Immunology Lecture 3 PDF

Immunology Lecture 3  1. Outcomes 1. Basic anatomy of the immune system (L1) 2. Immune responses (L2‐ L6) 4. Immune‐related pathology (L7 – L8) a. Innate immunity a. Cancer a. Organs involved in immune function...

Immunology Lecture 3  1. Outcomes 1. Basic anatomy of the immune system (L1) 2. Immune responses (L2‐ L6) 4. Immune‐related pathology (L7 – L8) a. Innate immunity a. Cancer a. Organs involved in immune function i. Non‐specific immunity b. Allergy b. Cells of the immune system and their basic b. Adaptive immunity c. Hypersensitivity functions i. Cell‐mediated immunity d. Auto‐immune disorders i. Basic white blood cell functions ii. Antibody‐mediated immunity e. Transplant rejection f. HIV ii. T and B cell‐specific functions iii. Antigen presenting cells 3. External defenses (L8) 2. Innate immunity Defenses include the following: Inflammation Interferon Natural killer cells Complement system 3. Innate immunity: Inflammation Non-specific response to tissue injury Goal is to bring phagocytes & plasma proteins to invaded or injured area Isolate, destroy, or inactivate the invaders Remove debris Prepare for subsequent healing and repair 4. Innate immunity: Inflammation Fig. 12-2, p. 421 6. Innate immunity: Inflammation Abbas, Abul K., Andrew H. Lichtman, and Shiv Pillai. Basic immunology: Functions and disorders of the immune system. Elsevier Health Sciences, 2014.  7. Innate immunity: Cytokines Chemical Secreted by Function Nitric oxide (NO) Macrophages Toxic to nearby microorganisms Lactoferrin Neutrophils Protein that binds with iron, making it unavailable for use by invading bacteria Tumor necrosis factor (TNF) Mast cells Induces local vasodilation and increases capillary permeability causes release of Histamine Kallikrein Neutrophils Converts specific plasma proteins precursors produced by liver into activated kinins – affects pain receptors, blood vessel dilation, chemotaxis Endogenous pyrogen (EP) Macrophages Induces development of fever (e.g. interleukin 1 and 6, TNF) Leukocyte endogenous mediator Macrophages Decreases the plasma concentration of iron by altering iron metabolism (LEM) (e.g. interleukin 1 and 6, TNF) within the liver, spleen and other tissues Acute phase proteins released due Liver upon Play role in inflammatory process, tissue repair, and immune cell activities to cytokine stimulation stimulation by LEM (e.g. C-reactive protein) C-reactive protein – also biomarker for inflammation, nonspecific opsonin Interleukin 1 (IL-1) Macrophages Enhances proliferation and differentiation of B and T lymphocytes  8. Innate immunity: Disease, repair & drugs Tissue repair: ‐ Cell division replaces lost cells with same kind of cells ‐ Lost cells are replaced with scar tissue → nonregenerative tissue (nerve and muscle) Acute (short term) versus chronic (long term) inflammation: ‐ Chronic inflammation can affect asthma, rheumatoid arthritis, obesity, cancer etc. Drugs that suppress with inflammation: ‐ Nonsteroidal anti‐inflammatory drugs (NSAIDs) [e.g. Aspirin, Ibuprofen] Asprin decreases histamine release & fever ‐ Glucocorticoids [e.g. cortisol] Suppress almost all aspects of inflammatory process. Reduce body’s ability to resist infection 10. Innate immunity: Interferon Interferon released from virus –infected cells Non‐specific resistance to viral infections 11. Innate immunity: Interferon Base/ Training Interferon = “whistle‐blower” ground * Soldiers Defense Tactics System Weapons 12.  13. Innate immunity: Natural killer cells ‐ Non‐specifically destroy virus infected cells and cancer cells ‐ Release chemicals to lyse cells (i.e., perforins and Granzymes) Base/ Training ground Soldiers Tactics A natural‐killer cell (pink) sidles up to a tumour cell (yellow). Credit: Eye of Science/SPL https://www.nature.com/articles/d41586‐018‐01812‐w Weapons 14. Innate immunity: Complement system Base/ Training Highly specialised protein punch ground Defense Soldiers Tactics System Weapons * 15. Innate immunity: Complement system Innate response: Nonspecific Adaptive immune response  16. Innate immunity: Complement system “Building” the punch/ activating the attack complex Individually many of these proteins can also affect inflammation E.g. acting as chemotaxins, opsonins, promoting histamine release, activating kinins Cell becomes leaky – influx of water – swell and burst 17. Innate immunity Defenses include the following Inflammation Interferon□ Natural killer cells□ Complement system□  18. Immune responses Base/ Training ground * Innate and non- Defense Soldiers System Tactics specific Adaptive (or acquired) and specific Differ in timing and defense mechanisms Weapons 19. Adaptive immunity 1. Antibody-mediated or humoral immunity - Involves production of antibodies by B lymphocyte derivatives known as plasma cells 2. Cell-mediated immunity - Involves production of activated T lymphocytes Directly attack unwanted cells  20. Adaptive immunity: Lymphoid tissues Maturation of T lymphocytes Produces hormone thymosin Thymosin enhances T cell proliferation and enhances immune ability of T cells Thymosin levels decrease after 30‐40 years Origin of blood cells-bone marrow Maturation of B lymphocytes Fig. 12-7, p. 428 21. Adaptive immunity: Antigen What is an antigen? Molecule that triggers a specific immune response.