Induction of IgG production in human B lymphoblastoid cell lines with normal human T cells

Abstract

THYMUS-DERIVED (T) lymphocytes play a critical part in the induction of B lymphocytes to antibody production¹, especially for conversion of IgM to IgG response². In humans, the presence of T lymphocytes is also essential for the induction of IgM or IgG production by pokeweed mitogen (PWM) stimulated B lymphocytes^3,4. In many experiments it has been shown that antigen-specific⁵ or nonspecific^6–8 soluble factors from T cells, together with antigen or other inducers, for example, anti-immunoglobulin antibody, acting on B-cell surface receptors⁹, can also provide the stimulus for Ig production in B cells. However, the chemical nature of a B-cell acceptor for the T–effector molecule, the biochemical events responsible for the differentiation of B cells to Ig-producing cells, and the mechanism of the switch of transcription from μ chain to γ chain genes under the influence of T cells remain largely unknown. Heterogeneity of B-cell population in spleen, lymph node and blood has hindered the molecular analysis of immune phenomena. In this situation, B lymphoblastoid cell lines may be useful models for such analysis, since they may be arrested at certain phases of their differentiative history and if influenced by T cells or T-cell factors might permit incisive analysis of induction and switching of gene action at the molecular level. We report here the induction of IgG production or enhancement of IgM secretion in several human B lymphoblastoid cell lines with the help of normal T cells.