Neutrophils infiltration is early event of an oral mucosal xenotransplantation model.

INTRODUCTION As important effector cells of the innate immune system, neutrophils are involved in rejection of solid organ and/or tissue transplants. But their role in rejection of oral mucosa transplantation (OMT) remains unclear. The aim of this study is to observe the spatial-temporal change of neutrophils during acute rejection of OMT. METHODS In a rat model of oral mucosal xenotransplantation, myeloperoxidase (MPO), an indicator of influx of neutrophils was detected by technique of ELISA on day 7 and 30 (D7, D30) of posttransplantation. RESULTS On D7, MPO level (6.183±0.416, x102 ng/mg) in the OMT group was significantly higher than in trauma (0.681±0.073, x102 ng/mg) and normal controls (0.262±0.043, x102 ng/mg) (P<0.001, respectively), and this level was found to correlate with the index of submandibular lymph nodes (ILN), an indicator of inflammation of rejection (r=0.909, P<0.05). Moreover, this level was decreased significantly under FK506 treatment (2.103±0.146, x102 ng/mg, P=0.005). On D30, MPO in the OMT group (1.063±0.096, x102 ng/mg) was lower significantly than that on D7 (P<0.001), although this level was still higher that of normal controls on D30 (0.532±0.112, x102 ng/mg, P=0.042). CONCLUSION Neutrophils infiltration was an early event of OMT, which may play important roles on acute rejection of OMT.