Segregation of reactivity to the mitogens lipopolysaccharide, lipoprotein and dextran sulfate in clones of the B cell lymphoma line WEHI 279.1.

The B cell lymphoma line WEHI 279.1 (surface IgM+, I-A+ and I-E+) was used as a model system to analyze functional reactivity of B lymphocytes to mitogens. Among the mitogens tested, lipopolysaccharide (LPS), lipoprotein (LP), and dextran sulfate (DxS) all induced a strong, dose-dependent growth inhibition of tumor cells. The analysis of independently derived clones, however, revealed that mitogen sensitivity could be lost in the absence of detectable alterations in the expression of those surface markers. Moreover, reactivity to LPS, LP and DxS segregated independently in these clones, suggesting distinct triggering mechanisms and functional receptors for these mitogens on the B cell membrane.