CXCR5 and infection: While both Tfh (CXCR5+Ly6C-) and Th1 (CXCR5-Ly6C+) cells were readily detectable in the draining lymph nodes following the establishment of memory (day 39 post-infection) after both LCMV infection and GP immunization, some germinal center Tfh (CXCR5+PD-1+) persisted (S1D Fig).