Identification of the CDR3 Gene Sequence on the β Chain of the T Cell Receptor in T Cell Leukemia Cell Line

In order to develop a method for the detection of minimal residual leukemic disease (MRD) in T cell acute lymphocytic leukemia (T cell ALL), T cell leukemia cell line was used to detect clonal TCR p chain mRNA and to synthesize CDR3 specific oligonucleotide probe. For the Jurkat cell line clonal TCR p chain cDNA was amplified by using RT-PCR with oligonucleotide primer, Vp universal primer. As the result of RT-PCR an approximate 300 bp fragment of the TCR chain was obtained, and the partial identification of the TCR p chain gene and the amino acid sequence of the fragment were done by gene cloning and sequencing. The gene sequence of TCR p obtained was identified as Vp8-Jp1.2-Cp2. Diversity gene segment could not be found. Within the p chain, the CDR3 region was identified as 12 amino acids (SFSTCSANYGYT). It is kown that TCR is expressed in about 40% of the all T cell ALL. However it is not kown what percentage of the TCR p chain mRNA expression translates into the actual TCR molecule. It is not certain how many patients with MRD can be detected by this method used in this study, but this technique might be useful to detect MRD in at least 40% of the patients with T-cell ALLprohibitio