • (95-99%)—a reflection of negative selection of self-reactive B cells
slide50
T/F
  • Positively selected B cells seed the peripheral lymphoid organs and tissues
when do b cells begin to migrate from the bursa to the periphery
When do B cells begin to migrate from the bursa to the periphery?
  • A few days prior to hatching
  • Thus neonatal surgical bursectomy can severely compromise the normal development of the B cell lineage but does not result in complete ablation of peripheral B cells
slide53
T/F
  • Bursectomy at 16 days of incubation can result in complete agammaglobulinemia
bone marrow is divided into two compartments
Bone marrow is divided into two compartments:
  • Hematopoietic compartment
  • Vascular compartment
what does the hematopoietic compartment contain
What does the hematopoietic compartment contain?
  • Precursors of all blood cells as well as macrophages, and lymphocytes
slide58
T/F
  • In mammals, the hematopoietic compartment of the bone marrow is both a 1o and 2o lymphoid organ
what are the functions of bone marrow
What are the functions of bone marrow?
  • Source of all blood cells
  • Site of maturation of B lymphocytes in mammals
  • Mononuclear phagocytes remove particulate antigens from circulating blood
slide61
T/F
  • Bone marrow contains numerous plasma cells, which develop in peripheral lymphoid tissues as a result of antigenic stimulation of B cells and then migrate to the bone marrow
slide63
T/F
  • Peripheral lymphoid organs arise late in fetal life and persist through adulthood
slide65
T/F
  • Removal of any of the peripheral lymphoid organs significantly reduces an individual or an animal’s immune capacity
false66
False
  • It does not significantly reduce it
all lymph nodes eventually drain into the
All lymph nodes eventually drain into the:
  • Thoracic duct system and back to the peripheral blood
b cells are organized into
B cells are organized into:
  • 1o and 2o follicles within the cortex
germinal centers develop in response to
Germinal centers develop in response to:
  • Antigenic stimulation of B cells; thus, B cell proliferation, selection of B cells producing high affinity Abs by FDCs, and generation of memory B cells, occur in the GC
contains mostly t cells some macrophages and interdigitating dendritic cells
Contains mostly T cells, some macrophages and interdigitating dendritic cells.
  • Paracortex
lymphocytes enter the node from the circulation through the in the paracortex
Lymphocytes enter the node from the circulation through the _____ _____ _______ in the paracortex.
  • High Endothelial Venules (HEVs)
slide75
Lymph entering a lymph node percolates through the nodal stroma, where the antigens are extracted from the fluid by APCs such as:
  • Macrophages
  • IDCs
  • B cells
which lymphocytes are found around the central arteriole
Which lymphocytes are found around the central arteriole?
  • T cells (about 67% are helper T cells, 37% are cytotoxic T cells)
slide83

The lymphoid tissue which contains macrophages, some activated B cells and plasma cells. It is a storage site for erythrocytes, platelets, and granulocytes.

  • Red pulp
what is the function of macrophages in the red pulp
What is the function of macrophages in the red pulp?
  • They phagocytose old platelets and RBCs and also clear the blood of microorganisms and other particles
slide85
T/F
  • The spleen is the major site for the phagocytosis of antibody-coated (opsonized) microbes
separates the white pulp from the red pulp it contains macrophages some b cells and some t cells
Separates the white pulp from the red pulp. It contains macrophages, some B cells and some T cells.
  • Marginal zone
slide88

Blood borne antigens and lymphocytes enter the spleen through the ___ ____, which divide into capillary branches that empty into the ___ ____; from here the blood enters the ____ _____ of the red pulp.

  • Central arteriole
  • Marginal zone
  • Vascular sinusoids
where does b cell activation occur
Where does B cell activation occur?
  • At the junctions of the follicles and the T cell-rich PALS.
  • Activated B cells subsequently migrate into GCs or into the red pulp (where they differentiate to become antibody-producing plasma cells)
slide91

This tissue comprises all lymphoid cells present as either solitary or aggregated nodules in epithelia, lamina propria and submucosa of the GIT, resp. tract and genitourinary tract.

  • Mucosal-associated lymphoid tissues (MALT)
the main sites of malt are
The main sites of MALT are:
  • Gut-associated lymphoid tissues (GALT)
  • Bronchial-associated lymphoid tissues (BALT)
  • Genitourinary tract
lymphoid tissues in the lamina propria of the intestines peyer s patches appendix and tonsils
Lymphoid tissues in the lamina propria of the intestines, Peyer’s patches, appendix, and tonsils:
  • Gut-associated lymphoid tissues (GALT)
slide94
Consists of lymphocytes and accessory cells in the epidermis and dermis that detect and respond to environmental antigens.
  • Cutaneous immune system
definition95
Definition:
  • The continuous movement of lymphocytes from one lymphoid organ or tissue to another via the blood and lymph, and, if activated, to peripheral inflammatory sites
slide97
T/F
  • Naïve lymphocytes specific for any given antigen are very few in number
slide98
True
  • Thus, lymphocyte recirculation ensures that an antigen-specific lymphocyte will come in contact with that antigen no matter where in the body the antigen is located.
slide100
T/F
  • Lymphocyte recirculation ensures that activated (effector) lymphocytes are delivered to the particular tissue where they are required for elimination of the antigen
slide103

Extravasation of lymphocytes from the blood into a peripheral ln. occurs selectively at modified post-capillary venules w/n the paracortex of the node, called:

  • High endothelial venules (HEVs)
slide104
T/F
  • HEVs are present in all of the 2o lymphoid organs
false105
False
  • All but the spleen
what type of cells do hevs possess
What type of cells do HEVs possess?
  • Cuboidal (plump) endothelial cells
slide107
Activated cells that express a variety of adhesion molecules not found on the flat resting endothelial cells of ordinary venules
  • Cuboidal endothelial cells of the HEVs
slide108

The attachment of lymphocytes to the endothelium of peripheral lymphoid tissues is mediated by ____ _____ on the lymphocytes and ______ on endothelial cells.

  • Homing receptors
  • Addressins
slide109
T/F
  • Ordinarily, there is continuous lymphocyte movement through the node, but when an antigen enters the nodes, there is a temporary shut down in lymphocyte traffic, allowing antigen-specific lymphocytes to be activated and change into effector cells or memory cells
what occurs if a na ve t cell does not encounter an antigen
What occurs if a naïve T cell does not encounter an antigen?
  • It exits through an efferent lymphatic vessel, reenters the circulation, and homes to another lymph node.
slide112
T/F
  • The recirculation patterns of effector and memory T cells are the same as those of naïve T cells
false113
False
  • The recirculation patterns differ
slide114

Effector and memory T cells express increased levels of certain cell adhesion molecules, allowing them to enter teriary _____ ______ and ___ _____ in addition to 2o lymphoid organs.

  • Extralymphoidal tissue
  • Sites of inflammation
where are na ve b lymphocytes mainly found
Where are naïve B lymphocytes mainly found?
  • In the peripheral lymphoid organs
why are na ve b lymphocytes found in peripheral lymphoid organs
Why are naïve B lymphocytes found in peripheral lymphoid organs?
  • B/C B cells produce antibodies that act at a distance, hence, they need not home to sites of inflammation to mediate host defense.
slide117
T/F
  • A large fraction of blood lymphocytes are naïve B cells
false118
False
  • Only a small fraction
what type of b lymphocytes do recirculation
What type of B lymphocytes DO recirculation?
  • Memory B cells
  • Some activated B cells
  • Plasma cells
slide121
T cell precursors differentiate into ______ T cells within the thymus before populating the peripheral lymphoid organs and tissues.
  • Immunocompetent T cells
slide122
T/F
  • T cells are relatively short-lived cells that survive for only a few days
false123
False!
  • T cells are relatively long-lived cells that may survive from 6 months to over 20 years
slide124
T cells possess receptors (CD2) that enable them to bind to sheep RBCs. The sRBCs stick to the T cells to form:
  • “rosettes”
the formation of rosettes with srbcs and t cell receptors is a technique used to
The formation of “rosettes” with sRBCs and T cell receptors is a technique used to:
  • Count T cells and to separate T cells from B cells
several proteins are found on the surface of na ve t cells among them are proteins involved in
Several proteins are found on the surface of naïve T cells. Among them are proteins involved in:
  • Antigen recognition
  • Signal transduction
  • Adhesion to APCs and target cells
a number of the cell surface proteins have been given a cd designation what is cd
A number of the cell surface proteins have been given a CD designation. What is CD?
  • Cluster of differentiation
  • CD refers to the group of monoclonal antibodies that recognize the same protein on a cell surface
slide128
Activation of a cell surface receptor, requires binding to its specific _____, which may be a ____-____ on another cell or a ____ _____.
  • Ligand
  • Counter-receptor
  • Soluble protein
the t cell receptor complex consists of
The T cell receptor complex consists of:
  • T cell receptor (TCR)
  • CD3 complex
  • Zeta proteins
slide130

A disulfide-linked heterodimer glycoprotein that enables T cells to recognize processed antigens presented in association with MHC molecules.

  • T cell receptor (TCR)
alpha beta chains are integral membrane proteins composed of
Alpha/Beta chains are integral membrane proteins composed of:
  • An extracellular domain
  • A transmembrane domain
  • A short cytoplasmic tail
the extracellular domains of the tcralpha beta chain consist of
The extracellular domains of the TCRalpha/beta chain consist of:
  • Variable, constant, and hinge regions
slide134

Type of region where CDRs reside w/n the variable region; they consist of unique amino acid sequences that form the antigen-binding site of the TCR.

  • Hypervariable regions (Complementarity-determining regions, CDRs)
slide135
T/F
  • Both chains possess 3 CDRs juxtaposed to one another
slide136
True
  • CDR1, CDR2, CDR3
which cdr is the center displaying most diversity and directly interacts with the antigens
Which CDR is the center, displaying most diversity, and directly interacts with the antigens?
  • CD3
slide139

The variable B chain contains a fourth hypervariable region, which doesn’t appear to participate in peptide recognition but is the binding site for microbial products called:

  • superantigens
slide141
T/F
  • The TCRs on the T cells are clonotypic, ie, they will recognize only a single epitope bound to an MHC protein.
slide144
T/F
  • The CD3 complex and the zeta chains are covalently linked to the TCRalpha/beta chains.
false145
False
  • They are noncovalently linked
slide147
T/F
  • The two zeta chains are the same on all T cells
when a tcr binds an antigen what must occur
When a TCR binds an antigen, what must occur?
  • A signal must be sent to the T cell in order to initiate a response
slide150
T/F
  • The cytoplasmic tail of the TCR is too small to transduce signals
slide151
True
  • Therefore the biochemical signals for T cell activation DO NOT come from the TCR, but from the CDR complex and the zeta chains
the cd3 complex also functions in
The CD3 complex also functions in:
  • Stabilizing cell surface expression of TCR
slide153
T/F
  • T cells effectively express TCR on the cell surface w/o the CD3 complex
false154
False
  • T cells DO NOT effectively express TCR on the cell surface w/o the CD3 complex
membrane proteins which play critical roles in t cell response to antigen
Membrane proteins which play critical roles in T cell response to antigen.
  • Accessory molecules
what do cd4 and cd8 molecules promote
What do CD4 and CD8 molecules promote?
  • Adhesion of T cells to APCs and target cells and also play a role in signal transduction, thereby potentially T cell activation
slide157
This TCR coreceptor is found on helper T cells, it binds to the B2 domain of the class II MHC molecule on the surface of professional APCs.
  • CD4 molecule
slide158

This TCR coreceptor is found on cytotoxic T cells. It’s function is the recognition of the alpha3 domain of class I MHC molecules, enabling cytotoxic T cells to bind to target cells.

  • CD8 molecule
these molecules strengthen interactions between t lymphocytes and professional apcs or target cells
These molecules strengthen interactions between T lymphocytes and professional APCs or target cells
  • Lymphocyte Adherence Molecules
slide161
This molecule binds T cells to CD54 molecules on APCs and target cells. Promotes T cell binding to endothelial cells:
  • CD11a/CD18
slide162

This molecule is found on resting T cells. Activated T cells express more than this molecule. It binds to a protein called CD58 present on APCs and target cells. It is also a T cell signal transducer.

  • CD2
slide163

This is a membrane receptor for co-stimulatory signals [signal 2] that activates naïve T cells. It’s ligand is B7-1 and B7-2 that are expressed on the professional APCs.

  • CD28
slide164
T/F
  • CD28 is constitutively expressed on >90% of naïve helper T cells and 50% of cytotoxic T cells
slide166
T/F
  • The repertoire of TCRs available to an animal or individual is carefully regulated, ie, can respond to as many different foreign antigens as possible but not to self antigens.
what is the gene encoding for alpha chains in humans beta chains
What is the gene encoding for alpha chains in humans? Beta chains?
  • Alpha:
  • Chromosome 14
  • Beta:
  • Chromosome 7
multiple variable v region genes 100 and joining j region genes 75 occur with this tcr locus
Multiple variable (V) region genes (100) and joining (J) region genes (75) occur with this TCR locus.
  • TCRalpha
slide170
T/F
  • During the rearrangement of alpha chain genes, a randomly selected V gene is joined to a J gene and the exon is transcribed, combined with a constant (Calpha) region gene, and translated.
slide172
Multiple variable (V) region genes (75), diversity (D) region genes (2) and joining (J) region genes (12) occur at this TCR locus.
  • TCRB
how is the b beta chain exon formed
How is the B (beta) chain exon formed?
  • By the random linkage of a V region gene, first to a D region gene and a J region gene, and then to a CB (beta) gene
when does allelic exclusion occur
When does allelic exclusion occur?
  • When only one of the parental alleles that code for the TCR is functional, rendering each T cell responsive to only a single epitope
how is the diversity of tcrs accounted for
How is the diversity of TCRs accounted for?
  • Multiple germ-line genes
  • Gene rearrangements
  • N-region addition (nucleotide sequences that are not present in the genome but are encoded by random nucleotide additions)
in humans the number of potentially different tcr a b combinations is on the order of
In humans, the number of potentially different TCR a/B combinations is on the order of:
  • Billions
slide179
T/F
  • Rearranged TCRs in the thymus do not display somatic hypermutation as with B-cell-derived Igs.
slide181
T cells whose TCRs bind strongly to self-peptides (______ ____) are negatively selected during maturation in the thymus.
  • Forbidden clones
slide184
These have been identified according to the particular function of them and the membrane markers (CD antigens) that they express.
  • Subsets of T cells
slide185
T cell subset that helps B cells produce antibodies to protein antigens and promotes activation and proliferation of other T cells.
  • Helper T cells
helper t cells play a major role in promoting
Helper T cells play a major role in promoting:
  • Innate and adaptive immune responses by releasing soluble helper factors [cytokines] that affect the activities of several cell types
slide188
T/F
  • Professional APCs (macrophages, B cells, Dendritic cells) activate Helper T cells which in turn produce cytokines
slide190
Helper T cells respond only to ____ ____ when it is presented by professional APCs in association with self-MHC class II molecules.
  • Processed antigens
slide191
T/F
  • Interaction with an APC involves multiple TH cell membrane proteins that recognize different ligands on the APC
na ve t h cell activation requires two signals what is involved with signal 1 signal 2
Naïve TH cell activation requires two signals. What is involved with signal 1? Signal 2?
  • Signal 1:
  • TCR complex and CD4 recognition of peptide-MHC complexes on the APC
  • Signal 2:
  • Co-stimulation
slide194
The best characterized co-stimulators for naïve TH cells, absent or expressed at low levels on resting APCs :
  • B7 proteins
when does enhanced expression of b7 proteins occur
When does enhanced expression of B7 proteins occur?
  • When APCs are stimulated by endotoxins (LPS), and binding of T cell CD40L to CD40 on the APCs occur.
signaling by cd28 enhances several t h cell responses to antigen including the following
Signaling by CD28 enhances several TH cell responses to antigen, including the following:
  • Production of cytokines
  • Differentiation of naïve T cells into effector cells
of the professional apcs which cells are the most potent activators of na ve t h cells why
Of the professional APCs, which cells are the most potent activators of naïve TH cells? Why?
  • Mature dendritic cells
  • B/C they express the most MHC molecules and co-stimulators.
slide199
T/F
  • CD40 is present all of the time on APCs
slide201
T/F
  • CD28 is always present on the T cell
cd40l binds to cd40 on the apc and stimulates the expression of
CD40L binds to CD40 on the APC and stimulates the expression of:
  • B7 molecules, which bind to:
  • CD28 on the helper T cell and the secretion of:
  • Cytokines that activate the:
  • Helper T cell
slide205
T/F
  • Only signals from APC to the helper T cell are considered 1st and 2nd signals
if il 2rs are bound by il 2 on the na ve helper t cell what occurs
If IL-2Rs are bound by IL-2 on the naïve helper T cell, what occurs?
  • The cell undergoes clonal expansion and differentiation of the daughter cells into effector cells or antigen-specific memory cells
slide208
The differentiated effector TH cells enter the circulation from the site of naïve TH cell activation and are carried to:
  • Peripheral tissues (lymphoid and nonlymphoid)
slide212
T/F
  • Effector cell responses decline following elimination of an antigen
slide214
T/F
  • The vast majority of antigen-activated T cells die by apoptosis within a few days
the decline in effector response is significant b c it returns the immune system to a state of
The decline in effector response is significant b/c it returns the immune system to a state of:
  • Rest or Homeostasis
what do the memory t h cells account for
What do the memory TH cells account for?
  • Increased and accelerated 2o responses on subsequent exposure to the same antigen
slide221
T/F
  • Memory TH cells are functionally quiescent until reexposure to the antigen induces them to proliferate and initiate effector functions
helper t cells are divided into
Helper T cells are divided into:
  • TH1 helper cells and TH2 helper cells
helper t cells divide on the basis of their
Helper T cells divide on the basis of their:
  • Production of and responses to specific cytokines
t h 1 and t h 2 subsets develop from the same
TH1 and TH2 subsets develop from the same:
  • Naïve CD4+ T lymphocytes [TH0] in the peripheral lymphoid organs
slide226
T/F
  • Thymus generates the TH0, TH1, and TH2
false227
False
  • The thymus only generates the TH0
when are cytokines produced
When are cytokines produced?
  • In the innate immune response to microorganisms or early in adaptive immune responses
slide230
T/F
  • The cytokines produced by the TH1 and TH2 subsets exhibit cross-regulation
slide231
True
  • Cytokines from TH1 cells can block the production and/or activity of the cytokines secreted by TH2 cells and vice versa
what is the consequence of cross regulation
What is the consequence of cross-regulation?
  • An immune response tends to settle into a TH1 type of response or a TH2 type of response
what is the t h 1 subset responsible for
What is the TH1 subset responsible for?
  • Classical cell mediated immune functions, eg, delayed-type hypersensitivity and activation of cytolytic T lymphocytes
what is the t h 2 subset mostly responsible for
What is the TH2 subset mostly responsible for?
  • As a helper for B cell activation and antibody production
slide235
Intracellular signaling proteins produced by cells that have autocrine, paracrine, or endocrine actions on themselves or other cells:
  • cytokines
slide236
T/F
  • Cytokines usually act locally by binding to high affinity cytokine receptors
slide238
T/F
  • Cytokines are antigen specific and bind to antigens
false239
False
  • Cytokines are not antigen specific and they do not bind to antigens
slide240
T/F
  • Cytokines are active at very high concentrations
false241
False
  • Cytokines are active at very low concentrations
slide242
T/F
  • Cytokine secretion is a brief, self-limited event
slide244
T/F
  • Cytokines often influence the synthesis of other cytokines
slide246
T/F
  • Cytokine receptors can have circulating forms that block the cytokine before it reaches its cellular target
what are the sources for interleukin 1 il 1
What are the sources for Interleukin-1 (IL-1)?
  • Activated macrophages
  • Endothelial cells
  • Langerhans cells
  • B cells
  • Epithelial cells
what is the function of il 1alpha
What is the function of IL-1alpha?
  • It binds to the macrophage membrane, enabling macrophages to activate lymphocytes that come in contact with them
what is the function of il 1beta
What is the function of IL-1beta?
  • It is secreted by cells, thus, most of the IL-1 found in circulation are IL-1beta.
slide256
T/F
  • Both forms of IL-1 bind to the same IL-1 receptors and mediate the same biologic activities
slide258

This is a third form of IL-1 that binds to IL-1 receptors but is biologically inactive so that it functions as a competitive inhibitor of IL-1:

  • IL-1 receptor antagonist (IL-1ra)
what is the purpose of il 1ra
What is the purpose of IL-1ra?
  • It is an endogenous regulator that serves to prevent excessive IL-1 driven inflammatory response
what are the principle activities of il 1
What are the principle activities of IL-1?
  • Lymphocyte activation
  • Acts on endothelial cells to increase expression of adhesion molecules that mediate leukocyte extravasation and secrete chemokines that activate leukocytes
  • Acute-phase reaction—stimulates hepatocytes to synthesize increased levels of acute-phase proteins in response to inflammation
  • Nervous System—acts on brain to cause fever, lethargy, malaise, and lack of appetite
  • Initiates metabolic wasting
slide261
T/F
  • IL-1 acts on the thermoregulatory center in the anterior hypothalamus, resulting in prostaglandin-induced fever
what is another name for il 2
What is another name for IL-2?
  • Lymphocyte Growth Factor
slide265
T/F
  • Activation of T cells by antigens and co-stimulators, stimulates transcription of the IL-2 gene and synthesis and secretion of IL-2
what are the principal activities of il 2
What are the principal activities of IL-2?
  • T helper cells: Proliferation and increased cytokine production
  • Cytotoxic T cells: proliferation and differentiation to mature Tc cells
  • B cells: promotes B cell growth and antibody synthesis
  • NK cells: Proliferation and enhanced cytolytic activity
what are the principle activities of il 4
What are the principle activities of IL-4?
  • Stimulates B cell differentiation and Ab synthesis
  • Down-regulates IFN-gamma synthesis by TH1 cells (inhibiting macrophage activation and suppressing cell-mediated immune responses)
  • Growth factor for mucosal mast cells
what are the principle activities of il 5
What are the principle activities of IL-5?
  • Functions synergistically with IL-2 and IL-4 in B cell growth and differentiation
  • The principle cytokine that stimulates growth and differentiation of eosinophils, activation of mature eosinophils
what are the principle activities of il 6
What are the principle activities of IL-6?
  • Promotes IL-2 and IL-2R production and T cell differentiation
  • Differentiation of B cells into plasma cells and Ab production
  • Stimulates synthesis of acute-phase proteins
what are the principal activities of il 10
What are the principal activities of IL-10?
  • Immunoregulatory cytokine that immunosuppresses CMI responses
  • Inhibits synthesis of IFN-gamma
  • Inhibits macrophage production
  • Inhibits the expression of MHC II molecules and co-stimulators on macrophages—inhibiting T cell activation
what are the principle activities of il 12
What are the principle activities of IL-12?
  • Counterpoint to IL-10
  • Stimulates the induction of TH1 subset from naïve CD4+ T cells
  • Stimulates production of IFN-gamma
  • Activates macrophages
  • Inhibits IgE isotype switch by suppressing IL-4 synthesis
what is the main source for tumor necrosis factor alpha tnf alpha
What is the main source for Tumor Necrosis Factor-alpha (TNF-alpha)
  • LPS-activated macrophages
what are the principle functions of tnf alpha
What are the principle functions of TNF-alpha?
  • Overlaps w/ IL-1 and IL-4 as acute-inflammatory response of hepatocytes and endogenous pyogen—fever
  • Expression of adhesion molecules and synthesis of chemokines
  • Activates neutrophils and macrophages
  • Causes pathologic abnormalities if prolonged production or high concentration
slide281
What are some examples of pathologic abnormalities resulting in prolonged production or high concentrations of TNF-alpha?
  • Intravascular thrombosis
  • Cachexia
  • Septic shock (observed in G- septicemia)
slide282

TNF stimulated endothelial cell expression of tissue factor, a potent activator of coagulation. Occurs in tumor vessels accounting for it’s tumor killing activity:

  • Intravascular thrombosis
characterized by wasting of muscles and fat cells
Characterized by wasting of muscles and fat cells:
  • Cachexia
  • TNF is referred to as “cachectin”
very large amounts of tnf result in
Very large amounts of TNF result in:
  • Inhibition of muscle tone and cardiac contractility
  • Decreased BP
  • Shock
what are the principle functions of tgf b
What are the principle functions of TGF-B?
  • Inhibits immune and inflammatory responses
  • Inhibits proliferation and differentiation of T cells and the activation of macrophages
  • Acts on neutrophils, endothelial cells, and other cell types to counteract the effects of production of IgA Ab
  • Enhances synth. Of extracellular matrix proteins such as collagens and proteins, proliferation of fibroblasts, promoting TISSUE REPAIR
slide287

A family of glycoproteins synthesized by somatic cells in response to virus stimulation, immune stimulation, mitogens, LPS, and synthetic dsRNA:

  • Interferons
slide288

Type of IFNs which inhibit virus replication and increase expression of MHC class I molecules. They also inhibit the proliferation of many cell types, including tumor cells:

  • Type I Interferons
type i interferons are divided into two forms
Type I Interferons are divided into two forms:
  • Interferon-alpha
  • Interferon-beta
interferon alpha are secreted by
Interferon-alpha are secreted by:
  • Macrophages and other leukocytes
interferon beta is secreted by
Interferon-beta is secreted by:
  • Fibroblasts and epithelial cells
what are the main sources of interferon gamma type ii interferon immune interferon
What are the main sources of Interferon-gamma (Type II Interferon; Immune interferon):
  • TH1 cells, CD8+ T cells, and NK cells
what are the principle activities of interferon gamma
What are the principle activities of Interferon-gamma?
  • Principal activator of macrophages
  • Induces Class I and II MHC expression
  • Promotes B cell IgG isotype switch
  • Promotes proliferation and cytolytic activities of NK cells and Tc cells
  • Acts on TH2 cells to inhibit production of IL-4, blocking IgE isotype switch by B cells
what are the growth hematopoietic cytokines
What are the Growth (Hematopoietic) Cytokines?
  • IL-3
  • IL-7
  • Granulocyte macrophage-colony stimulating factor (GM-CSF)
  • Monocyte-colony stimulating factor

(M-CSF)

  • Granulocyte-colony stimulating factor

(G-CSF)

  • Stem Cell Factor (SCF)
what are the sources for il 3
What are the sources for IL-3?
  • Activated T cells, mast cells, etc.
what is the primary activity of il 3
What is the primary activity of IL-3?
  • Promotes growth and differentiation of stem cells into all known mature cell types
what are the sources of il 7
What are the sources of IL-7?
  • Bone marrow and thymic stromal cells
what is the primary activity of il 7
What is the primary activity of IL-7?
  • Growth of immature thymocytes and pre-B cells
what are the sources of the genetically engineered hematopoietic cytokines
What are the sources of the genetically engineered hematopoietic cytokines?
  • Activated T cells
  • Macrophages
  • Endothelial cells
  • Bone marrow stromal cells
what are the primary activities of the genetically engineered hematopoietic cytokines
What are the primary activities of the genetically engineered hematopoietic cytokines?
  • Production of inflammatory leukocytes from bone marrow progenitor cells
  • Recombinant GM-CSF and G-CSF are used clinically to stimulate bone marrow recovery after cancer chemotherapy and bone marrow transplants
what is the source of stem cell factor scf
What is the source of Stem Cell factor (SCF)?
  • Bone marrow stromal cells as a transmembrane protein or a secreted protein
what are the primary activities of stem cell factors scfs
What are the primary activities of stem cell factors (SCFs)?
  • May be needed to make bone marrow stem cells responsive to other CSFs but that it does not cause colony formation by itself
  • May play a role in sustaining the viability and proliferative capacity of immature T cells in the thymus and of mast cells in mucosal tissues
slide304

Large family of small proteins that are involved in migration and activation of cells, especially phagocytic cells and lymphocytes. They play a role in inflammatory rxns:

  • Chemokines
what cells produce chemokines
What cells produce chemokines?
  • Leukocytes
  • Fibroblasts
  • Endothelial cells
  • Epithelial cells
what induces the secretion of chemokines from these cells
What induces the secretion of chemokines from these cells?
  • Pathogens
  • Inflammatory cytokines, principally TNF-alpha and IL-1
slide307

Chemokines bind to ______ _____ _______ on endothelial cells and extracellular matrix proteins; in turn, they are recognized by chemokine receptors on leukocytes.

  • Heparan sulfate proteoglycans
chemokines are classified into two subfamilies based on the sequence of two pairs of the amino acid
Chemokines are classified into two subfamilies based on the sequence of two pairs of the amino acid:
  • cysteine
what are the two subfamilies for chemokines
What are the two subfamilies for chemokines?
  • CXC chemokines (alpha-chemokines)
  • CC chemokines (beta-chemokines)
which subfamily of chemokines have their first two cysteines separated by one amino acid
Which subfamily of chemokines have their first two cysteines separated by one amino acid?
  • CXC chemokines (alpha chemokines)
cxc alpha chemokines mostly attract and activate
CXC (alpha) chemokines mostly attract and activate:
  • Neutrophils
  • The most important is:
  • IL-8
slide313
T/F
  • High concentrations of cytokines or chronic exposure to a cytokine, can result in various toxicities
high does of interferons can result in
High does of interferons can result in:
  • Severe fever
  • Malaise
  • Inappetance
high does of interferons also inhibit hematopoiesis resulting in
High does of interferons also inhibit hematopoiesis resulting in:
  • Thrombocytopenia and granulocytopenia
  • Liver, kidney, and neural toxicity
high levels of il 2 results in
High levels of IL-2 results in:
  • Fever
  • Chills
  • Vascular leak syndrome—resulting in excessive edema
enterotoxins produced by some strains of s aureus can act as and trigger polyclonal t cell response
Enterotoxins produced by some strains of S. aureus can act as _______ and trigger polyclonal T cell response:
  • superantigens
cytokines produced by these cells eg tnf alpha can cause
Cytokines produced by these cells (eg. TNF-alpha) can cause:
  • Fever
  • Hypotension
  • Damage to the liver and kidney
exam questions
EXAM QUESTIONS:
  • These are the answers that were on the exams, so I think they are right, but I didn’t look them up, so…ya know…check them if you think otherwise.
slide321
T/F
  • B cells only process antigens trapped by dendritic cells
  • False
slide322
T/F
  • A function of IL-1 is activation of endothelial cells, resulting in increased expression of adhesion molecules such as ICAM-1
  • True
slide323
T/F
  • An individual T cell expresses both alpha/beta [TCR2] and gamma/delta [TCR1] receptors
  • False
slide324
T/F
  • 1o and 2o granules are present in both neutrophils and macrophages
  • False
slide325
T/F
  • Genes in the MHC complex code for some complement proteins
  • True
slide326
T/F
  • High endothelial venules, site of extravasation of lymphocytes, are present in lymph nodes but not in the spleen
slide328
T/F
  • Rolling of leukocytes along vascular endothelium is observed only at sites of inflammation
  • False
slide329
T/F
  • B cell receptors present on a resting mature B cell consists of pentameric IgM and IgD
  • False
slide330
T/F
  • A function of S protein is the prevention of “bystander” lysis during complement activation
  • True
slide331
T/F
  • LPS is an antigen that requires processing to generate anti-LPS antibodies
  • False
slide332
T/F
  • A synonym for NK cells is large granular lymphocytes
  • True
slide333
T/F
  • B cell isotype switching occurs only when responding to protein antigens
  • True
slide334
T/F
  • A major source of complement proteins is neutrophils
  • False
slide336

Following a 1o antigen injection, there is an Ab response that consists most of __; the response following a 2o response challenge is mostly __.

  • IgM
  • IgG
following antigenic stimulation resulting daugher b cells become or
Following antigenic stimulation, resulting daugher B cells become ______ or _________.
  • Memory cells or plasma cells
the four phases of antibody response following antigenic challenge in order are and
The four phases of antibody response following antigenic challenge, in order, are ____, ____, ____, and ____.
  • Lag
  • Log
  • Plateau
  • Decline
in a lymph node b cells mainly populate the whereas t cells are found in the
In a lymph node, B cells mainly populate the ____ whereas T cells are found in the _____.
  • Cortex
  • Paracortex
cytokines that stimulate hepatocytes to release acute phase proteins include and
Cytokines that stimulate hepatocytes to release acute-phase proteins include ____ and ____.
  • IL-1 and TNF-alpha
define the following 2 pts each
Define the following (2 pts each):
  • C3 tickover
  • Defensins
  • Immunologic redundancy
the following are acute phase proteins synthesized by hepatocytes except
The following are acute-phase proteins synthesized by hepatocytes except:
  • A. C-reactive protein
  • B. Haptoglobin
  • C. Complement proteins
  • D. siderophore
an incorrect statement concerning the complement system
An incorrect statement concerning the complement system:
  • A. Alternative pathway proteins include factors B, D, and properdin
  • B. Sequence of classical pathway activation is C1, C4, and C2
  • C. Inactivation of C3b first requires the binding of factor I followed by inactivation of factor H
  • D. May result in disseminated intravascular coagulation
which of the following is not a source of il 1
Which of the following is not a source of IL-1?
  • A. Macrophages
  • B cells
  • C. Dendritic cells
  • D. T helper cells
slide351
A cytokine which acts as an angiogenesis factor, fibroblast growth factor can result in wasting of muscles and fat cells.
  • A. IL-2
  • B. Tumor necrosis factor-alpha
  • C. Interferon gamma
  • D. IL-1
which of the following is not a lymphocyte
Which of the following is not a lymphocyte?
  • A. NK cell
  • B. Dendritic cell
  • C. T cell
  • D. B cell
bacterial structure that protects g bacteria from complement lysis
Bacterial structure that protects G+ bacteria from complement lysis:
  • A. Peptidoglycan
  • B. Lipoprotein
  • C. LPS
  • D. Teichoic acid
the following are mhc class i genes except
The following are MHC class I genes except:
  • A. HLA-A
  • B. HLA-B
  • C. HLA-C
  • D. HLA-D
sources of passive immunity include all of the following except
Sources of passive immunity include all of the following except:
  • A. Vaccination
  • B. Hyperimmune serum
  • C. Colostrum
  • D. Egg yolk
approximate molecular size of an epitope
Approximate molecular size of an epitope:
  • A. 3,000 daltons
  • B. 5,000 daltons
  • C. 7,000 daltons
  • D. 10,000 daltons
which of the following statements is least accurate concerning il 1
Which of the following statements is least accurate concerning IL-1?
  • A. IL-1alpha is the form of IL-1 found in tissue fluids
  • B. IL-1 is involved in the development of fever by increasing PGE2 in the hypothalamus
  • C. IL-1 is a family of 3 cytokines, consisting of 2 agonists [IL-1alpha and IL-1beta] and one antagonist [IL-1ra]
  • D. An important action of IL-1 is as a mediator for the antigen recognition and clonal expansion phases of T and B cells.
match the following receptors with their corresponding ligands
Match the following receptors with their corresponding ligands:
  • 1. CD8
  • 2. CD2
  • 3. B-7
  • 4. C3b
  • Choices: CD28, CD40, CD35, MHC II, CD58, MHC I
slide368
1. MHC I
  • 2. CD58
  • 3. CD28
  • 4. CD35
slide369
T/F
  • Extravasation of neutrophils during acute inflammation occurs mainly at postcapillary venules
  • True
slide370
T/F
  • Integrin proteins used by leukocytes during transendothelial migration are mostly nonfunctional, requiring an activation signal from the endothelial cell to become active
  • True
slide371
T/F
  • Antibodies produced to a hapten can bind to the hapten only if the hapten is still conjugated to the carrier protein
  • False (free or conjugated)
slide372
T/F
  • Highly flexible molecules that have no fixed shape are poor antigens
  • True
slide373
T/F
  • Human MHC class I genes include HLA-A, HLA-E, and HLA-D genes
  • False (HLA-D are class II)
slide374
T/F
  • LPS is a potent activator of macrophages and B lymphocytes
  • False??
slide375
T/F
  • Macrophages are an important source of complement proteins and angiogenesis factor
  • True
slide376
T/F
  • Processed epitope presented by APC is recognized by the CD4 molecule of the antigen receptor complex of the T helper cell
  • ???
slide377
T/F
  • Differentiation of precursor cytotoxic T cell to functional or mature cytotoxic cell occurs in the thymus
  • True???
slide378
T/F
  • High endothelial venules (HEV) facilitate extravasation of blood lymphocytes into peripheral lymph nodes
  • True
slide379
T/F
  • The most important function of sIgA is as an anitgoxin
  • False
slide380
T/F
  • Chemical mediators produced at the site of inflammation, generally, have short tissue half-lives
  • True
slide381
T/F
  • Plasma proteins important in host immune response include gamma globulin, complement, and albumin
  • False (albumin is not important in immunity!)
antibody produced in the highest concentration following initial contact with antigen
Antibody produced in the highest concentration following initial contact with antigen: ____.
  • IgM
slide389

Neutrophil proteins that kill microbes by interacting with the microbial cell membrane to form channels through which essential metabolites escape: _______.

  • defensins
central lymphoid organs in avian species include and
Central lymphoid organs in avian species include ____ and _____.
  • Thymus and Bursa of Fabricius (BF)
define or explain the following 2 points each
Define or explain the following (2 points each):
  • Iccosomes
  • Antibody affinity
  • Isotype switching
which of the following is not a source of immune regulatory cytokines
Which of the following is not a source of immune regulatory cytokines?
  • A. T cells
  • B. Macrophages
  • C. Neutrophils
  • D. NK cells
which complement protein is associated with platelet aggregation
Which complement protein is associated with platelet aggregation?
  • A. C3b
  • B. C4b
  • C. C5a
  • D. Factor D
which of the following is not a target for il 1
Which of the following is not a target for IL-1?
  • A. Hypothalamus
  • B. Liver
  • C. Endothelial cells
  • D. Mast cells
long term antigen retention in the splenic follicles is mediated by
Long-term antigen retention in the splenic follicles is mediated by:
  • A. B cells
  • B. Dendritic cells
  • C. Macrophages
  • D. T cells
slide401
Together with antigen, the following can induce resting helper T cells to produce IL-2 and IL-2R except:
  • A. IL-5
  • B. IL-1
  • C. IL-12
  • D. B7-1
the following are produced or expressed by endothelial cells except
The following are produced or expressed by endothelial cells except:
  • A. E-selectin
  • B. VCAM-1
  • C. L-selectin
  • D. ICAM 1
which cytokine inhibits ige production
Which cytokine inhibits IgE production?
  • A. IL-2
  • B. Interferon-gamma
  • C. Tumor necrosis factor-B
  • D. IL-4
mononuclear cells important in host defense include the following except
Mononuclear cells important in host defense include the following except:
  • A. NK cells
  • B. Neutrophils
  • C. B cells
  • D. Macrophages
concerning dendritic cells which statement is least accurate
Concerning dendritic cells, which statement is least accurate?
  • A. Mononuclear cells with spine-like projections
  • B. Produce MHC II proteins
  • C. Possess Fc receptors
  • D. Presents antigens only to B cells
concerning interferon gamma which statement is least accurate
Concerning interferon-gamma, which statement is least accurate?
  • A. Secreted by activated helper T cells, macrophages, and NK cells
  • B. A potent activator of macrophages
  • C. Promotes Ab production by B cells
  • D. Increases synthesis of MHC class I by nucleated cells
slide419
Protein A produced by the bacterium binds to the Fc portion of IgG, enhancing colonization by preventing opsonization.
  • A. Streptococcus pyogenes
  • B. Staphylococcus aureus
  • C. Mycobacterium bovis
  • D. Listeria monocytogenes
the classical pathway of complement activation occurs when or antibodies bind to the target antigen
The classical pathway of complement activation occurs when ___ or ___ antibodies bind to the target antigen.
  • IgG or IgM
slide422

Refers to the increase in the binding strength of antibodies produced during the course of a humeral immune response as a result of somatic mutations.

  • Affinity maturation
slide423

Anaphylatoxins that serve to recruit fluid and inflammatory cells to sites of antigen invasion by stimulating mast cell degranulation includes ___ and ___.

  • C5a and C3a (????)
costimulatory molecules of helper t cells derived from antigen presenting cells include and
Costimulatory molecules of helper T cells derived from antigen-presenting cells include ___ and __.
  • IL-1 and IL-6
immunoglobulin molecule that facilitates the binding of nk cell to a virus infected cell
Immunoglobulin molecule that facilitates the binding of NK cell to a virus infected cell: _____.
  • IgG
antigen presenting cell also known as interdigitating dendritic cell
Antigen presenting cell also known as interdigitating dendritic cell: ___.
  • Langerhans cell
slide429
T/F
  • Vasoactive mediators of inflammation are derived exclusively from the injured tissue
  • False
slide430
T/F
  • Compared to the resting mature B cell, a higher dose of antigen is required to activate memory B cells.
  • False
slide431
T/F
  • Most cytokines have multiple activities and act on numerous cell types.
  • True
slide432
T/F
  • Membrane immunoglobulins act as B cell receptors [BCRs] on mature B lymphocytes
  • True
slide433
T/F
  • Integrin proteins present on nonactivated neutrophils have low affinity for immunoglobulin superfamily proteins on endothelial cells
  • True
slide434
T/F
  • B cells and other professional presenting cells partially degrade the antigen and present peptide epitopes or polysaccharide epitopes in association with MHC II proteins to helper T cells
  • False
slide435
T/F
  • A memory immune response has a shorter lag period compared to a primary immune response
  • True
slide436
T/F
  • In the thymus, production of T cells occurs predominantly in the medulla
  • False
slide437
T/F
  • Cell-mediated immune responses are more significant in the elimination of intracellular parasites
  • True
slide438
T/F
  • The alternative complement pathway can be activated by bacterial LPS
  • True
slide439
T/F
  • A distinguishing feature between neutrophils and macrophages in their microbicidal activities is that neutrophils can generate a respiratory burst whereas macrophages cannot
  • False
slide440
T/F
  • Cytokines secreted by lymphocytes are called lymphokines
  • True
slide441
T/F
  • During embryonic development, primary lymphoid organs appear before secondary lymphoid organs
  • True
slide442
T/F
  • The inactivation of activated complement components occurs by spontaneous decay, owing to the action of natural inhibitors in the serum
  • True
all of the following complement components are required in the alternative pathway except
All of the following complement components are required in the alternative pathway except:
  • A. C1, C2, C4
  • B. C5, C6, C7
  • C. Properdin
  • D. C3
the following properties render a substance immunogenic
The following properties render a substance immunogenic:
  • A. High molecular weight
  • B. Chemical complexity
  • C. Sufficient stability and persistence after injection
  • D. All of the above are essential but not sufficient
concerning haptens which statement is least accurate
Concerning haptens, which statement is least accurate?
  • A. Require carrier molecules in order to be immunogenic
  • B. They are generally low MW substances
  • C. Some haptens can bind to host cell proteins in vivo
  • D. Will not react with specific antibodies in vitro unless bound to the carrier protein
resting helper t cells can be activated by all of the following except
Resting helper T cells can be activated by all of the following except:
  • A. Langerhans cells
  • B. Neutrophils
  • C. B cells
  • D. Macrophages
which cell can generate a memory cell
Which cell can generate a memory cell?
  • A. NK cells
  • B. T cell
  • C. Macrophage
  • D. Eosinophil
the liver can enhance host defense in multiple ways except being
The liver can enhance host defense in multiple ways except being:
  • A. A source of complement proteins
  • B. A source of iron-binding proteins
  • C. A source of lymphocytes in the developing fetus
  • D. A source of cytokines
the d region of the mhc codes for
The D region of the MHC codes for:
  • A. Class I molecules
  • B. Class II molecules
  • C. Class III molecules
  • D. Class IV molecules
the rise in temperature that causes a fever is due to the hypothalamus responding to
The rise in temperature that causes a fever is due to the hypothalamus responding to:
  • A. IL-1
  • B. G+ bacteria
  • C. Complement
  • D. IL-2
the class specific amino acids of immunoglobulins are associated with
The class-specific amino acids of immunoglobulins are associated with:
  • A. J chains
  • B. Disulfide bonds
  • C. H chains
  • D. Variable regions
an incorrect statement concerning nk cells is
An incorrect statement concerning NK cells is:
  • A. They are lymphocytes
  • B. They produce cytokines
  • C. They express CD8 molecules
  • D. They produce cytolytic proteins such as perforins and granzymes
concerning macrophages which statement is least accurate
Concerning macrophages, which statement is least accurate?
  • A. They produce cytokines such as IL-2 and interferon gamma
  • B. They arise from monocytes
  • C. They play a role in the specific immune response
  • D. They synthesize and release inflammatory mediators such as prostaglandins and leukotrienes
which antibody is protected from proteolytic degradation by the secretory component
Which antibody is protected from proteolytic degradation by the secretory component?
  • A. IgA
  • B. IgE
  • C. IgG
  • D. IgM
mhc class i molecules
MHC class I molecules:
  • A. Regulate interaction btwn cytotoxic T cells and target cells
  • B. Restrict activity of regulatory T cells and target cells
  • C. Regulate interaction bwtn helper T cells and antigen-presenting cells
  • D. Represent components of the complement pathways
an incorrect statement concerning complement protein c3b is
An incorrect statement concerning complement protein C3b is:
  • A. It is an anaphylatoxin
  • B. It can bind to factor B
  • C. It is an opsonin
  • D. It can bind to C5 protein
iga isotype switching by daughter b cells is regulated by
IgA isotype switching by daughter B cells is regulated by:
  • A. IL-2, IL-4, and IL-6
  • B. Interferon gamma and IL-1
  • C. IL-4 and IL-12
  • D. TGF-B and Il-5
slide475
A bacterial cell that survives and multiplies in macrophages by preventing formation of the phagolysosome:
  • A. E. coli
  • B. Listeria monocytogenes
  • C. Mycobacterium bovis
  • D. Staphylococcus aureus
oxygen dependent antimicrobial products of neutrophils include all of the following except
Oxygen-dependent antimicrobial products of neutrophils include all of the following except:
  • A. Superoxide anion
  • B. Lactoferrin
  • C. H2O2
  • D. Singlet oxygen
slide479
T/F
  • Helper T cell-derived signals that activate B cells include cytokines and CD40L
  • True
slide480
T/F
  • Antigenic determinant or epitope is a specific region on an antibody that binds to the antigen
  • False
slide481
T/F
  • B cell mitogens used in vitro to study the functional status of B cells include condanavalin A
  • False
slide482
T/F
  • B cell receptors (BCRs) present on a resting B cell consist of IgD and pentameric IgM
  • False
slide483
T/F
  • Interferon-gamma is a potent activator of macrophages
  • True
slide484
T/F
  • Only protein antigens are processed and presented by antigen presenting cells
  • False (?)
slide485
T/F
  • The effector phase of an immune response follows the recognition and activation phases, and results in inactivation or destruction of the foreign antigen
  • True
slide486
T/F
  • For an autocoupling hapten to elicit an immune response in the host, it must first be bound to a carrier protein in vitro and then conjugate introduced into the host cell
  • False (in vivo)
slide487
T/F
  • Memory B cells express B cell receptors that have undergone affinity maturation, hence are activated by low antigenic dose
  • True
slide488
T/F
  • MHC class II proteins can be demonstrated on the cell membranes of every nucleated cell in the body
  • False
slide489
T/F
  • IgG molecules can activate the complement system only when they are first bound to an antigen
  • True
slide490
T/F
  • T cell receptors (TCRs) on a specific T cell are clonotypic
  • True
slide491
T/F
  • Genes in the class III loci of the MHC code for tumor necrosis factor and some complement proteins
  • True
the basic structure of an antibody molecule is composed of two identical and two identical
The basic structure of an antibody molecule is composed of two identical _____ and two identical ______.
  • Heavy chains
  • Light chains
virus infected cells displaying reduced or no mhc class i proteins are lysed by
Virus-infected cells displaying reduced or no MHC class I proteins are lysed by: _______.
  • CD8+ T cells
in the classical pathway of complement activation the substrates for the cls enzme are and
In the classical pathway of complement activation, the substrates for the Cls enzme are __ and __.
  • C4 and C2
in b cell response to a foreign antigen daughter b cells eventually differentiate into and
In B cell response to a foreign antigen, daughter B cells eventually differentiate into ___ and ___.
  • Plasma cells and memory cells
plasma proteins involved in host defense include and
Plasma proteins involved in host defense include ___ and ____.
  • Immunoglobulins
  • Complement proteins
which of the following events cannot be attributed to an activated endothelial cell
Which of the following events cannot be attributed to an activated endothelial cell?
  • A. Synthesis of histamine
  • B. Expression of P selectin
  • C. Synthesis of cytokines
  • D. Ability to retract
slide502
The highest rate of Ab production occurs during which of the following phases of humoral immune response?
  • A. Lag phase
  • B. Logarithmic phase
  • C. Plateau phase
  • D. Decline phase
slide508
In mammalian immunologic development, the precursors of lymphocytes arise from progenitor cells of the:
  • A. Yolk sac
  • B. Thymus
  • C. Liver
  • D. Both a and c
aids is caused by a human lentivirus that kills
AIDs is caused by a human lentivirus that kills:
  • A. B lymphocytes
  • B. Lymphocyte stem cells
  • C. CD4-positive T lymphocytes
  • D. CD8-positive T lymphocytes
complement activation refers to
Complement activation refers to:
  • A. The ingestion of C3b-coated bacteria by macrophages
  • B. The destruction of complement in serum by heating at 56 oC for 30 minutes
  • C. The binding of complement components by antigen-antibody complexes
  • D. The interaction of C3b with mast cells
natural killer cells are
Natural killer cells are:
  • A. B cells that can kill w/o comlement
  • B. Cytotoxic T cells
  • C. Monocytes that kill virus-infected cells
  • D. Able to kill virus-infected cells w/o prior sensitization
which one of the following substances is not released by an activated helper t cell
Which one of the following substances is not released by an activated helper T cell?
  • A. IL-1
  • B. Interferon-gamma
  • C. IL-2
  • D. IL-4
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Which cytokine is released by LPS-activated macrophages and can stimulate hepatocytes to release acute-phase proteins?
  • A. IL-2
  • B. Tumor necrosis factor alpha
  • C. Interferon-gamma
  • D. B7-1
an incorrect statement concerning macrophages is
An incorrect statement concerning macrophages is:
  • A. Macrophages play a role in the specific immune response
  • B. Macrophages are microbicidal
  • C. Activated macrophages can kill facultative intracellular bacteria
  • D. Macrophages possess both 1o and 2o lysosomal granules
concerning antibodies which statement is least accurate
Concerning antibodies, which statement is least accurate?
  • A. The hypervariable regions are also know as complementarity determining regions
  • B. All antibodies have a long half-life
  • C. In the memory response, IgG is the antibody produced in the highest concentration
  • D. A plasma cell produces a single Ab class
which of the following statements does not apply to 1 o lymphoid organs
Which of the following statements does not apply to 1o lymphoid organs?
  • A. Transformation of stem cells into antigen-specific T and B cells requires antigenic stimulation
  • B. Most 1o lymphoid organs regress later in life
  • C. Majority of developing T cells are destroyed in the thymus
  • D. They are also known as central lymphoid organs
which would you expect to activate cytotoxic cd8 t cells
Which would you expect to activate cytotoxic CD8+ T cells?
  • A. A killed viral preparation that has retained its antigenic properties but cannot replicate
  • B. An attenuated viral preparation that can still replicate within the host’s cells
  • C. A small protein such as insulin
  • D. None of the above
which of the following is not a chemotactic agent for neutrophils
Which of the following is not a chemotactic agent for neutrophils?
  • A. C5a
  • B. Rantes
  • C. LTB4
  • Interferon-gamma
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