A Quantitative Comparison of Anti-HIV Gene Therapy Delivered to Hematopoietic Stem Cells versus CD4+T Cells

作者:Savkovic Borislav*; Nichols James; Birkett Donald; Applegate Tanya; Ledger Scott; Symonds Geoff; Murray John M
来源:PLoS Computational Biology, 2014, 10(6): e1003681.
DOI:10.1371/journal.pcbi.1003681

摘要

Gene therapy represents an alternative and promising anti-HIV modality to highly active antiretroviral therapy. It involves the introduction of a protective gene into a cell, thereby conferring protection against HIV. While clinical trials to date have delivered gene therapy to CD4+T cells or to CD34+ hematopoietic stem cells (HSC), the relative benefits of each of these two cellular targets have not been conclusively determined. In the present analysis, we investigated the relative merits of delivering a dual construct (CCR5 entry inhibitor + C46 fusion inhibitor) to either CD4+ T cells or to CD34+ HSC. Using mathematical modelling, we determined the impact of each scenario in terms of total CD4+ T cell counts over a 10 year period, and also in terms of inhibition of CCR5 and CXCR4 tropic virus. Our modelling determined that therapy delivery to CD34+ HSC generally resulted in better outcomes than delivery to CD4+ T cells. An early one-off therapy delivery to CD34+ HSC, assuming that 20% of CD34+ HSC in the bone marrow were gene-modified (G+), resulted in total CD4+ T cell counts %26gt;= 180 cells/ mu L in peripheral blood after 10 years. If the uninfected G+ CD4+ T cells (in addition to exhibiting lower likelihood of becoming productively infected) also exhibited reduced levels of bystander apoptosis (92.5% reduction) over non gene-modified (G-) CD4+ T cells, then total CD4+ T cell counts of %26gt;= 350 cells/ mu L were observed after 10 years, even if initially only 10% of CD34+ HSC in the bone marrow received the protective gene. Taken together our results indicate that: 1.) therapy delivery to CD34+ HSC will result in better outcomes than delivery to CD4+ T cells, and 2.) a greater impact of gene therapy will be observed if G+ CD4+ T cells exhibit reduced levels of bystander apoptosis over G- CD4+ T cells.

  • 出版日期2014-6