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Lecture 27
Adaptive Immunity: B Lymphocytes
Term | Definition |
---|---|
Antigens | Substances that activate B and T lymphocytes. Most foreign, some self-antigensin autoimmune diseases. |
Antigen Presentation | Protein antigens Taken in + partially digested by macropahges Part of antigen linked to MHC protein,put in cell membrane B or T cellthen find protein complex leads to activating T cell attack on cells that have protein or have B cells produce antibodies. |
B Lymphocytes | Bind antigens-full activation. Requires T-helper cell contact antigen binding triggers call proliferation into plasma (B cell clone) cells and memory cells. |
Plasma Cells | Antibody factories-make antibodies to antigen that bound high ER for Ab production, loses other organelles. Limited lifetime ~ 1 week. |
Memory Cells | Both B and T cells. A few cells have very long life. Provide immunity from antigens. |
Primary Response | Activation of B or T cells is slow, short, and weak. |
Secondary Response | Activation of memory cells is fast,strong,and long. Massive response upon second exposure |
Immunoglobulins-Antibodies | IgG,IgA,IgD,IgM,IgE are y shaped proteins. Variable region:arm tips of the y shaped protein. Can bind 2 antigens/Ab, must be same type of antigen. Constant region: tall region. Activates some aspect of immune system when antigen bound. |
Antibody Functions | Major func: activate complement system to kill bacteria. Labels cells for ingestion by phagocytes. Activate natural killer cells. Minor physiological func: neutralization by binding. Used for laboratory testing. |
Blood Types | Based on surface carbs. Genes code for enzymes that add carbs. Transfusion reaction if mismatch. |
ABO Systems | A factor, B factor, AB has both factors. O has neither A or B antigen |
RH Factor | 2 gene system:gene for factor,activator gene. No activator:weak t reaction, formerly missed. Rhogam given to Rh- mothers of Rh+ children. |