Immunology Ch.11.7-12 Microbiology

11.7 Primary & Secondary Response Primary Response Barriers Innate Immunity Secondary Response Adaptive Immunity B & T cells

11.7 Antibody Proteins & Antigen Binding The tip of the antibody is very variable allowing for millions of antibodies with different antigen- binding sites to exist.

11.7 Antibody Genetic Diversity Two Processess Variable, Diverse, and Joining Regions (VDJ) recombination Point mutation-Somatic Hypermutation

11.7 Clonal Selection Hypothesis 1954 Niels Jerne Individual B cell expresses receptors specific to the distinct antigens are determined before the antibody ever encounters the antigen. Binding to a cell activates the cell causing proliferation of clone daughter cells.

11.7 Isotype Class Switching The antibody isotype of a B cell changes during development and activation.

11.7 Making Memory B cells After first infection the responding naïve cells can differentiate into effector B cells. They can survive for years, protecting against reinfection.

11.8 Cytotoxic T Lymphocytes Lymph nodes store B & T cells and other White Blood Cells (WBCs) The immune response triggers the release of WBC’s which are directed to the infected areas by hormones.

11.8 Classes of T cells Thymus Effector-stimulate growth of new cells Memory-antigen specific Regulatory-inhibits response and resolves inflammation

11.9 Dendritic cells & Macrophages Dendritic-antigen presenting cells Macrophages “big eaters”-engulf and destroy pathogens through phagocytosis “cell eating”

11.10 Immunity & Molecular Signals Clonal selection & Tolerance Protection against autoimmune diseases Cytokines & Chemokines Control growth of WBCs Superantigens Acute allergic reaction Complement system Magnifies innate immune response

11.11 The Major Histocompatibility Complex (MHC) MHC is a cell surface molecule that displays an epitope to mediate interactions of leukocytes with other leukocytes or body cells. Three subgroups: Polygenic Polymorphic Many Variants

11.12 Classifying Immunities Natural Active Immunity Exposure to disease Development of Antibodies Natural Passive Immunity Transferred from mother to baby through placenta or breast milk Not long lasting Artificial Immunity Intentional exposure Vaccinations Antibody Transfer