Sachiko Fukutani

Macrophage-produced oxygen radical generating activities for polymorphonuclear leukocytes

Guinea pig peritoneal macrophages were stimulated in vitro by bacterial lipopolysaccharide. After incubation, the supernatants of macrophage cultures were collected and tested for O2− production on guinea pig peritoneal polymorphonuclear leukocytes. The supernatants of macrophage cultures stimulated by lipopolysaccharide had significantly higher levels of O2−-generating activities in polymorphonuclear leukocytes, and these activities appeared in the macrophage cultures within 2 h after stimulation by lipopolysaccharide However, the supernatants obtained from the nonstimulated cultures could not produce these activities. These activities disappeared with heating or trypsin and were not produced in macrophage cultures by incubation with cycloheximide.

Characterization of leukocyte chemotactic activity of bacteriocin from Streptococcus mutans Rm-10.

Bacteriocins have several biological activities in addition to their antibacterial effect. We investigated the chemotactic properties and mode of action of purified streptococcal bacteriocin. Bacteriocin purified from a culture supernatant ofStreptococcus mutans (S. mutans) Rm-10 induced chemotaxis of human polymorphonuclear leukocytes and monocytes. Following purification, leukocyte migration appeared in one bacteriocin fraction, and this migration was dependent on the concentration gradient in dilution ranges from 1/960 to 1/15. Chemotactic activity of the bacteriocin was heat labile and trypsin sensitive. Moreover, preincubation of bacteriocin with varying dilutions of its antiserum prepared in rabbits resulted in a significant loss of the chemotactic activity.

Effect of Cepharantin on leukocyte chemotaxis induced by venom peptides.

Cepharanthin (CR), one of biscoclaurine alkaloids, are utilized for treatment in a wide variety of diseases, and also for the stings of wasps. In order to describe the pharmacological actions of CR, it was determined the effects of CR on leukocyte migration induced by chemotactic peptides isolated from venom sac of Vespinae. Vespid chemotactic peptides were isolated from Vespa tropica (VesCP-T) and Vespa mandarinia (Ves CP-M) . Human polymorphonuclear leukocyte (PMNL) and mononuclear leukocyte (MNL) were separated from peripheral blood, and in vitro chemotaxis assay was performed with membrane filter and multi-well chemotaxis chamber. VesCP-T and VesCP-M showed significant levels of chemotactic activities for PMNL and MNL, and these chemotactic migrations to VesCPs were decreased by addition of CR at a concentration over 10-5M. However, leukocyte migration induced by formyl peptide, synthetic chemoattractant, and buffer control were also depressed. These results suggest that the depression of leukocyte chemotaxis by CR in vitro was attributed to the direct action of CR to leukocytes.