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20 Cards in this Set
- Front
- Back
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What is the Clonal Selection Theory? (4)
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1. Each lymphocyte bears a single type of receptor with a unique specificity.
2. Interaction between a foreign molecule and a lymphocyte receptor capable of binding that molecule with high affinity leads to lymphocyte activation. 3. The effector cells will bear receptor of identical specificity to parent cell. 4. Lymphocytes bearing receptors specific for ubiquitous self molecules are deleted |
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What are the 4 types of T cell and what are there functions?
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1. Helper T Cell (CD4)
2. Killer T Cell (CD8) 3. Regulatory T Cell (Treg) 4. Natural Killer T Cell (NKT) |
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What is central tolerance?
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The elimination of autoreactive T cells in the thymus.
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What is Alloreactivity?
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Non-self MHC can activate T cells irregardless of the peptide.
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What is MHC Restriction?
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Requirement for T cells to have antigens presented to them by MHC.
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Where do T cells recirculate?
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High endothelial venules (HEV)
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What are the 2 types of memory cells?
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1. Central Memory T Cells
2. Effector Memory T Cells |
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What does TH1 cells release to activate what cell?
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Release INF gamma, TNF alpha, CD40L to activate macrophages.
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What does TH2 cells release to activate what cell?
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Release IL4, IL5, and CD40L to activate B Cells.
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What does cytotoxic CD8 T cells use to kill their targets? (3)
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Perforin, granzymes and FasL.
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What complex of enzyme is responsible for antibody recombination?
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V(D)J recombinase with Rag-1 and Rag-2 gene.
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Partial defect in Rag 1 and 2 leads to?
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Omenn syndrome.
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What 2 factors contribute to Ig diversity?
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1. Combinatorial Diversity
2. Junctional Diversity |
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What is it called when B cells can only be activated by a helper T cells that recognizes some part of the same antigen?
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Cognate help or Linked recognition.
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How are B-cells further modified after activation?
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1. Somatic hypermutation
2. Class switch recombination |
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In Somatic hypermutation what happens at what location?
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Affinity maturation occurs at complementarity determining regions.
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What cells are found in germinal centers?
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B Cells, Helper T Cells and Follicular dendritic cells.
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In a lymph node, where are B cells, T cells, macrophage and plasma cells found?
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B cell: Outer Cortex
T cell: Paracortical Area (T Cell Zone) Macrophage & plasma Cells: Medulla |
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Where does the B & T cells enter the lymph?
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From blood through high endothelial venules, located in paracortical areas.
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Where are T and B cells found in the spleen?
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T cell: Periarteriolar lymphoid sheath
B cell: B cell follicles and Marginal Zone (T-I antigens) |
