Luo Xin M, Maarschalk Emily, O'Connell Ryan M, Wang Pin, Yang Lili, Baltimore David
Division of Biology, California Institute of Technology, Pasadena, CA 91125, USA.
Blood. 2009 Feb 12;113(7):1422-31. doi: 10.1182/blood-2008-09-177139. Epub 2008 Dec 4.
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.
具有广泛中和作用的抗HIV抗体十分罕见，并且事实证明，很难用任何免疫原诱导产生这类抗体。我们已经在体外测试了这样一种理念，即可以通过慢病毒介导的基因转移，将这类抗体或其他抗病毒蛋白导入人造血干细胞/祖细胞（HSPCs），然后将转导后的细胞分化为B细胞（最强的抗体产生细胞）。为此，我们开发了一种高效系统，用于将CD34(+) HSPCs体外成熟为分泌性B淋巴细胞和浆细胞。这是一个三阶段的体外培养系统，支持从HSPCs到分泌抗体的成浆细胞（约36%）和浆细胞（约20%）的正常人类B系发育。通过用编码分泌性单克隆抗HIV抗体b12（IgG(1)）的慢病毒载体转导人脐带血CD34(+)细胞，我们能够使人类B细胞在体外产生高达1.5微克/毫升的这种具有广泛中和作用的抗体。我们的结果表明，HIV疫苗或许可以通过体外编程的HSPCs自体移植来递送，这些HSPCs在体内会发育为分泌抗体的B细胞，并持续提供抗HIV中和抗体。
