Mechanisms underlying the production of chemokine CXCL11 in the reaction of renal tubular epithelial cells with CD4+ and CD8+ T cells

Abstract

AimTo study the release mechanism of C-X-C motif chemokine 11 (CXCL11) and other chemokines after the co-cultivation of CD4+ and CD8+ T cells with the renal tubular epithelial cells (RTEC) in the process of allograft renal transplantation rejection. MethodsThe Human CD4+, CD8+ T cells were obtained from the blood of volunteers and kidney transplantation (Ktx) patients, and co-cultured with renal tubular epithelial cells (RTEC) in vitro. RT-PCR was run for detecting the mRNA transcription of CXCL11, IFN-induced protein of 10 (CXCL10), and IL-6 in cells after RTEC was stimulated with IFN-γ or co-cultured with CD4+ and CD8+ T cells. The concentration of CXCL11, CXCL10 and IL-6 in the culture medium was detected by Multiplex Assay after RTEC was stimulated with IFN-γ or co-cultured with CD4+ and CD8+ T cells. IFN-γ receptor antibody was used for interfering with the above reaction and the blocking effect was observed. Western blot was used for protein expression analysis. Finally, we applied renal biopsies from kidney transplantation patients with and without rejection to verify the results of the above experiments by using RT-PCR and Western blot. ResultsThe mRNA expression of CXCL11 and CXCL10 were significantly increased after RTEC was stimulated with IFN-γ or co-cultured with CD4+ and CD8+ T cells. Multiplex Assay showed that the concentration of CXCL11 and CXCL10 in the supernatant were significantly increased in a time-dependence fashion after stimulation RTEC by IFN-γ. Anti-IFN-γ receptor1 (anti-IFN-γR1) antibody could reduce the production of CXCL11 and CXCL10 in this situation. The concentration of CXCL11 and CXCL11 in the supernatant was significantly increased with a time-dependent effect after the co-culture of CD4+ and CD8+ T cells with RTEC. The anti-IFN-γR1 blocked this effect. Our study showed that the expression levels of CXCL11 and CXCL10 were upgraded in the biopsies of patients with renal transplant rejection comparatively to pre-transplant biopsies, both at mRNA and protein levels. ConclusionsRTEC and T cells can stimulate each other during the acute rejection of allogeneic kidney transplantation and secret CXCL11，CXCL10 and other chemokines. IFN-γ plays a key role in this process.