title: Spontaneous T cell proliferation and release of soluble interleukin-2 receptors in patients with HTLV-I-associated myelopathy.
abstract: Patients with human T lymphotropic virus type I (HTLV-I)-associated myelopathy (HAM) show increased serum levels of soluble interleukin-2 receptors (sIL-2R), a marker of T cell activation. We found that peripheral blood lymphocytes from HAM patients proliferated spontaneously and released sIL-2R when cultured in vitro. Spontaneous proliferation was observed in T cell populations (both CD4+ cells and CD8+ cells), but not in B cell-rich populations or monocyte-rich populations. There was a significant increase of IL-2 activity in the culture supernatants of peripheral blood mononuclear cells (PBMC) after 2-3 days cultivation. On the other hand, sIL-2R concentrations in the supernatants were much higher after 5 days of cultivation. Such spontaneous T lymphocytic proliferation and release of sIL-2R were also found in non-HAM HTLV-I carriers, but not as intensely as in HAM patients. HTLV-I infection causes T cell activation to release IL-2 and sIL-2R; such T cell responses may play a role in the pathogenesis of HTLV-I-associated myelopathy.
authors.affiliation: Institute for Medical Immunology, Kumamoto University Medical School, Japan.
authors.forename: M
authors.initials: M
authors.lastname: Matsumoto
authors.forename: M
authors.initials: M
authors.lastname: Sugimoto
authors.forename: H
authors.initials: H
authors.lastname: Nakashima
authors.forename: F
authors.initials: F
authors.lastname: Imamura
authors.forename: O
authors.initials: O
authors.lastname: Kawano
authors.forename: E
authors.initials: E
authors.lastname: Uyama
authors.forename: K
authors.initials: K
authors.lastname: Takatsu
authors.forename: S
authors.initials: S
authors.lastname: Araki
mesh_terms: D000328:Adult; D000368:Aged; D001402:B-Lymphocytes / Q000276:immunology; D002353:Carrier State / Q000276:immunology*; D005260:Female; D006801:Humans; D007150:Immunohistochemistry; D007958:Leukocyte Count; D007963:Leukocytes, Mononuclear / Q000276:immunology; D008213:Lymphocyte Activation; D008297:Male; D008875:Middle Aged; D009000:Monocytes / Q000276:immunology; D015493:Paraparesis, Tropical Spastic / Q000276:immunology*; D015375:Receptors, Interleukin-2 / Q000096:biosynthesis*; D013601:T-Lymphocytes / Q000276:immunology*
chemical_list: D015375:Receptors, Interleukin-2