Representative gating strategy and CD4 ⁺ T cell counts. (A and B) Gating strategy for determining the percentage of CD3⁺CD4⁺ T cells among CD45⁺ cells in PBMCs (A) and in whole blood samples (B). (C and D) Longitudinal analysis of CD4⁺ T cell counts in PBMCs (C) and LNs (D). Open circles represent rare time points for which flow cytometric quantification was unavailable. Due to the relative stability of the CD4⁺ population and close spacing of time points, we used the value closest to the missing value in date for the normalization calculation.