Expression profile of genes associated with mastitis in dairy cattle

Abstract

In order to characterize the expression of genes associated with immune response mechanisms to mastitis, we quantified the relative expression of the IL-2, IL-4, IL-6, IL-8, IL-10, IFN-g and TNF-a genes in milk cells of healthy cows and cows with clinical mastitis. Total RNA was extracted from milk cells of six Black and White Holstein (BW) cows and six Gyr cows, including three animals with and three without mastitis per breed. Gene expression was analyzed by real-time PCR. IL-10 gene expression was higher in the group of BW and Gyr cows with mastitis compared to animals free of infection from both breeds (p < 0.05). It was also higher in BW Holstein animals with clinical mastitis (p < 0.001), but it was not significant when Gyr cows with and without mastitis were compared (0.05 < p < 0.10). Among healthy cows, BW Holstein animals tended to present a higher expression of all genes studied, with a significant difference for the IL-2 and IFN-g genes (p < 0.001). For animals with mastitis no significant difference in gene expression was observed between the two breeds. These findings suggest that animals with mastitis develop a preferentially cell-mediated immune response. Further studies including larger samples are necessary to better characterize the gene expression profile in cows with mastitis.

Gene expression profile in zebu dairy cows (Bos taurus indicus) with mastitis caused by Streptococcus agalactiae

“…Nevertheless, despite this breed's importance to the dairy industry, few studies have been published identifying genes capable of conferring resistance to mastitis in animals other than taurine breeds (Bos taurus taurus). There are indications of the existence of differences in the response profile to clinical mastitis among Gyr, Holstein and cross-bred animals (Fonseca et al, 2009(Fonseca et al, , 2011. Besides this, one of the main results of The Bovine HapMap Consortium (2009) was confirmation that cattle are divided into three main groups: European, Indian and African.…”

Differential expression of genes during mastitis in Holstein-Zebu crossbreed dairy cows

“…Some studies have shown that TNF-α and IL-8 are present in the milk from udders infected by Gram-negative bacteria, such as Escherichia coli, Klebsiella pneumoniae or Pseudomonas aeruginosa, but they are present in lower concentrations or not detected in the milk from cows with mammary glands infected by Staphylococcus aureus (Shuster et al, 1997;Riollet et al, 2000;Bannerman et al, 2004aBannerman et al, ,b, 2005. Another study by our group with commercial cattle with and without mastitis caused by natural infection showed a difference in the expression profile of the IFN-γ, IL-2 and IL-10 genes among animals of the Holstein BW and Gyr breeds (Fonseca et al, 2009).…”

“…The majority of studies have examined European breeds with artificially induced infection. Like this study, that by Fonseca et al (2009) also evaluated the expression of some genes in naturally infected cows, but of separate Holstein BW and Gyr breeds rather than crossbreed animals. In that study, the IL-6, IL-8 and TNF-α genes also failed to show significantly different expression between cows with and without clinical mastitis.…”

“…The resistance response to mastitis is a complex characteristic and the genes involved in the immune response have been indicated as strong candidates in determining animal resistance (Shuster et al, 1993;Ferens et al, 1998;Alluwaimi et al, 2003;Rambeaud et al, 2003;Oviedo-Boyso et al, 2007;Fonseca et al, 2009). In light of this premise, the aim of this study was to characterize the expression of genes related to the phenotype determining resistance/susceptibility to mastitis, to better understand the immune response mechanisms.…”

Melhoramento genético visando à resistência a mastite em bovinos leiteiros

“…A resposta à resistência à mastite é uma característica complexa e os genes envolvidos na resposta imune têm sido indicados como fortes candidatos para determinar a resistência de animais (Ferens et al, 1998;Alluwaimi et al, 2003;Rambeaud et al, 2003;Oviedo-Boyso et al, 2007;Fonseca et al, 2009). O sistema imunológico é um mecanismo específico que um animal tem para limitar infecções, sendo fundamental para a sobrevivência do animal e, por isso, precisa atuar de forma eficiente.…”