High neutrophil and eosinophil chemotactic activities of soluble extract of Schistosoma japonicum cercariae (SjCe-ext) were detected in vitro by using blind-well chemotaxis chambers and Millipore filters in a dose-dependent manner. Low doses (total of 0.25 and 2.5 µg) of SjCe-ext induced significant neutrophilic infiltrations in normal and S. japonicum-infected (8 week) guinea pig tissues beginning at 2 hr after the intradermal injection. Eosinophilic responses were observed in the infected animals especially in early phase (2–8 hr post-injection of SjCe-ext). SjCe-ext elicited strong immediate skin reactions (at 30 min) in the infected guinea pigs. Possible roles of these chemotactic activities and hypersensitivity reaction in S. japonicum infection are discussed.
Present address: Yoichiro Horii, Department of Medical Zoology, Nagasaki University School of Medicine, Sakamoto-machi, Nagasaki 852, Japan.
Present address: Akira Ishii, Department of Parasitology, Okayama University Medical School, Shikata-machi, Okayama 700, Japan.