Term
| what is the humoral immune system of the adaptive immune response mediated by? How? |
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Definition
| b cells; release of antibodies |
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Term
| What is the cellular immune system of the adaptive immune response mediated by? How? |
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Definition
| t cells; control of immune response and directly lyse cells |
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Term
| Where are t and b cells activated? how? |
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Definition
| secondary lymphoid tissues; recognition of an antigen |
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Term
| Where do lymphnodes collect antigen from? spleen? GALTS? |
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Definition
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Term
| What is the size of most antigens? |
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Definition
| large - molecular weight of 10,000 or higher |
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Term
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Definition
| proteins or carbs that are recognized by antibodies |
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Term
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Definition
| small portions of antigens that are recognized by individual antibodies |
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Term
| What are haptens? examples? |
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Definition
| small molecules that are not antegenic unless attached to a carrier molecule; lipids, drugs, DNA, RNA |
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Term
| Are carrier proteins required at all times for haptens? when? |
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Definition
| no, when an antibody is already produced toward a hapten |
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Term
| What is the structure of a typical antibody? |
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Definition
| 4 proteins (2 heavy chains and 2 light chains), 2 dimers (between heavy and light chains), constant region (heavy chain), variable region |
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Term
| What is the constant region of an antibody? what does it bind to? |
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Definition
| part made up of ONLY heavy chains; binds to the immune cell at the Fc receptors |
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Term
| What are the variable tips on antibodies? |
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Definition
| they bind antigens (different for each antibody) |
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Term
| How many different antibodies can the variable regions of antibodies prduce? |
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Definition
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Term
| How are the variable regions of the antibody so variabel? |
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Definition
| each V, D, and J section can combine in differnt ways using different junctions (junctional diversity) |
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Term
| What is the only antibody that crosses the placenta? |
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Definition
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Term
| What are naive b cells? What kind of antibody do they express? |
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Definition
| b cells that have not encountered antigen; IgM |
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Term
| What is isotype class switching? |
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Definition
| somatic recomination event upon b cell activation that results in the production of a different antibody type |
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Term
| What are the 4 functions of antibodies in response to infection? |
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Definition
| complement fixation, opsonization, neutralization, agglutination |
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Term
| What is the result of complement fixation? |
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Definition
| lysis of bacterial ccells |
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Term
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Definition
| coating bacteria in antibodies so that the phagocytes will recognize them and more easily lyse them |
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Term
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Definition
| binding to virus or endotoxin to make it incapable of functioning (because it cant bind to anything) |
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Term
| What is the b cell receptor made up of? |
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Definition
| a membrane bound antibody and a dimer of the Ig alpha and beta chain |
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Term
| How are self reactive b cells eliminated? |
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Definition
| either killed in the bone marrow, change their b cell receptors, or made unresponsive if they escape the bone marrow (anergy) |
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Term
| What is clonal expansion? |
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Definition
| when antigen specific b cells greatly increase in number upon infection |
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Term
| What are t dependent antigens? |
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Definition
| require the help of t cells to induce b cell antibody responses |
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Term
| How do t dependent antigens work? |
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Definition
| they bind to the b cell receptor (resulting in b cell activation and uptake of the antigen), t cell specific for that antigen recognizes it in the b cell , t cell produces membrane bound and soluble cytokines (which provide a second activation signal for the b cell) |
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Term
| What are t independent cells? how do they work? |
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Definition
| do not require a t cell to activate b cell; t independednt antigens contain ligands for TLR's that cause a second response signal in the b cell |
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Term
| What are results of a t inderpendent response? |
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Definition
| weaker antibody response, only composed of IgM, and do not produce b cell memory |
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Term
| What are germinal centers |
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Definition
| activated b cells form a specific structure in the seconnday lymphoid organs that are needed for effectibve later responses of b cells |
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Term
| What are the functions of b cells that take place in the germinal centers? |
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Definition
| 1. b cell proliferation 2. production of plasma cells 3. isotype class switching 4. somatic hypermutation 5. production of memory b cells |
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Term
| What is somatic hypermuttion? |
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Definition
| antibody genes mutate to make high affinity antibodies |
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Term
| What is immunological memory? |
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Definition
| memory b cells are produced that are capanble of responding rapidly to reinfection from the same pathogen |
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Term
| What is the basis of vaccines? |
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Definition
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