The development of in vitro mutagenicity testing systems using T-lymphocytes: Progress report, November 1, 1987--May 31, 1988
We have investigated the mutagenic effects of ionizing irradiations in human T-lymphocytes. These have included in vitro exposure of G/sub 0/ phase peripheral blood T-lymphocytes to gamma irradiation, with subsequent growth for phenotypic expression and selection of 6-thioguanine resistant (TG/sup r/) colonies to measure mutation induction at the hprt mutations. We have studied the DNA alterations in both in vivo and in vitro induced mutants by Southern blot analysis with an hprt cDNA probe in order to investigate the possible specificity of radiation damage. We have employed Southern blot analyses with T-cell receptor (TCR) gene probes in order to define the clonality of these mutants and allow definition of the mutation frequency underlying the measured mutant frequency. This approach has allowed us to define the molecular nature of mutations induced both in vivo and in vitro by ionizing radiation. Southern blot analysis of 70 in vitro mutant clones induced by 300 rads of gamma irradiation have shown them to be the result of 24 independent mutations by TCR gene rearrangement patterns. Eighteen (0.66) of these were found to have large hprt DNA alterations. Individuals therapeutically exposed to ionizing irradiations show higher TG/sup r/ mutant frequencies than those found in normal controls and a higher fraction of these mutants also contain hprt gene alterations detected by Southern blot analysis (0.34 vs. 0.10--0.15 in controls, respectively). The fraction of mutations which contain detectable DNA alterations is thus elevated after both in vitro and in vivo irradiation of the cells. Analysis of breakpoints in these mutants has allowed us to estimate the maximum size deletion recoverable at the hprt locus. 8 refs., 5 figs., 4 tabs.
- Research Organization:
- Vermont Univ., Burlington (USA)
- DOE Contract Number:
- FG02-87ER60502
- OSTI ID:
- 7067742
- Report Number(s):
- DOE/ER/60502-2; ON: DE88011141
- Country of Publication:
- United States
- Language:
- English
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The development of in vitro mutagenicity testing systems using T-lymphocytes
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Related Subjects
Cells
& Tissue Culture
63 RADIATION, THERMAL, AND OTHER ENVIRON. POLLUTANT EFFECTS ON LIVING ORGS. AND BIOL. MAT.
ANIMAL CELLS
ANIMALS
ANTIGENS
BIOLOGICAL MATERIALS
BLOOD
BLOOD CELLS
BODY FLUIDS
CLONING
CONNECTIVE TISSUE CELLS
DESIGN
DNA-CLONING
DOCUMENT TYPES
DOSES
ELECTROMAGNETIC RADIATION
ELECTROPHORESIS
ENZYMES
GAMMA RADIATION
GENE MUTATIONS
GLYCOSYL TRANSFERASES
HISTOCOMPATIBILITY COMPLEX
HYPOXANTHINE PHOSPHORIBOSYLTRANSFERASE
IONIZING RADIATIONS
LEUKOCYTES
LYMPHOCYTES
MAMMALS
MAN
MATERIALS
MEMBRANE PROTEINS
MUTAGEN SCREENING
MUTATION FREQUENCY
MUTATIONS
ORGANIC COMPOUNDS
PENTOSYL TRANSFERASES
PRIMATES
PROGRESS REPORT
PROTEINS
RADIATION DOSES
RADIATIONS
RADIOSENSITIVITY
RECEPTORS
SCREENING
SOMATIC CELLS
TRANSFERASES
VERTEBRATES