Common γ-chain blocking peptide reduces in vitro immune activation markers in HTLV-1-associated myelopathy/tropical spastic paraparesis.
Human T-cell lymphotropic virus type 1 (HTLV-1)-associated myelopathy/tropical spastic paraparesis (HAM/TSP) is a progressive inflammatory myelopathy occurring in a subset of HTLV-1-infected individuals. Despite advances in understanding its immunopathogenesis, an effective treatment remains to be found. IL-2 and IL-15, members of the gamma chain (γc) family of cytokines, are prominently deregulated in HAM/TSP and underlie many of the characteristic immune abnormalities, such as spontaneous lymphocyte proliferation (SP), increased STAT5 phosphorylation in the lymphocytes, and increased frequency and cytotoxicity of virus-specific cytotoxic CD8(+) T lymphocytes (CTLs). In this study, we describe a novel immunomodulatory strategy consisting of selective blockade of certain γc family cytokines, including IL-2 and IL-15, with a γc antagonistic peptide. In vitro, a PEGylated form of the peptide, named BNZ132-1-40, reduced multiple immune activation markers such as SP, STAT5 phosphorylation, spontaneous degranulation of CD8(+) T cells, and the frequency of transactivator protein (Tax)-specific CD8(+) CTLs, thought to be major players in the immunopathogenesis of the disease. This strategy is thus a promising therapeutic approach to HAM/TSP with the potential of being more effective than single monoclonal antibodies targeting either IL-2 or IL-15 receptors and safer than inhibitors of downstream signaling molecules such as JAK1 inhibitors. Finally, selective cytokine blockade with antagonistic peptides might be applicable to multiple other conditions in which cytokines are pathogenic.
Viral Immunology Section, Neuroimmunology Branch, National Institute of Neurological Disorders and Stroke, National Institutes of Health, Bethesda, MD 20892;
Raya
R
Massoud
Viral Immunology Section, Neuroimmunology Branch, National Institute of Neurological Disorders and Stroke, National Institutes of Health, Bethesda, MD 20892;
Yoshimi
Y
Enose-Akahata
Cell Biology Laboratory, Division of Basic Science and Vaccine Research, University of Maryland School of Medicine, Baltimore, MD 21201;
Yutaka
Y
Tagaya
Bioniz, LLC, Irvine, CA 92618.
Nazli
N
Azimi
Bioniz, LLC, Irvine, CA 92618.
Asjad
A
Basheer
Viral Immunology Section, Neuroimmunology Branch, National Institute of Neurological Disorders and Stroke, National Institutes of Health, Bethesda, MD 20892; jacobsons@ninds.nih.gov.
Steven
S
Jacobson
D015415:Biomarkers / Q000378:metabolism*; D015550:Cell Degranulation / Q000187:drug effects; D006801:Humans; D066298:In Vitro Techniques; D015493:Paraparesis, Tropical Spastic / Q000276:immunology*; D010455:Peptides / Q000494:pharmacology*; D013601:T-Lymphocytes / Q000187:drug effects
D015415:Biomarkers; D010455:Peptides
HAM/TSP; IL-15; gamma chain; human T-cell lymphotropic virus type 1