The production of immunoglobulins by human peripheral blood lymphocytes in vitro.

We have demonstrated that the peripheral blood lymphocytes of normal humans show an increased production of immunoglobulins after non-specific stimulation by phytohaemagglutinin (PHA). The methods used include immunofluorescence and immune co-precipitation. Specific antigens to which the donor has been sensitized produce a similar effect in a smaller number of cells. The cells of persons with defects of immunoglobulin production can be stimulated by PHA to enlarge and divide, but their immunoglobulin content is abnormal and reflects the pattern of the circulating serum globulins. Preliminary results suggest that a portion of the immunoglobulin produced after either specific or non-specific stimulation of cells from sensitized donors behaves like specific antibody.