Derivation of a T cell hybridoma variant deprived of functional T cell receptor α and β chain transcripts reveals a nonfunctional α‐mRNA of BW5147 origin

We have isolated a variant of the DO-11.10.7 mouse T cell hybridoma which does not express functional T cell receptor alpha/beta chains. This variant, denoted 58 alpha-beta-, can be used as a recipient for T cell receptor alpha/beta gene transfer experiments to obtain cell lines which express only the products of the transfected alpha/beta genes at their surfaces. In the process of characterizing the defects affecting the 58 alpha-beta-T cell receptor genes, we have found that the parental BW5147 thymoma has undergone a previously unnoticed V alpha-J alpha rearrangement. This alpha rearrangement involves a V alpha pseudogene segment and accounts for the high level of alpha-mRNA transcripts present in the BW5147 alpha-beta- variant. Knowledge of the existence of this second, albeit nonfunctional, alpha-mRNA in BW5147 is of importance, since it could be, and actually already has been, mistakenly identified (due to partial nucleotide sequencing) in T hybrids as a functionally significant message donated by the normal T cell parent.