Conventional Alpha Beta (Alpha Beta) T Cells Do Not Contribute To Acute Intestinal Ischemiareperfusion Injury In Mice

Purpose Ischemia-reperfusion injury (IRI) is associated with significant patient mortality and morbidity. The complex cascade of IRI is incompletely understood, but inflammation is known to be a key mediator. In addition to the predominant innate immune responses, previous research has also indicated that alpha beta T cells contribute to IRI in various organ models. The aim of this study was to clarify the role alpha beta T cells play in IRI to the gut.Methods Adult wild-type (WT) and alpha beta T cell-deficient mice were subjected to acute intestinal IRI with 30min ischemia followed by 4h reperfusion. The gene expression of pro-inflammatory cytokines was measured by qPCR, and the influx of leukocyte subpopulations in the gut was assessed via flow cytometry and histology. Pro-inflammatory cytokines in the serum were measured, and transaminases were assessed as an indicator of distant organ IRI.Results Intestinal IRI led to an increased expression of pro-inflammatory cytokines in the gut tissue and an influx of leukocytes that predominantly consisted of neutrophils and macrophages. Furthermore, intestinal IRI increased serum IL-6, TNF-alpha, and ALT/AST levels. The alpha beta T cell-deficient mice did not exhibit a more significant increase in pro-inflammatory cytokines in the gut or serum following IR than the WT mice. There was also no difference between WT-and alpha beta T cell-deficient mice in terms of neutrophil infiltration or macrophage activation. Furthermore, the increase in transaminases was equal in both groups indicating that the level of distant organ injury was comparable.Conclusion An increasing body of evidence demonstrates that v T cells play a key role in IRI. In the gut, however, alpha beta T cells are not pivotal in the first hours following acute IRI as deficiency does not impact cytokine production, neutrophil recruitment, macrophage activation, or distant organ injury. Thus, alpha beta T cells may be considered innocent bystanders during the acute phase of intestinal IRI.