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

Abstract We have isolated a variant of the DO‐11.10.7 mouse T cell hybridoma which does not express functional T cell receptor α/β chains. This variant, denoted 58 α − β − , can be used as a recipient for T cell receptor α/β gene transfer experiments to obtain cell lines which express only the products of the transfected α/β genes at their surfaces. In the process of characterizing the defects affecting the 58 α − β − T cell receptor genes, we have found that the parental BW5147 thymoma has undergone a previously unnoticed V α ‐J α rearrangement. This α rearrangement involves a V α pseudogene segment and accounts for the high level of α‐mRNA transcripts present in the BW5147 α − β − variant. Knowledge of the existence of this second, albeit nonfunctional, α‐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.