Question

7) H-Y antigens are only found in cells of male mammals such as mice. Double positive T cells with a transgenic TCR specific for H-Y (male) antigen on an MHC class I protein present in that given strain of mouse

A. would develop normally in male and female mice

    B. would develop into both CD4+ T cells and CD8+ T cells in female mice but would not develop into mature T cells in male mice.

    C. would develop into CD4+ T cells and CD8+ T cells in female mice and would develop into CD4+ T cells in male mice.   

    D. would develop into CD8+ T cells in female mice but would not develop into mature T cells in male mice.

    E. would develop into CD8+ T cells in both female and male mice.

Answer 1

Ans. 7 (C) would develop into CD4+ T cells and CD8+T cells in female mice and would develop into CD4+T cells in male mice.

In the final stage of thymic development, immature T cells undergo three distinct processes( positive selection, negative selection and lineage commitment) that all depend on interaction of thymocyte TCRs with MHC molecules.

In the H-Y TCR transgenic model, CD8+ Tcells expressing transgenic TCR are positively slected in female mice by MHC class I molecule, whereas depletion of DP thymocytes occur in male mice.

CD4+ T cells expressing high levels of transgenic TCR are present in H-Y TCR transgenic mice.

CD4+ hybridomas can express high levels of transgenic TCR.