Chapter 23 Immune Systems. 4. Immune 1 adj. Derived from classical Latin Munia = duties 1. Exempt from something disagreeable or harmful 2. Not susceptible to some specified disease. 12. What can make you sick?. Cutting board Bacteria and Fungi, 300x 2. Legionella bacteria 3000x 2.
adj. Derived from classical Latin
Munia = duties
1. Exempt from something disagreeable or harmful
2. Not susceptible to some specified disease
Cutting board Bacteria and Fungi, 300x2
Anthrax spores in lung
Ragweed Pollen, 550x2
Polio Virus, 46,050x 2
1. Infection byPathogen
Infection: Entry of pathogen into the body
Pathogen: Any foreign body that can cause disease
When the body’s cells and tissues have been damaged by the pathogen so that they no longer functionThe Disease Process
Patho = suffering (Greek, Latin)
gen = producing (Latin)
In = in (Latin)
fect = to do or make (Latin)
Antigen = Any foreign material that activates the immune system; usually a protein. Need not be pathenogenic.
Why is an antigen called an antigen? See P. 604
Eg. Skin, bark, mucous membranes, low pH of stomach, antibacterial enzymes in sweat, tears, saliva
Specific Defenses (Adaptive Immunity)
Develops in 4-14 Days
Cell mediated response
Antibody mediated response
Memory cellsHow does the immune system prevent disease?
Resistance = “the ability to ward off infectious diseases” (447)
What’s fever for?
Phagocytic cells have special cell surface receptors which recognize antigens
Also recognize self
Engulf and destroy foreign bodies
Activate specific defenses
Response to injury, damage, or foreign antigens
Damaged capillaries leak fluid and cells into injury
Redness, swelling, warmth
Phagocytes remove debris and dead cellsNonspecific Defenses
Pus = Phagocytic cells, dead pathogens, debris
Alveolar macrophage phagocytosis of E. coli; 1315x 2
White blood cells
Figure 24.4Internal Nonspecific Defenses
P.S. The nail was driven into that person’s hand by a nail gun. OUCH!
HLA = Human Leukocyte Antigen
The cell “name tag” or “fingerprint
Each “flag” is a protein displayed on the cell’s surface.
Except in unusual cases or identical twins, a person’s combination of HLA factors is unique
Specificity: Immune system is NOT supposed to react to self HLA, but IS supposed to react to everything else.
to the rescue!Immunity through Leukocytes2
Blood with T Cells and Platelets; 2000x
Helper T cell (small cell) and B cell (large cell); 2000x
Remember… we need specificity and memory!
Lymphatic vessels, entering veins
Lymphatic vesselsLymphocytesa kind of leukocyte
2 Trillion in your body
Originate in bone marrow
Look at P. 609
from bone marrow (bursa)
Antibody mediated (Humoral)
Recognize antigens on pathogens
immune responseAdaptive Immunity
Helper T cell (small cell) and B cell (large cell); 2000x 2
Immune Surveillance: Both have receptors on their membranes to recognize antigens and travel through the body to “seek out and destroy.”
The point is thatstem cellscan turn into many different kinds of leukocytes!
T Cells need further development in the Thymus, B cells mature in the Bone marrow
Stimulate the production of antibodies by B cells
Cytotoxic T Cells (CTL)
Attack foreign cells
Attack infected “self” cells
Suppressor T Cells
Shut down the immune system
Reduce B and T cell activities
Memory T CellsCell Mediated Immunity and T Lymphocytes2
Activated by Antigen display by macrophages
Antigen fragments activate Helper and Cytotoxic T cells.
Macrophage displays antigen
APC stimulates the Helper T cell
Cytotoxic T Cells and B cells both need the cytokines of the Helper T cells to become active
After activation by TH cellsT-Cells destroy
~ non-self cells ~ altered or infected self cells
2. B Cell digests and displays a “ready” complex
3a. Helper T Cell recognizes complex and produces lymphokines
3b. Rapid mitosis occurs
Plasma cells make antibodies
Memory cells last a long time. Can make antibodies and more plasma cells.
Antibodies bind to antigen to mark it for destructionAntibody Mediated Immunity and B Lymphocytes3
4 polypeptides held together with disulfide bonds
Each B cell makes only one kind
Each kind binds one antigen
~106 different kindsSo, what is this thing called an Antibody?3
Each antibodybinds one antigenin a lock and key arrangement
Remember enzyme-substrate fit.Antibody-Antigen Binding14
Complement Binding Site
Remember… Each B cell only makes one antibody
So how is the immune response specific?
Antibodies bind to antigens making it easier for macrophages to surround and destroy
Binding of complement proteins to antibody also enhances phagocytosisAntibodies in Action5
1. Antibodies bind antigen
2. Binding activates complement proteins
3. Those complement proteins activate others
4. Complement proteins “drill” holes in microbe membrane (lyse cells), letting fluid pressure burst the cell
Activated complement also stimulates inflammationAntibodies and Complement8
7500 x 2.4 million = 18 billion possible kinds of antibodies!
After initial exposure to antigen
Stimulates specific B cells that respond to the antigen/pathogen
Secondary Immune Response
Memory cells immediately begin dividing to produce plasma cells (B cells)
Antibody production begins more quickly
Amount of Antibody
Time (days)Categories of Immunity9
Look at speed of response and amount of antibody produced the second time!
Chemical change in cell surface proteins
Cells no longer recognized as self
Immune system attacks those cells
See p. 624
Eg. Poison Ivy Reaction
Cell destruction causes swelling, redness, blistersWhen the system doesn’t work right
Hypersensitive Immune Systems
Also read about diseases and chemicals…
Hypersensitive Immune Systems
Immune system stops recognizing self HLA
Immune system attacks the body’s own cells
Vacca = cow
ation =action or process
Generally only works for one specific disease
Edward Jenner (1798)
Immune system remembers the cowpox
Vaccinated personimmune to smallpox
Last smallpox deaths occurred in 1978Immune System Memory and Vaccinations
Will the smallpox vaccine protect against other viruses?
The last known person in the world to have smallpox of any kind. Here 23-year-old Ali Maow Maalin of Merka, Somalia exhibits the pox of Variola minor.7
from reaction of immune system with antigen
fetus/newborn gets antibodies directly from mother, in colostrum/milk
from direct injection of antibodiesKinds of Immunity18
Which ones do you have NOW?
Cool Web Sites: www.iir.suite.dk/ IIR/IIRimsys.htm, www.mansfieldct.org/schools/mms/ staff/hand/Warriorsimm.htm
http://www.primaryimmune.org/library/immune/ ----- This is cartoons! -----
Macrophage Epitope Display: http://www.cat.cc.md.us/~gkaiser/microrlo/unit3/intro/mhc/mhctwo.html
1. Immunity: Webster’s New World Dictionary and Thesaurus, 1996.
2. www.denniskunkel.com, with permission.
3. Leukocyte Production, B Cell and Macrophage activation, antibody schematic, clonal selection: http://http://www.blc.arizona.edu/courses/181gh/Lectures_WJG.01/immunol_F.01/immunology.html
5. Macrophage ingesting bacteria covered with antibody: http://gened.emc.maricopa.edu/bio/bio181/BIOBK/BioBookIMMUN.html
8. Complement: http://www.sciam.com/explorations/2000/012400preg/IMG/complement.gif
9. Immune Response Graph: www-immuno.path.cam.ac.uk/~immuno/ part1/lec05/lec6_99.html
10. Poison Ivy Picture: http://www.leelanau.com/manitou/images/poison-ivy.jpg
11. Poison Ivy Face 1: http://www.sims.berkeley.edu/~mgebbie/Pictures/Timmons%20Spring%202000%20vacation/pages/Poison%20Ivy.htm
13. HLA: http://www.med.umich.edu/trans/public/hla/hla_&_you.html
14. Antibody Fit:www.nycornell.org/uo/ graphics/epitope.gif
15. Autoimmune Diseases: www.niaid.nih.gov/publications/ autoimmune/autoimmune.htm
16. Histamine Structure: http://www.perl.com/1999/08/onion/pix/histamine.gif
17. Allergy Diagram: http://www.mc.uky.edu/allergy/sneeze.asp
18 www.rush.edu/happening/ images/hiv-vaccine.jpg
19. BioCD. From Biology, Fifth Edition. Campbell, Reece, Mitchell. Addison, Wesley, Longman. 1999.
21. www.indianahandcenter.com/ handsafe.html
24. Bioshow: for Biology: Concepts and Connections, Second Edition. Campbell, Mitchell, and Reece