Immunology 1 Flashcards
Innate Immune System
Requires NO INFO. DOES NOT have random diversity!
Ex. Skin, Mucous membranes, pH, temperature, monocyte, neutrophils, macrophages, lysozyme, complement, (all except B and T cells). These are like the first line of defence! They come in and kill it first… too much for innate, that’s when we need adaptive!
Describe Adaptive Response
Divided into 2 categories, humoral and cellular response. Both of which are regulated by T-helper cells. In humoral response T-helper cells recognize antigen with MHC II and get activated releasing cytokines which activate B cells. These B cells are activated to proliferate and then differentiate into antibody producing plasma cells which kill the antigen. In the cellular response, T-helper cells recognize the MHC II on the antigen and then release cytokines which activate Cytotoxic T cells. These T cells then recognize the MHC I of an altered self cell and kill it.
Activation of T-helper Cells
A B cell, Macrophage, or Dendritic cell (Antigen Presenting cell, it displays MHC II) will eat an antigen. It will then chew it up and display MHC II molecules on its surface. T-helper cells will then come and recognize those molecules and bind to the cell. If it is a B cell, it will Then proliferate into Memory B cells and Plasma cells. If it is a Cytotoxic T cell (Tc) it will proliferate into Cytotoxic T memory cells and Cytotoxic T lymphocytes (killer T cells).
Endogenous vs Exogenous Antigens
Endogenous = arise from within the cell, example a virus! Will be displayed as MHC I Exogenous = arise from outside the antigen presenting cell, example extracellular bacteria, will be displayed as MHC II on surface
What happens if Innate immune response can’t contain an antigen infection?!
If innate can’t contain it, then dendritic cells may help. They will then eat an antigen, and travel through the lymphatic system to a lymph node where B and T cells are which will then generate an adaptive immune response!
Maturation and Clonal Selection of B and T cells
Body produces TONS of random B and T cells with RANDOM receptors. These then travel through body.. if it doesn’t bind to antigen it will probably die. If it DOES bind, it will with help, differentiate into memory cells which will be around for a long time!
