Schistosome eggs have a direct role in the induction of basophils capable of a high level of IL-4 production: Comparative study of single- and bisexual infection of Schistosoma mansoni in vivo
10.2149/tmh.2009-24
- Author:
William K. Anyan
;
Takashi Kumagai
;
Rieko F. Shimogawara
;
Takenori Seki
;
Nobuaki Akao
;
Kazushige Obata
;
Bethel Kwansa-Bentum
;
Kwabena Mante Bosompem
;
Daniel A Boakye
;
Michael D. Wilson
;
Hajime Karasuyama
;
Nobuo Ohta
- Publication Type:Journal Article
- Keywords:
Schsitosoma mansoni Immunoregulation;
Basophils;
Granuloma;
Eggs antigens
- From:Tropical Medicine and Health
2010;38(1):13-22
- CountryJapan
- Language:English
-
Abstract:
Immunobiological roles of schistosome eggs during murine experimental infection were investigated with special reference to the induction of basophilic leukocytes. After single- or bisexual infection with Schistosoma mansoni in BALB⁄c mice, splenomegaly and liver granulomas were observed only in bisexual infection in parallel with deposition of mature parasite eggs. Comparison of the kinetics of basophil response revealed a marked increase in number in the bone marrow of mice with bisexual infection at the 7th week post infection as opposed to a marginal increase in single- sex infections. In the spleen, bimodal response was observed in the basophil responses; a small but repeatable peak at the 4th week after infection, increasing again at the 8th week, which corresponded to the initiation and maturation of parasite eggs in the affected organs of infected mice. The same time course was observed for IL-4 production by the splenocytes from mice of bisexual infection. To obtain more concrete evidence of the role of eggs in the induction of basophils, we tested using the intravenous egg injection model. Injection of eggs induced basophilia, and it was accompanied by the up-regulation of IL-4 production in splenocytes from the 8th day. Basophils induced in this model showed a high level of IL-4 production confirmed by flow cytometry, while faint levels of IL-4 production were observed for CD4+ T cells at this time point. In addition, we demonstrate that egg deposition is the trigger of basophil induction and activation in the murine experimental model of S. mansoni infection, which might play an essential role in the initiation of Th1⁄2 conversion during the course of S. mansoni infection in vivo.
