Innate immunity gene expression profiles in conjunctival membrane biopsies from Amazonian buffalo

ABSTRACT Domestic buffalo production plays an economically important role in the Brazilian Amazon, but they are susceptible to many diseases favored by the tropical climate and annually flooded habitats, including ocular diseases. In this context, it is important to select genotypes that maximize innate ocular immunity in Amazonian herds. We aimed to characterise, for the first time, gene expression profiles of the innate immune system in the conjunctival membrane of buffalo. Ocular conjunctival tissue samples were collected from 60 clinically healthy slaughtered animals in the northern Brazilian state of Amapá. The samples were histologically processed for classification into three groups according to the quantitative degree of lymphoid tissue associated with the conjunctiva (discrete, G1; slight, G2; and moderate, G3 presence of lymphoid tissue). RT-PCR was used to quantify gene expression of inflammatory cytokine (IL6, IL10, TNFA, IFNG), Toll-like receptor 4 (TLR4), and Defensin beta 110 (DEFB110), relative to the endogenous GAPDH gene. G1 animals presented low expression for IL6, IL10, TNFA, and DEFB110, while G2 exhibited high expression for IL6, IL10, IFNG, and TLR4. All G3 animals showed high expression for all tested genes. These results suggest a greater resistance to pathogenic microorganisms of buffalos in the G3 group, and the proportion of lymphoid tissue associated with the conjunctiva may be related to the immune resistance of individuals.摘要：家养水牛养殖在巴西亚马逊地区占据重要经济地位，但该区域的热带气候与季节性淹水生境易使水牛罹患多种疾病，眼部疾病即为其一。在此背景下，筛选可最大化提升亚马逊水牛群眼部先天免疫能力的基因型具有重要意义。本研究首次对水牛结膜组织的先天免疫系统基因表达谱进行表征。研究人员从巴西北部阿马帕州的60头临床健康屠宰水牛体内采集结膜组织样本，通过组织学处理，依据结膜相关淋巴组织的量化程度将样本分为三组：离散型（G1组）、轻微型（G2组）与中度型（G3组）。采用实时荧光定量聚合酶链反应（RT-PCR），以内源GAPDH基因为参照，对炎症细胞因子（IL6、IL10、TNFA、IFNG）、Toll样受体4（TLR4）以及β防御素110（DEFB110）的基因表达水平进行定量检测。结果显示，G1组水牛的IL6、IL10、TNFA及DEFB110表达量较低；G2组水牛的IL6、IL10、IFNG及TLR4表达量较高；所有G3组水牛的全部检测基因均呈高表达。上述结果表明，G3组水牛对病原微生物的抵抗力更强，结膜相关淋巴组织的占比或与个体的免疫抗性密切相关。