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Mouse model for the equilibration interaction between the host immune system and human T-cell leukemia virus type 1 gene expression.

Authors :
Furuta RA
Sugiura K
Kawakita S
Inada T
Ikehara S
Matsuda T
Fujisawa J
Source :
Journal of virology [J Virol] 2002 Mar; Vol. 76 (6), pp. 2703-13.
Publication Year :
2002

Abstract

To study the involvement of immune responses against Tax of human T-cell leukemia virus type 1 (HTLV-1) in the growth of and gene suppression in Tax-expressing tumor cells in vivo, we established a model system involving C57BL/6J mice and a syngeneic lymphoma cell line, EL4. When mice were immunized by DNA-based immunization with Tax expression plasmids, solid tumor formation upon subcutaneous inoculation of EL4 cells expressing green fluorescent protein-fused Tax (Gax) under the control of the HTLV-1 enhancer was strongly inhibited, and in vitro analysis showed that DNA immunization elicited cytotoxic T-lymphocyte (CTL) responses but not production of antibodies to Tax protein. Since EL4/Gax cells inoculated into DNA-immunized mice were not completely eradicated but were maintained as small solid tumors for a long period, there appeared to be a certain equilibrium between CTL activity and the growth of Gax-expressing cells. With such a balance, expression of the Gax gene in EL4/Gax cells was strongly suppressed. These results suggested that gene expression under the control of the HTLV-1 long terminal repeat and Tax is silenced in vivo, resulting in an equilibrium between viral expression and the host immune system. Such a balance would represent a status of persistent infection by HTLV-1 in virus-infected individuals during the latency period.

Details

Language :
English
ISSN :
0022-538X
Volume :
76
Issue :
6
Database :
MEDLINE
Journal :
Journal of virology
Publication Type :
Academic Journal
Accession number :
11861837
Full Text :
https://doi.org/10.1128/jvi.76.6.2703-2713.2002