Diphtheria toxin resistance in human lymphocytes and lymphoblasts in the in vivo somatic cell mutation test
Abstract
It has been shown that circulating peripheral blood lymphocytes can be used for the enumeration of 6-thioguanine-resistant cells that presumably arise by mutation in vivo. This somatic cell mutation test has been studied in lymphocytes from human populations exposed to known mutagens and/or carcinogens. The sensitivity of the test could be further enhanced by including other gene markers, since there is evidence for locus-specific differences in response to mutagens. Resistance to diphtheria toxin (Dip/sup r/) seemed like a potential marker to incorporate into the test because the mutation acts codominantly, can readily be selected in human diploid fibroblasts and Chinese hamster cells with no evidence for cell density or cross-feeding effects, and can be assayed for in nondividing cells by measuring protein synthesis inhibition. Blood samples were collected from seven individuals, and fresh, cryopreserved, or Epstein-Barr virus (EBV)-transformed lymphocytes were tested for continued DNA synthesis (TH-thymidine, autoradiography) or protein synthesis (TVS-methionine, scintillation counting). Both fresh and cryopreserved lymphocytes, stimulated to divide with phytohemagglutinin (PHA), continued to synthesize DNA in the presence of high doses of diphtheria toxin (DT). Similarly, both dividing (PHA-stimulated) and nondividing fresh lymphocytes carried on significant levels of protein synthesis even 68 hr after exposure to 100more »
- Authors:
- Publication Date:
- Research Org.:
- McMaster Univ., Hamilton, Ontario
- OSTI Identifier:
- 6181486
- Resource Type:
- Journal Article
- Journal Name:
- Environ. Mutagen.; (United States)
- Additional Journal Information:
- Journal Volume: 7:6
- Country of Publication:
- United States
- Language:
- English
- Subject:
- 59 BASIC BIOLOGICAL SCIENCES; LYMPHOCYTES; AUTORADIOGRAPHY; SOMATIC MUTATIONS; BIOLOGICAL MARKERS; BIOSYNTHESIS; DIPHTHERIA; FIBROBLASTS; PROTEINS; SULFUR 35; THYMIDINE; TOXINS; TRITIUM COMPOUNDS; ANIMAL CELLS; ANTIGENS; AZINES; BACTERIAL DISEASES; BETA DECAY RADIOISOTOPES; BETA-MINUS DECAY RADIOISOTOPES; BIOLOGICAL MATERIALS; BLOOD; BLOOD CELLS; BODY FLUIDS; CONNECTIVE TISSUE CELLS; DAYS LIVING RADIOISOTOPES; DISEASES; EVEN-ODD NUCLEI; HETEROCYCLIC COMPOUNDS; INFECTIOUS DISEASES; ISOTOPES; LABELLED COMPOUNDS; LEUKOCYTES; LIGHT NUCLEI; MATERIALS; MUTATIONS; NUCLEI; NUCLEOSIDES; NUCLEOTIDES; ORGANIC COMPOUNDS; ORGANIC NITROGEN COMPOUNDS; PYRIMIDINES; RADIOISOTOPES; RIBOSIDES; SOMATIC CELLS; SULFUR ISOTOPES; SYNTHESIS; TOXIC MATERIALS; 550401* - Genetics- Tracer Techniques; 550301 - Cytology- Tracer Techniques
Citation Formats
Tomkins, D J, Wei, L, and Laurie, K E. Diphtheria toxin resistance in human lymphocytes and lymphoblasts in the in vivo somatic cell mutation test. United States: N. p., 1985.
Web. doi:10.1002/em.2860070603.
Tomkins, D J, Wei, L, & Laurie, K E. Diphtheria toxin resistance in human lymphocytes and lymphoblasts in the in vivo somatic cell mutation test. United States. https://doi.org/10.1002/em.2860070603
Tomkins, D J, Wei, L, and Laurie, K E. 1985.
"Diphtheria toxin resistance in human lymphocytes and lymphoblasts in the in vivo somatic cell mutation test". United States. https://doi.org/10.1002/em.2860070603.
@article{osti_6181486,
title = {Diphtheria toxin resistance in human lymphocytes and lymphoblasts in the in vivo somatic cell mutation test},
author = {Tomkins, D J and Wei, L and Laurie, K E},
abstractNote = {It has been shown that circulating peripheral blood lymphocytes can be used for the enumeration of 6-thioguanine-resistant cells that presumably arise by mutation in vivo. This somatic cell mutation test has been studied in lymphocytes from human populations exposed to known mutagens and/or carcinogens. The sensitivity of the test could be further enhanced by including other gene markers, since there is evidence for locus-specific differences in response to mutagens. Resistance to diphtheria toxin (Dip/sup r/) seemed like a potential marker to incorporate into the test because the mutation acts codominantly, can readily be selected in human diploid fibroblasts and Chinese hamster cells with no evidence for cell density or cross-feeding effects, and can be assayed for in nondividing cells by measuring protein synthesis inhibition. Blood samples were collected from seven individuals, and fresh, cryopreserved, or Epstein-Barr virus (EBV)-transformed lymphocytes were tested for continued DNA synthesis (TH-thymidine, autoradiography) or protein synthesis (TVS-methionine, scintillation counting). Both fresh and cryopreserved lymphocytes, stimulated to divide with phytohemagglutinin (PHA), continued to synthesize DNA in the presence of high doses of diphtheria toxin (DT). Similarly, both dividing (PHA-stimulated) and nondividing fresh lymphocytes carried on significant levels of protein synthesis even 68 hr after exposure to 100 flocculating units (LF)/ml DT. The results suggest that human T and B lymphocytes may not be as sensitive to DT protein synthesis inhibition as human fibroblast and Chinese hamster cells. For this reason, Dip/sup r/ may not be a suitable marker for the somatic cell mutation test.},
doi = {10.1002/em.2860070603},
url = {https://www.osti.gov/biblio/6181486},
journal = {Environ. Mutagen.; (United States)},
number = ,
volume = 7:6,
place = {United States},
year = {Tue Jan 01 00:00:00 EST 1985},
month = {Tue Jan 01 00:00:00 EST 1985}
}