Disruption of antigenic variation is crucial for effective parasite vaccine (Nat Med, 2010, 16:551-557)

報告日期: 2010/11/02
報告時間: 15:10/16:00
報告學生: 周佳璇
講評老師: 蕭璦莉

Full text: http://basicmed.med.ncku.edu.tw/admin/up_img/991102-1.pdf

Disruption of antigenic variation is crucial for effective parasite vaccine

Fernando D Rivero, Alicia Saura, Cesar G Prucca, Pedro G Carranza, Alessandro Torri & Hugo D Lujan

Nature Medicine, 16: 551-557, 2010


Speaker: Chia-Hsuan Chou (周佳璇)

Commentator: Dr. Ai-Li Shiau (蕭璦莉 教授)

Time: 15:10-16:00

Place: Room 602



The eukaryotic intestinal parasite, Giardia lamblia, is a common intestinal dwelling protozoan and a cause of diarrhoea in humans and animals world-wide. G. lamblia undergoes antigen variation and maintain long-term infections to evade the human immune system. The antigens belong to a family of variant-specific surface proteins (VSPs), are expressed on the surface of a given trophozoite at any time. In this study, the authors proposed that the control of surface antigen expression in G. lamblia involves a mechanism similar to RNAi. They used knocking down of Dicer and RdRP, to make a change from single to multiple VSPs expression in individual G. lamblia trophozoites. The surface antigen were confirmed by confocal direct immunofluorescence assays showed co-localization of more that one VSP on the surface of individual cells. The data indicated that in knocking down Dicer or RdRP treatment, there was a strong immune response against heterologous isolates which had unique VSP expression on the surface. And then, during primary infections, oral immunization with the entire repertoire of VSPs generated a strong immune response that prevented infection of these gerbils. Moreover, they would like to apply on human therapy, they confirmed the protections from the antibody in sera and intestinal content, particularly secretory IgA were detected. These results showed that the characteristics of infections in adult humans are highly variable. Thus, their idea is that deregulating antigenic variation could be useful in generating effective vaccines.



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