DETECTION OF THE CHEMOTACTIC FACTOR FOR CANINE PERIPHERAL-BLOOD MONONUCLEAR-CELLS AND POLYMORPHONUCLEAR CELLS IN THE CULTURE SUPERNATANT OFCOS7 CELLS TRANSFECTED WITH CANINE INTERLEUKIN-8 CDNA

Chemotactic activities in the culture supernatants of Cos7 cells trans fected with a cloned canine IL-8 cDNA (pcIL-8SR alpha 14) were evaluat ed by using mononuclear cells (MNC) and polymorphonuclear cells (PMN) from the peripheral blood of dogs. The culture supernatants of Cos7 ce lls were collected 66 hr after the transfection of pcIL-8SR alpha 14 ( Cos7/cIL-8). Chemotactic activities in the culture supernatants for MN C and PMN were determined as migration distances in Millipore membrane filters in a modified Boyden's chamber method. Peroxidase staining fo r MNC was effective not only for cells in cytospun smears but also for cells migrated in the filters. PMN in cytospun smears were well stain ed by peroxidase staining, whereas migrated PMN in the filters were st ained weakly. Chemotactic activities in the culture supernatant of Cos 7/cIL-8 cells for both MNC and PMN were significantly higher than thos e of control Cos7 cells. In addition, the culture supernatant of Cos7/ cIL-8 cells was chemotactic for peroxidase negative nonadherent MNC (l ymphocytes), but not for peroxidase positive adherent MNC (monocytes). This Cos7/cIL-8 supernatant also showed chemotactic activities for ne utrophils in a dose dependent manner. These results suggest that the c ulture supernatant of Cos7/cIL-8 is chemotactic for lymphocytes as wel l as for neutrophils.