Defective regulation of B lymphocyte colony formation in patients with systemic lupus erythematosus.

We have succeeded in generating B cell colonies from freshly separated human peripheral blood by the double agar layer technique and expanding them in liquid culture for several weeks. Populations of cells enriched in B cells were placed into the upper layer with or without bacterial LPS. Although B cell colonies were observed without LPS, the addition of LPS to the cells in the upper agar layer increased the number of colonies. Also necessary for optimal B cell colony formation was the presence in the lower agar layer of either culture supernatant of PHA-stimulated mononuclear cells or purified T cells and PHA. Without such helper factors in the lower layer, only a few B cell colonies were observed in the upper layer. By using these techniques, peripheral blood lymphocytes from normal individuals and patients with active systemic lupus erythematosus (SLE) were studied for the generation of B cell colonies. Significantly more B cell colonies were observed in patients with SLE, using either kind of "helper" factor. In addition, T cells from normal individuals and patients were tested for their ability to help B cell colony formation. The SLE T cells were found to be defective in this function relative to normal T cells. Thus, although patients with SLE were hyperactive in forming B cell colonies, thier T cells were defective in supporting the formation of B cell colonies from normal individuals.