Fig. 4

Comparison of antiviral T cell proliferative responses between primary and rechallenge FIPV infections. Frequencies of CD4 and CD8 T cells showing proliferation after stimulation with either WKV or FIPV peptides during primary FIPV infection with cats from all outcomes included, were compared to responses during rechallenge infection (a). Horizontal lines represent median values for each group. Frequencies of CD4 and CD8 T cells showing proliferation after stimulation with either viral immunogen were compared between cats rechallenged with FIPV-i3c2 within 6 months of the primary challenge (< 1 yr. rechallenged) and cats that had been inoculated more than 1 year prior to FIPV rechallenge (> 1 yr. rechallenged) (b). Numbers shown above any time-point data represent P values calculated using a one-tailed Mann-Whitney U test (GraphPad Prism) to compare median T cell proliferation frequencies determined for primary versus rechallenge infections for each time point (a) or determined between rechallenge infection groups for each time point of rechallenge infection (b). P values < 0.05 were considered significant