Expression of delta opioid receptors by splenocytes from SEB-treated mice and effects on phosphorylation of MAP kinase

Cell Immunol. 2000 Nov 1;205(2):84-93. doi: 10.1006/cimm.2000.1717.


Delta opioid receptors (DORs) are known to modulate multiple T-cell responses. However, little is known about the expression of these receptors. These studies evaluated the expression of DOR mRNA and protein after a single in vivo exposure to staphylococcal enterotoxin B (SEB). SEB (20 microg, ip) significantly enhanced splenocyte DOR mRNA expression 8 and 24 h after injection. SEB also increased the fractions of the total splenocyte (5 to 20%) and T-cell (8 to 50%) populations expressing DOR protein. In saline-treated animals, DOR relative fluorescence intensity per cell was 11.1 +/- 0.62 units (mean +/- SEM), increasing to 16.1 +/- 1.7 after exposure to SEB. DOR fluorescence intensity significantly increased to 33.5 +/- 2.0 units in a subpopulation of T-cells. Thus, SEB significantly increased DOR expression in vivo, affecting both mRNA and protein levels primarily within the T-cell population. To determine whether T-cell DORs modulate the activity of extracellular-regulated kinases (ERKs), the phosphorylation of ERKs 1 and 2 was studied using splenocytes from SEB-treated mice. At concentrations from 10(-8) to 10(-6) M, [d-Ala(2)-d-Leu(5)]-enkephalin, a selective DOR agonist, significantly inhibited anti-CD3-epsilon-induced phosphorylation of the ERKs. Therefore, the DORs expressed by activated T-cells are capable of attenuating T-cell activation that depends on ERK phosphorylation.

Publication types

  • Research Support, U.S. Gov't, P.H.S.

MeSH terms

  • Amino Acid Sequence
  • Animals
  • Cells, Cultured
  • Enterotoxins / immunology*
  • Female
  • Mice
  • Mice, Inbred BALB C
  • Mitogen-Activated Protein Kinase 1 / metabolism*
  • Mitogen-Activated Protein Kinase 3
  • Mitogen-Activated Protein Kinases / metabolism*
  • Molecular Sequence Data
  • Phosphorylation
  • RNA, Messenger / metabolism
  • Receptors, Opioid, delta / biosynthesis*
  • Receptors, Opioid, delta / genetics
  • Spleen / cytology
  • Spleen / immunology
  • Staphylococcus aureus / immunology*
  • Superantigens / immunology*


  • Enterotoxins
  • RNA, Messenger
  • Receptors, Opioid, delta
  • Superantigens
  • enterotoxin B, staphylococcal
  • Mitogen-Activated Protein Kinase 1
  • Mitogen-Activated Protein Kinase 3
  • Mitogen-Activated Protein Kinases