Differentially expressed genes associated with Staphylococcus aureus mastitis of Canadian Holstein cows.
To study pathway specific gene expression within the immune-endocrine axis of dairy cows with Staphylococcus aureus mastitis, mRNA was collected from blood mononuclear cells (BMCs) and milk somatic cells (MSCs) of cows (n=7) identified as culture positive for S. aureus and their matched negative control cows (n=7) with no evidence of S. aureus mastitis. Labeled cDNA probes derived from BMCs and MSCs of infected and healthy cows were applied to a bovine immune-endocrine cDNA array containing 167 genes. Genes with a log(2) ratio> or =0.5 were considered to be up-regulated and genes with a log(2) ratio< or =-0.5 to be down-regulated. In total, 22 genes were differentially displayed in BMCs and 16 genes in MSCs of case versus controls. Expression of selected genes in BMCs and MSCs were confirmed by real-time PCR. The RT-PCR results were highly correlated with microarray measurements. Some of these genes, such as interleukin (IL)-8 have been previously implicated in other bacterial diseases, and are known to regulate immune responses; whereas, others may reflect novel pathways or genes involved in progressive mammary gland disease. For example, IL-18 was up-regulated in BMCs but not MSCs of mastitic quarters, while IL-17 was more highly expressed in MSCs compared to BMCs. This study identified a number of differentially expressed genes associated with bovine S. aureus mastitis and demonstrates the intricacy of the patterns of gene expression that influence host response to a complex pathogen of significant relevance to both human and veterinary medicine.
Department of Pathobiology, University of Guelph, Guelph, Ontario, Canada N1G 2W1.
Wenjing
W
Tao
Bonnie
B
Mallard
D000818:Animals; D000907:Antibodies, Bacterial / Q000032:analysis / Q000276:immunology; D002170:Canada; D016022:Case-Control Studies; D002417:Cattle; D002452:Cell Count; D005260:Female; D020869:Gene Expression Profiling / Q000662:veterinary*; D005786:Gene Expression Regulation; D020382:Interleukin-18 / Q000235:genetics; D008414:Mastitis, Bovine / Q000097:blood / Q000235:genetics* / Q000276:immunology / Q000382:microbiology*; D008892:Milk / Q000737:chemistry / Q000166:cytology; D020411:Oligonucleotide Array Sequence Analysis; D015203:Reproducibility of Results; D020133:Reverse Transcriptase Polymerase Chain Reaction; D013203:Staphylococcal Infections / Q000235:genetics / Q000276:immunology / Q000382:microbiology / Q000662:veterinary*; D013211:Staphylococcus aureus
D000907:Antibodies, Bacterial; D020382:Interleukin-18