A role for mucosal IL-22 production and Th22 cells in HIV-associated mucosal immunopathogenesis

• Published in: Mucosal immunology Vol. 5; no. 6; pp. 670 - 680
• Main Authors: Kim, C J, Nazli, A, Rojas, O L, Chege, D, Alidina, Z, Huibner, S, Mujib, S, Benko, E, Kovacs, C, Shin, L Y Y, Grin, A, Kandel, G, Loutfy, M, Ostrowski, M, Gommerman, J L, Kaushic, C, Kaul, R
• Format: Journal Article
• Language: English
• Published: New York Nature Publishing Group US 01.11.2012; Elsevier Limited
• Subjects: 631/250/127/1213; 631/250/347; 692/420/2780; 692/699/249/1570/1901; Allergology; Anti-HIV Agents - pharmacology; Anti-HIV Agents - therapeutic use; Antibodies; Biomedical and Life Sciences; Biomedicine; Cell Lineage; Colon, Sigmoid - immunology; Colon, Sigmoid - pathology; Colon, Sigmoid - virology; Gastroenterology; HIV - physiology; HIV Infections - drug therapy; HIV Infections - immunology; HIV Infections - pathology; HIV Infections - virology; Humans; Immunity, Mucosal; Immunology; Interleukin-22; Interleukins - deficiency; Interleukins - immunology; Interleukins - pharmacology; Intestinal Mucosa - drug effects; Intestinal Mucosa - immunology; Intestinal Mucosa - pathology; Intestinal Mucosa - virology; Killer Cells, Natural - immunology; Killer Cells, Natural - pathology; Killer Cells, Natural - virology; Lymphocyte Count; Lymphocyte Depletion; Receptors, CCR5 - immunology; Recombinant Proteins - immunology; Recombinant Proteins - pharmacology; T-Lymphocytes, Helper-Inducer - immunology; T-Lymphocytes, Helper-Inducer - pathology; T-Lymphocytes, Helper-Inducer - virology; Time Factors; Tumor Necrosis Factor-alpha - immunology; Tumor Necrosis Factor-alpha - pharmacology
• ISSN: 1933-0219; 1935-3456
• DOI: 10.1038/mi.2012.72

Interleukin-22 (IL-22) is a cytokine with epithelial reparative and regenerative properties that is produced by Th22 cells and by other immune cell subsets. Therefore, we explored the hypothesis that disruption of the gut barrier during HIV infection involves dysregulation of these cells in the gastrointestinal mucosa. Sigmoid IL-22-producing T cell and Th22 cells were dramatically depleted during chronic HIV infection, epithelial integrity was compromised, and microbial translocation was increased. These alterations were reversed after long-term antiretroviral therapy. While all mucosal IL-22-producing T-cell subsets were also depleted very early during HIV infection, at these early stages IL-22 production by non-T-cell populations (including NKp44+ cells) was increased and gut epithelial integrity was maintained. Circulating Th22 cells expressed a higher level of the HIV co-receptor/binding molecules CCR5 and α4β7 than CD4+ T-cell subsets in HIV-uninfected participants, but this was not the case after HIV infection. Finally, recombinant IL-22 was protective against HIV and tumor necrosis factor-α-induced gut epithelial damage in a validated in vitro gut epithelial system. We conclude that reduced IL-22 production and Th22 depletion in the gut mucosa are important factors in HIV mucosal immunopathogenesis.