Preclinicai studies utilizing different AAV serotypes have demonstrated efficient gene transfer in animal models and stable correction of hemophilia in murine and canine models has been achieved. Early clinical trial data suggest that achievement of therapeutic levels of clotting factors is feasible in human subjects. However, the latter clinical trials have also underscored two major challenges, namely, a large patient cohort displaying pre-existing humoral immunity against AAV capsids and potential hepatotoxiclty associated with administration of high vector dose. The current proposal is focused on designing next generation AAV vectors that display potentia! to evade preexisting anti-capsid neutralizing antibodies (NAbs) and transduce human hepatocytes with high efficiency. To achieve such, we will utilize three complementary AAV capsid engineering techniques and two translational components, namely, a mouse model with humanized fiver and human serum containing anti-AAV capsid NAbs. In synergy with Project 1 of this PPG, we will first establish the hepatotropism of AAV clades with rationally altered antigenic epitopes in humanized mice. In the second and third aims, we will utilize a novel chemical engineering strategy and a combinatorial directed evolution approach, respectively to mask the antigenicity of hepatotropic AAV vectors. The proposed studies should (a) provide structural insight into the antigenicity and hepatotropism of AAV vectors, (b) humanized AAV vectors for preclinical evaluation in large animal models of hemophilia (Projects 3 &4) and (c) optimized vector candidates for clinical trials.
Eariy clinical trial data suggest that gene therapy of bleeding disorders might be feasible in human subjects. The current proposal is focused on tackling clinically relevant challenges, namely preexisting neutralizing antibodies and the need for humanized AAV vectors validated in translational animal models. This project will enable development of new AAV vectors simultaneously capable of enhanced gene transfer to human liver and escaping nrefixistina humoral immunitv in human suhierta '.
|Shen, Shen; Berry, Garrett E; Castellanos Rivera, Ruth M et al. (2015) Functional analysis of the putative integrin recognition motif on adeno-associated virus 9. J Biol Chem 290:1496-504|
|Suwanmanee, Thipparat; Hu, Genlin; Gui, Tong et al. (2014) Integration-deficient lentiviral vectors expressing codon-optimized R338L human FIX restore normal hemostasis in Hemophilia B mice. Mol Ther 22:567-74|
|Lau, A G; Sun, J; Hannah, W B et al. (2014) Joint bleeding in factor VIII deficient mice causes an acute loss of trabecular bone and calcification of joint soft tissues which is prevented with aggressive factor replacement. Haemophilia 20:716-22|
|Nicolson, Sarah C; Samulski, R Jude (2014) Recombinant adeno-associated virus utilizes host cell nuclear import machinery to enter the nucleus. J Virol 88:4132-44|
|Hemphill, Daniel D; McIlwraith, C Wayne; Samulski, R Jude et al. (2014) Adeno-associated viral vectors show serotype specific transduction of equine joint tissue explants and cultured monolayers. Sci Rep 4:5861|
|Mitchell, Angela M; Hirsch, Matthew L; Li, Chengwen et al. (2014) Promyelocytic leukemia protein is a cell-intrinsic factor inhibiting parvovirus DNA replication. J Virol 88:925-36|
|Shen, Shen; Horowitz, Eric D; Troupes, Andrew N et al. (2013) Engraftment of a galactose receptor footprint onto adeno-associated viral capsids improves transduction efficiency. J Biol Chem 288:28814-23|
|Gurda, Brittney L; DiMattia, Michael A; Miller, Edward B et al. (2013) Capsid antibodies to different adeno-associated virus serotypes bind common regions. J Virol 87:9111-24|
|Asokan, Aravind; Samulski, R Jude (2013) An emerging adeno-associated viral vector pipeline for cardiac gene therapy. Hum Gene Ther 24:906-13|
|Monahan, Paul E; Gui, Tong (2013) Gene therapy for hemophilia: advancing beyond the first clinical success. Curr Opin Hematol 20:410-6|