Figure 3.

Rejuvenated B cells in old lymphoma patients mount a young‐like population dynamic and function. Peripheral blood samples from young, old, and old‐depleted (lymphoma patients) were collected. (a + b) Cells were analyzed by flow cytometry for frequencies of B (CD19+) and T (CD19−/CD5+) lymphocytes (a) and for memory (CD19+/CD27+) or naïve (CD19+/CD27−/IgD+) B cells (b). Results from young (n = 14), old (n = 34), and old‐depleted (n = 18) patients are expressed. (c) IgH repertoire in peripheral blood was determined by CDR3 spectratyping using DNA extracted from peripheral blood mononuclear cells. The Morisita similarity index between every two spectratypes was measured. Shown are the 95% confidence intervals of these similarity indices within and between groups of patients: Y—young, O—old, D—old, B‐cell‐depleted patients. Statistical significance of differences between groups was calculated by ANOVA. (d) B cells were purified and cultured in vitro in the presence or absence of LPS. Supernatants were analyzed for secretion of IgM by quantitative ELISA. Results shown are expressed as fold increase (relative to unstimulated cells) and are mean ± SE of 5–6 patients