scholarly journals THE INTERACTION BETWEEN TOXOPLASMA GONDII AND MAMMALIAN CELLS

1972 ◽  
Vol 136 (5) ◽  
pp. 1157-1172 ◽  
Author(s):  
Thomas C. Jones ◽  
Shirley Yeh ◽  
James G. Hirsch
Keyword(s):  
Electron Microscopy ◽  
Toxoplasma Gondii ◽  
Cell Membrane ◽  
Hela Cell ◽  
Cell Cultures ◽  
Hela Cells ◽  
Generation Time ◽  
Mammalian Cells ◽  
Cell Types ◽  
Special Procedure

Macrophage, fibroblast, and HeLa cell cultures have been infected with Toxoplasma gondii, and observations have been made on parasite entry and fate. A special procedure was devised for studying the entry of toxoplasmas by electron microscopy. Toxoplasmas were centrifuged onto the cells in the cold; fixation 1–3 min after warming yielded specimens showing numerous examples of parasites in the process of entering cells. The mechanism of entry into macrophages, fibroblasts, and HeLa cells was in all cases by phagocytosis. Micropseudopods were extended by the cells to envelop the attached parasites in a typical phagocytic vacuole. Apparently the toxoplasmas stimulated this response of HeLa cells and fibroblasts, cell types not usually phagocytic. No instance was seen of penetration of toxoplasmas through the cell membrane, or of parasites located free in the cytoplasm. Essentially all of the toxoplasmas that entered HeLa cells divided with a generation time of 9 hr; the parasites formed large rosettes situated in vacuoles, eventually leading to host cell rupture. Macrophages took in larger numbers of toxoplasmas than did HeLa cells, but approximately half of the parasites inside of macrophages degenerated within a few hours. The surviving toxoplasmas in macrophages divided every 8 hr, forming rosettes and eventually rupturing the cells.

Interaction of Candida albicans with genital mucosa: effect of sex hormones on adherence of yeasts in vitro

1988 ◽  
Vol 34 (3) ◽  
pp. 224-228 ◽  
Author(s):  
Aliza Kalo ◽  
Esther Segal
Keyword(s):  
Candida Albicans ◽  
Hela Cell ◽  
Sex Hormones ◽  
Hela Cells ◽  
Cell Types ◽  
Vaginal Candidiasis ◽  
Genital Mucosa ◽  
Hela Cell Lines ◽  
I Cells

Findings from our previous studies revealed a correlation between the level of adherence in vitro of Candida albicans to human exfoliated vaginal epithelial cells (VEC) and the hormonal status of the cell donors. In the present study we investigated the effect of the sex hormones estradiol, estriol, progesterone, and testosterone on the binding of the yeasts to HeLa cell lines and VEC in vitro. Monolayers of HeLa cells were exposed to the hormones and yeasts under controlled conditions. The number of adherent yeasts per square millimetre of HeLa cell monolayers and the percentage of VEC with adherent yeasts was estimated by microscopic counts. The results showed that the tested sex hormones affected at various degrees the adhesion of yeasts to HeLa cells or VEC. Progesterone had the most marked effect, leading to a significant increase in the number of adherent yeasts to HeLa cells or in the percentage of adhesion of VEC. In addition, VEC were separated on Percoll gradients into the two cell types: superficial (S) and intermediate (I), cell types which appear physiologically under increased serum levels of estradiol or progesterone, respectively. Adhesion assays with the separated cell populations revealed an increased binding capacity of the I cells. The finding that progesterone increased the adherence of yeasts to genital mucosa and that VEC of the I type have a higher capacity to adhere the yeasts is compatible with our previous observation that increased numbers of I cells, appearing under high level of progesterone, are found in situations known to have predisposition to vaginal candidiasis. Thus, our data point to a possible involvement of the hormone progesterone in the adherence of C. albicans to genital epithelium.

scholarly journals Pathogenesis of shigella diarrhea. VII. Evidence for a cell membrane toxin receptor involving β1 {arrow} 4-linked N-acetyl-D-glucosamine oligomers

1977 ◽  
Vol 146 (2) ◽  
pp. 535-546 ◽  
Author(s):  
GT Keusch ◽  
M Jacewicz
Keyword(s):  
Cell Membrane ◽  
Cholera Toxin ◽  
Liver Cell ◽  
Hela Cells ◽  
Mammalian Cells ◽  
Cell Membranes ◽  
Proteolytic Enzymes ◽  
Cell Monolayer ◽  
Toxin Receptor ◽  
Toxin Uptake

The binding of ShigeUa dysenteriae 1 cytotoxin to HeLa cells in culture and to isolated rat liver cell membranes was studied by means of an indirect consumption assay of toxicity from the medium, or by determination of cytotoxicity to the HeLa cell monolayer. Both liver cell membranes and HeLa cells removed toxicity from the medium during incubation, in contrast to WI-38 and Y-1 mouse adrenal tumor cells, both of which neither bound nor were affected by the toxin. Uptake of toxin was directly related to concentration of membranes added, time,and temperature, and indirectly related to the ionic strength of the buffer used. The chemical nature of the membrane receptor was characterized by using three principal approaches: (a) enzymatic sensitivity; (b) competitive inhibition and (c) receptor blockade studies. The receptor was destroyed by proteolytic enzymes, phospholipases (which markedly altered the gross appearance of the membrane preparation) and by lysozyme, but not by a variety of other enzymes. Of 28 carbohydrate and glycoprotein haptens studied, including cholera toxin and ganglioside, only the chitin oligosaccharide lysozyme substrates, per N-acetylated chitotriose, chitotetraose, and chitopentaose were effective competitive inhibitors. Greatest inhibition was found with the trimer, N, N', N" triacetyl chitotriose. Of three lectins studied as possible receptor blockers, including phytohemagglutinin, concanavalin A, and wheat germ agglutinin, only the latter, which is known to possess specific binding affinity for N, N', N" triacetyl chitotriose, was able to block toxin uptake. Evidence from all three approaches indicate, therefore, existence of a glycoprotein toxin receptor on mammalian cells, with involvement of oligomeric β1{arrow}4-1inked N-acetyl glucosamine in the receptor. This receptor is clearly distinct from the G(M1) ganglioside thought to be involved in the binding of cholera toxin to the cell membrane of a variety of cell types susceptible to its action.

scholarly journals Inhibition of ornithine decarboxylase of HeLa cells by diamines and polyamines. Effect on cell proliferation

1980 ◽  
Vol 186 (3) ◽  
pp. 925-931 ◽  
Author(s):  
Andrew A. Branca ◽  
Edward J. Herbst
Keyword(s):  
Hela Cell ◽  
Ornithine Decarboxylase ◽  
Cell Cultures ◽  
Hela Cells ◽  
Horse Serum ◽  
Fresh Medium ◽  
Decarboxylase Activity ◽  
Inhibitory Protein ◽  
Ornithine Decarboxylase Activity ◽  
Stimulation Of

1. Ornithine decarboxylase activity is stimulated in high-density HeLa-cell cultures by dilution of or replacement of spent culture medium with fresh medium containing 10% (v/v) horse serum. 2. After stimulation, ornithine decarboxylase activity reaches a peak at 4–6h, then rapidly declines to the low enzyme activity characteristic of quiescent cultures, where it remains during the remainder of the cell cycle. 3. The stimulation of ornithine decarboxylase is eliminated by the addition of 0.5μm-spermine or -spermidine or 10μm-putrescine to the HeLa-cell cultures at the time of re-feeding with fresh medium. Much higher concentrations (1mm) of the non-physiological diamines, 1,3-diamino-propane or 1,3-diamino-2-hydroxypropane, are required to eliminate the stimulation of ornithine decarboxylase in re-fed HeLa-cell cultures. 4. A heat-labile, non-diffusible inhibitor, comparable with the inhibitory protein ornithine decarboxylase antizyme, is induced in HeLa cells by the addition of exogenous diamines or polyamines. 5. Intracellular putrescine is eliminated, intracellular spermidine and spermine are severely decreased and proliferation of HeLa cells is inhibited when cultures are maintained for 48h in the presence of the non-physiological inducer of ornithine decarboxylase antizyme, 1,3-diamino-2-hydroxypropane. Exogenous putrescine, a physiological inducer of the antizyme, does not decrease intracellular polyamines or interfere with proliferation of HeLa cells.

scholarly journals Cell surface hydrophobicity, adherence to HeLa cell cultures and haemagglutination pattern of pyelonephritogenicEscherichia colistrains

1990 ◽  
Vol 105 (2) ◽  
pp. 255-263 ◽  
Author(s):  
A. Brauner ◽  
M. Katouli ◽  
K. Tullus ◽  
S. H. Jacobson
Keyword(s):  
Escherichia Coli ◽  
Cell Surface ◽  
Hela Cell ◽  
Cell Cultures ◽  
Hela Cells ◽  
Acute Pyelonephritis ◽  
Cell Surface Hydrophobicity ◽  
Surface Hydrophobicity ◽  
Hydrophobic Properties ◽  
E Coli

SUMMARYCell surface hydrophobicity, haemagglutination pattern and adherence to HeLa cells were examined in 230 strains ofEscherichia colicollected from women (n= 61 strains) and children (n= 65 strains) with non-obstructive acute pyelonephritis and in 104 faecal control strains ofE. colifrom healthy adults (n= 71 strains) and children (n= 33 strains). PyelonephritogenicE. colistrains showed a significantly increased incidence of hydrophobic properties (90%) and mannose resistant haemagglutination (MRHA) of human erythrocytes (83%) than faecal control strains (64 and 23% respectively,P< 0·001 in both cases). Mannose sensitive haemagglutination (MSHA) was observed in 48% of the pyelonephritogenicE. colistrains and in 50% of the faecal control strains (NS). The incidence of adherence to HeLa cells was low both in pyelonephritogenic and faecal control strains, 6 and 7% respectively (NS). The bacterial phenotypes MRHA + MSHA + and MRHA + MSHA− appeared significantly more often in pyelonephritogenicE. colistrains (35 and 48% respectively) than in faecal control strains (5 and 17% respectively,P< 0·001 in both cases). The phenotype MRHA − MSHA + occurred significantly more often in control strains (45%) than in pyelonephritogenic strains (13%,P< 0·001). Eighty-three per cent of the pyelonephritogenicE. colistrains expressing hydrophobic properties showed MRHA and 50% of the hydrophobic strains showed MSHA. There were no significant correlations between cell surface hydrophobic properties and haemagglutination pattern or adherence to HeLa cells in pyelonephritogenicE. colistrains nor in faecal control strains.

scholarly journals Demonstration of dual rhinovirus infection in humans by isolation of different serotypes in human heteroploid (HeLa) and human diploid fibroblast cell cultures

1977 ◽  
Vol 5 (2) ◽  
pp. 202-207
Author(s):  
M K Cooney ◽  
G E Kenny
Keyword(s):  
Hela Cell ◽  
Cell Cultures ◽  
Hela Cells ◽  
Fibroblast Cell ◽  
Diploid Cell ◽  
Human Diploid Cell ◽  
Human Diploid Fibroblast ◽  
First Passage ◽  
Cytopathic Effects ◽  
Diploid Cells

The ability to isolate rhinoviruses in human heteroploid cell cultures was investigated by inoculating HeLa cells (HeLa M) with specimens previously shown to be positive in human diploid cell cultures. The 135 positive specimens selected were representative of 22 different rhinovirus types, and 4 to 9 specimens were available for each serotype. Specimens were inoculated into human diploid fetal tonsil fibroblasts (FT), HeLa cells with 30 mM Mg2+, and HeLa cells without increased Mg2+. One hundred twelve rhinovirus strains (83%) were reisolated in FT cells, whereas 76 rhinovirus strains (56%) were recovered in HeLa cells with 30 mM Mg2+. All strains recovered in FT were the same serotype as that originally recovered in diploid cells, but five of the HeLa cell isolates (3.7% of total specimens) were different serotypes, indicating dual rhinovirus infections. Four rhinovirus serotypes, (3, 42, 48, and 70) were recovered in HeLa but not in diploid cells; these serotypes were rare in our previous studies. Isolation of rhinovirus in FT cells was usually accomplished at first passage, whereas rhinovirus cytopathic effects in HeLa cells were not observed at first passage, but required one, two, or (rarely) three blind passages. Only 28 rhinoviruses (21%) were recovered in HeLa cells without increased Mg2+; however, three serotypes, types 16, 36, and 58, were recovered as effectively in HeLa cells, with or without added Mg2+, as they were in FT cells. In general, rhinoviruses were less efficiently recovered in HeLa cells; however, certain serotypes may be detected better by HeLa cells.

scholarly journals A STUDY OF THE PENETRATION OF MAMMALIAN CELLS BY DEOXYRIBONUCLEIC ACIDS

1961 ◽  
Vol 9 (1) ◽  
pp. 81-91 ◽  
Author(s):  
Ellen Borenfreund ◽  
Aaron Bendich
Keyword(s):  
Nucleic Acids ◽  
Hela Cell ◽  
Perchloric Acid ◽  
Hela Cells ◽  
Mammalian Cells ◽  
Deoxyribonucleic Acid ◽  
Degradation Products ◽  
Dna Bases ◽  
Human Dna ◽  
Nuclear Regions

Tritium-labeled deoxyribonucleic acid (DNA) from pneumococci and from human leukocytes was added to growing cultures of HeLa cells at 37°C. Autoradiography revealed an extensive localization of tritium in the nuclear regions. The label could not be removed by treatment with ribonuclease or dilute perchloric acid, but quantitative removal from the cells could be effected with deoxyribonuclease. Chemical and radioactivity determinations on nucleic acids isolated from the exposed HeLa cells revealed the presence of tritium in all 4 DNA bases. About 12 µg. of tritiated DNA was recovered from 6 x 106 HeLa cells which had been exposed for 24 hours to 240 µg. of the human DNA. From this, it is concluded that the amount of DNA, or its degradation products, taken up by the cells was equivalent to at least 10 per cent of the normal HeLa cell complement.

scholarly journals MOLECULAR GROWTH REQUIREMENTS OF SINGLE MAMMALIAN CELLS

1959 ◽  
Vol 109 (6) ◽  
pp. 649-660 ◽  
Author(s):  
Harold W. Fisher ◽  
Theodore T. Puck ◽  
Gordon Sato
Keyword(s):  
Cell Growth ◽  
Hela Cells ◽  
Generation Time ◽  
Mammalian Cells ◽  
Serum Free Medium ◽  
Free Medium ◽  
Serum Free ◽  
Growth Requirements ◽  
Cent Efficiency ◽  
Dialyzed Serum

Two purified serum protein fractions, fetuin and serum albumin, will replace whole or dialyzed serum in supporting the growth of single S3 HeLa cells in an otherwise chemically defined nutrient solution. In the serum-free medium, single S3 cells will form macroscopic colonies with essentially 100 per cent efficiency. The generation time of S3 cells in the serum-free medium is approximately 50 per cent greater than that observed in an optimal, serum-containing medium. All components of the serum-free medium are available commercially, except fetuin, which can easily be prepared in substantial quantities. The problem of the purity of the protein preparations and of their possible roles in promoting cell growth is discussed.

scholarly journals ELECTRON MICROSCOPY OF HELA CELLS AFTER THE INGESTION OF COLLOIDAL GOLD

1957 ◽  
Vol 3 (5) ◽  
pp. 749-756 ◽  
Author(s):  
Carl G. Harford ◽  
Alice Hamlin ◽  
Esther Parker
Keyword(s):  
Electron Microscopy ◽  
Endoplasmic Reticulum ◽  
Cell Membrane ◽  
Golgi Complex ◽  
Hela Cells ◽  
Colloidal Gold ◽  
Tissue Cultures ◽  
Cytoplasmic Matrix ◽  
Gold Particles ◽  
Dense Granules

Tissue cultures of HeLa cells were grown in media containing colloidal gold, and after various intervals, the cells were fixed, embedded, and sectioned for electron microscopy. Uncoated grids with small holes were used in many of the experiments. Intracellular particles of gold were identified in areas surrounded by single membranes, in moderately dense granules, in globoid bodies, and in the cytoplasmic matrix. Gold particles were not found in typical mitochondria, Golgi complex, ergastoplasm (granular forms of endoplasmic reticulum), or nuclei. The phenomenon of pinocytosis was considered to be the most likely means by which the gold particles were ingested, and the locations of gold particles appeared to have significance concerning theories that membranous organelles of the cytoplasm may be derived from the cell membrane.

Nuclear-Associated Plasmid, But Not Cell-Associated Plasmid, is Correlated With Transgene Expression in Cultured Mammalian Cells

2000 ◽  
Author(s):  
Molly B. James ◽  
Todd D. Giorgio
Keyword(s):  
Hela Cell ◽  
Hela Cells ◽  
Plasmid Dna ◽  
Mammalian Cells ◽  
Transgene Expression ◽  
Quantitative Method ◽  
Fluorescent Protein ◽  
Cmv Promoter ◽  
Green Fluorescent ◽  
Plasmid Delivery

Abstract Intracellular plasmid is rapidly incorporated into the nucleus of HeLa cells following cationic lipoplex transfection. CV1 cells are less effective in translocating plasmid to the nucleus and also express less transgene than HeLa cells. Cultured HeLa and CV1 cells and corresponding isolated nuclei were analyzed after transfection of a Cy3 labeled pGreenLantern plasmid (Cy3-pGL). Flow cytometry was used to measure both plasmid delivery and transgene expression from the plasmid encoding a CMV promoter driven green fluorescent protein. During transfection, HeLa cells rapidly incorporated the plasmid, reaching a maximum of 80% Cy3-pGL positive cells 8 hours post-transfection. The average Cy3-pGL positive HeLa cell contained approximately 2470 plasmid copies. 48% of the nuclei isolated from the transfected HeLa cells were positive for the plasmid marker after 8 hours. In contrast to HeLa cells, fewer CV1 cells and CV1 nuclei incorporated plasmid DNA with peak transfection occurring after 12 hours for 36% of the cells and after 8 hours for 12% of the nuclei. However, the average Cy3-pGL positive CV1 cell did not have a significantly different number of total cellular plasmid copies than the average positive HeLa cell. CV1 nuclei, however, had half as much plasmid as HeLa nuclei. HeLa cells are more efficient than CV1 cells at transporting plasmid from the cytoplasm to the nucleus. This study demonstrates the use of a novel quantitative method to study plasmid transport from the cytoplasm to nucleus and the effect on transgene expression.

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