Ultraviolet-induced suppressor T cells and factor(s) in murine contact photosensitivity. II. Igh-V restriction of T-cell-suppressor factor.

In murine contact photosensitivity (CPS) to 3,3',4',5-tetrachlorosalicylanilide, we have reported that antigen-specific suppressor T cells and factor(s) (TsF) are induced by preexposure of the photosensitizing site to low doses of ultraviolet B. The TsF is a single-chain factor bearing both antigen-binding site(s) and I-J determinants. In this report, we examined the genetic restriction of the factor in terms of both H-2 and Igh-associated genes. The CPS responses of BALB/c (H-2d, Igh-VaCa) and BALB.B (H-2b, Igh-VaCa) but not DBA/2 (H-2d, Igh-VcCc) were suppressed by the injection of the BALB/c TsF, and reciprocally, the response of BALB/c was suppressed by the BALB.B TsF. This demonstrated that H-2 identity was not a requirement for TsF function. Furthermore, the BALB/c TsF significantly suppressed the CPS reaction in BAB-14 (H-2d, Igh-VaCb) but not in either C.B-20 (H-2d, Igh-VbCb) or C.AL-20 (H-2d, Igh-VdCd). In addition, the BAB-14 TsF, but not the C.B-20 factor, induced suppression in BALB/c mice. These results indicated that identity at the Igh-V locus of the strain producing the factor and the recipient was required for suppression. Because of the single-chain nature of the factor, it seems that the I-J+ molecule present in our TsF is closely related to not only recognition but also Igh-V restriction functions.