Figure 11.

Env-specific T_FH cells are quantified in LN of vaccinated NHPs. The percentage of functional CD4+ T_FH cells stimulated by vaccine immunogens in inguinal lymph nodes of vaccinated macaques was assessed. (A) Lymphocytes collected 2 weeks after 4 (week 22) and 6 (week 43) immunizations were stimulated with both 7wpi_Luc and 54wpi_D Env proteins and analyzed by conventional intracellular staining where T_FH cells were defined as CD3+CD4+CD95+, PD-1hi, and Env-specific responses were measured by IL-21 and IFNg. (B) Correlations of immunogen-specific T_FH responses with neutralization activity in sera of vaccinated macaques. The number of immunizations given are shown in parenthesis in the x-axis title. P and r values were determined by Spearman's correlation. (C) Lymphocytes collected 2 weeks after 3 (week 14) immunizations were assessed after stimulation with 54 wpi_D Env protein. T_FH cell subpopulations were defined as CD20–CD3+CD4+, PD-1hi, CXCR5hi. Data shown is the percentage of functional CD4+ T_FH cells identified as the OX40+ and CD25+ subset. *Indicated no data for this NHP. No T/F Prime group in green and T/F Prime group in blue for all panels.