Spontaneous T cell proliferation and release of soluble interleukin-2 receptors in patients with HTLV-I-associated myelopathy.
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.
Matsumoto
M
M
Institute for Medical Immunology, Kumamoto University Medical School, Japan.
Sugimoto
M
M
Nakashima
H
H
Imamura
F
F
Kawano
O
O
Uyama
E
E
Takatsu
K
K
Araki
S
S
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*
D015375:Receptors, Interleukin-2