I. Apostolou et al., Evidence for two subgroups of CD4(-)CD8(-) NKT cells with distinct TCR alpha beta repertoires and differential distribution in lymphoid tissues, J IMMUNOL, 165(5), 2000, pp. 2481-2490
NKT cells are a subset of T lymphocytes that is mainly restricted by the no
nclassical MHC class I molecule, CD1d, and that includes several subpopulat
ions, in particular CD4(+) and CD4(-)CD8(-) (DN) cells. In the mouse, diffe
rential distribution of these subpopulations as well as heterogeneity in th
e expression of various markers as a function of tissue localization have b
een reported. We have thus undertaken a detailed study of the DN NKT cell s
ubpopulation. With a highly sensitive semiquantitative RT-PCR technique, it
s TCR repertoire was characterized in various tissues. We found that mouse
DN NKT cells are a variable mixture of two subgroups, one bearing the invar
iant V alpha 14 chain paired to rearranged V beta2, V beta7, V beta8.1, V b
eta8.2, or V beta8.3 beta -chains and the other exhibiting. unskewed alpha-
and beta -chains, The proportion of these subgroups varies from about 100:
0 in thymus, 80:20 in liver, and 50:50 in spleen to 20:80% in bone marrow,
respectively. Finally, further heterogeneity in the tissue-derived DN NKT c
ells was discovered by sequencing extensively V beta8.2-J beta2.5 rearrange
ments in individual mice. Despite a few recurrences in TCR sequences, we fo
und that each population exhibits its own and broad TCR beta diversity.