Characteristics of the response of ovine granulocytes (PMNs) to zymosan-activated serum (ZAS) and to recombinant human interleukin-8 (IL-8).
The chemotactic activity of zymosan-activated serum (ZAS) and of two concentrations of recombinant human IL-8 (IL-8(25), 25 ng/ml; IL-8(50), 50 ng/ml) for ovine polymorphonuclear granulocytes (PMNs) was tested in a modified Boyden chamber. Thick cellulose acetate filters and the leading front method were used to quantify the movements of the cells. Both ZAS and IL-8(25) exerted a chemotactic effect on ovine PMNs (P < 0.01): IL-8(50) induced a more homogeneous response (P < 0.001). To verify the characteristics of the responsiveness to the chemokines after short-term (st) or long-term (lt) repeated samplings, chemotaxis was investigated 1 (T1st), 2 (T2st), 24 (T3st) and 48 h (T4st) after the basal sampling (T0st) and 15 days (T1lt) after the basal sampling (T0lt). No differences in chemotaxis were found in long-term repeated samplings. In contrast an increase in the responsiveness to IL-8(25) and to IL-8(50) (P < 0.05) was detected at T2st in comparison with T0st. Furthermore, the significance of the distance run by activated PMNs compared with the controls, increased from T0st to T2st, as a sign of a more homogeneous response to the chemokines. In the absence of evident changes in circulating leucocyte numbers and in serum cortisol concentrations, these findings could be interpreted as a consequence of a different expression of chemoattractant receptors on the membrane of PMNs collected at different times.
Paltrinieri
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Istituto di Patologia Generale Veterinaria, Milano, Italy. savepal@mailserver.unimi.it
Panelli
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Sartorelli
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D000818:Animals; D001772:Blood Cell Count / Q000662:veterinary; D002634:Chemotaxis, Leukocyte / Q000502:physiology; D006854:Hydrocortisone / Q000097:blood; D016209:Interleukin-8 / Q000494:pharmacology*; D007958:Leukocyte Count / Q000662:veterinary; D009504:Neutrophils / Q000187:drug effects*; D011863:Radioimmunoassay / Q000662:veterinary; D011994:Recombinant Proteins / Q000494:pharmacology; D012756:Sheep / Q000502:physiology*; D018709:Statistics, Nonparametric; D015054:Zymosan / Q000494:pharmacology*
D016209:Interleukin-8; D011994:Recombinant Proteins; D015054:Zymosan; D006854:Hydrocortisone