Effect of intramammary infusion of recombinant bovine GM-CSF and IL-8 on CMT score, somatic cell count, and milk mononuclear cell populations in Holstein cows with Staphylococcus aureus subclinical mastitis

Abstract

The effect of intramammary infusion of recombinant bovine granulocyte-macrophage colony-stimulating factor (rbGM-CSF) and interleukin-8 (rbIL-8) on mononuclear cell populations in quarters, somatic cell count (SCC) and the California Mastitis Test (CMT) score were investigated. From the selected cows with naturally occurring Staphylococcus aureus subclinical mastitis, one quarter of each cow were selected for the infusions of rbGM-CSF (400 μg/5 mL/quarter, n = 9), rbIL-8 (1 mg/5 mL/quarter, n = 9), and phosphate-buffered saline (5 mL/quarter, n = 7). The CMT score of both cytokines post infusion temporarily increased between days 0 and 1 and significantly decreased between days 7 and 14 compared to the preinfusion level. The SCC on day 14 after infusions of rbGM-CSF tended to be lower than that of the control group. The percentage of CD14+ cells increased on days 1 and 2 post infusion of rbGM-CSF. The percentage of CD4+ and CD8+ cells also increased on days 2 and 3, suggesting that the infusion of rbGM-CSF enhanced cellular immunity in the mammary gland. In contrast, the percentage of CD14+ cells decreased on days 0.25 and 1 post infusion of rbIL-8. No significant changes in the percentages of CD4+ and CD8+ cells in milk after infusion of rbIL-8 were evident during the experimental period, which suggested that rbIL-8 had little effect on the function of T cells in the mammary gland. These results indicated that rbGM-CSF and rbIL-8 decreased the CMT score by a different mechanism and may have a potential as therapeutic agents for subclinical mastitis.

Immunoproteomics to identify Staphylococcus aureus antigens expressed in bovine milk during mastitis

“…Bovine mastitis is an important and economically relevant disease that affects the dairy industry worldwide (Bar et al, 2011; Gomes and Henriques, 2016). This disease causes large economic losses every year; estimated to be as high as $2 billion/year in the United States alone (Blosser, 1979; Petrovski et al, 2006) These losses are mainly due to reduced milk yield, antibiotic therapy, veterinary services, and the reduced price of culled animals (Blosser, 1979; Kiku et al, 2017). Mastitis is most often an acute or chronic inflammation of the mammary glands caused by bacterial infection and commonly leads to increased SCC, cytokine production, antibody secretion, and bacterial load in milk (De Vliegher et al, 2012; Thompson-Crispi et al, 2014).…”

Proteomic Analyses of Mammary Glands Provide Insight into the Immunity and Metabolism Pathways Associated with Clinical Mastitis in Meat Sheep

“…[23,24]. During mastitis, invasive pathogenic bacteria activates the immune response systems, such as innate immunity [25], cellular immunity [26,27] and humoral immunity [26]. The mucosal immune system is the main site of local non-specific immune function and plays important roles in function of the innate immune system, serving as the first-line of defence against infections [28], which consists of intestinal, respiratory, urogenital mucosa, and the exocrine glands [26].…”

Three Novel Players: PTK2B, SYK, and TNFRSF21 Were Identified to Be Involved in the Regulation of Bovine Mastitis Susceptibility via GWAS and Post-transcriptional Analysis

“…Previous studies have shown that cow mastitis has complex traits (clinical and subclinical mastitis) and is affected by multiple factors, including genetic features, nutrition, and hygiene standard, pathogen infections, and seasonal changes. Among them, pathogen infection (Gram-negative, such as Escherichia coli ; Gram-positive, such as Staphylococcus aureus and Streptococcus uberis ) is the main cause of mastitis (8–13). Therefore, rapid identification of pathogens is critical to determine the symptoms of infection (14).…”