Southern blot analysis of T-cell receptor gene rearrangements in cynomolgus monkeys, and identification of a progenitor cell HPRT mutation

✍ Scribed by S. S. Mattano; D. M. Zimmer; P. R. Harbach; T. C. Hunter; Dr. C. S. Aaron

• Publisher: John Wiley and Sons
• Year: 1995
• Tongue: English
• Weight: 793 KB
• Volume: 26
• Category: Article
• ISSN: 0893-6692
• DOI: 10.1002/em.2850260205

✦ Synopsis

Increases in peripheral blood T-lymphocyte HPRT mutant frequency may reflect either a number of independent HPRT gene mutational events or clonal proliferation of a single HPRT mutant. Sequence analysis of HPRT mutations in conjunction with Tcell receptor (TCR) gene rearrangement pattern analysis can distinguish these possibilities. Our laboratory previously characterized a nonhuman primate model for in vivo mutation studies using the clonal HPRT mutation assay. In the present study we report the use of probes for human TCR p and y genes to characterize TCR rearrangements in cynomolgus monkeys. Together, these methods were used to examine a monkey which exhibited a mean spontaneous HPRT mutant frequency (MF) of 16.4 X 1 0-6, compared to the normal mean MF of 3.03 x 1 O-6.

The elevated MF resulted from the occurrence of a single HPRT mutation in a lymphocyte progenitor cell or stem cell, since Tcell clones isolated from the monkey exhibited a G to T transversion at base pair 539 in the HPRT coding region, and had unique rearrangements of TCR y along with an apparent germline TCR p configuration. In a preliminary in vivo mutation study, the animal was treated with the investigational potent mutagen and antitumor agent adozelesin (U-73975). No increase in HPRT mutant frequency was observed. The HPRT mutant clones isolated after treatment showed rearrangement of both TCR y and p genes. Possible explanations for these findings are discussed.