CXCR3-Expressing T Cells in Infections and Autoimmunity

Abstract

The chemokine receptor CXCR3 and its ligands (MIG/CXCL9, IP-10/CXCL10, and I-TAC/CXCL11) play a central role in the generation of cellular inflammation, both in the protective responses to invading pathogens, and in different pathological conditions associated with autoimmunity. It is worth noting that CXCR3 is highly expressed on innate and adaptive lymphocytes, as well as on various cell subsets that are localized in non-immune organs and tissues. Our review focuses exclusively on CXCR3-expressing T cells, including Th1, Th17.1, Tfh17, Tfh17.1, CXCR3⁺ Treg cells, and Tc1 CD8⁺ T cells. Currently, numerous studies have highlighted the role of CXCR3-dependent interactions in the coordination of inflammation in the peripheral tissues, both to increase recruitment of CD4⁺ and CD8⁺ T cells that upregulate inflammation, and also for recruitment of CXCR3⁺ T regulatory cells to dampen overexuberant responses. Understanding the role of CXCR3 and its ligands might help to apply them as new and effective therapeutic targets in a wide range of diseases.

Keywords: COVID-19; CXCR3 chemokines; CXCR3 receptor; CXCR3⁺ Treg; Tc1; Th1 cells; Th17.1 cells; autoimmunity; follicular Th cell subsets; infection.