Suppressor T cell circuits in contact sensitivity. II. Induction and characterization of an efferent-acting, antigen-specific, H-2-restricted, monoclonal T cell hybrid-derived suppressor factor specific for DNFB contact hypersensitivity

This report defines a methodology for the production and characterization of an antigen-specific, monoclonal T cell hybrid-derived suppressor T cell factor (TsF) that suppresses the passive transfer of 2,4-dinitrofluorobenzene (DNFB) contact hypersensitivity. Fusion of T cells from BALB/c (H-2(d)) mice tolerized with syngeneic DNP-spleen cells to BW 5147 thymoma cells resulted in several hybrids that constitutively produce a soluble regulatory molecule. One of these hybrids, 26.10.2, was subsequently cloned, and its soluble factor was characterized with respect to its antigen specificity, biochemical nature, MHC restriction pattern, and identity of its target cell. 26.10.2 TsF suppresses the passive transfer of delayed-type hypersensitivity (DTH) mediated by DNP- but not trinitrochlorobenzene- or oxazalone-primed DTH T cells (T(DH)) after a 1 hr incubation at 37°C. In contrast, 26.10.2 TsF had no suppressive effect on secondary in vitro DNP-specific T cell proliferative responses. 26.10.2 TsF therefore represents an antigen-specific factor with effector (efferent-acting) function. The monoclonal TsF was shown to consist of a two-chain, disulfide-bonded molecule, and to bear a receptor(s) specific for DNP and determinants encoded by the I region of the H-2 complex. Effector suppressive activity of 26.10.2 TsF was restricted by Class I H-2D(d) determinants. One cellular target of this monoclonal factor was shown to be the DNP-specific T(DH) cell, because DNFB-primed lymph node cells from cyclophosphamide-pretreated donors (lacing Ts-auxiliary (Ts-aux) cells) were efficiently suppressed. The TsF appears to focus on passively bound, T(DH) receptor-associated, DNP-Class I determinants, as suggested by the observation that freshly prepared, but not overnight cultured, DNP-specific T(DH) cells were susceptible to suppression.