ABSTRACT
OBJECTIVE: To study the anti-HIV-1 effects of the delivery of anti-gp41 monoclonal antibody (mAb) and soluble CD4 (sCD4) immunoadhesin by genetically modified cells in HIV-1-infected, humanized severe combined immunodeficient (SCID) mice. DESIGN: The complementary DNA of mAb 2F5, an anti-HIV-1 gp41 antibody, and of sCD4-IgG chimeric immunoadhesin were transferred into 3T3 cells using Moloney murine leukaemia virus vectors. The cells were then incorporated into a collagen structure called the neo-organ, which allowed the continuous production of the therapeutic molecules. METHODS: The antiviral effects in vivo of 2F5 or sCD4-IgG or both compounds were evaluated in neo-organ-implanted SCID mice that were grafted with human CD4 CEM T cells and challenged with HIV-1 Lai or MN. RESULTS: In SCID mice implanted with 2F5 neo-organs, antibody plasma levels reached 500-2000 ng/ml. Viral loads after HIV-1 challenge were significantly reduced in neo-organ-implanted HIV-infected mice. Although 29 x 10(7) and 13 x 10(8) HIV-1-RNA copies/ml were detected at 12 days in the controls (mice injected with Lai and MN, respectively) less than 16.5 x 10(3) HIV-1-RNA copies/ml were observed in all implanted mice injected with either Lai or MN. The intracellular viral load was also reduced in CD4 cells recovered from the implanted mice. Comparable antiviral effects were obtained with CD4-IgG neo-organs. CONCLUSION: Our results confirm the anti-HIV properties of 2F5 and sCD4-IgG continuously produced in vivo after ex-vivo gene therapy in SCID mice.
Subject(s)
CD4 Immunoadhesins/therapeutic use , Genetic Therapy , HIV Antibodies/therapeutic use , HIV Envelope Protein gp41/immunology , HIV Infections/therapy , 3T3 Cells/transplantation , Animals , Antibodies, Monoclonal/genetics , Antibodies, Monoclonal/immunology , Antibodies, Monoclonal/therapeutic use , CD4 Immunoadhesins/genetics , DNA, Viral/analysis , Disease Models, Animal , HIV Antibodies/genetics , HIV Antibodies/immunology , HIV Infections/virology , HIV-1/pathogenicity , HIV-1/physiology , Humans , Mice , Mice, SCID , Transduction, Genetic , Viral LoadABSTRACT
OBJECTIVES: To evaluate in vitro and in vivo a strategy for gene therapy for AIDS based on the transfer on interferon (IFN)-alpha, -beta and -gamma genes to human cells. DESIGN: Human U937 promonocytic cells were stably transfected with Tat-inducible IFN expression vectors conferring an antiviral state against infection with HIV. METHODS: Transfected cells were either infected by HIV-1 in vitro or transplanted into severe combined immunodeficient (SCID) mice for an HIV challenge in vivo. RESULTS: U937 cell lines stably carrying IFN transgenes under the positive control of the HIV-1 Tat protein were highly resistant to HIV-1 replication in vitro. This antiviral resistance was associated with a strong induction of IFN synthesis immediately following the viral infection. HIV-1 proteins were found to be specifically trapped within the genetically modified cells. In contrast, all IFN-U937 cells permitted full HIV-2 replication. Transfected cells injected into SCID mice and challenged against HIV-1 were strongly resistant to infection when cells were transduced with IFN-alpha of IFN-beta genes. However, IFN-gamma-transfected cells permitted HIV-1 infection in vivo despite the induction of a high level of IFN-gamma secretion. The quantity of proviral DNA was 10(5)-fold lower in IFN-alpha- or IFN-beta-transfected U937 cells collected from these SCID mice than that in non-transfected cells. CONCLUSIONS: Our results substantiated the validity of a strategy, bases on the transfer of HIV-1-inducible IFN-alpha or IFN-beta genes, to confer antiviral resistance to human cells.
Subject(s)
Acquired Immunodeficiency Syndrome/therapy , Gene Products, tat/physiology , Genetic Therapy , HIV-1/physiology , Interferon-alpha/genetics , Interferon-beta/genetics , Interferon-gamma/genetics , Animals , Cell Transplantation , Disease Models, Animal , Humans , Interferon-alpha/biosynthesis , Interferon-alpha/immunology , Interferon-beta/biosynthesis , Interferon-beta/immunology , Interferon-gamma/biosynthesis , Interferon-gamma/immunology , Mice , Mice, SCID , Tumor Cells, Cultured , tat Gene Products, Human Immunodeficiency VirusABSTRACT
A decrease in natural killer (NK) cell activity is a common feature of the immune dysfunction found in patients with human immunodeficiency virus (HIV)-induced acquired immune deficiency syndrome (AIDS). The present study was aimed at exploring the NK and the lymphokine-activated killer (LAK) cell activities of lymphocytes from HIV-seropositive subjects. The in vitro production of interleukins (IL-2 and IL-10) in response to mitogens was also studied. Two groups of HIV-seropositive subjects were studied: asymptomatic and AIDS patients. Controls were normal blood donors. The NK cell activity in peripheral blood mononuclear cells (PBMC) from AIDS patients was significantly lower than that in PBMC from both HIV-seronegative subjects and asymptomatic patients. There was no significant difference between asymptomatic patients and controls. Exposure of PBMC from all three groups of individuals to an optimal dose of IL-2 in vitro enhanced LAK cell activity. At all three effector: target cell ratios, the LAK activity in AIDS patients remained below that in normal subjects. However, the proportional increase of lytic activity with IL-2 was slightly higher in AIDS patients than in HIV-seronegative subjects. The mitogen-induced production of IL-2 was especially reduced in AIDS patients. In contrast, very high levels of mitogen-induced production of IL-10 were found in the AIDS group, as compared to asymptomatic subjects or to controls. We therefore conclude that the alteration of NK cell activity occurs at an advanced stage of HIV infection, that the reduction of cytotoxic activity is partially restored by exogenous IL-2, and that decreased production of IL-2 and increased production of IL-10 may account for part of this reduction in cytotoxicity.
