Isolation and characterization of tox mutants of corynebacteriophage beta

Laird, W; Groman, Neal B.

doi:10.1128/jvi.19.1.220-227.1976

Cited by 53 publications

(23 citation statements)

References 18 publications

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“…As illustrated in Figure 5, a linear relationship can be observed between AMFI values and cytotoxic activity of DT-IT to the TfnR, as well as to CD3 and to CD5 Ag in Jurkat cells. A relationship overlapping that obtained with DT-IT can also be observed when a mutant DT (CRM 107) lacking cell-surface-binding activity (Laird and Groman, 1976;Greenfield et al, 1987) is used instead of DT as the toxic component of anti-TfnR and anti-CD3 conjugates (Fig. 5).…”

Section: Correlation Of Amfi Values and Cytotoxic Eficacy Of Itsupporting

confidence: 56%

Distribution of endocytosed molecules to intracellular acidic environments correlates with immunotoxin activity

Chignola

Colombatti

Dell'Arciprete

et al. 1990

Intl Journal of Cancer

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We have investigated the internalization to low pH intracellular compartments of transferrin (Tfn), diphtheria toxin (DT) and of anti-cell surface antibodies (MAb) by a cytofluorometric assay based on low pH quenching of fluorescein (FITC) emission. FITC-labelled Tfn, anti-CD3, anti-CD5 and anti-Thy 1.2 MAb internalization resulted in a progressively lower FITC quenching effect. Following internalization, a distinction could be made between molecules that enter low pH compartments without undergoing intracellular degradation (e.g., Tfn, anti-CD3 MAb) and molecules that are internalized through low pH organelles and are then degraded within the cell (e.g., DT). A strict correlation was observed between quenching of internalized FITC-protein fluorescent emission and the cytotoxic activity of DT-based immunotoxins (IT).

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Section: Correlation Of Amfi Values and Cytotoxic Eficacy Of Itsupporting

confidence: 56%

Distribution of endocytosed molecules to intracellular acidic environments correlates with immunotoxin activity

Chignola

Colombatti

Dell'Arciprete

et al. 1990

Intl Journal of Cancer

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“…Whether nontoxinogenic strains of C. diphtheriae carry the tox gene in whole or in part is in itself a significant question for the epidemiology of diphtheria. Some time ago we reported the isolation of gamma nonconverting phage from a nontoxinogenic strain of C. diphtheriae (8), and we subsequently presented both genetic and physical evidence demonstrating the presence of all or part of the tox gene in this phage (2,12). From our data we concluded that nonexpression of the tox gene was due to the insertion of a piece of bacterial DNA either in a regulatory site or early in the structural gene for diphtheria toxin.…”

mentioning

confidence: 80%

“…Other mutational events such as point mutations, deletions, or inversions can also be invoked to explain the various phenotypes. Mutants have been produced artifically by nitrosoguanidine treatment of }-converting phage with phenotypes identical to those found naturally in the tox-, Tox-isolates (9,12,19). In addition to mutation in phage genes, it is clear that host gene mutations may also be responsible for variation in the expression of the tox gene (11).…”

Section: Infect Immun 54mentioning

confidence: 99%

Detection and expression of DNA homologous to the tox gene in nontoxinogenic isolates of Corynebacterium diphtheriae

Groman¹,

Cianciotto²,

Bjorn³

et al. 1983

Infect Immun

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Three probes have been described which can be used to detect the presence of DNA sequences homologous to the tox gene of Corynebacterium diphtheriae. Probes "A" and "B" detected sequences coding for A and B fragments of diphtheria toxin, respectively. The third "A-B" probe contained both the A and B coding sequences. The B probe was completely unambiguous in detecting only toxin-related sequences, and the A probe was only slightly less so. The efficacy of the probes was tested on a series of toxinogenic and nontoxinogenic isolates of C. diphtheriae. All isolates which were toxinogenic as characterized by the gel immunodiffusion technique gave positive reactions with the probes. Of particular interest was the finding that 14 of 43 nontoxinogenic isolates also carried DNA homologous to both the A and B probes. All 14 isolates were nontoxinogenic by the rabbit intracutaneous test as well as by the gel immunodiffusion test; however, 12 of them produced ADP-ribosylating activity, whereas two were negative. The isolates producing ADP-ribosylating activity belonged to a cohort of cultures, of which 11 were isolated in South Dakota and 1 was isolated in Montana. Genomic DNAs of all 12 appeared to be identical when restriction enzyme digest patterns were compared, and the same fragment carried the tox gene in all of them. The tox-bearing nontoxinogenic isolates from Alaska and Florida each had unique restriction patterns and did not produce ADP-ribosylating activity. A number of genomic fragments of all the tox-bearing nontoxinogenic isolates hybridized with beta converting phage DNA. The significance of these observations to the natural history of diphtheria was discussed.

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“…A positive C7(p)t'ox control was streaked adjacent to each test culture so that a merger with the line for DT could be easily verified. The identity of this line with DT is based on the absence of any line when the isogenic, nontoxinogenic C7(-) is tested and on observations that some mutations in n-converting phage leading to the loss of toxin activity correlate with the loss of this line in the standard Elek test (18). Diphtheria antitoxin was obtained from the Connaught Laboratories, Inc. (Ontario, Canada).…”

mentioning

confidence: 99%

Corynebacterium ulcerans and Corynebacterium pseudotuberculosis responses to DNA probes derived from corynephage beta and Corynebacterium diphtheriae

Groman¹,

Schiller²,

Russell³

1984

Infect Immun

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Strains of Corynebacterium ulcerans and Corynebacterium pseudotuberculosis (Corynebacterium ovis) were examined for the production of diphtheria toxin. A majority of C. ulcerans strains (25 of 37) and 1 C. pseudotuberculosis strain (1 of 14) gave a positive Elek test for diphtheria toxin, and for all strains but 1, production of diphtheria toxin was inhibited at the same level of Fe2' as was the Corynebacterium diphtheriae control. All Elek-positive cultures as well as two Elek-negative isolates of C. ulcerans gave a positive signal when hybridized with a DNA probe unambiguous for the diphtheria toxin gene (tox) under conditions of high stringency. The majority of probe-positive C. ulcerans strains contained three or more DNA restriction fragments that hybridized with converting corynephage II, suggesting that in C. ulcerans as in C. diphtheriae there may be a relationship between toxinogeny and carriage of I-related phage. Selected strains of C. diphtheriae, C. ulcerans, and C. pseudotuberculosis were examined for DNA homology by a semiquantitative technique. There was very little homology between C. diphtheriae and members of the other two species. Strains of C. ulcerans and C. pseudotuberculosis, although more closely related, appeared to belong to distinct species as well.

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Isolation and characterization of tox mutants of corynebacteriophage beta

Cited by 53 publications

References 18 publications

Distribution of endocytosed molecules to intracellular acidic environments correlates with immunotoxin activity

Distribution of endocytosed molecules to intracellular acidic environments correlates with immunotoxin activity

Detection and expression of DNA homologous to the tox gene in nontoxinogenic isolates of Corynebacterium diphtheriae

Corynebacterium ulcerans and Corynebacterium pseudotuberculosis responses to DNA probes derived from corynephage beta and Corynebacterium diphtheriae

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