We found positive correlations of PD-1+ cTFH cells and Env-specific cTFH cells with LN-TFH cells as early as day 3 following immunizations, supporting the notion that LN and circulating TFH cellular populations are related. (GC) B cell affinity maturation. Circulating CXCR5+ CD4+ T (cTFH) cells have supported memory B cell Continue Reading