Characterization of a B cell-derived growth-enhancing factor produced by a @entity1 B cell line established from a @entity1 with XXXX .

@entity1 @entity1356 @entity1192 @entity1199 @entity309
A @entity1 B cell line, TKS-1, which was established from the peripheral blood of a @entity1 with @entity309 , was found to spontaneously produce a factor which enhances the activity of @entity1356 ). This factor, designated B cell-derived growth-enhancing factor (BGEF), enhanced @entity1356 -induced proliferation of peanut agglutinin nonagglutinated thymocytes. BGEF also enhanced @entity1356 -induced production of @entity1199 ( @entity1199 ) by both thymocytes and a @entity1 T cell clone, HSB.2 C5B2. BGEF alone did not induce the production of @entity1199 . BGEF failed to induce proliferation of the @entity1199 -dependent T cell clone, and did not enhance its response to @entity1199 . The activity of BGEF was not blocked by antisera against @entity1 @entity1192 or @entity1 @entity1356 . Gel filtration analysis revealed that BGEF has a m.w. of 60,000 to 65,000 in its native state. We concluded that BGEF differed from @entity1356 and @entity1199 , but is a novel factor produced by TKS-1 cells. In addition, we found that partially purified B cells from @entity1 with @entity309 produced factors which enhanced the activity of @entity1356 .
