Term
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Definition
substance against which the immune response occurs.
Chemical nature
proteins and carbohydrates |
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Term
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Definition
Antigenic Determinants:
specific part of antigen targeted by immune response
may only be a few amino acids
Several may be present in one protein molecule. |
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Term
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Definition
Lymphocytes that encounter their antigenic determinant early in differentiation process are eliminated.
Lymphocytes that encounter their antigenic determinant later will participate in an immune response. |
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Term
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Definition
differentiate in thymus
TH (T helper cells)
CD4+
TC (T cytotoxic cells)
CD8+
Cell mediated Immunity |
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Term
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Definition
do not enter thymus
Antibody production in Humoral Immunity
Activation:
Cell division creates a large population of B cells that target this AD
Some form the memory for this AD
Some become plasma cells that secrete proteins called antibodies (immunoglobulins) that specifically bind to that antigenic determinant. |
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Term
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Definition
Cell Mediated Immunity
TH (T helper cells)
CD4+
TC (T cytotoxic cells)
CD8+ |
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Term
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Definition
TH (T helper cells)
Bind to MHC-II plus AD displayed on APC.
Activated TH cells:
-Undergo cell division.
Larger population of cells targeted to antigen proven to be a threat
Several active types of TH cells and memory TH
-Secrete cytokines.
Required for activation of TC cells, most B cells, and several other types of cells (macrophages, eosinophils, basophils, etc.) |
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Term
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Definition
TC (cytotoxic T cells)
CTL
Activation Requirements:
-TCs bind to MHC-I plus AD displayed on APC
-Cytokines from activated TH cells
Activation Results:
-Cell division
-Larger population of activated cells (CTL’s) targeted to current threat.
-Memory
Activated CTLs bind to ADs on infected cells and secrete cytotoxins that kill the cells. |
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Term
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Definition
Antigen Presenting Cells
macrophages and dendritic cells |
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Term
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Definition
Antibodies
complement activation (classical pathway)
opsonization (Fc region binds to phagocytes)
agglutination (inactivation &/or increased efficiency of phagocytosis)
neutralization (toxins, viruses)
antibody-dependent cell-mediated cytotoxicity
On surface of B cell as a receptor
secreted during the humoral response |
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Term
| T-dependent B cell Activation |
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Definition
B cell binds to antigen (via surface antibody) and presents AD.
TH binds to presented AD and secretes cytokines. |
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Term
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Definition
first exposure to AD
7 - 10 days for rise in titer due to time needed for T and B cells to proliferate
time for microbe to grow and disease symptoms to appear
TH and TC memory cells are also produced during primary response. |
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Term
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Definition
Secondary Response -
subsequent exposure to AD
memory - large pool of cells programmed for this AD - some can immediately become plasma cells
rapid increase in titer prevents significant increase in number of microbes so no illness
rapid response by TH and TC memory cells to secondary infections |
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Term
| Acquired immunity - natural |
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Definition
Active: Antigens enter the body naturally, body produces antibodies and specialized lymphocytes
Passive: Antibodies via placenta or in mother's milk |
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Term
| Acquired immunity - artificial |
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Definition
Active: Antigens are introduced in vaccines, body produces antibodies and specialized lymphocytes
Passive: Preformed antibodies in immune serum introduced into the body by injection. |
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