1. Human B-cell ontogeny in humanized NOD/SCID γcnull mice generates a diverse yet auto/poly- and HIV-1-reactive antibody repertoire
- Author
-
Madhura M. Panditrao, Wayne A. Marasco, Subhabrata Biswas, Phuong Thi Nguyen Sarkis, Shusheng Geng, Quan Karen Zhu, Hong Chang, and Aimee St. Clair Tallarico
- Subjects
Male ,Immunology ,Gene Rearrangement, B-Lymphocyte, Heavy Chain ,Somatic hypermutation ,Mice, SCID ,Nod ,HIV Antibodies ,Biology ,Article ,Mice ,03 medical and health sciences ,0302 clinical medicine ,Immune system ,Antibody Repertoire ,Mice, Inbred NOD ,antibody repertoire ,autoreactive ,Genetics ,checkpoint control ,Animals ,Humans ,Genetics (clinical) ,Autoantibodies ,030304 developmental biology ,B-Lymphocytes ,0303 health sciences ,V(D)J recombination ,env Gene Products, Human Immunodeficiency Virus ,Gene rearrangement ,Virology ,Molecular biology ,V(D)J Recombination ,3. Good health ,single B-cell ,Humanized mouse ,HIV-1 ,biology.protein ,humanized mouse ,Female ,Somatic Hypermutation, Immunoglobulin ,Antibody ,Immunoglobulin Heavy Chains ,Protein Binding ,030215 immunology - Abstract
Characterization of the human antibody (Ab) repertoire in mouse models of the human immune system is essential to establish their relevance in translational studies. Single human B cells were sorted from bone marrow and periphery of humanized NOD/SCID γc(null) (hNSG) mice at 8-10 months post engraftment with human cord blood-derived CD34(+) stem cells. Human IG variable heavy (V(H)) and kappa (V(κ)) genes were amplified, cognate V(H)-V(κ) gene-pairs assembled as single-chain variable fragment-Fc Abs (scFvFcs) and functional studies were performed. Although overall distribution of V(H) genes approximated the normal human Ab repertoire, analysis of the V(H)-third complementarity-determining regions in the mature B-cell subset demonstrated an increase in length and positive charges, suggesting autoimmune characteristics. Additionally, >70% of V(κ) sequences utilized V(κ)4-1, a germline gene associated with autoimmunity. The mature B-cell subset-derived scFvFcs displayed the highest frequency of autoreactivity and polyspecificity, suggesting defects in checkpoint control mechanisms. Furthermore, these scFvFcs demonstrated binding to recombinant HIV envelope corroborating previous observations of poly/autoreactivity in anti-HIVgp140 Abs. These data lend support to the hypothesis that anti-HIV broadly neutralizing antibodies may be derived from auto/polyspecific Abs that escaped immune elimination and that the hNSG mouse could provide a new experimental platform for studying the origin of anti-HIV-neutralizing Ab responses.
- Published
- 2012