title: Ectopic expression of anti-HIV-1 shRNAs protects CD8(+) T cells modified with CD4ζ CAR from HIV-1 infection and alleviates impairment of cell proliferation.
abstract: Chimeric antigen receptors (CARs) are artificially engineered receptors that confer a desired specificity to immune effector T cells. As an HIV-1-specific CAR, CD4ζ CAR has been extensively tested in vitro as well as in clinical trials. T cells modified with this CAR mediated highly potent anti-HIV-1 activities in vitro and were well-tolerated in vivo, but exerted limited effects on viral load and reservoir size due to poor survival and/or functionality of the transduced cells in patients. We hypothesize that ectopic expression of CD4ζ on CD8(+) T cells renders them susceptible to HIV-1 infection, resulting in poor survival of those cells. To test this possibility, highly purified CD8(+) T cells were genetically modified with a CD4ζ-encoding lentiviral vector and infected with HIV-1. CD8(+) T cells were vulnerable to HIV-1 infection upon expression of CD4ζ as evidenced by elevated levels of p24(Gag) in cells and culture supernatants. Concurrently, the number of CD4ζ-modified CD8(+) T cells was reduced relative to control cells upon HIV-1 infection. To protect these cells from HIV-1 infection, we co-expressed two anti-HIV-1 shRNAs previously developed by our group together with CD4ζ. This combination vector was able to suppress HIV-1 infection without impairing HIV-1-dependent effector activities of CD4ζ. In addition, the number of CD4ζ-modified CD8(+) T cells maintained similar levels to that of the control even under HIV-1 infection. These results suggest that protecting CD4ζ-modified CD8(+) T cells from HIV-1 infection is required for prolonged HIV-1-specific immune surveillance.
authors.affiliation: Division of Hematology-Oncology, David Geffen School of Medicine at UCLA, Los Angeles, CA, USA. Electronic address: masa3k@ucla.edu.
authors.forename: Masakazu
authors.initials: M
authors.lastname: Kamata
authors.affiliation: Department of Microbiology, Immunology, and Molecular Genetics, David Geffen School of Medicine at UCLA, Los Angeles, CA, USA.
authors.forename: Patrick Y
authors.initials: PY
authors.lastname: Kim
authors.affiliation: Division of Infectious Diseases, David Geffen School of Medicine at UCLA, Los Angeles, CA, USA.
authors.forename: Hwee L
authors.initials: HL
authors.lastname: Ng
authors.affiliation: Department of Microbiology, Immunology, and Molecular Genetics, David Geffen School of Medicine at UCLA, Los Angeles, CA, USA.
authors.forename: Gene-Errol E
authors.initials: GE
authors.lastname: Ringpis
authors.affiliation: Department of Microbiology, Immunology, and Molecular Genetics, David Geffen School of Medicine at UCLA, Los Angeles, CA, USA.
authors.forename: Emiko
authors.initials: E
authors.lastname: Kranz
authors.affiliation: Department of Microbiology, Immunology, and Molecular Genetics, David Geffen School of Medicine at UCLA, Los Angeles, CA, USA.
authors.forename: Joshua
authors.initials: J
authors.lastname: Chan
authors.affiliation: Department of Microbiology, Immunology, and Molecular Genetics, David Geffen School of Medicine at UCLA, Los Angeles, CA, USA.
authors.forename: Sean
authors.initials: S
authors.lastname: O'Connor
authors.affiliation: Department of Microbiology, Immunology, and Molecular Genetics, David Geffen School of Medicine at UCLA, Los Angeles, CA, USA; Division of Infectious Diseases, David Geffen School of Medicine at UCLA, Los Angeles, CA, USA; UCLA AIDS Institute, Los Angeles, CA, USA; AIDS Healthcare Foundation, Los Angeles, CA, USA.
authors.forename: Otto O
authors.initials: OO
authors.lastname: Yang
authors.affiliation: Division of Hematology-Oncology, David Geffen School of Medicine at UCLA, Los Angeles, CA, USA; Department of Microbiology, Immunology, and Molecular Genetics, David Geffen School of Medicine at UCLA, Los Angeles, CA, USA; UCLA AIDS Institute, Los Angeles, CA, USA.
authors.forename: Irvin S Y
authors.initials: IS
authors.lastname: Chen
mesh_terms: D015704:CD4 Antigens / Q000235:genetics / Q000276:immunology*; D018414:CD8-Positive T-Lymphocytes / Q000276:immunology* / Q000821:virology*; D060846:Cell Engineering; D049109:Cell Proliferation; D002478:Cells, Cultured; D015870:Gene Expression; D015658:HIV Infections / Q000276:immunology / Q000628:therapy*; D015497:HIV-1 / Q000235:genetics / Q000276:immunology*; D006801:Humans; D007167:Immunotherapy; D034741:RNA, Small Interfering / Q000235:genetics / Q000276:immunology*
chemical_list: D015704:CD4 Antigens; D034741:RNA, Small Interfering
keywords: CD4ζ; Chimeric antigen receptor (CAR); HIV-1; Immunotherapy; shRNA