T-cell regulation of human peripheral blood B-cells responsiveness.

We have investigated the influence of human T cells on the synthesis and secretion of immunoglobulin by peripheral blood B cells. The plaque-forming assay used, which identified the number of B cells secreting Ig, is a short-term assay which requires no exogenous stimulation. We have shown that the B-cell population alone contains fewer secreting cells than the total lymphocyte population, and that T cells are required to achieve maximal plaque-forming cell levels. Cycloheximide treatment of cells at concentrations known to inhibit protein synthesis does not affect the cooperative potential of these cells. Additionally, this cooperation effect is markedly better among autologous mixtures of Ig- and Ig+ cells, than among mixtures obtained from randomly selected individuals.