Effect of Recombinant Glutathione-S-Transferase A3 Protein on the Expression of Host Defense Resistance and Pattern Recognition Receptor in the Thiram Induced Tibial Dyschondroplasia Chicken Erythrocytes

ABSTRACT Tibial dyschondroplasia (TD) is one of the most common problems in broiler chickens. Chicken erythro-cyte is the most abundant cell found in blood vessels, in which host defense resistance (HDR) and pattern recognition receptors (PRRs) play a significant role in the immune response. However, the function of HDR and PRRs in thiram induce TD chicken is not fully known yet. Therefore, this study was designed to evaluate the effect of recombinant glutathione-S-transferase A3 (rGSTA3) protein on HDR and PRRs in the thiram-induced TD chicken. One hundred twenty arbor acres (AA+) broiler chickens of seven-day-old were equally divided into six groups. Group A, B, and C were treated with 0, 20, 50 µg.kg-1 of rGSTA3 protein, respectively. Group D, E and F were treated with 0, 20, 50 µg.kg-1 of rGSTA3 protein + thiram 100 µg.kg-1. The results showed that chicks treated with thiram showed a higher TD score with typical lesions in the proximal growth plate than the rGSTA3 supplementary group. A morphological characteris-tic of TD was measured by TD index. Chicken erythrocytes constitutively expressed transcripts for HDR and PRRs genes. Moreover, the quantitative real time PCR (qRT-PCR) results showed that HDRs and PPRs expressions were suppressed by thiram, which found upregulated in rGSTA3 protein supplementa-ry group. These findings demonstrated that mRNA expressions of HDRs and PPRs are highly related to thiram. Moreover, rGSTA3 protein increased the immune response of HDRs and PPRs. Conclusively the results of this study provide the strong evidence that rGSTA3 protein can promote an immune response in chicken erythrocytes by up regulating the expression of HDR and PRRs genes.