title: Characterization of mAbs to chicken anemia virus and epitope mapping on its viral protein, VP1.
abstract: Three (MoCAV/F2, MoCAV/F8 and MoCAV/F11) of four mouse mAbs established against the A2/76 strain of chicken anemia virus (CAV) showed neutralization activity. Immunoprecipitation showed a band at ~50 kDa in A2/76-infected cell lysates by neutralizing mAbs, corresponding to the 50 kDa capsid protein (VP1) of CAV, and the mAbs reacted with recombinant VP1 proteins expressed in Cos7 cells. MoCAV/F2 and MoCAV/F8 neutralized the 14 CAV strains tested, whereas MoCAV/F11 did not neutralize five of the strains, indicating distinct antigenic variation amongst the strains. In blocking immunofluorescence tests with the A2/76-infected cells, binding of MoCAV/F11 was not inhibited by the other mAbs. MoCAV/F2 inhibited the binding of MoCAV/F8 to the antigens and vice versa, suggesting that the two mAbs recognized the same epitope. However, mutations were found in different parts of VP1 of the escape mutants of each mAb: EsCAV/F2 (deletion of T89+A90), EsCAV/F8 (I261T) and EsCAV/F11 (E144G). Thus, the epitopes recognized by MoCAV/F2 and MoCAV/F8 seemed to be topographically close in the VP1 structure, suggesting that VP1 has at least two different neutralizing epitopes. However, MoCAV/F8 did not react with EsCAV/F2 or EsCAV/F8, suggesting that binding of MoCAV/F8 to the epitope requires coexistence of the epitope recognized by MoCAV/F2. In addition, MoCAV/F2, with a titre of 1 : 12 800 to the parent strain, neutralized EsCAV/F2 and EsCAV/F8 with low titres of 32 and 152, respectively. The similarity of the reactivity of MoCAV/F2 and MoCAV/F8 to VP1 may also suggest the existence of a single epitope recognized by these mAbs.
authors.affiliation: National Institute of Veterinary Research, 86 Truong Chinh, Dong Da, Hanoi, Vietnam.|Research Center for Animal Hygiene and Food Safety, Obihiro University of Agriculture and Veterinary Medicine, 2-11 Inada, Obihiro, Hokkaido 080-8555, Japan.
authors.forename: Dai Q
authors.initials: DQ
authors.lastname: Trinh
authors.affiliation: Research Center for Animal Hygiene and Food Safety, Obihiro University of Agriculture and Veterinary Medicine, 2-11 Inada, Obihiro, Hokkaido 080-8555, Japan.
authors.forename: Haruko
authors.initials: H
authors.lastname: Ogawa
authors.affiliation: National Institute of Veterinary Research, 86 Truong Chinh, Dong Da, Hanoi, Vietnam.|Research Center for Animal Hygiene and Food Safety, Obihiro University of Agriculture and Veterinary Medicine, 2-11 Inada, Obihiro, Hokkaido 080-8555, Japan.
authors.forename: Vuong N
authors.initials: VN
authors.lastname: Bui
authors.affiliation: Research Center for Animal Hygiene and Food Safety, Obihiro University of Agriculture and Veterinary Medicine, 2-11 Inada, Obihiro, Hokkaido 080-8555, Japan.
authors.forename: Tugsbaatar
authors.initials: T
authors.lastname: Baatartsogt
authors.affiliation: College of Veterinary Medicine, Animal Resources and Biosecurity, Makerere University, Kampala, Uganda.|Research Center for Animal Hygiene and Food Safety, Obihiro University of Agriculture and Veterinary Medicine, 2-11 Inada, Obihiro, Hokkaido 080-8555, Japan.
authors.forename: Mugimba K
authors.initials: MK
authors.lastname: Kizito
authors.affiliation: Japan Livestock Technology Association, 3-20-9 Yushima, Bunkyo-ku, Tokyo 113-0034, Japan.
authors.forename: Shigeo
authors.initials: S
authors.lastname: Yamaguchi
authors.affiliation: Research Center for Animal Hygiene and Food Safety, Obihiro University of Agriculture and Veterinary Medicine, 2-11 Inada, Obihiro, Hokkaido 080-8555, Japan.
authors.forename: Kunitoshi
authors.initials: K
authors.lastname: Imai
mesh_terms: D000818:Animals; D000911:Antibodies, Monoclonal / Q000276:immunology* / Q000302:isolation & purification; D057134:Antibodies, Neutralizing / Q000276:immunology / Q000302:isolation & purification; D000914:Antibodies, Viral / Q000276:immunology* / Q000302:isolation & purification; D036022:Capsid Proteins / Q000235:genetics / Q000276:immunology*; D017727:Chicken anemia virus / Q000235:genetics / Q000276:immunology*; D004279:DNA, Viral / Q000737:chemistry / Q000235:genetics; D018604:Epitope Mapping; D047468:Immunoprecipitation; D008807:Mice, Inbred BALB C; D008969:Molecular Sequence Data; D009500:Neutralization Tests; D017422:Sequence Analysis, DNA
chemical_list: D000911:Antibodies, Monoclonal; D057134:Antibodies, Neutralizing; D000914:Antibodies, Viral; D036022:Capsid Proteins; D004279:DNA, Viral; C442548:VP1 protein, Chicken anemia virus