IgA specific T-cell factor produced by a human T-T hybridoma.

A human T-T hybridoma was produced, which was a fusion product between and HGPRT-deficient T-cell line, Jurkat 3, and an OKT4+ activated peripheral blood T-cell. The hybrid expressed a receptor for IgM Fc and was negative for IgA Fc. It was shown to produce a factor capable of specifically enhancing IgA production and secretion by isolated human B-cells. The factor exerts its effect directly on B-cells and appears to be different from T-cell-replacing factors previously described.