Developmental and Functional Analyses of CD8+ NK1.1+ T Cells in Class-I-Restricted TCR Transgenic Mice

Using a class-I-restricted T cell receptor (TCR) transgenic mice (Tgm), 2C (Vα3.1/Vβ 8.2, specific for Ld + LSPFPFDL), the development and cytokine production of tg-TCR+ NKT cells were analyzed. We found that CD8+ or double negative (DN) NKT cells constituted a major population of NKT cells in the H-2b/b 2C Tgm (positive selecting background) or the H-2b/d 2C Tgm (negative selecting background), respectively. Virtually no NKT cells were generated in the H-2k/k 2C Tgm (neutral selecting background). CD8+ NKT cells in the H-2b/b 2C Tgm expressed CD8αβ heterodimers, whereas those in the H-2b/d 2C Tgm expressed CD8αα homodimers. These findings suggest that development of a subpopulation of NKT cells is influenced by the H-2 molecules. Upon stimulation with anti-CD3 mAb, tg-TCR+ NKT cells generated in the H-2b/b and H-2b/d backgrounds produced IFN-γ, but not IL-4.