Functional role and sequence analysis of a lymphocyte orphan opioid receptor.
Pharmacological evidence indicates that lymphocytes express opioid receptors, but this finding has been questioned. By DNA sequencing of reverse transcription-polymerase chain reaction products, we have found that mouse lymphocytes express mRNA encoding an orphan opioid receptor. These mRNA transcripts were detected in the CD4+, CD8+, and CD4- CD8- lymphocyte subpopulations. Northern blot analysis confirmed that splenic lymphocytes express a 1.5-kb orphan opioid receptor mRNA. Fifteen bases encoding Tyr71-Arg75 in the first intracellular loop are alternatively spliced, suggesting that orphan opioid receptor mRNA encodes two receptor subtypes. Treatment of lipopolysaccharide-stimulated lymphocytes with orphan opioid receptor antisense oligonucleotides suppressed polyclonal IgG and IgM production by 50%. Our results provide direct evidence that lymphocytes express an opioid-like receptor gene, and suggest that this receptor plays a functional role in immunocompetence.
Halford
W P
WP
Department of Microbiology, LSU Medical Center, New Orleans 70112-1393, USA.
Gebhardt
B M
BM
Carr
D J
DJ
D000595:Amino Acid Sequence; D000818:Animals; D001483:Base Sequence; D015152:Blotting, Northern; D018076:DNA, Complementary / Q000737:chemistry; D008214:Lymphocytes / Q000737:chemistry*; D051379:Mice; D008807:Mice, Inbred BALB C; D008811:Mice, Inbred DBA; D008813:Mice, Inbred ICR; D008969:Molecular Sequence Data; D016376:Oligonucleotides, Antisense / Q000494:pharmacology; D016133:Polymerase Chain Reaction; D012333:RNA, Messenger / Q000032:analysis*; D011957:Receptors, Opioid / Q000737:chemistry / Q000235:genetics* / Q000502:physiology
D018076:DNA, Complementary; D016376:Oligonucleotides, Antisense; D012333:RNA, Messenger; D011957:Receptors, Opioid