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 × 107 and 13 × 108 HIV-1-RNA copies/ml were detected at 12 days in the controls (mice injected with Lai and MN, respectively) less than 16.5 × 103 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.
From the aLaboratoires des Déficits Immunitaires et de Rétrovirologie, Faculté de Médecine RTH Laënnec, rue Guillaume Paradin, 69008 Lyon, and Pavillon P, Hôpital E. Herriot, 69437 Lyon, France; bTransgène SA, 11 rue de Molsheim, 67000 Strasbourg, France; cDepartement de Virologie, Groupe Hospitalier Necker-Enfants Malades, 149 rue de Sèvres, 75743 Paris, France; and dLaboratoire de Virologie, Faculté de Médecine Rockefeller, 69008 Lyon, France. +co-first author.
Correspondence and requests for reprints to: Professor Jean-Louis Touraine, Pavillon P, Hôpital E. Herriot, 69437 Lyon 03, France.
Received: 13 March 2000;
revised: 1 September 2000; accepted: 12 September 2000.
Sponsorship: This work was supported by the French SIDACTION (ECS°6) and the French agency for AIDS research (ANRS).