Research Article Novel polymorphisms in bovine CD4 and LAG-3 genes associated with somatic cell counts of clinical mastitis cows

Abstract

Clinical mastitis cows normally produce clotted milk, thus the much higher somatic cells in milk are unable to be counted by routine FOSS machine. The proteins coded by CD4 and LAG-3 genes can bind to MHC class II molecules and play important roles in inflammatory diseases. The present study was designed to investigate the effects of single nucleotide polymorphisms (SNPs) in bovine CD4 and LAG-3 genes on the somatic cell counts (SCCs) of clinical mastitis Holstein cows. For the first time, we detected SCCs in the clinical mastitis cows' milk by Newman's staining combined with microscope assays. Our association results showed that two novel SNPs (T104010752C and C104028410T) identified in bovine CD4 and LAG-3 genes respectively were significantly associated with SCCs of clinical mastitis cows (P<0.05). In addition, the combined genotypic effect of both the SNPs was also significant on SCCs (P<0.05). The results imply that the novel SNPs in CD4 and LAG-3 genes could be significant candidate markers against Clinical mastitis in Holstein cattle.

Genetics of Animal Health and Disease in Livestock

“…Bacteriocins produced by certain non-aureus Staphylococci (NAS) and Corynebacterium species colonizing the teat apices and teat canals may inhibit growth of major mastitis pathogens [89]. Within complex ecosystems, ecosystem diversity can increase resiliency against an influx of external species by supporting favorable interactivity [90]. The complexity of microbe to microbe communications concerning the functional properties of the mammary ecosystem are difficult to understand.…”

“…A study reported the up-regulation of CXCL8 and TNF-α in E. coli induced mastitis in mammary epithelial cells [88]. In addition, the high expression of CXCL10, CCL2, CCL5 and CCL20 was noticed in bovine mammary epithelial cells in E. coli induced mastitis, which is essential for the recruitment of leucocytes [90]. The expression levels of IL-6, complement factor 3 (C3), NFKBIA and MMP9 were also elevated during mammary gland infection [90].…”

Role of the JAK-STAT Pathway in Bovine Mastitis and Milk Production

“…That is why, nowadays, more interest is paid to the increase in cells and cytokine levels in milk and blood, respectively, rather than just the overall SCC, which may provide an early status of udder health [ 89 ]. A study showed that inflammatory cytokines (IL-6, IL-17, and IFN-γ, TNF-α) could be used as subclinical mastitis indicators, in addition to SCSs and SCCs [ 51 , 86 , 90 ]. In addition, it is predicted that the 39645396C/T SNP changes lysine to asparagine [ 86 ].…”

“…It has been reported that IL-17A and IL-17F play a critical role in regulating host–pathogen interactions during the development of mastitis [ 99 ]. The SNPs in IL-17F and IL-17A have been shown to be associated with milk SCCs [ 90 ]. Moreover, IL-17 also activates IL-6 with IFN-γ and tumor necrosis factor-alpha (TNF-α) [ 100 ].…”

“…These findings show that a decrease in the level of CD4+ T-cells in lactating dairy might be one of the reasons for susceptibility to infection during this stage [ 105 ]. Usman et al reported a significant association of variant T104010752C in the CD4 gene with milk SCCs [ 90 ]. In the previous study, it was noticed that polymorphisms in CD4 and STAT5B genes are significantly linked with mastitis-resistance phenotypic traits [ 83 ].…”