• interleukin-1β;
  • interleukin-8;
  • bovine neutrophil;
  • migration;
  • mastitis


A co-culture system was established by culturing a bovine mammary epithelial cell line (MAC-T) and a bovine aortic endothelial cell line on calf tail collagen pre-coated inserts. This system allowed us to study bovine neutrophil migration across endothelium, extracellular matrix (ECM), and epithelium in the correct sequence and direction in vitro. The effect of recombinant interleukin-1β (rHIL-1β) and interleukin-8 (rHIL-8) on bovine neutrophil migration was investigated using this system. rHIL-8 stimulated bovine neutrophil migration in a dose-dependent fashion. The level of migrating bovine neutrophils increased up to approximately 25% when 100ng/ml of rHIL-8 was used. On the other hand, rHIL-1β at concentrations up to 100ng/ml did not directly induce bovine neutrophil migration. Furthermore, pre-incubation with 5ng/ml of rHIL-1β in the co-culture system for 4 or 24h failed to have any effect. These results suggest that IL-8 plays an important role in neutrophil migration into bovine mammary glands during mastitis.