Impaired induction of delayed hypersensitivity following anterior chamber inoculation of alloantigens.

BALB/c mice that receive allogeneic P815 tumor cells (DBA/2 origin) into the anterior chamber of the eye (intracamerally, i.c.) fail to develop DBA/2-specific delayed hypersensitivity (DH). We have previously shown that this failure results, in part, from the generation of efferent T suppressor cells. To determine whether DH effector cells are even activated in these mice, a local adoptive transfer assay for DH was developed: Mixtures of responder lymphocytes and irradiated stimulator cells were injected into the pinnae of normal mice, syngeneic with the responders. In this assay, spleen cells from i.c. injected donors failed to evoke a local DH. Moreover, when spleen cells from i.c. injected donors were mixed with specifically immune BALB/c anti-DBA/2 lymphoid cells and similarly assayed, DH was effectively suppressed. Spleen cells from i.c. injected mice, depleted of Lyt-2+ suppressor cells, remained unresponsive in this assay, even if before injection they had been exposed to 5 days of in vitro culture with DBA/2 alloantigens. We conclude that anterior chamber inoculation of P815 cells in BALB/c mice fails to activate DH effector cells. Therefore, the inability of i.c. injected mice to mount DH responses results not only from efferent suppression but also from selective impairment of DH induction. The latter effect may be due to the activation of an afferent suppressor mechanism that acts selectively on T cell help for DH but that has no effect on help for B cells or cytotoxic T cell precursors.