Blagitz M G, Souza F N, Batista C F, Diniz S A, Azevedo L F F, Silva M X, Haddad J P A, Heinemann M B, Cerqueira M M O P, Della Libera A M M P
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.
Escola de Veterinária, Universidade Federal de Minas Gerais, Belo Horizonte 31270-010, Brazil.
J Dairy Sci. 2015 Apr;98(4):2401-8. doi: 10.3168/jds.2014-8727. Epub 2015 Feb 11.
An important question about intramammary infections that is still debated in the literature is the independence or interdependence of the quarters of dairy cows. The present study sought to explore milk neutrophil function and the milk lymphocyte profile of uninfected quarters from uninfected and infected (one infected quarter per cow) udders to evaluate interdependence of the quarters. Thus, 32 (8 cows) and 18 (6 cows) uninfected quarters from uninfected and infected udders were used, respectively. Using flow cytometry, we evaluated the percentage of milk neutrophils and their expression of adhesion molecules L-selectin (CD62L), β2-integrin (CD11b), and an endothelial-selectin ligand (CD44); levels of intracellular reactive oxygen species (ROS); phagocytosis of Staphylococcus aureus by milk neutrophils; and neutrophil viability. Furthermore, we assessed the percentage of B-cell (CD21(+)) and T-lymphocyte subsets (CD3(+)/CD4(+)/CD8(-), CD3(+)/CD8(+)/CD4(-), CD3(+)/CD4(+)/CD25(-), CD3(+)/CD4(+)/CD25(+), and CD3(+)/CD4(-)/CD25(-)) using flow cytometry with monoclonal antibodies. The infected quarter did not affect somatic cell count or the percentage of neutrophils in the neighboring uninfected quarters. Furthermore, the infected quarter did not influence neutrophil viability, intracellular reactive oxygen species production, or phagocytosis of S. aureus by milk neutrophils. Conversely, the expression of adhesion molecules CD11b, CD62L, and CD44 by milk neutrophils differed between uninfected quarters from infected versus uninfected udders. The lymphocyte subsets did not differ between groups, except for a higher percentage of B cells in uninfected quarters from infected udders than in those from uninfected udders. Thus, our study strongly supports the hypothesis of interdependence of quarters based on the influence of infection on both the percentage of B cells and the expression of adhesion molecules by milk neutrophils in the neighboring uninfected quarters.
关于乳房内感染，文献中仍在争论的一个重要问题是奶牛各个乳腺区之间的独立性或相互依赖性。本研究旨在探究未感染乳房（每头奶牛有一个感染乳腺区）中未感染乳腺区的乳中性粒细胞功能和乳淋巴细胞谱，以评估乳腺区之间的相互依赖性。因此，分别使用了来自未感染乳房和感染乳房的32个（8头奶牛）和18个（6头奶牛）未感染乳腺区。通过流式细胞术，我们评估了乳中性粒细胞的百分比及其黏附分子L-选择素（CD62L）、β2-整合素（CD11b）和内皮选择素配体（CD44）的表达；细胞内活性氧（ROS）水平；乳中性粒细胞对金黄色葡萄球菌的吞噬作用；以及中性粒细胞活力。此外，我们使用单克隆抗体通过流式细胞术评估了B细胞（CD21(+)）和T淋巴细胞亚群（CD3(+)/CD4(+)/CD8(-)、CD3(+)/CD8(+)/CD4(-)、CD3(+)/CD4(+)/CD25(-)、CD3(+)/CD4(+)/CD25(+)和CD3(+)/CD4(-)/CD25(-)）的百分比。感染的乳腺区对相邻未感染乳腺区的体细胞计数或中性粒细胞百分比没有影响。此外，感染的乳腺区不影响中性粒细胞活力、细胞内活性氧的产生或乳中性粒细胞对金黄色葡萄球菌的吞噬作用。相反，感染乳房与未感染乳房的未感染乳腺区中，乳中性粒细胞黏附分子CD11b、CD62L和CD44的表达存在差异。除了感染乳房的未感染乳腺区中B细胞百分比高于未感染乳房的未感染乳腺区外，两组之间的淋巴细胞亚群没有差异。因此，我们的研究有力地支持了基于感染对相邻未感染乳腺区中B细胞百分比和乳中性粒细胞黏附分子表达的影响而提出的乳腺区相互依赖的假说。
