Cytotoxic Activity of Partially Purified Escherichia Coli Alpha Haemolysin

Cavalieri, S J; Snyder, Irvin S.

doi:10.1099/00222615-15-1-11

Cited by 65 publications

(44 citation statements)

References 25 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…The results extend brief earlier reports (21,22) were added 22 g polyethyleneglycol 4000 (PEG) per 100 ml fluid. After stirring for 20 min, 4C, the PEG precipitates were collected by centrifugation, dissolved in 5 ml of distilled water, and sterile filtered.…”

Section: Introductionsupporting

confidence: 79%

Effects of Escherichia coli hemolysin on human monocytes. Cytocidal action and stimulation of interleukin 1 release.

Bhakdi¹,

Muhly²,

Korom³

et al. 1990

J. Clin. Invest.

130

View full text Add to dashboard Cite

This study reports on the potent cytocidal and interleukin-1 releasing properties of Escherichia coli hemolysin (ECH) on human monocytes. Nanomolar concentrations of purified ECH (250-2,000 ng/ml) caused rapid and irreversible depletion of cellular ATP to levels below 20% of controls within 60 min. Subcytocidal doses (10-200 ng/ml) of ECH induced rapid release within 60-120 min of large amounts of interleukin 1,8 (IL-1(3) from cultured monocytes. IL-103 release occurred in the presence of actinomycin D and cycloheximide, and was thus probably due to processing and export of intracellular IL-1, precursor. Incubation of toxin-producing E. coli at ratios of only 0.3-3 colony-forming units per monocyte evoked 50% depletion of total cellular ATP within 90 min. Toxin producers also stimulated synthesis and release of large amounts of interleukin 1, but not of tumor necrosis factor within the same time span. In contrast, non-toxin producers caused neither cell death nor rapid interleukin 1 release. Stimulation of rapid interleukin 1 release coupled with potent cytocidal effects on cells of monocytic origin may represent pathogenetically significant events incurred by bacterial strains that produce ECH and related cytolysins. (J. Clin. Invest. 1990.

show abstract

Section: Introductionsupporting

confidence: 79%

Effects of Escherichia coli hemolysin on human monocytes. Cytocidal action and stimulation of interleukin 1 release.

Bhakdi¹,

Muhly²,

Korom³

et al. 1990

J. Clin. Invest.

130

View full text Add to dashboard Cite

show abstract

“…Recent investigations performed by Cavalieri and Snyder indicate that E. coli hemolysin is cytotoxic for mouse fibroblasts and human peripheral leukocytes (9)(10)(11). When treated with subcytolytic doses of toxin, human granulocytes displayed decreased phagocytic capacity despite activation of oxidative metabolism (10, ll ).…”

Section: Action Of E Coli Hemolysin On Nucleated Cellsmentioning

confidence: 99%

The hemolysin of escherichia coli

Bhakdi¹,

Mackman

Menestrina

et al. 1988

Eur J Epidemiol

View full text Add to dashboard Cite

Many strains of E. coli elaborate a hemolysin which is responsible for the zone of beta-hemolysis surrounding bacterial colonies on blood agar. The significance of this cytolysin as a determinant of bacterial pathogenicity has been established in animal models with the use of genetically engineered, isogenic bacterial strains. An analogous role in human infections has been inferred from the high association of hemolysin production with disease. Studies at a molecular genetical level have defined 4 genes that are required for the synthesis, post-translational modification and secretion of the hemolysin. The structural gene hlyA encodes for a 107-110,000 polypeptide, which must be modified in an unknown manner to its active form by the product of the neighboring hlyC gene. Genes hlyB and hlyD encode for proteins that export the molecule to the extracellular medium. The signal for secretion is contained in the C-terminal portion of the toxin molecule. The secreted hemolysin attacks plasma membranes of target mammalian cells by inserting as a monomer into the bilayer and generating hydrophilic transmembrane pores of approximately 2 nm effective diameter. The pores display a marked selectivity for cations over anions and pore-opening is dependent on the presence of a correct transmembrane potential. Binding to a membrane target does not require the presence of a specific receptor, and pores may be generated in planar lipid membranes consisting solely of phosphatidylcholine. Pore formation in nucleated cells can trigger secondary reactions such as stimulation of arachidonate metabolism with release of lipid mediators, probably initiated by passive influx of extracellular Ca2+.(ABSTRACT TRUNCATED AT 250 WORDS)

show abstract

“…While bacterial hemolysins have been implicated in the pathogenesis of bacteria producing them (7,8,55), their specific roles in the disease processes are often poorly understood. The ability to trigger the release of inflammatory mediators (histamines, leukotrienes) from a number of cell types has been demonstrated for the E. coli alpha-hemolysin (17) and for hemolytic S. inarcescens (18), suggesting that the ability to lyse erythrocytes may be secondary to their real function.…”

mentioning

confidence: 99%

Molecular characterization of the hemolysin determinant of Serratia marcescens

1988

View full text Add to dashboard Cite

The nucleotide sequence of a 7.3-kilobase-pair fragment of DNA encoding a hemolytic activity from Serratia marcescens was determined. Two large open reading frames were identified, designated shlA (Serratia hemolysin) and shlB, capable of encoding polypeptides of 165, 056 and 61,897 molecular weight, respectively. Both reading frames were expressed in vivo. The shlB gene product was localized to the outer membrane of Escherichia coli cells harboring the S. marcescens hemolysin determinant. Consistent with this location, a signallike sequence was identified at the N terminus of the polypeptide predicted from the nucleotide sequence of the shlB gene. Hyperexpression of the shlB locus permitted the identification of two shlB-encoded polypeptides of 65,000 and 62,000 molecular weight, respectively. Determination of the N-terminal amino acid sequence of the purified 62,000-molecular-weight protein confirmed that it was the mature form of the ShlB protein initially synthesized as a precursor (65,000-molecular-weight protein). By using polyclonal antisera raised against the purified proteins, ShlA and ShlB were identified in the outer membrane of S. marcescens. The shlA gene product was shown to interact with erythrocyte membranes, confirming it as the hemolysin proper. Both hemolysis and the interaction of ShlA with erythrocyte membranes did, however, require the ShlB function. Progressive deletion of the C terminus of the ShlA protein gradually reduced hemolytic activity until 37% of the amino acids had been removed. Elimination of 54% of the amino acids produced a nonhemolytic protein which, however, was still capable of associating with erythrocyte membranes.

show abstract

Cytotoxic Activity of Partially Purified Escherichia Coli Alpha Haemolysin

Cited by 65 publications

References 25 publications

Effects of Escherichia coli hemolysin on human monocytes. Cytocidal action and stimulation of interleukin 1 release.

Effects of Escherichia coli hemolysin on human monocytes. Cytocidal action and stimulation of interleukin 1 release.

The hemolysin of escherichia coli

Molecular characterization of the hemolysin determinant of Serratia marcescens

Contact Info

Product

Resources

About