Antigen-specific suppressive factor produced by a transplantable I-J bearing T-cell hybridoma

Abstract

THE demonstration of a definite antigen-binding specificity possessed by suppressor T cells and suppressor factors^1–6 has provided an important strategy to determine the T-cell receptor for antigen. Although the gene coding for the determinant on the suppressor molecule has been unambiguously mapped in the I–J subregion of the mouse major histocompatibility complex (MHC)^3,7, the chemistry and the mode of action of the active molecule have been only poorly analysed—probably because of the difficulty in collecting sufficient materials from suppressor T cells for each studies. The establishment of T-cell hybridomas with specific suppressor function would provide an ideal tool to analyse the suppressor molecule and the mechanism of its action. We have been successful in obtaining a number of hybrid cell lines continuously secreting molecules having both antigen-specific suppressor function and I–J determinants. High frequency of fused cells with I–J determinants was reproducibly made by the combination of two procedures; the method to enrich antigen-specific Ig⁻ T cells from primed spleen cells by adsorption to and elution from antigen-coated Petri dishes, and the selection of I–J⁺ hybrids by sorting out with fluorescence activated cell sorter (FACS) after staining the fused cells with appropriate fluorescence reagents⁸. Here we report the derivation of an I–J bearing hybrid cell line, which is transplantable to H–2^b/k F₁ hybrid mice, secreting the antigen-specific suppressor molecule. Some physiochemical and immunochemical properties are also described.