title: The neutrophil function and lymphocyte profile of milk from bovine mammary glands infected with Streptococcus dysgalactiae.
abstract: Streptococcus dysgalactiae is a bacterium that accounts for a notable proportion of both clinical and subclinical intramammary infections (IMIs). Thus, the present study explores the function of milk neutrophils and the lymphocyte profile in mammary glands naturally infected with Streptococcus dysgalactiae. Here, we used 32 culture-negative control quarters from eight clinically healthy dairy cows with low somatic cell counts and 13 S. dysgalactiae-infected quarters from six dairy cows. Using flow cytometry, we evaluated the percentage of milk monocytes/macrophages and neutrophils, expression of CD62L, CD11b and CD44 by milk neutrophils, the levels of intracellular reactive oxygen species (ROS) production and phagocytosis of Staphylococcus aureus by milk neutrophils, and neutrophil viability. Furthermore, the percentages of B cell (CD21(+)) and T lymphocyte subsets (CD3(+)/CD4(+)/CD8(-); CD3(+)/CD8(+)/CD4(-); and CD3(+)/CD8(-)/CD4(-)), and the expression of CD25 by T milk lymphocytes (CD3(+)) and T CD4(+) milk cells were also assessed by flow cytometry using monoclonal antibodies. The present study showed a higher SCC and percentage of milk neutrophils, and a decrease in the percentage of milk monocytes/macrophages from S. dysgalactiae-infected quarters when compared to uninfected ones. We also observed a higher expression of CD11b by milk neutrophils and a tendency toward a decrease in neutrophil apoptosis rate in S. dysgalactiae-infected quarters. In addition, the S. dysgalactiae-infected quarters had higher percentages of milk T cells (CD3(+)) and their subset CD3(+)CD8(+)CD4(-) cells. Overall, the present study provided new insights into S. dysgalactiae IMIs, including distinct lymphocyte profiles, and a tendency toward an inhibition of apoptosis in milk neutrophils.
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.
authors.forename: Maiara G
authors.initials: MG
authors.lastname: Blagitz
authors.affiliation: Departamento de Medicina Veterinária Preventiva,Escola de Veterinária,Universidade Federal de Minas Gerais,Belo Horizonte,Minas Gerais 31270-010,Brazil.
authors.forename: Fernando N
authors.initials: FN
authors.lastname: Souza
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.
authors.forename: Camila F
authors.initials: CF
authors.lastname: Batista
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.
authors.forename: Luis Fernando F
authors.initials: LF
authors.lastname: Azevedo
authors.affiliation: Departamento de Medicina Veterinária Preventiva e Saúde Animal,Faculdade de Medicina Veterinária e Zootecnia,Universidade de São Paulo,São Paulo 05508-270,Brazil.
authors.forename: Nilson Roberti
authors.initials: NR
authors.lastname: Benites
authors.affiliation: Departamento de Medicina Veterinária Preventiva e Saúde Animal,Faculdade de Medicina Veterinária e Zootecnia,Universidade de São Paulo,São Paulo 05508-270,Brazil.
authors.forename: Priscilla Anne
authors.initials: PA
authors.lastname: Melville
authors.affiliation: Departamento de Medicina Veterinária Preventiva,Escola de Veterinária,Universidade Federal de Minas Gerais,Belo Horizonte,Minas Gerais 31270-010,Brazil.
authors.forename: Soraia A
authors.initials: SA
authors.lastname: Diniz
authors.affiliation: Departamento de Medicina Veterinária Preventiva,Escola de Veterinária,Universidade Federal de Minas Gerais,Belo Horizonte,Minas Gerais 31270-010,Brazil.
authors.forename: Marcos X
authors.initials: MX
authors.lastname: Silva
authors.affiliation: Departamento de Medicina Veterinária Preventiva,Escola de Veterinária,Universidade Federal de Minas Gerais,Belo Horizonte,Minas Gerais 31270-010,Brazil.
authors.forename: João Paulo A
authors.initials: JP
authors.lastname: Haddad
authors.affiliation: Departamento de Medicina Veterinária Preventiva e Saúde Animal,Faculdade de Medicina Veterinária e Zootecnia,Universidade de São Paulo,São Paulo 05508-270,Brazil.
authors.forename: Marcos Bryan
authors.initials: MB
authors.lastname: Heinnemann
authors.affiliation: Departamento de Tecnologia e Inspeção de Produtos de Origem Animal,Escola de Veterinária,Universidade Federal de Minas Gerais,Belo Horizonte,Minas Gerais 31270-010,Brazil.
authors.forename: Mônica M O P
authors.initials: MM
authors.lastname: Cerqueira
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.
authors.forename: Alice M M P
authors.initials: AM
authors.lastname: Della Libera
mesh_terms: D000818:Animals; D000911:Antibodies, Monoclonal; D015703:Antigens, CD / Q000235:genetics / Q000378:metabolism; D018821:CD18 Antigens / Q000235:genetics / Q000378:metabolism; D002417:Cattle; D005260:Female; D005434:Flow Cytometry; D005786:Gene Expression Regulation; D016131:Lymphocyte Subsets / Q000502:physiology*; D008264:Macrophages / Q000502:physiology; D008414:Mastitis, Bovine; D008892:Milk / Q000166:cytology*; D009504:Neutrophils / Q000502:physiology*; D019087:Selectins / Q000235:genetics / Q000378:metabolism; D013290:Streptococcal Infections / Q000473:pathology / Q000662:veterinary*; D013291:Streptococcus / Q000145:classification*
chemical_list: D000911:Antibodies, Monoclonal; D015703:Antigens, CD; D018821:CD18 Antigens; D019087:Selectins
keywords: Immune response; dairy cow; mastitis; somatic cell count