Mouse macrophages release a neutrophil chemotactic mediator following stimulation by staphylococcal enterotoxin type A.
OBJECTIVE
To examine the role of macrophages in the neutrophil migration induced by staphylococcal enterotoxin type A (SEA) in mice.


METHODS
Peritoneal macrophages were harvested from male Swiss mice pre-treated with thioglycollate. After adhering to plastic tissue culture dishes, the cells were washed and incubated with RPMI or SEA (0.62-2.5 microg/ml) and washed again prior to further incubation with RPMI alone. The medium was then collected, sterilized and assayed for promigratory activity in the mouse peritoneal cavity.


RESULTS
Mouse macrophage monolayers stimulated with SEA secreted a thermolabile neutrophil chemotactic component (MNCC-SEA) with a molecular mass >100 kDa (by ultrafiltration). This release was dose- and time-dependent and was inhibited by dexamethasone but not by indomethacin or BW755C. Dexamethasone, indomethacin, BWA4C, BW755C, BN52021, cimetidine and SR48968 had no effect on the neutrophil migration induced by MNCC-SEA while capsaicin and SR 140333 reduced this phenomenon.


CONCLUSIONS
Macrophages play a key role in the neutrophil recruitment induced by SEA probably by releasing an MNCC-SEA that presumably induces neutrophil migration via a mechanism mediated by substance P.
Desouza
I A
IA
Department of Physiology and Biophysics, Institute of Biology, State University of Campinas, SP, Brazil. ivanidesouza@uol.com.br
Hyslop
S
S
Franco-Penteado
C F
CF
Ribeiro-DaSilva
G
G
D015772:4,5-Dihydro-1-(3-(trifluoromethyl)phenyl)-1H-pyrazol-3-amine / Q000494:pharmacology; D000818:Animals; D001549:Benzamides / Q000494:pharmacology; D002118:Calcium / Q000494:pharmacology; D002211:Capsaicin / Q000494:pharmacology; D002630:Chemotactic Factors / Q000378:metabolism* / Q000494:pharmacology; D002634:Chemotaxis, Leukocyte; D016861:Cyclooxygenase Inhibitors / Q000494:pharmacology; D003907:Dexamethasone / Q000494:pharmacology; D004355:Drug Stability; D004768:Enterotoxins / Q000494:pharmacology*; D005938:Glucocorticoids / Q000494:pharmacology; D005947:Glucose / Q000494:pharmacology; D007213:Indomethacin / Q000494:pharmacology; D017737:Macrophages, Peritoneal / Q000378:metabolism*; D008274:Magnesium / Q000494:pharmacology; D008297:Male; D051379:Mice; D008970:Molecular Weight; D009504:Neutrophils / Q000502:physiology*; D010880:Piperidines / Q000494:pharmacology; D018041:Receptors, Neurokinin-2 / Q000037:antagonists & inhibitors; D013864:Thioglycolates / Q000494:pharmacology
D001549:Benzamides; D002630:Chemotactic Factors; D016861:Cyclooxygenase Inhibitors; D004768:Enterotoxins; D005938:Glucocorticoids; D010880:Piperidines; D018041:Receptors, Neurokinin-2; D013864:Thioglycolates; C026066:enterotoxin A, Staphylococcal; D015772:4,5-Dihydro-1-(3-(trifluoromethyl)phenyl)-1H-pyrazol-3-amine; C073839:SR 48968; D003907:Dexamethasone; D008274:Magnesium; D005947:Glucose; D002211:Capsaicin; D002118:Calcium; D007213:Indomethacin