Barber M R, Yang T J
Department of Pathobiology, University of Connecticut, Storrs 06269-3089, USA.
Clin Diagn Lab Immunol. 1998 Jan;5(1):82-6. doi: 10.1128/CDLI.5.1.82-86.1998.
Due to its association with low-quality milk and a decrease in milk production in bovines, mastitis is a major cause of economic loss. Additionally, mastitis can be harmful to suckling newborns and can cause damage to the mammary gland. In mastitic mammary secretions there is a substantial increase in somatic cells, specifically neutrophils. In this study we examined the ability of mastitic and nonmastitic mammary secretions to cause in vitro neutrophil chemotaxis using a microchemotaxis assay. Also, the role of the inflammatory chemokine interleukin-8 (IL-8) in neutrophil recruitment during mastitis was addressed in these in vitro experiments. We found that both nonmastitic and mastitic mammary secretions were chemotactic, not chemokinetic, for neutrophils. The neutrophil chemotactic activity in mastitic, but not nonmastitic, mammary secretions was blocked by anti-IL-8 antibodies. Molecular mass separation of the active components showed that the chemotactic activity of the mastitic secretions was present in the 10-kDa-or-less fraction and was blocked by anti-IL-8 antibodies. These results indicate that IL-8 plays a major role in neutrophil recruitment during mastitis. An understanding of its role will be of help in designing strategies for immunomodulatory therapies for mastitis.
由于乳腺炎与劣质牛奶以及奶牛产奶量下降有关，它是造成经济损失的主要原因。此外，乳腺炎可能对哺乳的新生儿有害，并会对乳腺造成损害。在患乳腺炎的乳腺分泌物中，体细胞尤其是中性粒细胞大量增加。在本研究中，我们使用微量趋化性分析检测了患乳腺炎和未患乳腺炎的乳腺分泌物引起体外中性粒细胞趋化性的能力。此外，在这些体外实验中还探讨了炎症趋化因子白细胞介素-8（IL-8）在乳腺炎期间中性粒细胞募集过程中的作用。我们发现，未患乳腺炎和患乳腺炎的乳腺分泌物对中性粒细胞均具有趋化作用，而非趋动作用。抗IL-8抗体可阻断患乳腺炎但未患乳腺炎的乳腺分泌物中的中性粒细胞趋化活性。对活性成分进行分子量分离显示，患乳腺炎分泌物的趋化活性存在于10 kDa及以下的组分中，且被抗IL-8抗体阻断。这些结果表明，IL-8在乳腺炎期间中性粒细胞募集中起主要作用。了解其作用将有助于设计乳腺炎免疫调节治疗策略。
