Figure 7.

IgM and IgG subclass responses to FV. Plasma at 28 days post-infection in WT and SAMHD1 KO mice pre-treated with LPS were evaluated for (A-E) IgM and IgG subclass levels; and (F-I) IgM and IgG subclass binding titers to FV virions. (A-E) The concentrations of IgM, IgG1, IgG2b, IgG2c and IgG3 were measured in an ELISA. The data were interpolated from the respective antibody standard curves. (F-I) FV-reactive IgM, IgG1, IgG2b and IgG2c were measured in ELISA plates coated with FV virions using serial dilutions of plasma as noted in Fig. 5A–B. Reciprocal binding titers corresponding to an arbitrary absorbance cut-off (0.25 for IgM and IgG2c, and 0.5 for IgG1 and IgG2b) from a best-fit nonlinear regression curve were plotted in log2 scale. Each dot corresponds to a mouse and the data were pooled from 2 independent cohorts of WT and SAMHD1 KO mice. Experiment 1 had 7 WT and 6 SAMHD1 KO mice, and experiment 2 had 7 WT and 5 SAMHD1 KO mice. Differences between the cohorts were analyzed using a 2-tailed unpaired Student’s t-test or Mann-Whitney U test depending on whether the data distribution was normal. **, p<0.01; *, p<0.05; NS, not significant (p>0.05).