Inflammatory responses of bovine polymorphonuclear neutrophils induced by staphylococcal enterotoxin C via stimulation of mononuclear cells.
To elucidate the pathological roles of staphylococcal enterotoxin C (SEC) in bovine staphylococcal mastitis, a histopathological analysis of SEC-inoculated mammary glands was performed. SEC-inoculated mammary glands exhibited interstitial inflammation, and the leukocytes that migrated into the gland were predominantly polymorphonuclear neutrophils (PMN). In the gland cistern tissues dissected from SEC-inoculated mammary glands, epithelial cellular degeneration was observed. We also investigated the physiological effects of SEC on PMN in vitro. PMN migration was induced by culture supernatant of SEC-stimulated peripheral blood mononuclear cells (S-PBMC sup) but not by that of nonstimulated PBMC (N-PBMC sup). The concentration of interleukin-8 was significantly (P < 0.05) higher in S-PBMC sup than N-PBMC sup, and a significantly (P < 0.05) higher mRNA expression of growth-regulated oncogenes was detected in SEC-stimulated PBMC than in nonstimulated PBMC. Milk PMN collected from SEC-inoculated mammary glands produced more than 2 times the amount of superoxide at 1 day postinoculation (dpi) than at 0 dpi in the presence of phorbol 12-myristate 13-acetate (PMA). PMN cultured with S-PBMC sup for 24 h also produced significantly (P < 0.05) larger amounts of superoxide than those cultured with N-PBMC sup in the presence of PMA. Moreover, S-PBMC sup induced the long-time survival of PMN. These results indicate that SEC induces the activation of PMN via the stimulation of mononuclear cells.
Kuroishi
Toshinobu
T
T Cell Research Institute, Aoba-ku, Sendai 989-3204, Japan. tcr5@icr-eq.co.jp
Komine
Ken-ichi
K
Asai
Ken-ichi
K
Kobayashi
Jin
J
Watanabe
Kouichi
K
Yamaguchi
Takahiro
T
Kamata
Shin-ichi
S
Kumagai
Katsuo
K
D000818:Animals; D002417:Cattle; D002478:Cells, Cultured; D002633:Chemotaxis / Q000187:drug effects; D004768:Enterotoxins / Q000276:immunology / Q000494:pharmacology*; D004847:Epithelial Cells / Q000473:pathology; D005260:Female; D007249:Inflammation / Q000139:chemically induced / Q000209:etiology*; D007963:Leukocytes, Mononuclear / Q000276:immunology; D008321:Mammary Glands, Animal / Q000276:immunology / Q000473:pathology; D008414:Mastitis, Bovine / Q000276:immunology / Q000473:pathology; D018375:Neutrophil Activation / Q000187:drug effects; D009504:Neutrophils / Q000187:drug effects / Q000276:immunology*
D004768:Enterotoxins; C034959:enterotoxin C, staphylococcal