Figure 2

Natural SP-D multimers bind more strongly to IAV than SP-D trimers. Natural SP-D multimers and trimers were purified from amniotic fluid and tested for binding to Phil82 IAV by ELISA using the 246-04 mAb for detection of bound SP-D. Natural SP-D multimers showed significantly greater binding than trimers (** indicates p < 0.01; n = 3; Panel A). Binding of natural SP-D trimers was significantly above background binding to BSA at 640 ng/ml only (* indicates p < 0.01). In panel B we compared binding of recombinant human trimers and multimers isolated by gel filtration. Again binding of multimers was significantly greater than binding of trimers. In panel B background binding to BSA coated plates was subtracted from the results shown.