Figure 4

Viral neutralization by HNPs alone or in combination with natural SP-D multimers and trimers. Viral neutralization was assessed as in figure 1 and expressed as % of control infectious foci in samples treated with SP-D preparations alone (control; black and gray bars), HNP1 or 2 alone (HNP1 or HNP2; 5 μg/ml; white bars), or combination of HNP1 or 2 with the SP-D preparations (HNP1 or HNP2; black and gray bars; SP-D concentration 350 ng/ml). SP-D multimers caused significantly greater neutralization than trimers as in figure 3 (n = 5; p < 0.01). HNPs 1 and 2 also caused significant neutralization on their own. When SP-D multimers were combined with HNPs a significant increase in neutralization was observed (* indicates significantly different from control or SP-D multimers or HNPs alone by ANOVA).