TLR5 Agonists Flagellin Prevents Acute Graft-Versus-Host Disease After Mice Allogeneic Bone Marrow Transplantation In The Preliminary Research

Objective：To evaluate the effect of FLAGELLIN, A TLR5（Toll 1ike Receptor）AGONIST on acutegraft-versus-host disease (aGVHD) prophylaxis and may be effctive mechance after allogeneicbone marrow transplantation ( allo-BMT) in a murine model.Methods：With major histocompatibility antigen (MHC) totally unreasonable purebredmice which were the [donor rat: male C57BL / 6; receptor mouse: female rat BALB/c ]built allo-BMT/aGVHD animal model. receptor mice were divided randomly intothree groups. Experimental group mice in two times before and after transplantationwere given high purity (purity frequency 95%) of the flagellin (5μg/only time) 50μl. Control group mice gave no drug as aGVHD prophylaxis after transplantation andOnly gave the same dose PBS. Blank control group mice only were illuminated andwere not transplanted，also Only gave the same dose PBS. And let us observe andcompare their aGVHD performance between experimental group and control groupafter transplantation.Results： Transplantation mice appear typical aGVHD symptoms. The death peak ofControl group mice which gave no aGVHD prophylaxis appears four to five daysafter transplantation .Experimental group mice with flagellin as aGVHD prophylaxissignificantly reduce aGVHD symptoms, the mean survival time (MST) is muchlonger than control group (P＜0.05). The numbers of white cell of three groupsmice in peripheral blood before transplantation have no difference (P＞0.05). Butafter transplantation in 14-21 days, The numbers of white cell of experimental groupmice in peripheral blood have much different than control group (P＜0.05). Andexperimental group mice with flagellin as aGVHD prophylaxis Which symptomshave much less than control group mice. By Flow cytometric detection experimentalgroup and control group mice Which Treg cell/CD4 + T cells percent before and aftertransplantation at different time points (at -1W,0W,2W,3W, 4W )also show that twogroups results have significant difference (P＜0.05) after transplantation 2-4 W, theexperimental group mice Which Treg cell numbers have increased significantlycompared with control group mice.Conclusions：Flagellin can effectively prevent the mice aGVHD after allo-BMT, ease thesymptoms and pathological damage degrees, the mean survival time has significantprolong. Therefore, it can be argued that flagellin increase mice Treg cell numbersafter transplantation and improve and reduce the occurrence of aGVHD .