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

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.