Changes in the expression of transcriptional factors associated with the differentiation of Tfh cells during SIV infection.

<p>(A) Representative expression of Bcl-6 in Tfh (CXCR5<sup>+</sup>PD-1<sup>bright</sup>) and naïve non Tfh CD3<sup>+</sup>CD4<sup>+</sup> T cells in the spleen of a healthy RM. (B) Mean fluorescence intensity (geometric) of c-Maf expression in Tfh (CXCR5<sup>+</sup>PD-1<sup>bright</sup>) and naïve non Tfh CD3<sup>+</sup>CD4<sup>+</sup> T cells in both the LNs and spleen of RMs at different days post-infection. (C) Percentages of c-Maf<sup>+</sup> Tfh cells in LNs and spleen. Each dot represents an individual RM. Statistical analyses were performed using Mann Whitney test. *, p<0.05; **, p<0.01. At day>180, open circles represent fast progressor RMs PB023 and PB028; and full diamonds represent slow progressor RMs PB013 and PB044. Axillary and Inguinal LNs are represented separately by two distinct dots for each RMs at day>180. (D) Histograms show RT-PCR quantification of <i>BCL6</i>, <i>MAF</i> and <i>CXCR5</i> mRNA in splenocytes of chronically SIV-infected RMs of Chinese origin compared to <i>Leishmania infantum</i>-infected RMs, and healthy RMs. Each dot represents an individual RM. Statistical analyses were performed using Mann Whitney test. *, p<0.05; **, p<0.01. (E) Histograms show geometric mean fluorescence intensity (MFI) of Foxo1, KLF2, T-bet and Eomes in Tfh cells of RMs at the indicated time compared to naïve non Tfh CD3<sup>+</sup>CD4<sup>+</sup> T cells of an healthy RM. LNs (upper panel) and spleen (bottom panel) are shown. (F) RT-PCR quantification of IL-21 mRNA expression in naive, central memory (CM), effector memory (EM), and Tfh cells of SIV-infected RMs.</p>