Proportions of circulating follicular helper T cells are reduced and correlate with memory B cells in HIV-infected children.

Introduction: HIV causes defects in memory B cells in children, but the mechanisms of those defects have not been fully elucidated. One possible mechanism is the lack of T-cell help to B cells during immune reactions. However, few studies have assessed the effect of HIV on follicular helper T cells (T_FH cells) in children. Methods: In this study, follicular-homing CD4 T cells and memory B cells were assessed in HIV-infected children and compared with children from the community. CXCR5 and CD45RO were used as markers of follicular-homing T cells and memory T cells, respectively. Memory T_FH cells were identified as CD3⁺CD8^-CD4⁺CXCR5⁺CD45RO⁺PD1⁺. Central memory T cells were identified based on CCR7 expression. Relationship between the proportions of follicular-homing CD4 T cells and memory B cells were determined in multivariable regression models. Results: Highly viremic HIV-infected children had lower proportions of memory T_FH cells when compared with community control children. In multivariable analyses, high proportions of memory T_FH cells were associated with increased percentages of resting memory B cells after adjusting for other covariates. Conclusion: The impact of HIV on follicular helper T cells could influence the accumulation of memory B cells in HIV-infected children. [ABSTRACT FROM AUTHOR]