Variant-Specific Surface Protein Switching in Giardia lamblia

Variant-specific surface protein switching in Giardia lamblia.

Surface antigen switching in Giardia lamblia was analyzed using monoclonal antibodies specific for two variant-specific surface proteins (VSPs). Two VSPs were detected on the surface of single trophozoites. Dual expression persisted for 13 h but disappeared at 36 h, as in other parasites that undergo surface antigenic variation.

Experimental Verification of the Identity of Variant-Specific Surface Proteins in Giardia lamblia Trophozoites

The cell membrane of a Giardia lamblia trophozoite is covered with a single species of variant-specific surface protein (VSP) that is replaced by another VSP every 6 to 13 generations of cell growth, possibly for an evasion of host immunity. Experimentally, only six VSP species have been verified to localize to the cell membrane thus far. By assuming that VSP contains multiple CXXC motifs, 219 ...

Simultaneous expression of different variant-specific surface proteins in single Giardia lamblia trophozoites during encystation.

A novel variant-specific surface protein (VSP) from Giardia was identified using the monoclonal antibody 9B10, raised against purified cyst walls. VSP9B10B is preferentially induced during encystation and expressed simultaneously with other VSPs on the surface of encysting trophozoites. These results support the hypothesis that encystation and antigenic variation are processes that are mechanis...

Vacuolar Protein Sorting Receptor in Giardia lamblia

In Giardia, lysosome-like peripheral vacuoles (PVs) need to specifically coordinate their endosomal and lysosomal functions to be able to successfully perform endocytosis, protein degradation and protein delivery, but how cargo, ligands and molecular components generate specific routes to the PVs remains poorly understood. Recently, we found that delivering membrane Cathepsin C and the soluble ...

Giardia Lamblia.