CXCR6 is expressed on T cells in both T helper type 1 (Th1) inflammation and allergen‐induced Th2 lung inflammation but is only a weak mediator of chemotaxis

Abstract

Summary Numerous chemokine receptors are increased in number on T cells in inflamed tissues. Our objective was to examine CXCR6 expression on lymphocytes during immune and inflammatory reactions and its potential for mediating T‐cell recruitment. The cDNA for rat CXCR6 was cloned and monoclonal antibodies (mAbs) to CXCR6 were developed. CXCR6 was present on 4–6% of CD4 and CD8 T cells in blood, normal lymph nodes (LNs) and the spleen, primarily on memory T cells. In vitro antigen re‐stimulation of LN T cells from animals with autoimmune arthritis and experimental autoimmune encephalomyelitis (EAE) increased the proportion of CXCR6+ T cells to 35–50% and anti‐T‐cell receptor (TCR) activation to 60–80%. In vivo, after antigen challenge of LNs there was only a small increase in CXCR6+ T cells on the lymphoblasts in the LNs, and a much higher percentage of T cells were CXCR6+ in virus‐induced peritoneal exudates (∼47%) and in allergen‐induced lung inflammation (33%). Chemotaxis of CXCR6‐expressing inflammatory T cells to CXCL16 was poor, but that to CXCL10 was robust. We conclude that few T cells in normal and antigen‐challenged LNs are CXCR6+, whereas a high proportion of in vitro activated T cells and T cells from inflammatory sites are CXCR6+, but these cells migrate poorly to CXCL16. This suggests that CXCR6 may contribute to T‐cell positioning and activation, rather than recruitment. CXCR6 is also expressed on T cells not only in T helper type 1 (Th1) inflammation (arthritis and EAE) but also, as shown here, in Th2 inflammation, where it is increased after allergen challenge.

CXCR6 identifies a putative population of retained human lung T cells characterised by co-expression of activation markers

“…We therefore hypothesise that CXCR6 positive cells recruited into the lung, become attracted to AM and to other APCs expressing CXCL16. This suggestion has also been made by Latta et al (2007). If those cells are also expressing cognate antigen then this results in up-regulation of CD69, CD49a and particularly CD103 which are involved in anchoring the T cells within the tissue possibly through adherence to the APCs themselves or to collagen (VLA-1) or E-cadherin in the case of CD103.…”

Allelic Variation in CXCL16 Determines CD3+ T Lymphocyte Susceptibility to Equine Arteritis Virus Infection and Establishment of Long-Term Carrier State in the Stallion

“…Moreover, expression on these cell types is upregulated by inflammatory mediators and bacterial lipopolysaccharides [27,29,36,[38][39][40]. Both soluble and membrane-bound forms of HuCXCL16 specifically interact with its receptor CXCR6 (also known as STRL33/ BONZO/TYMSTR) expressed on the surface of CD4 + and CD8 + T lymphocytes, NKT cells, and NK cells [27,[41][42][43]. Binding to the CXCR6 receptor is facilitated by the mucin-stalk located within the extracellular domain of the molecule [44,45].…”

CXCR6 Is a Marker for Protective Antigen-Specific Cells in the Lungs after Intranasal Immunization against Mycobacterium tuberculosis

“…immunization, but CXCL16 has been reported to be poorly chemotactic (25). Therefore, we tested the effect of administering recombinant CXCL16 i.n.…”