title: Prophylaxis against a Melanesian variant of human T-lymphotropic virus type I (HTLV-I) in rabbits using HTLV-I immune globulin from asymptomatically infected Japanese carriers.
abstract: Molecular variants of human T-lymphotropic virus type I (HTLV-I), which diverge significantly from the so-called cosmopolitan prototypes, have been discovered in Melanesia. In this study, HTLV-I IgG (I-IgG) prepared from seropositive healthy Japanese carriers was evaluated for its protective effect against a Melanesian isolate, HTLV-IMEL5, in rabbits. Normal IgG (N-IgG) prepared from seronegative healthy Japanese was used as control. Both preparations contained 50 mg/mL of IgG and I-IgG had a high neutralizing antibody titer, as determined by vesicular stomatitis virus--HTLV-I pseudotype assay. Of four experimental groups (A, B, C, and D), each with three rabbits, groups A and B were infused with 10 mL of N-IgG and I-IgG, respectively, and animals were challenged immediately by transfusion of 5 mL of blood from a rabbit infected with HTLV-IMEL5. Animals in groups C and D were immunized with 10 mL of I-IgG 24 and 48 hours, respectively, after being transfused with 5 mL of blood from the virus-infected rabbit. HTLV-I infection, as determined by seroconversion and verified by polymerase chain reaction, occurred in all rabbits in groups A and D after 2 to 6 weeks, but in none of the animals in groups B and C. These data indicate that I-IgG is protective against HTLV-IMEL5 infection when administered before or within 24 hours of transfusion with virus-contaminated blood. Moreover, our study shows that the neutralizing domains of the so-called cosmopolitan and Melanesian strains of HTLV-I are functionally indistinguishable.
authors.affiliation: Department of Medicine, Kochi Medical School, Japan.
authors.forename: Y
authors.initials: Y
authors.lastname: Tanaka
authors.forename: K
authors.initials: K
authors.lastname: Ishii
authors.forename: T
authors.initials: T
authors.lastname: Sawada
authors.forename: Y
authors.initials: Y
authors.lastname: Ohtsuki
authors.forename: H
authors.initials: H
authors.lastname: Hoshino
authors.forename: R
authors.initials: R
authors.lastname: Yanagihara
authors.forename: I
authors.initials: I
authors.lastname: Miyoshi
mesh_terms: D000818:Animals; D000914:Antibodies, Viral / Q000097:blood / Q000302:isolation & purification / Q000627:therapeutic use*; D015153:Blotting, Western; D002353:Carrier State / Q000097:blood / Q000276:immunology*; D004797:Enzyme-Linked Immunosorbent Assay; D005260:Female; D005312:Fetal Blood / Q000276:immunology; D014644:Genetic Variation; D015490:HTLV-I Infections / Q000097:blood / Q000276:immunology* / Q000517:prevention & control*; D015368:Human T-lymphotropic virus 1 / Q000276:immunology* / Q000302:isolation & purification; D006801:Humans; D007074:Immunoglobulin G / Q000097:blood / Q000302:isolation & purification / Q000627:therapeutic use*; D007231:Infant, Newborn; D008297:Male; D008542:Melanesia; D008875:Middle Aged; D011817:Rabbits
chemical_list: D000914:Antibodies, Viral; D007074:Immunoglobulin G