“COMPLEMENT FIXATION” IS THE PROCESS OF INITIATING THE COMPLEMENT CASCADE. OPSONIZATI0N MEMBRANE ATTACK COMPLEX VASCULAR PERMEABILITY CHEMOTAXIS
The stage and the players (review): Cytokines Antigens Antibodies Lymph system Lymph nodes Leukocytes Lymphocytes Macrophages B cells T cells (helper and cytotoxic) Complement
Innate (non-specific) immunity 1. Based on pattern recognition receptors 2. Employs an arsenal that already exists, particularly appropriate for defense against bacteria and other small pathogenic organisms 3. Responds quickly and locally 4. Can lead to the initiation of an adaptive immune response
INFLAMMATION AND INNATE IMMUNE RESPONSES
Acquired (adaptive, specific) immunity 1. Cell-mediated immunity 1. Cytotoxic T cells are stimulated by cells displaying foreign antigens that bind to their receptor 2. When stimulated, cytotoxic T cells multiply in a clone all members of which display the same receptor 3. Cytotoxic T cells then bind to cells displaying the foreign antigen and secrete chemicals (perforins) that destroy the integrity of the cell membrane leading to cell death. 4. Cytotoxic T cells attack virus infected cells and tumor cells as well as foreign organisms.
Acquired (adaptive, specific) immunity 2. Humoral immunity 1. Macrophages and B cells present foreign antigens on their surface where helper T cells watch for them. 2. Helper T cells with a “good enough” fit between their receptor and the antigen are stimulated to multiply and to secrete cytokines that activate B cells that they encounter which also bind the antigen. 3. Activated B cells multiply in clones. 4. Some of the clonally produced cells become “plasma” cells and secrete antibodies that bind the antigen. 5. When antibodies bind to an antigen on an intact pathogen they trigger complement fixation and facilitate macrophages.
- Fall '10
- cells, Cytotoxic Cells, Cytotoxic T cells