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Science 25 January 1974:
Vol. 183. no. 4122, pp. 269 - 273
DOI: 10.1126/science.183.4122.269

Articles

Some Aspects of Intracellular Parasitism

Intracellular protozoa enter host cells in subtle ways and escape the cell's digestive processes

William Trager 1

1 Rockefeller University, New York 10021

In intracellular parasitism the host cell is a true and hospitable host. The parasite does not have to break in the door. It has subtle ways of inducing the host to open the door and welcome it in. One of the exciting fields in the future of parasitology is to find out what these ways are and why they are sometimes so highly specific that the cell that invites one parasite in will not open the door to another closely related species. Once inside, the parasite not only exploits nutrients already available in the cell, and the cell's energy-yielding system, but it further induces the cell to assist actively in its nutrition. Like a bandit who has cajoled his way in, the parasite now forces his host to prepare a banquet for him. Finally it may destroy its host cell, as in most of the associations I have described herein, or it may stimulate its host cell to abnormal increase in size or to have an altered metabolism with the formation of new products. Or it may even contribute some positive benefit to the host cell or to the multicellular organism of which the cell is a part, so that the two kinds of organisms then live together in a state of mutualism or symbiosis (26).


THIS ARTICLE HAS BEEN CITED BY OTHER ARTICLES:
Multiplication of a human parasite (Leishmania donovani) in phagolysosomes of hamster macrophages in vitro.
K. Chang and D. Dwyer (1976)
Science 193, 678-680
   Abstract »    PDF »
Invasion of erythrocytes by malaria merozoites.
J. Dvorak, L. Miller, W. Whitehouse, and T Shiroishi (1975)
Science 187, 748-750
   Abstract »    PDF »



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Science. ISSN 0036-8075 (print), 1095-9203 (online)