Anti-inflammation Mediator Lipoxin A4 Can Attenuate Cell Infiltration Of Allograft But Not Influence Apoptosis And Proliferation Of MRL(Mixed Lymphocyte Reaction) In Vitro

Background: Endogenous anti-inflammatory mediator lipoxin A4 can inhibit neutrophil, promote the resolution of inflammation. Moreover, recent study revealed an early protective in allogeneic BMT-induced GvHD. It is supposed a potential protective allograft against rejection.Aims: To determine the protective of anti-inflammation mediator lipoxin A4 on cardiac allograft in mouse and splenocytes injection (C57BL/6 to CB6F1) induced graft-vs-host disease(GVHD).Explore the effects of lipoxin A4 on apoptosis and proliferation of MRL in vitro.Methods: Mouse were divided into four experimental groups ( 7 cases in group A, B,3 cases in C and D respectively). Group A and B were allograft heart transplants from male BALB/C to C57BL/6, Group C and D were isografts of C57BL/6. Recipients in Group A and Group B, were injected with 1ml of Lipoxin A4 (1ug/per) or 0.9% sodium chloride iv. 0, 2, 4 day posttr- ansplantation, respectively. The general appearance and weight were observed every day. On day 7, all mouses were sacrificed, pathology of acute rejection was evaluated. The plasma was collected, and IL-2,10 , INF-γwere detected using ELISA. In vitro splenocyte were extracted, purified from BALB/C and C57BL/6, and MLR was performed according to literature, and the lympholeukocytes were pretreatmented with lipoxin A4(1,10,100 ug/L) or sodium chloride as control. Flow cytometric analysis was used detecting apoptosis, and AlamarBlue were used for measurement proliferation. Injection of C57BL/6 (B6) splenocytes into (C57BL/6×BALB/c)F1 can induce graft-vs-host disease(GVHD).On day 0 and 7,108 splenocytes were injected to CB6F1, LXA4 (1ug/108 cells ) was administrated to donor cells or without, and clinical indicators of weight, skin lesions, were monitored. On day 14, all mouses were sacrificed, liver function and pathology of liver, spleen, lung was evaluated.Results: The general appearance in group A is better than group B. Cardiac biopsy grading were group A; 1 B, 3.1±0.6; C, 0 and D 0 respectively 7 day after operation. In group A, the infiltration of inflammatory cells was less than group B significantly, and cytokine were TH2 bias in group A. But in vitro the proliferation and apoptosis of MRL have no difference in lipoxin A4 pretreatment group and sodium chloride group. In GVHD clinical indicators, liver function and pathology with LXA4 were better than the mices without lipoxin administration.Conclusion: Anti-inflammation mediator Lipoxin A4 can attenuates cell infiltration of allograft acute rejection, improve the general appearance posttransplantation, and induce TH2 bias. But in vitro lipoxin A4 does not influence the proliferation and apoptosis of MRL in experiment concentration. Whether lipoxin A4 can prolong the allograft survival is not clear yet and needs further study. In GVHD model, LXA4 administration can attenuate the GVHD and improve the liver function.