Question

A preliminary study of a human T-cell clone indicates that it has been derived by cloning a regulatory ?? T cell. Therefore, the subsequent analyses are expected to detect the presence of [complete the sentence and assess the resulting statements (83-94) as either factually correct (= true) or incorrect (= false)]:

83. TCR ? chain mRNA.

84. CD8 mRNA.

85. CD4 mRNA.

86. AIRE mRNA.

87. IL-2R ? chain mRNA.

88. FoxP3 mRNA.

89. MHC class I ? chain mRNA.

90. MHC class II ? chain mRNA. 91. ?2-microglobulin mRNA.

92. IgG heavy chain DNA.

93. TCR ? chain DNA.

94. TCR ? chain DNA.

Answer 1

83) The subsequent analysis is expected to detect the presence of TCR chain mRNA. This statement is Correct. The most of the T cells express receptor in association with CD3 invariable chain and are referred as T- cells. The mRNAs of both the subunits of receptor ( and subunits) are expected to be present in T-cell

84) The subsequent analysis is expected to detect the presence of CD8 mRNA. This statement is Correct. The expression of CD8+ protein on T-cells places it under the category of cytotoxic T-cells.

85) The subsequent analysis is expected to detect the presence of CD4 mRNA. This statement is Correct. The expression of CD4+ protein on T-cells places it under the category of helper T-cells. A T-cell will either express CD4+ on its surface or CD8+ and never the both.

86)The subsequent analysis is expected to detect the presence of AIRE mRNA. This statement is Incorrect. AIRE or autoimmune receptor is expressed by medulla of thymus and are involved in the negative selection of T-cell clones. Suzuki et al., has however reported AIRE mRNA expression in human peripheral blood B and T cells, in addition to other non-thymic tissues that express this receptor.

87)  The subsequent analysis is expected to detect the presence of IL-2R chain mRNA. This statement is Correct. IL-2R acts as a cytokine receptor and is expressed by most of the white blood cells including T-cells.

89) The subsequent analysis is expected to detect the presence of MHC class I chain mRNA. This statement is Correct. MHC class I protein is expressed by all the nucleated cells of body and present the endogenous toxin to CD8+ cytotoxic T cells.

90) The subsequent analysis is expected to detect the presence of MHC class lI chain mRNA. This statement is Incorrect.  MHC class lI molecules are only expressed by antigen presenting cells like B cell and dendritic cells and present exogenous antigen to CD4+ T helper cells.

93) The subsequent analysis is expected to detect the presence of IgG heavy chain DNA. This statement is Incorrect.   IgG heavy chain is a part of IgG antibody which is synthesized on and only in B-cells