The Toxic Effect of<i>Entamoeba Histolytica</i>on Leucocytes

Jarumilinta, Rawewan; Kradolfer, F

doi:10.1080/00034983.1964.11686259

Cited by 93 publications

(28 citation statements)

References 8 publications

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“…Some features of host-cell damage have been ascribed to the action of cytolytic substances released by amoebae, notably the appearance of a clear halo around trophozoites in brain tissue (Maitra et al, 1974(Maitra et al, , 1976Visvesvara and Callaway, 1974). Carter (1972) has noted that N. fowleri resembles E. histolytica in terms of invasiveness and ability to cause tissue necrosis, and E. histolytica has also been reported to kill and lyse mammalian cells on contact (Jarumilinta and Kradolfer, 1964). According to Eaton, Meerovitch and Costerton (1 969, 1970), the surface of the organism is pitted with cup-shaped lysosomes, complete with a trigger mechanism, that discharge cytolytic enzymes when stimulated by contact with a susceptible host cell, but this hypothesis is open to criticism (Griffin and Juniper, 1971;Griffin, 1972;Newton, 1972).…”

Section: Fig 13-thin Section Of Me-cell Culture 25 H After Inoculamentioning

confidence: 99%

Observations by Immunofluorescence Microscopy and Electron Microscopy on the Cytopathogenicity of Naegleria Fowleri in Mouse Embryo-Cell Cultures

Brown

1979

Journal of Medical Microbiology

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IT has been suggested (Brown, , 1979 that Naegleria fowleri may destroy cultured mouse-embryo (ME) cells by a phagocytosis-like mechanism alone, although the evidence for this is not conclusive. ME cells in contact with vigorously motile trophozoites were seen by phase-contrast microscopy to suffer gradual loss of cytoplasm , but observations at high magnification were hampered by peripheral image halos that obscured fine detail and the process of engulfment itself could not be discerned. Further studies of the cytopathogenicity of N . fowleri were carried out, therefore, by immunofluorescence and electron-microscopic techniques designed to show clearly how amoebae attack and destroy mammalian cells in vitro. MATERIALS AND METHODS Cultures.Trophozoites of Naegleria fo wleri strain HB-1 were maintained at 37°C in Fulton's medium A (Fulton, 1970) and harvested for inoculation of cell cultures as described previously .Secondary ME-cell cultures and associated media were prepared according to . M E-cell coverslip cultures for immunofluorescence studies were established in Leighton tubes. For electron microscopy, the technique of Persijn and Scherft (1965) was used whereby ME-cell monolayers were cultured on 25 x 17-mm thin mica slips (Mica and Micanite Supplies Ltd, London) in 30-mm plastic petri dishes. The freshly seeded dishes were incubated for 2 days at 37°C in a humidified atmosphere of 5% (v/v) CO2 in air, then changed to maintenance medium (MM).Preparation of ME-cell antiserum. Two-day-old secondary ME-cell monolayers in 20-oz (568 ml) screw-capped glass bottles were trypsinised and the cells washed by centrifugation at 800 g for 5 min. in three changes of phosphate-buffered saline (PBS), pH 7.3. The cells were suspended at a concentration of 1 x 106/ml in 0.1% (v/v) formol saline and the suspension was divided into two equal parts. One part was sonicated for 2 min. in a Mullard 50-watt ultrasonic disintegrator (Medical and Scientific Equipment Ltd, Crawley, Sussex); the other was centrifuged at 800 g for 5 min. and the deposit resuspended in the sonicated preparation. The formolised antigen, containing whole cells and sub-cellular components, was stored at 4°C in small volumes for up to 18 days until required for inoculation of animals.New Zealand White rabbits were given intravenous inoculations of ME-cell antigen according to a schedule similar to that described previously for the preparation of amoeba-specific

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Section: Fig 13-thin Section Of Me-cell Culture 25 H After Inoculamentioning

confidence: 99%

Observations by Immunofluorescence Microscopy and Electron Microscopy on the Cytopathogenicity of Naegleria Fowleri in Mouse Embryo-Cell Cultures

Brown

1979

Journal of Medical Microbiology

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“…While revealing some evidence for phagocytic activity by trophozoites, these studies did not exclude the possibility that amoebae possess membrane-associated cytotoxic enzymes that are activated by contact with a susceptible host cell and participate in its destruction. Costerton (1969, 1970) have proposed such a mechanism for the in-vitro cytopathogenicity of Entamoeba histolytica, which also appears to kill cells on contact (Jarumilinta and Kradolfer, 1964), and certain features of tissue damage by N. fowleri in mice have likewise been interpreted in terms of enzyme-mediated cytolysis (Martinez et al, 1973;Maitra et al, 1974Maitra et al, , 1976Visvesvara and Callaway, 1974). It was decided, therefore, to investigate the possible existence of amoeba-associated cytotoxins by observing whether the cytopathogenicity of Naegleria in ME-cell cultures could still be expressed in the presence of non-lethal inhibitors of trophozoite motility and phagocytosis.…”

Section: Plate XXIIImentioning

confidence: 99%

Inhibition by Amoeba-Specific Antiserum and by Cytochalasin B of the Cytopathogenicity of Naegleria Fowleri in Mouse Embryo-Cell Cultures

Brown

1979

Journal of Medical Microbiology

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“…Killing of target cells by amebas requires the function of microfilaments, as evidenced by inhibition with cytochalasins, but not microtubules (3,4). The purposes of the present studies were to examine the adherence of amebas to target cells (Chinese hamster ovary [CHO]' cells, and human, bovine, and sheep 1 Abbreviations used in this paper: BRBC, bovine erythrocytes; CHO, Chinese hamster ovary; Cyto, cytochalasin; Eh, Entamoeba histolytica; FCS, fetal calf serum; HRBC, human erythrocytes; llInOx, llIlndium oxine; PBS, phosphatebuffered saline; PSF, puck saline F; SRBC, sheep erythrocytes; TYI, trypticase-yeast extract-iron. red blood cells), the role of adherence in the killing of target cells by amebas, and the specificity of the adherence mechanism.…”

Section: Introductionmentioning

confidence: 99%

Role of Adherence in Cytopathogenic Mechanisms of Entamoeba Histolytica

Ravdin¹,

Guerrant²

1981

J. Clin. Invest.

341

114

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A B S T R A C T The enteric pathogen, Entamoeba histolytica, appears to cause disease by adhering to and then destroying mucosal barriers. Using an in vitro method of studying the interaction of E ing ameba-CHO cells rosettes in dextran, we found that GALNAc (1%) reversibly inhibits amebic adherence (P < 0.0005) and that cytochalasins decrease amebic killing of adherent CHO cells (P < 0.025).These findings indicate that the adherence of E. histolytica to target cells requires microfilament function, is via a specific amebic receptor that has affinity for GALNAc, and is required to lyse cells. Inhibition of the adherence of E. histolytica may alter the pathogenicity of this organism.

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The Toxic Effect ofEntamoeba Histolyticaon Leucocytes

Cited by 93 publications

References 8 publications

Observations by Immunofluorescence Microscopy and Electron Microscopy on the Cytopathogenicity of Naegleria Fowleri in Mouse Embryo-Cell Cultures

Observations by Immunofluorescence Microscopy and Electron Microscopy on the Cytopathogenicity of Naegleria Fowleri in Mouse Embryo-Cell Cultures

Inhibition by Amoeba-Specific Antiserum and by Cytochalasin B of the Cytopathogenicity of Naegleria Fowleri in Mouse Embryo-Cell Cultures

Role of Adherence in Cytopathogenic Mechanisms of Entamoeba Histolytica

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