A novel mother-to-child human T-cell leukaemia virus type 1 (HTLV-1) transmission model for investigating the role of maternal anti-HTLV-1 antibodies using orally infected mother rats.
Human T-cell leukaemia virus type 1 (HTLV-1) is a human retrovirus that is a causative agent of adult T-cell leukaemia/lymphoma (ATL) and is mainly transmitted from an infected mother to her child via breastfeeding. Such an HTLV-1 infection during childhood is believed to be a risk factor for ATL development. Although it has been suggested that an increased proviral load (PVL), a higher titre of antibody (Ab) in the infected mother and prolonged breastfeeding are associated with an increased risk of mother-to-child transmission (MTCT), the mechanisms underlying MTCT of HTLV-1 remain largely unknown. In this study, we developed an MTCT model using orally HTLV-1-infected rats that have no Ab responses against viral antigens, such as Gag and Env. In this model, HTLV-1 could be transmitted from the infected mother rats to their offspring at a high rate (50-100 %), and the rate of MTCT tended to be correlated with the PVL of the infected mother rats. Furthermore, passive immunization of uninfected adult rats and an infected mother rat with a rat anti-HTLV-1 Env gp46-neutralizing mAb was unable to suppress primary oral HTLV-1 infection to the adult rats and vertical HTLV-1 transmission to the offspring, respectively. Our findings indicate that this MTCT model would be useful to investigate not only the mechanisms of MTCT but also the role of anti-HTLV-1 Ab in MTCT of HTLV-1. They also provide some information on the role of maternal Abs in MTCT, which should be considered when designing a strategy for prevention of MTCT of HTLV-1.
Department of Immunotherapeutics, Tokyo Medical and Dental University, Tokyo, Japan.
Yuji
Y
Murakami
Department of Immunotherapeutics, Tokyo Medical and Dental University, Tokyo, Japan.
Atsuhiko
A
Hasegawa
Department of Immunotherapeutics, Tokyo Medical and Dental University, Tokyo, Japan.
Satomi
S
Ando
Department of Immunology, University of the Ryukyus, Okinawa, Japan.
Reiko
R
Tanaka
Department of Immunotherapeutics, Tokyo Medical and Dental University, Tokyo, Japan.
Takao
T
Masuda
Department of Immunology, University of the Ryukyus, Okinawa, Japan.
Yuetsu
Y
Tanaka
Department of Immunotherapeutics, Tokyo Medical and Dental University, Tokyo, Japan.
Mari
M
Kannagi
D000818:Animals; D000914:Antibodies, Viral / Q000097:blood*; D004195:Disease Models, Animal; D015490:HTLV-I Infections / Q000635:transmission*; D015368:Human T-lymphotropic virus 1 / Q000276:immunology*; D018445:Infectious Disease Transmission, Vertical; D051381:Rats
D000914:Antibodies, Viral