Effects of bovine leukemia virus infection on milk neutrophil function and the milk lymphocyte profile

Author(s)

Melville Paiva Della Libera, Alice Maria ^[1] ; de Souza, Fernando Nogueira ^[2] ; Batista, Camila Freitas ^[1] ; Santos, Bruna Parapinski ^[1] ; Fernandes de Azevedo, Luis Fernando ^[1] ; Ramos Sanchez, Eduardo Milton ^[3] ; Diniz, Soraia Araujo ^[2] ; Silva, Marcos Xavier ^[2] ; Haddad, Joao Paulo ^[2] ; Blagitz, Maiara Garcia ^[1]

Affiliation

^[1] Univ Sao Paulo, Fac Med Vet & Zootecnia, Dept Clin Med, BR-05508270 Sao Paulo - Brazil

^[2] Univ Fed Minas Gerais, Escola Vet, Dept Med Vet Prevent, BR-31270010 Belo Horizonte, MG - Brazil

^[3] Univ Sao Paulo, Inst Med Trop, Lab Sorol & Imunobiol, BR-05403000 Sao Paulo - Brazil

• Document type: Journal article
• Source: VETERINARY RESEARCH; v. 46, JAN 17 2015.
• Web of Science Citations: 11

Abstract

The effects of bovine leukemia virus (BLV) on the immune response have been extensively investigated; however, its effects on mammary gland immunity are only speculative. Although BLV has a tropism for B cells, it can affect both adaptive and innate immunities because these systems share many effector mechanisms. This scenario is the basis of this investigation of the effects of BLV on mammary gland immunity, which is largely dependent upon neutrophilic functions. Thus, the present study sought to examine neutrophilic functions and the lymphocyte profile in the milk of naturally BLV-infected cows. The viability of the milk neutrophils and the percentage of milk neutrophils that produced reactive oxygen species (ROS) or phagocytosed Staphylococcus aureus were similar between BLV-infected and BLV-uninfected dairy cows. Furthermore, the expression of CD62L and CD11b by the milk neutrophils and the percentage of milk neutrophils (CH138(+) cells) that were obtained from the udder quarters of the BLV-infected cows were not altered. Conversely, the median fluorescence intensity (MFI) representing intracellular ROS production and the phagocytosis of S. aureus, the expression of CD44 by the milk neutrophils and the percentage of apoptotic B cells were lower in the milk cells from BLV-infected dairy cows, particularly those from animals with persistent lymphocytosis (PL). The lymphocyte subsets were not different among the groups, with the exception of the percentage of CD5-/CD11b(-) B cells, which was higher in the milk cells from BLV-infected cows, particularly those with PL. Thus, the present study provides novel insight into the implications of BLV infection for mammary gland immunity. (AU)

• FAPESP's process: 09/50672-0 - Functional evaluation of blood and milk leukocytes of cows naturally infected by bovine leukosis virus
• Grantee: Alice Maria Melville Paiva Della Libera
• Support Opportunities: Regular Research Grants