Regulation of human natural cytotoxicity by enkephalins and selective opiate agonists

Dorothy R. Oleson, Donald R. Johnson

Research output: Contribution to journalArticlepeer-review

60 Scopus citations


This study reports a bidirectional effect of the enkephalins and selective opiate receptor agonists on human natural killer (NK) cell activity. Peripheral blood mononuclear cells (PBMC) were obtained from healthy donors and enriched for T lymphocytes and large granular lymphocytes (LGL) by passage over nylon wool columns. Nylon wool nonadherent cell populations were preincubated for 18 h in the presence of fetal bovine serum with and without methionine-enkephalin, leucine-enkephalin, dynorphin (fragment 1-3), [d-Ser2]-leucine-enkephalin-Thr (DSLET), and [d-Ala2,N Me-Phe4, Gly-ol5]-enkephalin (DAGO). NK activity was measured by a standard 51Cr release assay with radiolabeled K562 cells. The cytolytic capacity of low NK responder populations was enhanced by the endogenous opioids while the NK activity of high responder populations was suppressed. These results suggest an immunoregulatory action of opioid peptides on NK activity. This possibility was confirmed using a serum-free system in conjunction with recombinant interferon-α. In addition, the classic opioid receptor antagonist naloxone displayed both antagonist and direct immunomodulatory properties, which may indicate the presence of lymphocyte derived opioid peptides in the culture system.

Original languageEnglish (US)
Pages (from-to)171-186
Number of pages16
JournalBrain Behavior and Immunity
Issue number3
StatePublished - Sep 1988

ASJC Scopus subject areas

  • Immunology
  • Endocrine and Autonomic Systems
  • Behavioral Neuroscience


Dive into the research topics of 'Regulation of human natural cytotoxicity by enkephalins and selective opiate agonists'. Together they form a unique fingerprint.

Cite this