Oral administration of human T-cell leukemia virus type 1 induces immune unresponsiveness with persistent infection in adult rats.
The major route of human T-cell leukemia virus type 1 (HTLV-1) infection is mother-to-child transmission caused by breast-feeding. We investigated the host immune responses to orally established persistent HTLV-1 infection in adult rats. HTLV-1-producing MT-2 cells were inoculated into immunocompetent adult rats either orally, intravenously, or intraperitoneally. HTLV-1 proviruses were detected in the peripheral blood and several organs for at least 12 weeks. Transmission of HTLV-1 to these animals was confirmed by analysis of HTLV-1 flanking regions. Despite persistent HTLV-1 presence, none of the orally inoculated rats produced detectable levels of anti-HTLV-1 antibodies, whereas all intravenously or intraperitoneally inoculated rats showed significant anti-HTLV-1 antibody responses. T-cell proliferative responses against HTLV-1 were also absent in orally inoculated rats. Our findings suggest that gastrointestinal exposure of adult rats to HTLV-1-infected cells induces persistent HTLV-1 infection in the absence of both humoral and cellular immune responses against HTLV-1. This immune unresponsiveness at primary infection may subsequently affect the host defense ability against HTLV-1.
Kato
H
H
Department of Immunotherapeutics, Medical Research Division, Tokyo Medical and Dental University, Tokyo 113, Japan.
Koya
Y
Y
Ohashi
T
T
Hanabuchi
S
S
Takemura
F
F
Fujii
M
M
Tsujimoto
H
H
Hasegawa
A
A
Kannagi
M
M
D000284:Administration, Oral; D000818:Animals; D002455:Cell Division; D002461:Cell Line, Transformed; D015480:Deltaretrovirus Antibodies / Q000494:pharmacology; D005260:Female; D015490:HTLV-I Infections / Q000276:immunology*; D015368:Human T-lymphotropic virus 1 / Q000276:immunology* / Q000502:physiology; D006801:Humans; D007274:Injections, Intraperitoneal; D007275:Injections, Intravenous; D011533:Proviruses / Q000235:genetics; D051381:Rats; D011916:Rats, Inbred F344; D013601:T-Lymphocytes / Q000276:immunology; D013997:Time Factors; D014018:Tissue Distribution; D017735:Virus Latency
D015480:Deltaretrovirus Antibodies