Persistent human immunodeficiency virus‐1 antigenaemia affects the expression of interleukin‐7Rα on central and effector memory CD4+ and CD8+ T cell subsets
Interleukin (IL)‐7 and its receptor (IL‐7Rα) play important roles in regulating lymphopoiesis. Previous studies have reported that human immunodeficiency virus‐1 (HIV‐1) viraemia affects the expression of IL‐7Rα, but its effects on CD4+ and CD8+ T cell memory subsets have not been studied. Using eight‐colour flow cytometry, we compared the immunophenotypic patterns of CD4+ and CD8+ T cell subsets expressing IL‐7Rα and activation markers, as well as circulating IL‐7 levels, in three well‐defined groups of HIV‐1‐infected subjects: successfully treated, viraemic and long‐term non‐progressor (LTNP). Compared with successfully treated and LTNP subjects, viraemic patients had reduced expression of IL‐7Rα on both CD4+ and CD8+ T cells, particularly on central and effector memory T cell compartments, and substantially elevated expression of activation markers on CD8+ T cell subsets. Circulating IL‐7 levels were correlated negatively with the number of CD4+ and CD8+ T cell subsets expressing IL‐7Rα; these associations were stronger with CD4+ T cell subsets and mainly with central and effector memory cells. The expression of activation markers on CD4+ and CD8+ cell T subsets was not related to circulating IL‐7 levels. A strong negative correlation was observed between central memory CD4+ or CD8+ T cells expressing IL‐7Rα and those expressing activation markers, independently of IL‐7 levels. Collectively, these results provide further insight on the role of unsuppressed viral load in disrupting the IL‐7/IL‐7Rα system and contributing to HIV‐1 disease progression.