title: Human IgM monoclonal antibodies reactive with HIV-1-infected cells generated using a trans-chromosome mouse.
abstract: The trans-chromosome (TC) mouse that we used harbors human chromosomes 2, 14 and/or 22, and has undergone knock-out of its endogeneous genes coding for mu-and kappa-chains of immunoglobulin. One of these TC mice was immunized with HIV-1-infected U937 cells, and spleen cells from the immunized animal were fused with the mouse myeloma cell line to generate hybridoma cells. We selected hybridomas that produce human IgM antibodies (Abs) reactive with HIV-1-infected MOLT4 cells but not with uninfected MOLT4 cells. Two hybridoma cell lines were established termed 9F11 and 2G9. Although 0.4 mug/ml of 9F11 was able to induce complement-mediated cytolysis of the infected cells in the presence of fresh human serum, 2G9 could not. There was no difference between the two monoclonal Abs in the base sequences of cDNAs coding for the constant regions of mu-and kappa-chains. Therefore, we speculate that the ability to activate complement on homologous cell membranes might reflect the structural presentation of antigenic molecules, which could facilitate the binding of an IgM Ab to multiple binding sites resulting in escape from restriction by species-specific inhibitors of complement such as DAF (CD55) and CD59. On the other hand, 2G9 induced apoptosis of HIV-1-infected cells, including latently infected OM10.1 cells, although the Ag for 2G9 remains to be identified. Since both of the Abs had reduced reactivity toward HIV-1-infected MOLT4 cells following cultivation in the presence of tunicamycin, the responsible antigens would involve a sugar moiety.
authors.affiliation: Department of Biodefense, Nagoya City University Graduate School of Medical Sciences, Nagoya, Aichi, Japan. drnoriko@med.nagoya-cu.ac.jp
authors.forename: Noriko
authors.initials: N
authors.lastname: Okada
authors.forename: Shuping
authors.initials: S
authors.lastname: Yin
authors.forename: Suzuka
authors.initials: S
authors.lastname: Asai
authors.forename: Noriaki
authors.initials: N
authors.lastname: Kimbara
authors.forename: Natsuki
authors.initials: N
authors.lastname: Dohi
authors.forename: Masato
authors.initials: M
authors.lastname: Hosokawa
authors.forename: Xiaoshan
authors.initials: X
authors.lastname: Wu
authors.forename: Hidechika
authors.initials: H
authors.lastname: Okada
mesh_terms: D000595:Amino Acid Sequence; D000818:Animals; D000911:Antibodies, Monoclonal / Q000096:biosynthesis / Q000276:immunology*; D017209:Apoptosis; D002460:Cell Line; D002877:Chromosomes, Human / Q000235:genetics; D003169:Complement Inactivator Proteins / Q000502:physiology; D003165:Complement System Proteins / Q000276:immunology*; D003602:Cytotoxicity, Immunologic; D015497:HIV-1 / Q000276:immunology*; D006801:Humans; D006825:Hybridomas / Q000276:immunology; D007127:Immunoglobulin Constant Regions / Q000235:genetics; D007075:Immunoglobulin M / Q000096:biosynthesis / Q000276:immunology*; D007145:Immunoglobulin kappa-Chains / Q000235:genetics; D007148:Immunoglobulin mu-Chains / Q000235:genetics; D051379:Mice; D018345:Mice, Knockout; D008822:Mice, Transgenic; D008969:Molecular Sequence Data; D017422:Sequence Analysis, DNA
chemical_list: D000911:Antibodies, Monoclonal; D003169:Complement Inactivator Proteins; D007127:Immunoglobulin Constant Regions; D007075:Immunoglobulin M; D007145:Immunoglobulin kappa-Chains; D007148:Immunoglobulin mu-Chains; D003165:Complement System Proteins