Targeting Pseudotyped Retroviral Vectors

Abstract

The present invention relates to retroviral vectors, particularly lentiviral vectors, pseudotyped with Sindbis envelope and targeted to specific cell types via a targeting moiety linked to the envelope.

Description

CROSS-REFERENCES TO RELATED APPLICATIONS[0001]This application claims the benefit of U.S. Provisional Patent Application No. 60 / 577,248, filed Jun. 3, 2004, the disclosure of which is hereby incorporated herein by reference in its entirety for all purposes.STATEMENT AS TO RIGHTS TO INVENTIONS MADE UNDER FEDERALLY SPONSORED RESEARCH AND DEVELOPMENT[0002]This invention was made with Government support under Grant Nos. 5R01 DK54912-06 and 5R01AI39975-01, awarded by the National Institutes of Health. The Government has certain rights in this invention.FIELD OF THE INVENTION[0003]The present invention relates to lentiviral vectors pseudotyped with Sindbis envelope and targeted to specific cell types via a targeting moiety linked to the envelope.BACKGROUND OF THE INVENTION[0004]Clinically effective gene therapy protocols for various diseases would ideally utilize procedures for efficient and specific targeting of therapeutic genes to affected cells while maintaining stable transduction an...

AI Technical Summary

Benefits of technology

[0009]In order to further reduce the natural tropism of the Sindbis virus envelope and thereby increase the specificity of targeted gene transduction in vivo, we screened a panel of E2 mutants. We identified several mutants within E2 that reduced the endogenous tropism of E2. We utilized our modified ZZ SINDBIS envelope, designated m168, and a lentiviral reporter vector to target P-glycoprotein (P-gp) expressing melanoma cells in the lungs of a murine model for metastatic melanoma. We demonstrate specific targeting of metastatic tumor cells through direct injection of the vector into the bloodstream.

Problems solved by technology

2, 273-293 (2002)) Although these vectors have been used successfully in vitro, for targeting to specific cells, their usefulness in vivo has been limited by their natural tropism (Muller et al., Nat. Blotechnol. 21, 1040-1046 (2003)), especially to liver cells (Martin et al., Mol. Ther. 8, 485-494 (2003)).

The application of specific targeting with retroviral vectors has been problematic and the few studies of retroviral vector targeting in living animals are not efficient (Martin et al., Mol. Ther. 5, 269-274 (2002); Jiang and Domburg, Gene Ther.

In general, most strategies have suffered from inconsistent specificity and low viral titers as a result of modification of the retroviral envelope (Han et al., Proc Natl.

The modified envelope proteins appear to have specific binding activity but low fusion activity resulting in inefficient entry into cells (Martin et al., J. Virol. 73, 6923-6929 (1999); Zhao et al., Proc Natl.

However, since Sindbis virus vectors are cytotoxic (Tseng et al.

(2003)) and unable to stably transduce their target cells, they cannot be used where stable expression is desired.

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