Quantitative analyses of specific B cells for sheep red blood cell, phosphorylcholine, and hepatitis B surface antigen in human B cell populations by polyclonal transformation with Epstein-Barr virus.

An experimental system was developed to analyse quantitatively specific B cells for various antigens in human B cell populations by polyclonal transformation and immunoglobulin production induced by in vitro infection with Epstein-Barr virus (EBV). EBV-infected cells were cultured in microtest plates for three weeks and specific antibody activities for sheep red blood cell (SRBC) were detected in the culture supernatants by hemolysis and those for phosphorylcholine (PC) and for hepatitis B surface antigen (HBsAg) by passive hemagglutination. It was shown that frequencies of positive cultures with specific antibodies followed one hit-type of Poisson's distribution. Large numbers of cultures showed specific antibody activities for SRBC and for PC with tonsillar lymphocytes obtained from four donors. On the other hand, positive cultured with anti-HBsAg antibodies were practically undetectable with three donors. With fourth donor, however, quite a large fraction of cultures showed specific antibody activities for HBsAg. Frequencies of positive cultures with anti-HBsAg antibodies were further analysed with peripheral blood lymphocytes obtained from five donors with serum anti-HBsAg. Comparable frequencies of cultures were shown to be positive with anti-SRBC antibodies with these donors. The frequencies of cultures with anti-HBsAg antibodies were, however, quite variable among these donors. It was considered that these results directly reflected the sizes of clones with these specificities in human lymphocytes populations obtained from donors with various immunological histories.