Figure 5: Clonal replacement in virus-specific CD4+ T cells independently of Bcl6-dependent Tfh differentiation or germinal center reaction.
From: Stepwise B-cell-dependent expansion of T helper clonotypes diversifies the T-cell response
(a) Frequency of germinal center-phenotype (CD38loGL7hi) cells in CD19+IgDlo splenic B cells 35 days after FV infection of WT or Tnfrsf1a−/− mice (n=3). (b) Germinal center (B220+IgD−GL7+) presence in the spleen of the same mice in a. The scale bar is 250 μm. (c) Absolute numbers (left) and Vα composition (right) of env-reactive donor EF4.1 CD4+ T cells in the spleens of WT or Tnfrsf1a−/− recipient mice after adoptive T-cell transfer and FV infection (n=3–9 mice per time point). (d) Absolute numbers of WT or Bcl6-conditional (Bcl6c) env-reactive donor EF4.1 CD4+ T cells, additionally carrying the Tnfrsf4Cre and Gt(ROSA)26SorYFP alleles, in the spleens of recipient mice after adoptive T-cell transfer and FV infection (n=3–9 mice per time point). (e) YFP expression on day 7 (left) and frequency of YFP+ cells over time (right) in the same env-reactive donor EF4.1 CD4+ T cells as in d. (f) Vα2 frequency in YFP+ and YFP− Bcl6-conditional env-reactive donor EF4.1 CD4+ T cells as in d. In c–f, closed symbols are the means (±s.e.m.); open symbols are individual mice.
