T cell extravasation: Demonstration of synergy between activation of CXCR3 and the T cell receptor

Abstract

Endothelial cells present chemokines to T cells and can also stimulate the T cell antigen receptor by presentation of peptide–MHC antigen complexes. This study was designed to investigate the potential synergy between stimulation of the chemokine receptor CXCR3 and the human T cell receptor complex. Transendothelial T cell migration towards CXCL10 was modified by crosslinking CD3 immediately before addition to the endothelium. When resting endothelium was used, T cells which had been activated by crosslinking CD3 for only 1 min showed a significant reduction (p < 0.0001) in migration when compared with untreated T cells. By contrast, endothelial cells which had been activated by stimulation with interferon-γ and tumour necrosis factor-α supported a specific increase in the migration of activated T cells; this was most apparent after CD3 had been activated for 90 min (p < 0.0001). The molecular basis for synergy between CXCR3 and the T cell receptor complex was investigated by measurement of fluorescence resonance energy transfer. This showed that CXCL10 induced a close (<10 nm) spatial association between CXCR3 and the CD3ɛ subunit on the cell-surface. These data demonstrate that stimulation of both CXCR3 and the T cell receptor has the potential to enhance specifically both the proliferation and extravasation of specific T cells during episodes of local inflammation.

Human immune compartment comparisons: Optimization of proliferative assays for blood and gut T lymphocytes

“…While we confirmed previously established efficacy of staining PBMC (using 10×10 6 CD3 T cells) with 2.5 μM CFSE [12] (data not shown), limitations in biopsy-derived gut (MMC) cell numbers existed (due to IRB-safety limits and need for concurrent other assays); thus, only 2–3 × 10 6 gut derived CD3 T cells from each subject were available for culture/proliferation assay. The efficacy of exposing 2–3 × 10 6 gut derived CD3 T cells prior to culture with the same 2.5 μM CFSE concentration used for PBMC was evaluated in MMC from two subjects (Fig.…”

Chemokine receptor CXCR3 agonist prevents human T-cell migration in a humanized model of arthritic inflammation

“…PBMC were isolated as described previously (17). Purified T lymphocytes were extracted using RosetteSep human T-cell enrichment mixture antibody (StemCell Technologies) (9). Activated T cells were cultured in RPMI medium 1640 (Sigma), containing 10% (vol/vol) FCS, 100 U/mL penicillin, and 100 μg/mL streptomycin.…”

“…As well as promoting T-cell migration, CXCR3 forms a ligand-dependent association with the T-cell receptor complex (9). In this situation both CXCR3 and the T-cell receptor share downstream signaling molecules, potentially allowing cross-regulation (9).…”

“…As well as promoting T-cell migration, CXCR3 forms a ligand-dependent association with the T-cell receptor complex (9). In this situation both CXCR3 and the T-cell receptor share downstream signaling molecules, potentially allowing cross-regulation (9). Cells expressing CXCR3 have been implicated in a range of diseases, including psoriasis (10), multiple sclerosis (11), inflammatory bowel disease (12), and rheumatoid arthritis (13).…”

CXCR3 in T cell function

“…However, these outcomes were not correlated with differences in T cell-DC interactions in the LN. In vitro CXCL10 increases tethering of T cells to antigen presenting cells and synergy has been shown between CXCR3 and CD3ε signaling, due to spatial association of these receptors and subsequent tyrosine phosphorylation of the same signaling molecules [69–71]. DEC-205+ DCs appear to be a primary source of CXCL10 in the draining LN.…”