Publication Date:
1990-08-10
Description:
After actively entering its host cells, the protozoan parasite Toxoplasma gondii resides in an intracellular vacuole that is completely unable to fuse with other endocytic or biosynthetic organelles. The fusion blocking requires entry of viable organisms but is irreversible: fusion competence of the vacuole is not restored if the parasite is killed after entry. The fusion block can be overcome, however, by altering the parasite's route of entry. Thus, phagocytosis of viable antibody-coated T. gondii by Chinese hamster ovary cells transfected with macrophage-lymphocyte Fc receptors results in the formation of vacuoles that are capable of both fusion and acidification. Phagocytosis and fusion appear to involve a domain of the Fc receptor cytoplasmic tail distinct from that required for localization at clathrin-coated pits. These results suggest that the mechanism of fusion inhibition is likely to reflect a modification of the vacuole membrane at the time of its formation, as opposed to the secretion of a soluble inhibitor by the parasite.〈br /〉〈span class="detail_caption"〉Notes: 〈/span〉Joiner, K A -- Fuhrman, S A -- Miettinen, H M -- Kasper, L H -- Mellman, I -- New York, N.Y. -- Science. 1990 Aug 10;249(4969):641-6.〈br /〉〈span class="detail_caption"〉Author address: 〈/span〉Department of Medicine, Yale University School of Medicine, New Haven, CT 06510.〈br /〉〈span class="detail_caption"〉Record origin:〈/span〉 〈a href="http://www.ncbi.nlm.nih.gov/pubmed/2200126" target="_blank"〉PubMed〈/a〉
Keywords:
Animals
;
Cell Line
;
Fibroblasts/parasitology/physiology/ultrastructure
;
Fluorescent Antibody Technique
;
Lysosomes/physiology/ultrastructure
;
Macrophages/immunology
;
Membrane Fusion
;
Mice
;
Mice, Inbred BALB C
;
Phagocytosis
;
Receptors, Fc/genetics/*physiology
;
Toxoplasma/growth & development/*physiology
;
*Transfection
;
Vacuoles/*parasitology/physiology/ultrastructure
Print ISSN:
0036-8075
Electronic ISSN:
1095-9203
Topics:
Biology
,
Chemistry and Pharmacology
,
Computer Science
,
Medicine
,
Natural Sciences in General
,
Physics
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