Opioid growth factor and low-dose naltrexone impair central nervous system infiltration by CD4 + T lymphocytes in established experimental autoimmune encephalomyelitis, a model of multiple sclerosis

Leslie A. Hammer, Hanspeter Waldner, Ian S. Zagon, Patricia J. McLaughlin

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11 Scopus citations


Multiple sclerosis (MS) is an autoimmune disease of the central nervous system (CNS), characterized by infiltrating myelin-reactive T lymphocytes and demyelinating lesions. Experimental autoimmune encephalomyelitis (EAE) is the animal model widely utilized to study MS. EAE is mediated by CD4+ T cells and can be induced in EAE-susceptible mice through immunization with a myelin antigen, such as proteolipid protein 139–151 (PLP139-151) in SJL mice. In this PLP-induced EAE model, autoreactive CD4+ T cells migrate from peripheral tissues into the CNS where they are reactivated resulting in CNS damage. Th1 and Th17 cells produce the pro-inflammatory cytokines IFNγ and IL-17, respectively, that have been shown to have pathogenic roles in EAE and MS. Anti-inflammatory Th2, IL-4 secreting cells, have been indicated to inhibit EAE exacerbation. However, given the inflammatory environment of EAE, Th2 effector cells are outnumbered by Th1/Th17 cells. Regulatory CD4+ T cells suppress immune reactions and have been demonstrated to be dysfunctional in MS patients. Opioid growth factor (OGF), chemically termed [Met5]-enkephalin, is a negative growth factor that interacts with the OGF receptor. The OGF-OGFr axis can be activated through exogenous administration of OGF or a low dosage of naltrexone (LDN), an opioid antagonist. We have previously demonstrated that modulation of the OGF-OGFr axis results in alleviation from relapse-remitting EAE, and that CNS-infiltrating CD3+ T cells are diminished with exogenous OGF or intermittent blockade with LDN administration. In this paper, we aimed to determine whether OGF or LDN alter the Th effector responses of CD4+ T lymphocytes within the CNS in established EAE. We report in these studies that the numbers of CD4+ T lymphocytes in the CNS of EAE mice are decreased following treatment with OGF for five days but not LDN. However, modulation of the OGF-OGFr axis did not result in changes to CD4+ Th effector cell responses in the CNS of EAE mice.

Original languageEnglish (US)
Pages (from-to)71-78
Number of pages8
JournalExperimental Biology and Medicine
Issue number1
Publication statusPublished - Jan 1 2016


All Science Journal Classification (ASJC) codes

  • Biochemistry, Genetics and Molecular Biology(all)

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