Figure 5.

Inhibition of mitogen-stimulated B cell proliferation ex vivo by MV infection. Spleen cells from infected animals 4 days after infection and noninfected animals were stimulated either with pokeweed mitogen (PWM) (stimulating T and B cell growth) or a cross-link by antiserum reacting with cotton rat immunoglobulins and 10 μg/ml S. typhosa lipopolysaccharide (LPS) (stimulating B cells only). After stimulation with PWM, proliferation ranged from 50,000 to 80,000 cpm, and after B cell-specific stimulation, proliferation ranged from 13,000 to 20,000 cpm. Proliferation with medium alone was 100–1,000 cpm. The stimulation index was calculated as cpm stimulation/cpm medium and expressed as an average of four animals per group.