Identification of κ‐ and δ‐opioid receptor transcripts in immune cells

Abstract

To investigate the role of opioids as direct modulators of the immune response, we have searched for expression of the recently cloned 6,/~ and K opioid receptors in immune cells. We have devised a reverse transcriptase-polymerase chain reaction strategy which specifically detects a region spanning putative transmembrane regions 2 to 7 for each transcript in both human and mouse immune cells. In human peripheral blood lymphocyte and monocyte preparations, 6 was undetectable while the g transcript was present. The analysis of human cell lines revealed low but significant levels of 6 opioid receptor transcripts in T, B or monocyte cell lines while the K transcript was found in B cell lines only. Investigation of routine cells showed the presence of transcript for the 6 receptor in splenocytes and in some T and B cell lines. Unexpectedly, no expression of the bt receptor was detected. Sequence analysis of PCR products demonstrated nucleotide identity between immune and neuronal transcripts, indicating that they derive from the same genes. In conclusion, our results lead to the identification of K and 6 opioid receptor transcripts in immune cells.

Regulation of delta opioid receptor expression by anti-CD3-ε, PMA, and ionomycin in murine splenocytes and T cells

“…By using RT-PCR, Gaveriaux et al [14] found that delta opioid receptor (DOR) transcripts were detectable at low levels in human T and monocyte cell lines and at high levels in human B cell lines, but were undetectable in human peripheral blood lymphocyte and monocyte populations. Recently, it was reported that DOR mRNA was detectable in CD4 ϩ and CD8 ϩ T cells purified from concanavalin A-stimulated murine splenocytes [9,15].…”

Abolition of morphine-immunosuppression in mice lacking the μ-opioid receptor gene

“…Genes encoding these receptors are referred as to MOR (), DOR (␦), and KOR (). Their mRNAs are largely distributed throughout the nervous system (16) and some reports indicate detectable expression in immune cells also (17,18), suggesting that they are targets for direct action. The implication of these cloned opioid receptors in opiate immunomodulation in vivo however has not been demonstrated.…”

Gene Therapy Approach: HSV-Enkephalin Reduces Fibrosis, Inflammation, and Pain

“…Opioid receptors are constitutively expressed in non-neuronal sites including vascular endothelial cells (Cadet et al, 2000 andSaeed et al, 2000), on immune cells such as macrophages and lymphocytes (Gavériaux et al, 1995), and keratinocytes (Bigliardi et al, 2002). A role for neuronal opiates has also been shown for reduction of inflammation (for review see Machelska and Stein, 2003).…”