Effect of bovine leukemia virus on bovine mammary epithelial cells

• Published in: Virus research 2019-10, Vol.271, p.197678-197678, Article 197678
• Main Authors: Martinez Cuesta, Lucia, Nieto Farias, Maria Victoria, Lendez, Pamela A., Rowland, Raymond R.R., Sheahan, Maureen A., Cheuquepán Valenzuela, Felipe A., Marin, Maia S., Dolcini, Guillermina, Ceriani, Maria Carolina
• Format: Article
• Language: English
• Subjects: BLV; Immune response; Mastitis; TLRs
• ISSN: 0168-1702; 1872-7492
• DOI: 10.1016/j.virusres.2019.197678

•MAC-T cell line infection by BLV is stable and productive.•BLV infection alters cells morphology, proliferation rate, and apoptosis.•MAC-T BLV viability disminishes after exposure to S. aureus.•MAC-T BLV TLR2 and Bcl-2 expression decreases after exposure to S. aureus. Bovine leukemia virus (BLV) is a retrovirus that infects cattle and is associated with an increase in secondary infections. The objective of this study was to analyze the effect of BLV infection on cell viability, apoptosis and morphology of a bovine mammary epithelial cell line (MAC-T), as well as Toll like receptors (TLR) and cytokine mRNA expression. Our findings show that BLV infection causes late syncytium formation, a decrease in cell viability, downregulation of the anti-apoptotic gene Bcl-2, and an increase in TLR9 mRNA expression. Moreover, we analyzed how this stably infected cell line respond to the exposure to Staphylococcus aureus (S. aureus), a pathogen known to cause chronic mastitis. In the presence of S. aureus, MAC-T BLV cells had decreased viability and decreased Bcl-2 and TLR2 mRNA expression. The results suggest that mammary epithelial cells infected with BLV have altered the apoptotic and immune pathways, probably affecting their response to bacteria and favoring the development of mastitis.