Syngeneic mixed lymphocyte reaction (SMLR) with dendritic cells: direct visualization of dividing T cell subsets in SMLR.

Syngeneic mixed lymphocyte reaction (SMLR) has been considered to represent T cell response to self antigens. In this study using stimulator dendritic cells (DC), we analyzed cellular components responding to the syngeneic DC. It was shown that the predominant dividing cells were <f>CD8+</f> T cells although the response of <f>CD4+</f> T cells was essential for initiation of SMLR. In spite of the vigorous proliferation and expression of several activation markers, these SMLR-activated <f>CD8+</f> T cells hardly killed syngeneic targets and most of the <f>CD8+</f> T cells produced no interferon-<f>γ</f> upon restimulation with DC. Furthermore, in SMLR where <f>CD8+</f> T cells were absent or inhibited, a considerable proliferation of <f>CD4−</f> <f>CD8−</f> double negative-T cells that included TCR<f>α/β+</f> natural killer-T cells (NKT cells), TCR<f>γ/δ+</f> NKT cells and TCR<f>γ/δ+</f> T cells was observed. [Copyright &y& Elsevier]