Thermal injury promotes bacterial translocation from the gastrointestinal tract in mice with impaired T-cell-mediated immunity.
Thermal injury promotes bacterial translocation from the gastrointestinal tract in mice with impaired T-cell-mediated immunity.
复制标题
在 T 细胞介导的免疫受损的小鼠中，热损伤会促进细菌从胃肠道移位。
作者：
E. Deitch;J. Winterton;R. Berg
我们之前已经证明，热损伤后，如果正常的本土微生物群被破坏，活细菌将穿过完整的胃肠粘膜（细菌易位）侵入肠系膜淋巴结和其他器官，从而导致细菌过度生长。为了确定T细胞介导的免疫（T-CMI）对于防止具有完整正常菌群的动物热损伤后的易位是否重要，将接受30％三度烧伤的常规（+/+）、无胸腺（nu/nu）和杂合（nu/+）小鼠在烧伤后以不同的时间间隔处死并培养其器官。细菌易位并未发生在具有完整 T-CMI 的对照或烧伤的无特定病原体小鼠中，但确实发生在具有缺陷 T-CMI 的无胸腺小鼠中。热损伤后，阳性器官的发生率和每克器官的易位细菌数均增加。这些发现与细菌过度生长无关，因为烧伤组和非烧伤组之间盲肠肠道细菌的水平没有差异。由于无胸腺烧伤小鼠中易位发生的程度高于对照无胸腺小鼠，因此热损伤似乎通过损害除 T-CMI 之外的其他宿主防御系统来促进易位。
We have shown previously that after thermal trauma viable bacteria will cross the intact gastrointestinal mucosa (bacterial translocation) to invade the mesenteric lymph nodes and other organs if the normal indigenous microflora is disrupted, allowing bacterial overgrowth. To determine whether T-cell-mediated immunity (T-CMI) was important in preventing translocation after thermal injury in animals with an intact normal flora, conventional (+/+), athymic (nu/nu), and heterozygous (nu/+) mice receiving a 30% third-degree burn were killed at various intervals after burn and their organs cultured. Bacterial translocation did not occur in control or burned specific pathogen-free mice with intact T-CMI but did occur in athymic mice with deficient T-CMI. Both the incidence of positive organs and the numbers of translocated bacteria per gram of organ were increased after thermal injury. Bacterial overgrowth was not responsible for these findings, since the levels of cecal enteric bacteria were not different between the burned and nonburned groups. Since translocation occurred to a greater extent in athymic burned mice than control athymic mice, it appears that a thermal injury promotes translocation by impairing other host defense systems in addition to the T-CMI.