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Pathology

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Immunopathology

Question
7 out of 14
 

Which of the following is not true regarding super antigens - (AIPG, 2010)



A Bind T cells irrespective of antigen specificity of TCR

B Bind directly to both MHC II and T cell receptor causing T cell activation.

C Bind to cleft or antigen binding groove in the MHC II molecule

D Binds directly to lateral aspect of T cell receptor

Ans. C i.e., Bind to cleft (or antigen binding groove) in the MHC II molecule

[Ref Harrison 181hle p. 2671-2672 & 17lhle p. 2034]

Superantigens

a. Superantigens are potent. activators of T-lymphocytes.

b. Superantigens stimulate very large numbers of T cells, without relation to their epitope specificity. This leads to an excessive and dysregulated immune response with release of cytokines IL - 1, IL - 2, TNF - α and IF - γ

c. Conventional antigens bind to MHC class I or II molecules in the groove of the αβ dimer (T cell receptor).

d. However, superantigen bind directly to the lateral portion of TCR β chain and MHC class II β chain.

e. For superantigens, antigen specificity of TCR is not required.

Immunopathology Flashcard List

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