Fig. 6: Staining of NK, MHC-E + and SIV-RNA positive cells in LN during acute and chronic SIVmac and SIVagm infections.

a, b Illustration of a the increase during SIVmac infection and b decrease during SIVagm infection of MHC-E expression on memory CD4⁺ T cells. Results are shown for a representative MAC and a representative AGM among six animals analyzed for each species. The time points analyzed are indicated on the right side of the panels. The viSNE plot was generated according to CD28, CD95, PD-1, CXCR5, and MHC-E expression gated on CD45⁺CD3⁺CD14⁻CD4⁺ cells in LN using proportional sampling with 54,422 events. The first column represents the distribution of CD4⁺ T cell subpopulations based on CD28 and CD95 expression: naïve (CD28⁺CD95⁻, blue), memory (CD28⁺CD95⁺, orange), effector (CD28⁻CD95⁺, red), and remaining CD28^-CD95^- CD4⁺ T cells (green). The red and blue colors indicate higher and lower mean fluorescence intensity (MFI) of markers measured in blood NK cells at a given time point. c–e Confocal images of LN from MAC and AGM collected in acute or chronic infection. Representative examples are shown for one animal among four studied. Pseudocolors were attributed to each marker (blue for DAPI, green for MHC-E, red for CD3 or SIV RNA, as indicated on the figure). Scale bars are shown on the figure. c B cell follicles co-stained for MHC-E and CD3. d B cell follicles co-stained for MHC-E and SIV. e Whole LN at the top in chronic SIV infection and magnification at the bottom showing co-staining for MHC-E and SIV RNA. f Lymph nodes from six AGM and five MAC infected with SIVagm and SIVmac, respectively, were analyzed at days 9 and 150 p.i. One LN per animal was analyzed for each time point. Representative confocal images of LN sections are shown with MHC-E (red), NKG2a (green), and total nucleus (blue).