title: Effects of bovine leukemia virus infection on milk neutrophil function and the milk lymphocyte profile.
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.
authors.affiliation: Departamento de Clínica Médica, Faculdade de Medicina Veterinária e Zootecnia, Universidade de São Paulo, Av, Prof, Dr, Orlando Marques de Paiva, 87, Cidade Universitária, São Paulo 05508-270, Brazil. dellalibera@usp.br.
authors.forename: Alice Maria Melville Paiva
authors.initials: AM
authors.lastname: Della Libera
authors.forename: Fernando Nogueira
authors.initials: FN
authors.lastname: de Souza
authors.forename: Camila Freitas
authors.initials: CF
authors.lastname: Batista
authors.forename: Bruna Parapinski
authors.initials: BP
authors.lastname: Santos
authors.forename: Luis Fernando Fernandes
authors.initials: LF
authors.lastname: de Azevedo
authors.forename: Eduardo Milton Ramos
authors.initials: EM
authors.lastname: Sanchez
authors.forename: Soraia Araújo
authors.initials: SA
authors.lastname: Diniz
authors.forename: Marcos Xavier
authors.initials: MX
authors.lastname: Silva
authors.forename: João Paulo
authors.initials: JP
authors.lastname: Haddad
authors.forename: Maiara Garcia
authors.initials: MG
authors.lastname: Blagitz
mesh_terms: D000818:Animals; D001402:B-Lymphocytes / Q000276:immunology*; D002417:Cattle; D016583:Enzootic Bovine Leukosis / Q000276:immunology* / Q000473:pathology / Q000821:virology; D005260:Female; D001909:Leukemia Virus, Bovine / Q000276:immunology; D016131:Lymphocyte Subsets / Q000276:immunology*; D008321:Mammary Glands, Animal / Q000276:immunology; D008892:Milk / Q000166:cytology*; D009504:Neutrophils / Q000276:immunology*; D010587:Phagocytosis; D017382:Reactive Oxygen Species / Q000378:metabolism; D013211:Staphylococcus aureus / Q000502:physiology
chemical_list: D017382:Reactive Oxygen Species