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Published on: September 5, 2016
Engineering Cellular Resistance to HIV-1 Infection In Vivo Using a Dual Therapeutic Lentiviral Vector
Bryan P Burke1, Bernard R Levin2, Jane Zhang1
1Calimmune, Inc., Los Angeles, California, USA.
Abstract:
We described earlier a dual-combination anti-HIV type 1 (HIV-1) lentiviral vector (LVsh5/C46) that downregulates CCR5 expression of transduced cells via RNAi and inhibits HIV-1 fusion via cell surface expression of cell membrane-anchored C46 antiviral peptide. This combinatorial approach has two points of inhibition for R5-tropic HIV-1 and is also active against X4-tropic HIV-1. Here, we utilize the humanized bone marrow, liver, thymus (BLT) mouse model to characterize the in vivo efficacy of LVsh5/C46 (Cal-1) vector to engineer cellular resistance to HIV-1 pathogenesis. Human CD34+ hematopoietic stem/progenitor cells (HSPC) either nonmodified or transduced with LVsh5/C46 vector were transplanted to generate control and treatment groups, respectively. Control and experimental groups displayed similar engraftment and multilineage hematopoietic differentiation that included robust CD4+ T-cell development. Splenocytes isolated from the treatment group were resistant to both R5- and X4-tropic HIV-1 during ex vivo challenge experiments. Treatment group animals challenged with R5-tropic HIV-1 displayed significant protection of CD4+ T-cells and reduced viral load within peripheral blood and lymphoid tissues up to 14 weeks postinfection. Gene-marking and transgene expression were confirmed stable at 26 weeks post-transplantation. These data strongly support the use of LVsh5/C46 lentiviral vector in gene and cell therapeutic applications for inhibition of HIV-1 infection.
Insights
A novel lentiviral vector (LVsh5/C46) engineered cellular resistance to HIV-1 in humanized mice. This dual-action gene therapy protected CD4+ T-cells and reduced viral load, showing promise for HIV-1 inhibition.
Area of Science:
- Gene Therapy
- Virology
- Immunology
Background:
- Human immunodeficiency virus type 1 (HIV-1) remains a global health challenge.
- Existing therapies face challenges with drug resistance and lifelong adherence.
- Novel strategies are needed to engineer cellular resistance to HIV-1 infection.
Purpose of the Study:
- To evaluate the in vivo efficacy of a dual-combination anti-HIV-1 lentiviral vector (LVsh5/C46) in a humanized bone marrow, liver, thymus (BLT) mouse model.
- To assess the vector's ability to confer resistance to both R5- and X4-tropic HIV-1 strains.
- To determine the long-term stability of gene marking and transgene expression.
Main Methods:
- Human CD34+ hematopoietic stem/progenitor cells (HSPC) were transduced with the LVsh5/C46 vector.
- Transduced and non-modified HSPC were transplanted into immunodeficient mice to create control and treatment groups.
- Animals were challenged with R5-tropic HIV-1, and immune cell populations, viral load, and gene expression were monitored.
Main Results:
- Successful engraftment and multilineage hematopoietic differentiation, including CD4+ T-cell development, were observed in both groups.
- Splenocytes from the treatment group exhibited resistance to both R5- and X4-tropic HIV-1 ex vivo.
- Treatment group animals showed significant protection of CD4+ T-cells and reduced viral load up to 14 weeks post-infection.
- Gene marking and transgene expression remained stable at 26 weeks post-transplantation.
Conclusions:
- The LVsh5/C46 lentiviral vector effectively engineers cellular resistance to HIV-1 in vivo.
- This combinatorial gene therapy approach demonstrates significant protection against HIV-1 pathogenesis in a humanized mouse model.
- LVsh5/C46 holds strong potential for gene and cell therapeutic applications aimed at inhibiting HIV-1 infection.
