High expression of a specific T-cell receptor γ transcript in epithelial cells of the prostate

We have identified expression of T-cell receptor γ chain (TCRγ) mRNA in human prostate and have shown that it originates from epithelial cells of the prostate and not from infiltrating T-lymphocytes. In contrast, the T-cell receptor δ chain (TCRδ) gene is silent in human prostate. The major TCRγ transcript in prostate has a different size than the transcript expressed in thymus, spleen, and blood leukocytes. It is expressed in normal prostate epithelium, adenocarcinoma of the prostate, and the prostatic adenocarcinoma cell line LNCaP. The RNA originates from an unrearranged TCRγ locus, and it is initiated within the intronic sequence directly upstream of the Jγ1.2 gene segment. The prostate-specific TCRγ transcript consists of the Jγ1.2 and Cγ1 gene segments, and it has an untranslated sequence including a polyadenylation signal and poly(A) sequence at the 3′end. The finding that prostate epithelial cells express a high level of a transcript from a gene that was thought to by exclusively expressed by T-lymphocytes is highly unexpected.