Figure 4.
Viral induction of IL-12 p40 without a change in constitutive p35 expression in airway epithelial cells. Wild-type C57BL/6J mice underwent intranasal inoculation with SdV (5,000 EID50 in 30 μl of PBS), and lungs were removed and fixed in formalin on day 1, 3, 5, and 8 after inoculation. In each case, tissue was immunostained for IL-12 P-40 and p35 as described in the legend to Fig. 3 and similarly for viral protein (labeled SdV) using rat anti-SdV pAb. In mice inoculated with UV-inactivated Sdv, IL-12 p40 immunostaining was not detected and IL-12 p35 constitutive immunostaining was unchanged from untreated control mice (not shown). Control rat, goat, or rabbit nonimmune IgG gave no signal above background (data not shown). Bar, 20 μm.