Objective By using mouse orthotopic lung transplant model, we investigated the immune mechanisms of an-ti-CD3 induced lung allograft protection .Our study intends to further dissect the features of lung transplant immunology and to provide a novel therapeutic insight for the clinical application of anti-CD3 mAbs after lung transplantation.Methods Murine orthotopic allogeneic lung transplants were performed in C57BL/6 wild type(WT) mice using major histocompatibility complex (MHC) fully mismatched BALB/c donors.Syngeneic transplants were also performed in WT C57BL/6 mice using C57BL/6 donors.For immunosuppressive therapy, allograft recipients received 50g dose of anti-CD3 by intraperitoneal injection on days 2, 3, 4, 5, 6 and 9 post-operation(n=4).At day 10, histopathologic characteristics and rejection status of the pulmonary grafts were assessed.The severity of acute rejection was graded by the pathological score , and T cell and neutrophil infiltration in the pulmonary grafts was evaluated by immunohistochemical(IHC) staining for CD3 and myeloperoxidase(MPO) respective-ly.Real-time RT-PCR was performed for FoxP3, IL-17A and IFN-γexpression in the pulmonary grafts.The percentage of FoxP3+Treg in total CD4+T lymphocytes from the recipient spleens was analyzed by FACS.Results 10 days after transplan-tation, histopathologic examination demonstrated that there is no apparent acute rejection observed in the pulmonary isografts , whereas allografts from untreated recipients have marked inflammatory cell infiltration and pulmonary parenchyma lesion .IHC staining for CD3 and MPO showed that the allograft-infiltrating cells of perivascular layers are mainly T lymphocytes , and the cells around the small airways are mostly neutrophils .Anti-CD3 treatment significantly alleviated the acute rejection of pulmo-nary allografts, when compared with the untreated group.Real-time RT-PCR showed that the expression levels of IL-17A and IFN-γin allografts were markedly elevated compared to those in isografts, and anti-CD3 increased the expression of FoxP3, and reduced the expression of IL-17A and IFN-γin the pulmonary allografts.FACS analysis of splenocytes showed that the percent-age of Treg in total CD4+T lymphocytes increased significantly in the anti-CD3 treated allograft recipients, as compared with the isograft and untreated allograft recipients.Conclusion Anti-CD3 mAbs may alleviate acute rejection of the pulmonary al-lografts by promoting FoxP3 expression and Treg development.

Objectives To generate an orthotopic left lung transplantation model in mice, and to observe the early changes of respiratory system resistance andγδT lymphocytes infiltrated in grafts? Methods The research time was from March 2014 to May 2015? The male C57BL/6 mice ( n=35) and BALB/c mice (syngenic group,n=10) were randomly divided into five groups. Control group (n=5): wild C57BL/6 mice; syngenic transplant group ( n=10 ): C57BL/6→C57BL/6; allogenic transplant group ( allogenic group,n=10): BALB/c→C57BL/6; each transplant group was randomly divided into 3?day and 7?day subgroups ( n=5 )? Respiratory system resistance and histological features of grafts were assessed, and differences in graft infiltrating γδT lymphocytes and mRNA expression of interleukin ( IL )?17A were quantified on 3 and 7 days after transplantation? Multiple comparisons were performed using one?way analysis of variance and least significant difference analysis? Results ( 1 ) The respiratory system resistance of syngenic group and allogenic group were (2?61±0?59) cmH2O·s/ml and (2?84±0?31) cmH2O·s/ml 3 days post?operation, both of them increased compared to control group (1?39±0?17) cmH2O·s/ml (1 cmH2O=0?098 kPa) (P=0?001, 0?000). The respiratory system resistance of allogenic group were (4?33±0?67) cmH2 O·s/ml 7 days post?operation, which was significantly higher than that of syngenic 7?day subgroup (1?87±0?27) cmH2O·s/ml and control group (1?39±0?17) cmH2O·s/ml (P=0?000, 0?000)?(2) The isografts of syngenic group showed a relatively normal histological appearance with minimal infiltration of inflammatory cells, and the allografts of allogenic group infiltrated apparently by inflammatory cells, especially 7?day subgroup showed acute cellular rejection? ( 3) The percentage of γδT lymphocytes infiltrated in isografts and allografts were 3?90%± 0?86% and 4?40%± 0?57%, respectively, which were significantly increased compared to that of control lungs 2?00%±0?23% 3 days post?operation(P=0?000, 0?000);The percentage ofγδT lymphocytes infiltrated in 7 days allografts was 5?40%±0?98% , which was higher compared to that of 7 days isografts 2?60%± 0?54% and control lungs 2?00%± 0?23% ( P=0?000, 0?000)? (4) IL?17A mRNA expression levels were 3?37±0?55 and 5?23±1?50 in isografts and 6?77± 0?93 and 27?32±4?20 in allografts, on postoperative day 3 and 7 respectively? All of them were significantly upregulated compared to that of control lungs 0?99±0?08 (P=0?000, 0?000), and allografts exhibited significantly greater IL?17A transcript levels compared to isografts on postoperative day 3 and 7 ( P=0?000, 0?000) . Conclusion The rise of respiratory system resistance of lung grafts after transplantation may relate to the increased IL?17A?producing γδT lymphocytes infiltrated in the grafts.

Objectives To generate an orthotopic left lung transplantation model in mice, and to observe the early changes of respiratory system resistance andγδT lymphocytes infiltrated in grafts? Methods The research time was from March 2014 to May 2015? The male C57BL/6 mice ( n=35) and BALB/c mice (syngenic group,n=10) were randomly divided into five groups. Control group (n=5): wild C57BL/6 mice; syngenic transplant group ( n=10 ): C57BL/6→C57BL/6; allogenic transplant group ( allogenic group,n=10): BALB/c→C57BL/6; each transplant group was randomly divided into 3?day and 7?day subgroups ( n=5 )? Respiratory system resistance and histological features of grafts were assessed, and differences in graft infiltrating γδT lymphocytes and mRNA expression of interleukin ( IL )?17A were quantified on 3 and 7 days after transplantation? Multiple comparisons were performed using one?way analysis of variance and least significant difference analysis? Results ( 1 ) The respiratory system resistance of syngenic group and allogenic group were (2?61±0?59) cmH2O·s/ml and (2?84±0?31) cmH2O·s/ml 3 days post?operation, both of them increased compared to control group (1?39±0?17) cmH2O·s/ml (1 cmH2O=0?098 kPa) (P=0?001, 0?000). The respiratory system resistance of allogenic group were (4?33±0?67) cmH2 O·s/ml 7 days post?operation, which was significantly higher than that of syngenic 7?day subgroup (1?87±0?27) cmH2O·s/ml and control group (1?39±0?17) cmH2O·s/ml (P=0?000, 0?000)?(2) The isografts of syngenic group showed a relatively normal histological appearance with minimal infiltration of inflammatory cells, and the allografts of allogenic group infiltrated apparently by inflammatory cells, especially 7?day subgroup showed acute cellular rejection? ( 3) The percentage of γδT lymphocytes infiltrated in isografts and allografts were 3?90%± 0?86% and 4?40%± 0?57%, respectively, which were significantly increased compared to that of control lungs 2?00%±0?23% 3 days post?operation(P=0?000, 0?000);The percentage ofγδT lymphocytes infiltrated in 7 days allografts was 5?40%±0?98% , which was higher compared to that of 7 days isografts 2?60%± 0?54% and control lungs 2?00%± 0?23% ( P=0?000, 0?000)? (4) IL?17A mRNA expression levels were 3?37±0?55 and 5?23±1?50 in isografts and 6?77± 0?93 and 27?32±4?20 in allografts, on postoperative day 3 and 7 respectively? All of them were significantly upregulated compared to that of control lungs 0?99±0?08 (P=0?000, 0?000), and allografts exhibited significantly greater IL?17A transcript levels compared to isografts on postoperative day 3 and 7 ( P=0?000, 0?000) . Conclusion The rise of respiratory system resistance of lung grafts after transplantation may relate to the increased IL?17A?producing γδT lymphocytes infiltrated in the grafts.