In vitro characterization of Acanthamoeba castellanii cytopathic effect

W. M. Taylor, M. S. Pidherney, H. Alizadeh, J. Y. Niederkorn

Research output: Contribution to journalArticle

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Abstract

This study examined the mechanism of the cytopathic effect (CPE) of Acanthamoeba castellanii on human target cells. Pathogenic Acanthamoeba trophozoites were incubated with human ocular melanoma (OCM1) cells for 30 min, 1 hr, and 3 hr. The amoebae were treated with a calcium ionophore (A23187), phorbol myristate ester (PMA), calcium channel blocker (Bepridil), cytochalasin D, and L-leucyl-L-leucine methyl ester (leu-leu-OMe). Cytolysis was quantified using a spectrophotometric assay. Cocultures of amoeba and cells were also observed by transmission electron microscopy at 1, 2, and 3 hr. Results show that trophozoites formed pseudopodia that made intimate contact with the target cell membrane. Neither amebostomes nor phagocytosis was seen. The calcium ionophore A23187 increased the cytopathic effect of the trophozoites on the cultured OCM1. In contrast, cytochalasin D, Bepridil, and PMA reduced the cytopathic effect. Leu-leu-OMe did not result in killing of Acanthamoeba trophozoites. The results suggest that the cytopathic effect of Acanthamoeba trophozoites involves calcium channels and cytoskeletal elements. There was no evidence of trogocytosis or phagocytosis as sometimes occurs in cytolysis by other free-living amoeba. Although Acanthamoeba- mediated CPE in some ways resembles CPE produced by cytotoxic lymphocytes, the mechanisms are not identical.

Original languageEnglish (US)
Pages (from-to)603-609
Number of pages7
JournalJournal of Parasitology
Volume81
Issue number4
DOIs
StatePublished - 1995

Fingerprint

Acanthamoeba castellanii
Trophozoites
cytopathogenicity
Acanthamoeba
trophozoites
Amoeba
Bepridil
Cytochalasin D
calcium
Calcium Ionophores
cytolysis
ester
cytochalasin D
Calcimycin
Myristic Acid
Phorbol Esters
Phagocytosis
esters
ionophores
phagocytosis

ASJC Scopus subject areas

  • Agricultural and Biological Sciences(all)
  • Parasitology
  • Microbiology

Cite this

In vitro characterization of Acanthamoeba castellanii cytopathic effect. / Taylor, W. M.; Pidherney, M. S.; Alizadeh, H.; Niederkorn, J. Y.

In: Journal of Parasitology, Vol. 81, No. 4, 1995, p. 603-609.

Research output: Contribution to journalArticle

Taylor, W. M. ; Pidherney, M. S. ; Alizadeh, H. ; Niederkorn, J. Y. / In vitro characterization of Acanthamoeba castellanii cytopathic effect. In: Journal of Parasitology. 1995 ; Vol. 81, No. 4. pp. 603-609.
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