Association between circulating levels of TNFα, Ab response to influenza vaccination and T cell activation and senescence.

<p>(<b>A</b>) Correlation between TNFα plasma levels at t0 and the reciprocal of vaccine-specific Ab titers at week 4 was established for 12 HIV^– and 14 HIV⁺ aging women. Plasma TNFα levels were measured using a customized MILLIPLEX™ Cytokine Human Ultrasensitive magnetic bead panel (EMD Millipore). (<b>B</b>-<b>D</b>) T cells were immunophenotyped using MoAbs specific for activation (CD38, HLA-DR), proliferation (Ki-67) and senescence (CD28, CD57) markers. Frequencies of CD4, pTfh and CD8 T cell subsets expressing these markers were correlated with pre-vaccination TNFα plasma levels. Statistical analysis was performed using Pearson correlation.