In Situ Expression of Yak in Mammary Glands as a Treatment for Bovine -Induced Mastitis in Mice.

Since the development of dairy farming, bovine mastitis has been a problem plaguing the whole industry, which has led to a decrease in milk production, a reduction in dairy product quality, and an increase in costs. The use of antibiotics to treat mastitis can cause a series of problems, which can bring a series of harm to the animal itself, such as the development of bacterial resistance and dramatic changes in the gut flora. However, the in vivo and in vitro antibacterial activity of yak Interleukin-22 (IL-22) and its application in mastitis caused by have not been reported. In this study, the mammary gland-specific expression plasmid pLF-IL22 of the yak gene was constructed and expressed in MAC-T cells and mammary tissue of postpartum female mice. The coding region of the gene in yaks is 573 bp, which can encode 190 amino acids, and the homology difference in the gene in yaks is less than 30%, which indicates certain conservation. IL-22 is a hydrophilic protein with a total positive charge of four, the presence of a signal peptide, and the absence of a transmembrane domain. Sufficient expression of effectively inhibited the high expression of inflammatory factors caused by , reduced the symptoms of mammary gland histopathology, and alleviated mastitis. Under the action of IL-22, the intestinal flora of mastitis mice also changed, the abundance of intestinal Bacilli, and in mice increased after treatment, and the pathogenic bacteria decreased. These findings provide new insights into the potential application of the yak gene in the treatment of bovine mastitis in the future.