口咽胃肠道环境对Der p2-rBCG行为的影响

Influence of oral cavity and gastrointestinal tract environment on Der p2-rBCG biological behavior

目的:观察口服接种过敏原基因(Der p2)重组(r)BCG口咽胃肠道环境对Der p2-rBCG行为的影响. 方法:以野生BCG为对照,给予Balb/c小鼠口服接种三种方式(分泌、胞壁和胞内)表达Der p2的rBCG1×109CFU,连续5 d,计数不同时间粪便、口咽淋巴组织(OLT)、消化道相关淋巴组织(GALT)以及肝脏、脾脏和肺脏中BCG的细菌数;用PCR和内参照RT—PCR法测定由rBCG携带入各组织中的Der p2存在和表达状况. 结果:三种rBCG均可通过口咽和胃肠道黏膜,进入黏膜相关淋巴组织;各淋巴组织中的rBCG仍能表达其所携带的外源基因,并在各淋巴组织中表达外源蛋白. 结论:rBCG口服免疫后口咽胃肠道环境对rBCG生物学行为所产生的影响并不妨碍诱导理想的免疫应答.

AIM: To investigate the influence of oral cavity and gastrointestinal tract environment on the biological behavior of recombinant Bacillus Calmette-Guerin (rBCG) that expresses with allergen Der p2 after oral inoculation. METHODS: Four groups of 6 to 8 week old Balb/c mice were vaccinated orally with 100 μL of 109CFU with natural BCG or three kinds of rBCGs. The BCG CFU was counted in several tissue (oral pharyngeal lymphoid tissues (OLT), gut associated lymphoid tissues (GALT), spleen, lung and liver) and feces from the inoculated Balb/ c mice at different time after inoculation. The DNA and mRNA of Der p2 gene in various tissue were identified by PCR and RT-PCR, respectively. RESULTS: All three kinds of rBCGs were observed in mu-cosal-associated lymphoid tissues, indicating that they could penetrate the mucosa of oral cavity and gastrointestinal tract. The Der p2 gene was expressed by rBCG in above tissues. CONCLUSION: It is suggested that the oral cavity and gastrointestinal tract environment does not interrupt rBCG expressed Der p2 from inducing immune response after oral inoculation.