16S rRNA sequencing of fecal samples from Atg16l1 T300A and wildtype littermate mice that were exposed to mainstream cigarette smoking co-housed with mice from the same genotype but not exposed to cigarette smoking

We found that mainstream cigarette smoking (4 cigarettes/day, 5 days/week for 2 weeks using Kentucky Research Cigarettes 3R4F) resulted in >20% decrease in the percentage of normal Paneth cell population in Atg16l1 T300A mice but showed minimal effect in wildtype littermate control mice, indicating that Atg16l1 T300A polymorphism confers sensitivity to cigarette smoking-induced Paneth cell damage. We performed cohousing experiments to test if Paneth cell phenotype is horizontally transmissible as is microbiota. Atg16l1 T300A and littermate controls that were exposed to cigarette smoking were used as microbiota donors, and these donor mice were exposed to smoking for 2 weeks prior to cohousing. Separate groups of Atg16l1 T300A and littermate controls that were not exposed to cigarette smoking were used as microbiota recipients. The microbiota recipients were co-housed with microbiota donors of the same genotype for 4 weeks, during this period the donors continued to be exposed to cigarette smoking. Cigarette smoking was performed using smoking chamber with the dosage and schedule as described above. At the end of the experiment, the fecal microbiota composition was analyzed by 16S rRNA sequencing.

本研究发现，采用肯塔基研究用卷烟3R4F（Kentucky Research Cigarettes 3R4F）进行主流香烟烟雾暴露造模（每日4支，每周5天，持续2周）后，Atg16l1 T300A小鼠体内正常潘氏细胞（Paneth cell）占比下降超过20%，但该处理对其野生型同窝对照小鼠仅产生极微弱影响，提示Atg16l1 T300A多态性赋予小鼠对吸烟诱导的潘氏细胞损伤的易感性。为验证潘氏细胞表型是否如微生物群（microbiota）一样可水平传播，本研究开展了同笼饲养实验。将经吸烟暴露的Atg16l1 T300A小鼠及同窝对照小鼠作为微生物群供体，这些供体小鼠在同笼饲养前已接受2周吸烟暴露。将未接受吸烟暴露的独立分组Atg16l1 T300A小鼠及同窝对照小鼠作为微生物群受体。将受体小鼠与同基因型的微生物群供体同笼饲养4周，期间供体小鼠持续接受吸烟暴露。本研究采用染毒箱进行吸烟造模，造模剂量与方案如前文所述。实验结束后，通过16S rRNA测序分析粪便微生物群组成。