T-cell hybrids bear Fcγ receptors and secrete suppressor immunoglobulin binding factor

Abstract

PROGRESS in the study of antibody structure and function came from the establishment of plasmocytomas and B-cell hybrids¹ which produce large amounts of monoclonal antibodies. Another set of immune molecules, the T-cell factors regulating antibody production², have not previously been extensively characterised, mainly because of the lack of homogenous and reproducible sources. The use of T-cell hybrids^3–5 which would produce large amounts of a given factor would therefore be very useful for the characterisation of these molecules. Among the T-cell factors regulating antibody production, Gisler and W.H.F.⁶ have described an immunoglobulin binding factor (IBF) which binds to IgG, not to IgM and suppresses antibody production to T-dependent and T-independent antigens nonspecifically in vitro. IBF is the soluble form of the T-cell Fcγ receptor⁷ which is expressed on non antigen-specific suppressor T cells^8,9. As the Fcγ receptor is a marker of a set of suppressor T cells, one would expect that selection of T-cell hybrids for the expression of this receptor may lead to selection of T-cell lines producing permanently non antigen-specific suppressor factor. We report here the establishment of T-cell hybrids which express Fcγ receptors and produce suppressor IBF.