1. Review: Cells of the Immune System Leukocytes – White blood cells Myelocytes –macrophage, neutrophil, eosinophil,basophil Leukocytes – B, T and NK cells From Larsson and Karlsson (2005)

2. Review: Cells of the Immune System Larsson and Karlsson (2005)

3. Review: Myelocytes Dendritic cell

4. Review: Myelocytes Macrophages – phagocytes, antigen presenting cells (APCs), specialized cells different organs, secrete cytokines, produce complement proteins, can produce ROS/RNS. Neutrophils – phagoctyes, can produce ROS/RNS, secrete antimicrobial peptides, 1 st cell type to migrate from blood to infections, main targets are bacteria and fungi Eosinophils – phagocyte, targets parasites Basophils – secrete cytokines, involved in allergic response

5. Lymphocytes: T cells B cells Natural killer cells Review: Lymphocytes

6. B cells – naïve B cells: contain antigen binding receptor (or membrane bound antibody), once activated – memory cells: provides memory of antigen/antibody interaction; plasma cells: secrete soluble antibody Review: Lymphocytes

7. T cells - contain antigen binding receptor (TCR) T H cells: secretes cytokines that activate B cells, T C cells, macrophages and others. T C cells: eliminates altered/damaged self cells (particularly those infected by viruses), fights tumors cells, secrete cytotoxins. T reg cells: helps suppress immune response, plays a role in tolerance. Review: Lymphocytes T reg cell

8. Natural killer cells – distinct from T and B cells due to lack of an antigen binding receptor, similar in function to T C cells, macrophage activation, defense against viruses, fight tumor formation, secrete cytotoxins. Review: Cells of the Immune System

9. Derived from both lymphoid and myeloid precursors Dendritic cells – phagoctyes, antigen presenting cells (APCs), can produce ROS, secrete proinflammatory cytokines, secrete antimicrobial peptides. Review: Cells of the Immune System

10. Review: Organs of the Immune System Primary and secondary lymphoid organs: 1°- maturation of lymphocytes 2°- sites where mature lymphocytes interact with antigen. Level of organization: collection of cells vs. lymphoid follicle

11. Review: Innate and adaptive immunity

12. Review: Innate Immune Response

13. Review: Adaptive Immune Response Antigen/Antibody interactions:  Antigen – any substance that binds specifically to an antibody or a T cell receptor (TCR).  Antibody- a protein (immunoglobulin) that recognizes a specific region (component) of an antigen. Properties of immunogenicity: Foreignness Molecular size Chemical composition/complexity Processing/presentation Host factors Dosage Route of entry

14. Antibody-Mediated Effector Functions Opsonization Assist/activate complement system ADCC

15. Humoral and Cellular Immunity Cellular immunity – Host defenses that are mediated by antigen- specific T cells and various nonspecific cells of the immune system. Humoral immunity – Host defenses that are mediated by antibody present in the plasma, lymph and tissue fluids.

16. The Complement System Ricklin and Lambris 2007

17. The Complement System Functions of the Complement System

18. The Complement System Components of the Complement System: proteins and glycoproteins synthesized mainly by liver 5% of serum circulate as zymogens Designation of complement components: numerals (C1-C9) letter symbols (factor D) trivial names (homologous restriction factor) cleavage products – “a” and “b”

19. The Complement System Complement Activation Pathways: Classical Pathway Alternative Pathway Lectin Pathway