Journal of Microbiology, Immunology and Infection (Dec 2023)

Caecum OX40+CD4 T-cell subset associates with mucosal damage and key markers of disease in treated HIV-infection

  • Isaac Rosado-Sánchez,
  • Inés Herrero-Fernández,
  • Salvador Sobrino,
  • Ana E. Carvajal,
  • Miguel Genebat,
  • Laura Tarancón-Díez,
  • María Carmen Garcia-Guerrero,
  • María Carmen Puertas,
  • Rocío M. de Pablos,
  • Rocío Ruiz,
  • Javier Martinez-Picado,
  • Manuel Leal,
  • Yolanda M. Pacheco

Journal volume & issue
Vol. 56, no. 6
pp. 1129 – 1138

Abstract

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Background: Blood OX40-expressing CD4 T-cells from antiretroviral (ART)-treated people living with HIV (PWH) were found to be enriched for clonally-expanded HIV sequences, hence contributing to the HIV reservoir. OX40-OX40L is also a checkpoint regulator of inflammation in multiple diseases. We explored gut mucosal OX40+CD4+ T-cells and their potential significance in HIV disease. Methods: Biopsies of caecum and terminal-ileum of ART-treated PWH (n = 32) were obtained and mucosal damage and HIV reservoir were assessed. Mucosal OX40+ and Ki67+ CD4 T-cell subsets, as well as several tissue T-cell subsets modulating mucosal integrity and homeostasis (Th17, Th22, Treg, Tc17, Tc22, IL17+TCRγδ, IL22+TCRγδ) were quantified. Inflammatory-related markers, T-cell activation and thymic output were also determined in blood samples. Correlations were explored using Spearman rank test and corrected for multiple comparisons by Benjamini-Hochberg. Results: Compared to healthy controls, a high frequency of mucosal, mainly caecum, CD4 T-cells were OX40+ in PWH. Such frequency strongly correlated with nadir CD4 (r = −0.836; p < 0.0001), CD4/CD8 ratio (r = −0.630; p = 0.002), caecum mucosal damage (r = 0.606; p = 0.008), caecum Th22 (r = −0.635; p = 0.002), caecum Th17 (r = 0.474; p = 0.03) and thymic output (r = −0.686; p < 0.001). It also correlated with Neutrophil-to-Lymphocyte Ratio and blood CD4 T-cell activation and tended to with mucosal HIV reservoir. Conclusion: High frequencies of caecum OX40+CD4 T-cells are found in people with HIV (PWH) and successful viral control. Interestingly, this cellular subset reflects key markers of disease and peripheral T-cell activation, as well as HIV-driven mucosal damage. OX40+CD4 T-cells deserve further investigation since they could expand because of T-cell homeostatic proliferation and relate to the Th22/Th17 gut mucosal ratio.

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