高温高湿环境下犬肢体火器伤后细胞免疫学变化

THE CHANGES IN CELLULAR IMMUNITY IN A CANINE MODEL OF GUNSHOT WOUND IN EXTREMITIES IN HOT AND HUMID ENVIRONMENT

为研究高温高湿环境下犬肢体火器伤后的细胞免疫学变化 ,将 18只杂种犬随机分为常温常湿组、高温高湿组、热习服组 ,用流式细胞仪荧光抗体技术检测犬肢体枪伤后外周血淋巴细胞表面CD4 + 、CD8+ 、CD11a+ 、CD11b+ 亚群及中性粒细胞表面CD11a、CD11b的表达情况。结果显示 ,高温高湿组伤后 1h淋巴细胞CD4 + 亚群表达水平短暂升高 ,随后下降 ,10h后明显降低 ;CD8+ 亚群 4h后表达水平显著增高 ,相应导致CD4 + /CD8+ 比值 8h后持续降低 ;CD11a+ 亚群 8h后降低 ,而CD11b+ 亚群的变化轻微 ;热习服能够增加CD4 + 的表达值 ,抑制CD8+ 大量表达。常温常湿组CD11a、CD11b在致伤后即刻以及伤后 4h显著增高 ;与常温常湿组比较 ,高温高湿组第 2峰表达水平显著增高 ,但下降时间提前 ;犬热习服后可以降低第 2峰的高度并且延长其平台期。提示高温高湿环境及火器伤等复合因素共同抑制了机体免疫功能 ,热习服则能减轻这些不利因素造成的损害 。

Eighteen Chinese mongrel dogs were divided into 3 groups randomly according to the given environment: normal environment (NE) group, hot and humid environment (HHE) group, heat acclimatization (HA) group. The dynamic changes in the lymphocyte subsets with CD4 + , CD8 + ,CD11a + ,CD11b + expressions and neutrophil with CD11a and CD11b expressions in peripheral blood were detected post trauma using mAb FACS immuno fluerescence technique. In HHE group, there was a temporary increase (1h) and prolonged decrease (10h) in CD4 + subset, with an increase in CD8 + subset (4h later), resulting in final decrease in CD4 + /CD8 + ratio. In addition, CD11a + T cell decreased 8h later, with a mild change in CD11b + subset. The mechanism is unclear presently. Adaptive training seemed to raise the level of CD4 + and CD11a + lymphocyte subsets and suppress the expression of CD8 + subset. The expression of CD11a and CD11b in NE group increased immediately after injury, presenting a second peak at 4h. The second peak with a higher level was also observed in HHE group, but its duration was shorter than that of the NE group. Heat acclimatization lowered the level of the second peak, though it was remarkably prolonged. Changes in lymphocyte subsets and adhesion molecules of neutrophil suggested that hot and humid environment might suppress the immunity after gunshot injuries, while adaptive exercise could blunt the immunosuppressive response.