Fig 2: Leptin increased CD4+ T cell proliferation in obese compared to lean PLWH. PBMCs from obese and lean PLWH, as well as obese HIV negative controls, were pre-treated with recombinant leptin at the indicated concentrations for 48 hours, then stimulated with anti-CD3/CD28/CD49d for 2 days. (A) Representative flow gating of Ki67+CD4+ T cells in obese and lean PLWH and HIV negative controls after 0 or 10 nM leptin treatment. (B) Quantification of the percentage of Ki67+CD4+ T cells under 0 or 10 nM leptin treatment. Quantification of the percentage change in Ki67 expression (relative to 0 nM conditions) in CD4+ T cells from (C) lean PLWH, (D) obese PLWH and (E) obese HIV negative control following 0, 10, 50 or 100 nM leptin treatment. In (B), Wilcoxon-matched pairs rank signed tests were used to compare 0 and 10 nM values for each person. Mann-Whitney tests were used to compare 10 nM leptin treatment between groups. In (C–E), Kruskal-Wallis tests were used to compare the relative change compared to vehicle treatment in each metabolic group. n = 4-7 people per group. *p < 0.05 was considered statistically significant. Data shows one representative experiment repeated two times.

Fig 3: Leptin receptor expression is decreased in CD4+ T cells from obese PLWH compared to lean PLWH. PBMCs from obese and lean PLWH, as well obese HIV negative controls, were stimulated with anti-CD3/CD28/CD49d for 2 days. (A) Representative flow gating of leptin receptor (LepR) surface expression in CD4+ T cells following activation. (B) Quantification of the percentage of LepR+CD4+ T cells. Relationship between percentage of LepR+CD4+ cells and (C) plasma leptin levels or (D) by BMI. In (B), Mann-Whitney tests were used to compare obese and lean PLWH, or obese PLWH and obese HIV negative controls. n = 8-9 persons per group. *p < 0.05 was considered statistically significant. Data shows one representative experiment repeated three times. n.s. means not statistically significant. In (C, D), Spearman’s rank correlations were conducted for plasma leptin and BMI measurements.