Abstract: Caenorhabditis elegans is an important model organism to study aging. However, it lacks an index of immuno-aging. In this study, through establishing C. elegans-Pseudomonas aeruginosa infection model, the relationship between anti-infective immune ability and aging of C. elegans was studied, and an index of C. elegans immuno-aging was established. Firstly, infection model was established using P. aeruginosa to infect C. elegans. C. elegans in different degrees of aging were used in the infection model to investigate the relationship between survival time and degree of aging. The survival time after infection was used as an anti-infective immuno-aging index. The data of immuno-aging index was compared with the data of antioxidant capacity and the lifespan. The results indicated that with the aging of C. elegans (7 d, 14 d and 21 d old), the survival time of infected C. elegans decreased sequentially, which was consistent with the decline of their antioxidant capacity. Compared with wildtype, daf-2 mutation C. elegans with long lifespan exhibited longer survival time after infection, while daf-16 mutation C. elegans with short lifespan exhibited shorter survival time with infection. The results of anti-infective immuno-aging index were in accordance with the data of lifespan index. Tyrosine, a compound with anti-aging activity, prolonged the survival time of C. elegans after infection. Collectively, C. elegans-P. aeruginosa infection model can be used to evaluate the immuno-aging of C. elegans. The survival time of C. elegans after infection can be used as an index to indicate immuno-aging of C. elegans.

Key words: Caenorhabditis elegans, Pseudomonas aeruginosa, anti-infection, immuno-aging

摘要： 秀丽隐杆线虫是研究衰老的重要模式生物，但目前对其免疫衰老的研究缺乏评价指标。建立了秀丽隐杆线虫-铜绿假单胞菌感染模型，考察了线虫抗感染免疫能力与衰老之间的关系，建立了线虫免疫衰老的评价指标。首先用铜绿假单胞菌感染线虫建立模型，将处于不同衰老程度的线虫用于感染实验，考察了线虫感染后的生存时间与衰老程度的关系；将感染后的生存时间作为抗感染免疫衰老的指标，其结果与线虫抗氧化能力和寿命指标的结果相互印证。结果显示，7 d、14 d、21 d龄的线虫感染后的生存时间依次减少，与抗氧化能力的衰退情况相符；与野生型相比，长寿线虫（daf-2突变线虫）感染后的生存时间延长，短寿线虫（daf-16突变线虫）感染后的生存时间缩短，线虫的抗感染免疫指标与寿命指标结果相符；能延长线虫寿命的化合物酪氨酸也延长了线虫感染后的生存时间。因此线虫-铜绿假单胞菌感染模型可以用于评价线虫的免疫衰老，感染后线虫的生存时间可作为免疫衰老的评价指标。

关键词: 秀丽隐杆线虫, 铜绿假单胞菌, 抗感染, 免疫衰老