Figure 4.

C4BP interacts with IAV through multiple CCP domains. ELISA showing binding of C4BP CCP deletion mutants to (A) H1N1, (B) H3N2 and (C) VSV-G: microtiter wells were coated with 5 µg/ml of the mutant C4BP protein (as described in Table 1 ). 1000 PFU/ml of H1N1 or H3N2 virus was added to all the wells. After incubation and washing steps, the bound virus was measured with either monoclonal anti-influenza virus H1, polyclonal anti-influenza virus H3 or polyclonal anti-VSV-G antibody. Results are normalised against full length C4BP α chain. The data were expressed as the mean of three independent experiments done in triplicates ± SEM. Significance was determined using the two-way ANOVA test (*p < 0.05, **p < 0.01, and ****p < 0.0001) (n = 3).