title: Engineering human hematopoietic stem/progenitor cells to produce a broadly neutralizing anti-HIV antibody after in vitro maturation to human B lymphocytes.
abstract: Broadly neutralizing anti-HIV antibodies are rare and have proved hard to elicit with any immunogen. We have tested in vitro the notion that such antibodies or other antiviral proteins could be made by lentivirus-mediated gene transfer into human hematopoietic stem/progenitor cells (HSPCs), followed by differentiation of the transduced cells into B cells, the most potent antibody-producing cells. To do this, we have developed a highly efficient system for in vitro maturation of secreting B lymphocytes and plasma cells from CD34(+) HSPCs. It is a 3-stage, in vitro culture system that supports normal human B-lineage development from HSPCs to antibody-secreting plasmablasts (approximately 36%) and plasma cells (approximately 20%). By transducing human cord blood CD34(+) cells with lentiviral vectors encoding a secretory monoclonal anti-HIV antibody, b12 (IgG(1)), we were able to program human B cells to produce in vitro up to 1.5 microg/mL of this broadly neutralizing antibody. Our results suggest that an HIV vaccine might be delivered by autologous transplantation of in vitro-programmed HSPCs, which would develop into antibody-secreting B cells in vivo and provide a continuous supply of anti-HIV neutralizing antibodies.
authors.affiliation: Division of Biology, California Institute of Technology, Pasadena, CA 91125, USA.
authors.forename: Xin M
authors.initials: XM
authors.lastname: Luo
authors.forename: Emily
authors.initials: E
authors.lastname: Maarschalk
authors.forename: Ryan M
authors.initials: RM
authors.lastname: O'Connell
authors.forename: Pin
authors.initials: P
authors.lastname: Wang
authors.forename: Lili
authors.initials: L
authors.lastname: Yang
authors.forename: David
authors.initials: D
authors.lastname: Baltimore
mesh_terms: D016915:AIDS Vaccines / Q000235:genetics / Q000276:immunology* / Q000378:metabolism; D001402:B-Lymphocytes / Q000166:cytology* / Q000276:immunology* / Q000378:metabolism; D018929:Cell Culture Techniques; D002454:Cell Differentiation / Q000276:immunology; D019070:Cell Lineage / Q000276:immunology; D002478:Cells, Cultured; D015316:Genetic Therapy / Q000379:methods*; D015483:HIV Antibodies / Q000235:genetics / Q000276:immunology / Q000378:metabolism; D015658:HIV Infections / Q000276:immunology / Q000628:therapy*; D015497:HIV-1 / Q000276:immunology*; D006412:Hematopoietic Stem Cells / Q000166:cytology*; D006801:Humans; D007074:Immunoglobulin G / Q000276:immunology / Q000378:metabolism; D016086:Lentivirus / Q000235:genetics; D009500:Neutralization Tests; D010950:Plasma Cells / Q000166:cytology / Q000276:immunology / Q000378:metabolism; D017154:Stromal Cells / Q000166:cytology; D014161:Transduction, Genetic
chemical_list: D016915:AIDS Vaccines; D015483:HIV Antibodies; D007074:Immunoglobulin G