Similarity of in vivo somatic mutations at an autosomal adenine phosphoribosyltransferase locus between T- and B-cells in human peripheral blood.
In vivo somatic mutations have been detected at several human loci by using clonal cultures of peripheral blood T-cells. It has not been fully understood whether or not the somatic mutations in T-cells are similar to those of other cell types. To address this issue, we cloned, from human peripheral blood, T- and B-cells with mutations at an autosomal adenine phosphoribosyltransferase (APRT) locus. For the efficient detection of somatic mutations at the APRT locus, a blood sample from a human individual heterozygous for germline APRT deficiency was used. T- and B-cells deficient in APRT enzyme activity were cloned from peripheral blood mononuclear cells using a selecting agent, 2,6-diaminopurine. The APRT-deficient mutant frequencies were on the order of 10(-4) in both T- and B-cells. The single-strand conformation polymorphism analysis of the APRT DNA of mutant B-cell clones suggested that the molecular mechanisms leading to the APRT deficiency in B-cells were similar to those in T-cells. Our observations suggest that both the frequency and the mode of in vivo somatic mutations occurring spontaneously at general autosomal loci in B-cells are similar to those in T-cells.
Hakoda
M
M
Institute of Rheumatology, Tokyo Women's Medical College, Japan. kamatani@ims.u-tokyo.ac.jp
Kamatani
N
N
Terai
C
C
Yamanaka
H
H
Taniguchi
A
A
Ueda
H
H
Kashiwazaki
S
S
D000228:Adenine Phosphoribosyltransferase / Q000172:deficiency / Q000235:genetics*; D001402:B-Lymphocytes / Q000201:enzymology*; D006579:Heterozygote; D006801:Humans; D009154:Mutation; D018807:Polymorphism, Single-Stranded Conformational; D013601:T-Lymphocytes / Q000201:enzymology*
D000228:Adenine Phosphoribosyltransferase