Blood, 1 September 2000, Vol. 96, No. 5, pp. 1994-1995
BRIEF REPORT
Class I-unrestricted noncytotoxic anti-HTLV-I activity of
CD8+ T cells
Masako Moriuchi and
Hiroyuki Moriuchi
From the Division of Medical Virology, Department of
Molecular Microbiology and Immunology, Nagasaki University Graduate
School of Medical Sciences, and Department of Pediatrics, Nagasaki
University School of Medicine, Nagasaki, Japan.
Although it is widely believed that viral clearance is
mediated principally by the destruction of infected cells by cytotoxic T cells, noncytolytic antiviral activity of CD8+ T cells
may play a role in preventing the progression to disease in infections
with immunodeficiency viruses and hepatitis B virus. We demonstrate
here that (1) replication of human T-lymphotropic virus type I (HTLV-I)
is more readily detected from CD8+ T-cell-depleted
(CD8
) peripheral blood mononuclear cells (PBMCs) of
healthy HTLV-I carriers than from unfractionated PBMCs, (2) cocultures
of CD8 PBMCs with autologous or allogeneic
CD8+ T cells suppressed HTLV-I replication, and (3)
CD8+ T-cell anti-HTLV-I activity is not abrogated in
trans-well cultures in which CD8+ cells are
separated from CD8 PBMCs by a permeable membrane filter.
These results suggest that class I-unrestricted noncytolytic
anti-HTLV-I activity is mediated, at least in part by a soluble
factor(s), and may play a role in the pathogenesis of HTLV-I infection.
