Figure 2.

SP-A-mediated HPV16-PsVs uptake by RAW264.7 macrophages is calcium-dependent, but not dependent on the CRD. AF488-labelled HPV16-PsVs were incubated in the presence of 10-fold (w/w) excess SP-A and (A) with or without 2 mM or 5 mM calcium chloride in the presence or absence of 10 mM EDTA as indicated, or (B) various concentrations of mannose. Shown are summaries of viral internalisation experiments as determined by FACS as described in Figure 1C. Fluorescent readings are displayed relative to HPV16-PsVs internalisation in the presence of SP-A only which was set as 1. Quantification of three independent experiments performed in duplicate are shown. Statistical significance was determined using one-way ANOVA and Tukey post-hoc tests. * = p < 0.05, ** = p < 0.01, *** = p < 0.001. Bars depict mean values, with error bars showing SEM.