CD8(+) T lymphocytes in double alpha beta TCR transgenic mice. I. TCR expression and thymus selection in the absence or in the presence of self-antigen
N. Legrand et Aa. Freitas, CD8(+) T lymphocytes in double alpha beta TCR transgenic mice. I. TCR expression and thymus selection in the absence or in the presence of self-antigen, J IMMUNOL, 167(11), 2001, pp. 6150-6157
We derived Rag2-deficient mice bearing two rearranged ap TCR transgenes, on
e specific for the HY male Ag and the second specific for the gp33-41 pepti
de of lymphocytic choriomeningitis virus, both restricted to the MHC H-2D(b
) class I molecule. We found that, in female double transgenic (DTg) mice,
most CD8 T cells express only the TCR beta chain from the aHY transgene. By
comparing the mRNA species for both beta -chains, we observed that in T ce
lls from DTg mice the aHY TCR beta chain transcripts are abundant, whereas
the anti-lymphocytic choriomeningitis virus TCR beta chain transcripts are
rare. In contrast to TCR beta chain expression, most of the T cells from DT
g mice express two TCR alpha chains. We examined the thymus selection of th
e dual-receptor CD8 T cells in the presence of self-Ag. We found that the p
resence of a second TCRa chain allows a significant number of CD8 T cells e
xpressing a self-reactive receptor to escape central deletion and migrate t
o the peripheral pools of male mice. Differences in TCR and coreceptor expr
ession between female and male MoaHY and DTg mice suggest that peripheral T
cell survival requires an optimal level of signaling, which implies a proc
ess of "adaptation" of lymphocyte populations to the host environment.