不同选育环境对动物免疫稳态与应答的影响OA

To investigate the effects of different breeding environments on the development and functional regulation of the animal immune system,this study selected two groups of New Zealand rabbits(24 each)originating from the same population but bred for 10 years in either a specific pathogen-free(SPF)or a conventional environment(P).Immune homeostasis and response were compared through blood physiological and biochemical analysis,LPS challenge tests,and gene expression analysis of the TLR4 signaling pathway.The results showed that P rabbits had significantly higher physiological and biochemical indicators,including total white blood cell count,neutrophil percentage,red blood cell count and creatine kinase,than SPF rabbits(P<0.05),indicating maintained higher immune activity under natural microbial exposure.Following LPS stimulation,rabbits bred in the conventional environment exhibited an exceptionally rapid and intense immune response at the gene expression level,with marked upregulation of key signaling molecules such as TLR4 and its downstream effectors of MyD88 and NF-κB.In contrast to the swift alterations in gene expression,the changes in multiple immune parameters were relatively moderate,suggesting that their immune reaction was characterized by"rapid signal initiation with robust effector output".In comparison,SPF-bred rabbits demonstrated a notably delayed and weaker response initiation,accompanied by more pronounced fluctuations in humoral parameters.Thus,rabbits raised in conventional conditions displayed the fine-tuned regulatory capacity typical of a mature immune system,whereas the immune system of SPF-bred rabbits remained in a naive state,lacking effective homeostatic regulatory mechanisms.The findings demonstrate that long-term breeding in distinct environments shapes immune divergence:Moderate microbial exposure helps maintain immune homeostasis and responsiveness,whereas prolonged high cleanliness may lead to reduced immune sensitivity.This study reveals the critical role of different immune environments in shaping immune adaptability,confirms the warning significance of the hygiene hypothesis in intensive farming,and provides a theoretical basis for optimizing animal genetic breeding and healthful farming systems.