Fig. 10.

New insights into the heterogeneity of human Th17 cells at homeostasis and during ART-controlled HIV-1 infection. In this work we identified two new subsets of CCR6⁺ T-cells, CCR6⁺DN/CCR4⁻CXCR3⁻ and CCR6⁺DP/CCR4⁺CXCR3⁺, that share Th17 features with the previously described Th17/CCR4⁺CXCR3⁻ and Th1Th17/CCR4⁻CXCR3⁺ [5]. Despite these similarities, CCR6⁺DN distinguished from the other three subsets by superior their ability to produce Th17 effector cytokines (e.g., IL-17F, IL-8, and IL-21) and their predominant frequency/counts in the blood and lymph nodes HIV-infected individuals receiving ART. Finally, we demonstrate that CCR6⁺DN harbor replication-competent HIV-DNA. Thus, we reveal the existence in humans of four Th17-polarized CCR6⁺ subsets that represent distinct stages of Th17 differentiation, with CCR6⁺DN being the most predominant and contributing to HIV reservoir persistence under ART