Figure 1: Clonotypic diversity of virus-specific CD4⁺ T cells increases over the course of FV infection.

(a) Absolute numbers and (b) Vα composition of env-reactive donor EF4.1 CD4⁺ T cells in the spleens of recipient mice after adoptive T-cell transfer and FV infection (n=9–61 mice per time point; P<0.001 between Vα2 frequency on day 7 and any later time point, Mann–Whitney rank sum test). (c) Frequency of various Vα2 and Vα3 clonotypes in total EF4.1 CD4⁺ T cells from two uninfected donor mice (preimmune; donors 1 and 2) or in env-reactive EF4.1 CD4⁺ T cells from the spleens of recipient mice after adoptive T-cell transfer from the indicated donor and FV infection. Each bar graph represents an individual mouse. Clonotypes with frequencies <0.5% are not plotted for simplicity. Identical clonotypes within Vα2 and Vα3 subsets are marked with the same color, with red color indicating the dominant Vα2 and Vα3 clonotypes. The scale of the Vα2 and Vα3 plots are adjusted to the relative ratio of the two subsets at a given time point.