Induction of B cell responsiveness to growth factors by Epstein-Barr virus conversion: comparison of endogenous factors and interleukin-1.
Immortalized B lymphocytes produce a factor(s) that stimulates growth of B cell lines carrying Epstein-Barr virus (EBV). Stimulatory supernatants derived from B cells also exhibit interleukin-1 (IL-1) activity in costimulator assays with the D10.G4.1 helper T cell line. Experiments with purified macrophage-derived IL-1 and recombinant IL-1 beta demonstrate that IL-1 stimulates proliferation of the cell lines that respond to the factors from B lymphocyte lines. One B cell line, Ramos, an EBV-Burkitt's lymphoma, contrasts with other B cell lines in that it is refractory to the growth enhancing effects of B cell conditioned medium and macrophage-derived IL-1. When EBV was introduced into Ramos cells, growth was enhanced by the factor(s) in B cell conditioned medium (six out of seven lines); growth of EBV-converted Ramos lines (six out of seven lines) also was enhanced by IL-1. These findings demonstrate that infection of a non-responsive transformed B lymphocyte by EBV induces cellular responsiveness to factor-mediated growth stimulation.
Blazar
B A
BA
Department of Biological Sciences, Wellesley College, MA 02181.
Murphy
A M
AM
D001402:B-Lymphocytes / Q000187:drug effects* / Q000276:immunology; D002461:Cell Line, Transformed; D006133:Growth Substances / Q000494:pharmacology*; D004854:Herpesvirus 4, Human / Q000276:immunology*; D006801:Humans; D007375:Interleukin-1 / Q000494:pharmacology*; D008213:Lymphocyte Activation / Q000187:drug effects*; D006377:T-Lymphocytes, Helper-Inducer / Q000276:immunology
D006133:Growth Substances; D007375:Interleukin-1