1 / 14

Immune system

Immune system. Supplementary slides Biol 384N. Immune System. More concept than a system Separates “what’s me” from “what’s not me” Every cell → some immune function Some estimates, 25 % total body weight Some ways, most important system (immediate death if immunity fails).

aldan
Download Presentation

Immune system

An Image/Link below is provided (as is) to download presentation Download Policy: Content on the Website is provided to you AS IS for your information and personal use and may not be sold / licensed / shared on other websites without getting consent from its author. Content is provided to you AS IS for your information and personal use only. Download presentation by click this link. While downloading, if for some reason you are not able to download a presentation, the publisher may have deleted the file from their server. During download, if you can't get a presentation, the file might be deleted by the publisher.

E N D

Presentation Transcript

  1. Immune system Supplementary slides Biol 384N

  2. Immune System • More concept than a system • Separates “what’s me” from “what’s not me” • Every cell → some immune function • Some estimates, 25% total body weight • Some ways, most important system • (immediate death if immunity fails)

  3. Immune System • Conventionally said to include

  4. Thymus

  5. Lymph system

  6. Spleen

  7. Bone Marrow

  8. Innate Immunity • Developmentally the earliest • Nonspecific defenses: fevers, vomiting, diarrhea, urination. • Purging the body of pathogens. • Risky, especially for infants • Granulocytes and monocytes: phagocytes, neutrophils, macrophages.

  9. Acquired Immunity • Cell-mediated = activated T cells. • Thymus: • • processes these immature T cells, • •differentiates them, • • “teaches” them to recognize specific antigens, • •selects those T cells which can recognize the antigen. • •destroys T cells that self-react. • Antigen exposure → massive release of T cells (macrophages release cytokines). • (cytokines = communicator peptides) • e.g., IL-1 cause T cells to proliferate to combat antigens.

  10. Types of T cells • •Cytotoxic (effector T cells) recognize and lyse abnormal cells such as those infected with bacteria, viruses, or fungi, or cancer cells or cells with the “wrong” HLA complex as in tissue transplantation. • •Helper (CD4+) generate cytokines that stimulate other parts of the immune system.

  11. Types of T cells • Suppressor T cells help dampen immune reactions • (Prevent clonal selection of T cell clones that react against self-antigens) • •Memory T cells are the way the immune system resembles which antibodies work against which type of invaders. Similar to consulting its library or database for what worked before. • •Natural killer can survey the body and attack antigens without any pre-sensitization. Important in fighting precancerous cells or chronic viral infections.

  12. Delayed Hypersensitivity Reactions (DHR) • Component of cell-mediated immunity • DHR T cells attract other immune system cells such as macrophages or neutrophils to the site of an infection, eventually generating a strong inflammatory reaction • Examples: bee stings, nuts, poison oak • Repeat exposure strengthens the DHR • DHR mediates anaphylaxis

  13. Immediate Hypersensitivity Reaction • Allergies mediated by an antibody called IgE that directs mast cells to produce histamine → swelling, watery eyes, sneezing

  14. Auto-immunity • An immune response to one’s own tissues • RA was a recently discussed example • Thought to be due to weakened immune system and general depletion rather than “immune overdrive” • Difficult to treat via conventional medicine

More Related