Final review

Final review - BICD 136 Review for Final Exam The Immune...

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BICD 136 Review for Final Exam The Immune System Define: memory cell, receptor, CTL Memory Cell : are formed from activated B-cells that are specific to one antigen encountered during the adaptive immune response (humoral immunity). These cells are able to live for a long time and can respond quickly following a second exposure to the same antigen. Receptor : a receptor can any cell surface protein which binds to a signaling molecule (ex: insulin). TCR: specific type of receptor that binds only to antigens on the surface of the cell. Viral Receptor: the molecule on the target cell that the virus binds to. Every virus has a favorite target and whatever the virus binds to is called the viral receptor. CD4 is the viral receptor for HIV. CTL : Cytotoxic T- lymphocyte. - An activated T8 cell. It destroys virally infected cells. Describe the purpose and function of T-cells . - An infected host cell displays pieces of the invader on its surface. A T-cell receptor binds to the pieces of the invader that are being displayed and kills the infected cell. - Cellular immunity What causes each type to take action? What action(s) does each take? T8 Cell : binds to a particular antigen on any cell type and kills the infected cell. CTL. T4 Cell : Helper T-cell - Sends signals to B-cell and T8 cells to activate their immune responses - Binds to macrophages and dendritic cells that have phagocytosed an infected cell. These macrophages and dendritic cells present pieces of the infection on their cell surface to T4 can bind. How did T8 cells and T4 cells get their names? What else are they called? T8 : Cytotoxic T-cell T4 : helper T cell Why is the T4 cell so central to the immune response as a whole? - T4 cells have co-receptors called CD4 which assist the T-cell receptor. CD4 amplifies the signals generated by the T-cell receptors. - When a T4 cell binds to its antigen on the surface of an antigen presenting cell, it secretes chemical signals that stimulate activation of T8 cells and B-cells. - When T4 cells don’t function, so signals are activated that stimulate B-cells to target antigen presenting cells. T8 cells also don’t receive signals to become activated and kill the infected cells. Immune system failure.
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In addition to T cells, what other cell types bear the CD4 molecule? - Macrophages - Dendritic cell Which lymphocytes are the primary line of defense against free-floating microbes? Why? Which defend against intracellular parasites? Why? - B-cells are the primary form of defense against free floating microbes. B-cells can secrete antibodies that binds to antigens on free-floating microbes. - T cells defend against intracellular parasites. The infected cell displays pieces of the virus on its surface, and then T-cells bind in order to kill the infection. All viruses are obligate intracellular parasites. Describe the sequence of events as the immune system goes into action when you get an
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This note was uploaded on 10/12/2009 for the course BICD 655698 taught by Professor Gustafson-brown,cindy during the Spring '09 term at UCSD.

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Final review - BICD 136 Review for Final Exam The Immune...

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