Published in:
01-09-2015 | Original Article
Decreased PD-1/PD-L1 Expression Is Associated with the Reduction in Mucosal Immunoglobulin A in Mice with Intestinal Ischemia Reperfusion
Published in: Digestive Diseases and Sciences | Issue 9/2015
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Background
Intestinal ischemia/reperfusion (I/R) disrupts intestinal mucosal integrity and immunoglobulin A (IgA) generation. It has recently been shown that the programmed cell death-1 receptor (PD-1) plays a crucial role in regulating intestinal secreted IgA (sIgA).
Aims
To evaluate changes in PD-1 and PD-ligand 1 (PD-L1) expression on Peyer’s patches (PP) CD4+ T cells and to investigate the correlation between PD-1/PD-L1 and intestinal IgA production/mucosal integrity in mice following intestinal I/R.
Methods
I/R injury was induced by clamping the superior mesenteric artery for 1 h followed by 2-h reperfusion. PD-1/PD-L1 expression on PP CD4+ T cells was measured in I/R and sham-operated mice. Additionally, transforming growth factor-β1 (TGF-β1) and interleukin-21 (IL-21) mRNA in CD4+ T cells and IgA+ and IgM+ in PP B cells, as well as intestinal mucosal injury and sIgA levels, were assessed.
Results
PD-1/PD-L1, TGF-β1, and IL-21 expression was down-regulated after intestinal I/R. Furthermore, IgA+ B cells decreased and IgM+ B cells increased in mice with intestinal I/R. Importantly, decreased PD-1/PD-L1 expression was correlated with increased mucosal injury and decreased IgA levels, as well as with decreased TGF-β1 and IL-21 expression.
Conclusions
Intestinal I/R inhibits PD-1/PD-L1 expression on PP CD4+ T cells, which was associated with an impaired intestinal immune system and mechanical barriers. Our study indicates that PD-1/PD-L1 expression on CD4+ T cells may be involved in the pathogenesis of intestinal I/R injury.