Characterization of κ-opioid receptor transcripts expressed by T cells and macrophages

We have found that the immature T cell lines R1.1 and DPK and the macrophage lines P388D(1) and WEHI-S also express K-opioid receptor (KOR) mRNA. Characterization of the KOR transcripts in both brain tissue and these T cells has revealed both the normal full-length as well as a truncated form of the mRNA. Our results show that the truncated transcript lacks the second exon. Primary macrophages express this truncated form of the transcript in the absence of detectable levels of the full-length form. These results suggest a degree of heterogeneity in the expression of the opioid receptors which has not previously been reported. (C) 1998 Elsevier Science B.V. All rights reserved.