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Journal of Biomedicine and Biotechnology
Volume 2010 (2010), Article ID 202397, 12 pages
http://dx.doi.org/10.1155/2010/202397
Research Article

Activation-Induced T Helper Cell Death Contributes to Th1/Th2 Polarization following Murine Schistosoma japonicum Infection

1Department of Pathogen Biology and Immunology, Department of Pharmacology, Jiangsu Key Laboratory of Pathogen Biology, Nanjing Medical University, 140 Hanzhong Road, Nanjing, Jiangsu 210029, China
2Department of Clinical Laboratories, First Affiliated Hospital of Nanjing Medical University, Nanjing, Jiangsu 210029, China

Received 29 July 2009; Accepted 15 October 2009

Academic Editor: Luis I. Terrazas

Copyright © 2010 Xinyu Xu et al. This is an open access article distributed under the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited.

Abstract

In chronic infectious diseases, such as schistosomiasis, pathogen growth and immunopathology are affected by the induction of a proper balanced Th1/Th2 response to the pathogen and by antigen-triggered activation-induced T cell death. Here, by using S. japonicum infection or schistosome antigens-immunized mouse model, or antigens in vitro stimulation, we report that during the early stage of S. japonicum infection, nonegg antigens trigger Th2 cell apoptosis via the granzyme B signal pathway, contributing to Th1 polarization, which is thought to be associated with worm clearance and severe schistosomiasis. Meanwhile, after the adult worms lay their eggs, the egg antigens trigger Th1 cell apoptosis via the caspase pathway, contributing to Th2 polarization, which is associated with mild pathology and enhanced survival of both worms and their hosts. Thus, our study suggests that S. japonicum antigen-induced Th1 and Th2 cell apoptosis involves the Th1/Th2 shift and favorites both hosts and parasites.