Differentiation phenotype of pathogen-specific CD4 T cells and the associated HIV infection. (A) CFSE_lowCD3⁺CD8⁻ T cells in antigen-stimulated PBMCs were gated for analysis. (B-C) Representative flow cytometric plots (B) and statistical comparison (C), shown as box and Whisker plots, for the frequencies of CM (CD27⁺CD45RO⁺), EM (CD27⁻CD45RO⁺), and terminally differentiated (TD: CD27⁻CD57⁺) subsets between pathogen-specific CD4 T-cell populations. (D-E) Representative flow cytometric plots (D) and statistical comparison (E), shown as box and Whisker plots, for HIV infection of different differentiation subsets between pathogen-specific CD4 T-cell populations. The HIV infection rate is expressed as the proportion of each subset expressing p24. For panels D and E, only the CFSE_low CD3⁺CD8⁻CD45RO⁺ memory population was gated for analysis. A total of 6 donors and at least 6 independent experiments were performed. Statistical analysis was performed using the Mann-Whitney test. ***P < .005; **P < .01; *P < .05.