Polymorphism of cytokine and innate immunity genes associated with bovine brucellosis in cattle.

Genetic susceptibility to brucellosis is multifactorial, and it is known that impairment of the immune system could contribute to risk for getting brucellosis. The aim of the study was to find association of bovine brucellosis with 20 SNPs pertaining to bovine cytokine (IFNG, IFNGR1, IFNGR2, TNFA) and innate immunity (SLC11A1, TLR1, TLR4, and TLR9) genes using PCR-RFLP genotyping technique and it was observed that SLC11A1 (+1066 C/G), TLR1 (+1446 C/A), TLR1 (+1380 G/A), TLR4 (+10 C/T) and TLR4 (+399 C/T) loci were significantly (P≤0.05) associated with bovine brucellosis. The odds ratios (OR) of CG and CC genotypes versus GG genotype were 0.31 (0.12-0.82; 95% CI) and 0.18 (0.03-1.06; 95% CI) at SLC11A1 (+1066 C/G) locus in cases of brucellosis affected cattle. For TLR1 (+1380 G/A) locus, the OR for AG and AA genotypes versus GG genotypes were 0.15 (0.05-0.44; 95% CI) and 0.26 (0.04-1.47; 95% CI) which indicated that proportion of GG homozygote was significantly higher in brucellosis affected animals as compared to control. At TLR1 (+1446 C/A) locus the OR of AC genotype versus CC genotype was 0.24 (0.08-0.68; 95% CI) which revealed that relative proportion CC genotypes was significantly higher in case population. The TLR4 (+10 C/T) locus had three genotypes (TT, CT and CC) where OR of CT and CC genotypes versus TT genotype were near to zero. The OR of CT genotypes versus CC genotypes was 8.25 (0.94-71.92; 95% CI) at TLR4 (+399 C/T) locus and indicated that CT genotype had higher odds of bovine brucellosis than control animals.