Immune System_The Players.pdf

IMMUNE SYSTEM – THE PLAYERS Date: 09/12/2023 PHM 310 Avinash Kumar, Ph.D. Announcements Office Hours: By Appointment (Email) Office: WL 203 Email: [email protected] Objectives ü Enlist the players (the cells and organs) of the immune system ü Describe the players of the immune system How...

IMMUNE SYSTEM – THE PLAYERS Date: 09/12/2023 PHM 310 Avinash Kumar, Ph.D. Announcements Office Hours: By Appointment (Email) Office: WL 203 Email: [email protected] Objectives ü Enlist the players (the cells and organs) of the immune system ü Describe the players of the immune system How does a society/community protect itself or keep itself safe? - Barriers - Specific points for entry - Means and ways to detect misconduct - Security guards to detain misconductee How does an organism protect itself or keep itself safe? Physical and Chemical Barriers – The 1st Line of Defense http://www.vce.bioninja.com.au/aos-2-detecting-and-respond/defence-against-disease/first-line-of-defence.html Immune System Immune – protect, defend, keep safe Against harmful/disease causing organisms (pathogens) Immunity – protection, defense, safety/security Immune System Innate Immune System § Generic § Non-specific § 2nd Line of defense Innate Immunity Acquired Immune System (Adaptive/Specific) § Specific § 3rd Line of defense Acquired Immunity (Adaptive/Specific) Pathogens Ø Bacteria ü Intracellular - Salmonella ü Extracellular - Vibrio Ø Fungi ü Intracellular - Candida ü Extracellular - Cryptococcus Ø Viruses ü Intracellular – HPV, HIV Ø Parasites v Protozoans ü Intracellular - Plasmodium ü Extracellular - Entamoeba v Helminths ü Extracellular – Pinworm, Tapeworm, Ascaris How does immune system protect or keep an organism safe? WHO? The players; security guards; cells/organs HOW? WHAT? Means/ways; immune response Cells of the immune system White blood cells (WBCs); leukocytes Ø Granulocytes (multi-lobed nucleus, granules in cytoplasm) ü Eosinophils ü Neutrophils ü Basophils and Mast Cells Ø Agranulocytes (single-lobed nucleus, no granules in cytoplasm) ü Monocytes/mononuclear phagocytes/macrophages ü Lymphocytes (B, T, and Natural Killer [NK] cells) Granulocytes Innate Immune System Agranulocytes https://labtestsonline.org/tests/blood-smear Acquired Immune System https://www.rnceus.com/cbc/cbcwbc.html http://www.bloodjournal.org/content/124/14/2314?sso-checked=true Cells of the innate immune system Phagocytosis - eat and destroy • Neutrophils • Phagocytose bacterial antigens and digest in lysosome. • Recruited to sites of infection by IL8 or complement via chemotaxis • Eosinophils • Phagocytose, but not as efficiently as neutrophils • Defense against parasites • Release factors that destroy extracellular parasites, cause inflammation and exfoliation of respiratory epithelial cells, and trigger histamine release (airway hyperreactivity) • Basophils (bloodstream) Mast Cells (Tissues) • Allergic (hypersensitivity) responses. • Bind IgE antibodies • Release histamines, leukotrienes, prostaglandins, and platelet-activating factor (PAF) causing inflammation • Monocytes (bloodstream) Macrophages (Tissues) • Phagocytose antigens and digest in lysosome. • Can serve as antigen presenting cells (APCs). Cells of the acquired immune system Organs of the immune system • Primary organs (makes immune cells, no immune response occurs here) • Bone Marrow • All blood cells are made here. • Pluripotent stem cells give rise to lymphocytes, monocytes, granulocytes (neutrophils, eosinophils and basophils), red blood cells, and megakaryocytes (platelets) • Thymus • Produces T lymphocytes • Positive and negative selection of T lymphocytes (Do you recognize self? Destroyed! Do you recognize something foreign? Kept.) – Self Tolerance • Failure to destroy self-recognizing T cells causes autoimmune disease https://www.eurostemcell.or g/regenerating-thymus • Secondary organs (immune response occurs here) • Lymph nodes, spleen, and lymphoid tissues • Localize antigen, promote cell cell interaction and lymphocyte activation, prevent spread of infection • Contains B and T lymphocytes • GALT = gut associated lymphoid tissue (tonsils, peyer patches in the small intestine, appendix) • Spleen – filters and processes antigens from the blood and filters out old red blood cells Conclusions Ø Innate immune system (non-specific/generic) – 1st and 2nd line of defense • Skin – 1st line of defense Ø Cells of the Innate immune system • Neutrophils - Bacteria • Eosinophils - Parasites • Basophils Mast cells – Allergy/Hypersensitivity • Monocytes Macrophages – Antigen presentation 2nd line of defense Ø Acquired immune system (specific/adaptive) – 3rd line of defense Ø Cells of the Innate immune system • B and T Lymphocytes • Natural Killer (NK) cells Ø Organs of the Immune System • Primary organs ü Bone marrow and Thymus – Immune Cells are produced here • Secondary organs ü Lymph nodes, Lymphoid tissue and Spleen – Immune Response occurs here