Abstract
The fate ofToxoplasma gondii dense-granule (GRA2, GRA3), rhoptry (ROP1), and surface (SAG1) proteins was followed by immunofluorescence assay (IFA) and immunoelectron microscopy at different stages after infection. Dense-granule exocytosis occurred in the apical area of the tachyzoite within minutes of invasion. Several exocytic events were found simultaneously in the same organism, both by serial sectioning and by freeze-fracture studies. Dense-granule contents were first found as a dense material trapped between parasite and vacuole membranes before either the vacuolar network or the vacuole membrane could be immunolabeled with specific antibodies. The vacuolar network was strongly labeled with dense-granule antibodies but not with the SAG1-specific probe, which suggests that the network is not enriched in membrane proteins. In addition to strongly labeling the vacuole membrane, GRA3 antibodies also labeled strands extending from the parasitophorous vacuoles into the host-cell cytoplasm.
This is a preview of subscription content, log in via an institution to check access.
Similar content being viewed by others
References
Achbarou A, Mercereau-Puijalon O, Sadak A, Fortier B, Leriche MA, Camus D, Dubremetz JF (1991) Differential targeting of dense granule proteins in the parasitophorous vacuole ofToxoplasma gondii. Parasitology 103:321–329
Cesbron-Delauw MF, Guy B, Torpier G, Pierce RJ, Lenzen G, Cesbron JY, Charif H, Lepage P, Darcy F, Lecocq JP, Capron A (1989) Molecular characterization of a 23-kilodalton major antigen secreted byToxoplasma gondii. Proc Natl Acad Sci USA 86:7537–7541
Charif H, Darcy F, Torpier G, Cesbron-Delauw MF, Capron A (1990)Toxoplasma gondii: characterization and localisation of antigens secreted from tachyzoites. Exp Parasitol 71:114–124
Couvreur G, Sadak A, Fortier B, Dubremetz JF (1988) Surface antigens ofToxoplasma gondii. Parasitology 97:1–10
Entzeroth R, Dubremetz JF, Hodick D, Ferreira E (1986) Immuno-electronmicroscopic demonstration of the exocytosis of dense granules contents into the secondary parasitophorous vacuole ofSarcocystis muris (Protozoa Apicomplexa). Eur J Cell Biol 41:182–188
Kimata I, Tanabe K (1987) Secretion byToxoplasma gondii of an antigen that appears to become associated with the parasitophorous vacuole membrane upon invasion of the host cell. J Cell Sci 88:231–239
Leriche MA, Dubremetz JF (1990) Exocytosis of dense granules after host-cell invasion byToxoplasma gondii. Parasitol Res 76:559–562
Leriche MA, Dubremetz JF (1991) Characterization of the protein contents of rhoptries and dense granules ofToxoplasma gondii tachyzoites by subcellular fractionation and monoclonal antibodies. Mol Biochem Parasitol 45:249–260
Saffer L, Mercereau-Puijalon O, Dubremetz JF, Schwartzman JD (1992) Localization of aToxoplasma gondii rhoptry protein by immunoelectron microscopy during and after host cell penetration. J Protozool 39:526–530
Sibley LD, Boothroyd JC (1991) Calcium regulated secretion and modification of host cell endocytic compartment byToxoplasma. J Cell Biol 115:5A
Sibley LD, Krahenbuhl JL, Adams GMW, Weidner E (1986)Toxoplasma modifies macrophage phagosomes by secretion of a vesicular network rich in surface proteins. J Cell Biol 103:867–874
Author information
Authors and Affiliations
Rights and permissions
About this article
Cite this article
Dubremetz, J.F., Achbarou, A., Bermudes, D. et al. Kinetics and pattern of organelle exocytosis duringToxoplasma gondii/host-cell interaction. Parasitol Res 79, 402–408 (1993). https://doi.org/10.1007/BF00931830
Received:
Accepted:
Issue Date:
DOI: https://doi.org/10.1007/BF00931830