Analysis of the CD4+ T cell compartment.
PBMCs obtained from age-matched healthy controls (n = 13) and patients with S. aureus infections (n = 11) were stained with CD3, CD4, CCR7, CD45RA, and CD62L antibodies and analyzed by flow cytometry. CD4 T cell subsets are labeled as (A) central memory T cells (TCM), (B) naïve T cells, and (C) effector memory T cells (TEM). (a) Flow cytometry plots of CD4 T cell subsets in a representative S. aureus patient and healthy control. CD62L expression is shown for each CD4 T cell subset. (b) Graphs show the absolute numbers of CD4 T cells and CD4 T cell subsets expressed as absolute number of cells per mL of blood. Horizontal lines represent median values. Statistical analysis was performed using a Mann-Whitney test.