Increased helper cell activity of NZB mice against H-2-identical allogeneic cells.

The T cells of NZB mice become hyperreactive after stimulation with minor histocompatibility (MIH) antigens. This hyperreactivity has previously been demonstrated only for cytotoxic T cells of NZB, although there was some evidence for an increase of their T-helper cell activity facilitating the response. Here we report a quantitative analysis of T-cell help and help of T-cell subpopulations against autologous, MIH, and H-2 antigens in a limiting dilution assay. After stimulation of NZB T cells with autologous and H-2 antigens, the T-helper cell frequencies did not differ from that of normal mice. After stimulation with MIH antigens however, Lyt 1<sup>+</sup>2<sup>+</sup…