Figure 2.
No effect of ultraviolet B (UVB) radiation on the proliferative response of lymph node cells (LNC). 2,4-Dinitrofluorobenzene (DNFB) (0·4%) was painted for two consecutive days on the shaved dorsa of B6 mice after UVB irradiation. LNC (4 × 105) from regional lymph nodes were cultured with 2 × 105 antigen-presenting cells (APC) pulsed with various haptens, and proliferative responses were measured 4 days later. The data reported represent the mean counts per minute (c.p.m.) of triplicate cultures [standard error of the mean (SEM) < 10%]. LNC from UVB-irradiated or from non-irradiated mice showed strong proliferative responses only when co-cultured with DNFB and were statistically significant. *P < 0·0001 when using a one-way factorial analysis of variance (anova). FB, fluorobenzene; Ox, 4-ethoxymethylene-2-phenyl-2-oxazolin-5-one; PCl, picryl chloride (2,4,6-trinitrochlorobenzene).