Browsing by Author "Judd, Justin"

Now showing 1 - 4 of 4
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    Encryption of Adeno-Associated Virus for Protease-Controlled Gene Therapy
    (2013-09-16) Judd, Justin; Suh, Junghae; Silberg, Jonathan J.; Segatori, Laura
    Gene therapy holds the unprecedented potential to treat disease by manipulating the underlying genetic blueprints of phenotypic behavior. Targeting of gene delivery is essential to achieve specificity for the intended tissue, which is especially critical in cancer gene therapy to avoid destruction of healthy tissue. Adeno-associated virus (AAV) is considered the safest viral vector and, compared to non-viral vectors, offers several advantages: higher efficiency, genetic modification, combinatorial panning, and high monodispersity. Classic viral targeting has focused on engineering ligand-receptor interactions, but many cell surface targets do not support post-binding transduction events. Furthermore, many potential target tissues – such as triple negative breast cancer – may not display a single, unique identifying surface receptor, so new methods of targeting are needed. Alternatively, many pathological states, including most cancers, exhibit upregulation of proteolytic enzymes in the extracellular milieu. The present work describes the development of an AAV platform that has been engineered to activate in response to disease-related proteases. The specificity and sensitivity of these protease-activatable viruses (PAVs) can be tuned to meet the demands of various clinical scenarios, giving the platform some therapeutic versatility. This work represents the first demonstration of a protease-controlled, non-enveloped virus for genetic therapy. These results extend the therapeutic value of AAV, the safest gene vector currently being explored in 73 clinical trials worldwide.
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    Encryption of adeno-associated viruses with enzymatically decoded peptide locks
    (2018-08-14) Judd, Justin; Suh, Junghae; Silberg, Jonathan; Rice University; United States Patent and Trademark Office
    The present invention is a peptide lock that comprises at least one peptide that is genetically encoded into the Adeno-associated virus (AAV) capsid that block biologically active domains on the virus capsid surface. The peptide lock, can be processed by biological enzymes to restore biological behavior of the capsid-displayed domains, thus ‘decoding the lock’ or opening the lock. A method of forming the peptide lock comprises providing at least one peptide, providing an Adeno-associated virus capsid and genetically inserting the at least one peptide into the Adeno-associated virus capsid to block the biologically active domains on the virus capsid surface.
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    Random Insertion of mCherry Into VP3 Domain of Adeno- associated Virus Yields Fluorescent Capsids With no Loss of Infectivity
    (American Society of Gene & Cell Therapy, 2012) Judd, Justin; Wei, Fang; Nguyen, Peter Q.; Tartaglia, Lawrence J.; Agbandje-McKenna, Mavis; Silberg, Jonathan J.; Suh, Junghae; Bioengineering; Biosciences
    Adeno-associated virus (AAV)-derived vectors are promising gene delivery systems, and a number of design strategies have been pursued to improve their performance. For example, genetic insertion of proteins into the capsid may be used to achieve vector retargeting, reduced immunogenicity, or to track vector transport. Unfortunately, rational approaches to genetic insertion have experienced limited success due to the unpredictable context-dependent nature of protein folding and the complexity of the capsid's macroassembly. We report the construction and use of a frame-enriched DNase-based random insertion library based on AAV2 cap, called pAAV2_RaPID (Random Peptide Insertion by DNase). The fluorescent mCherry protein was inserted randomly throughout the AAV2 capsid and the library was selected for fluorescent and infectious variants. A capsid site was identified in VP3 that can tolerate the large protein insertion. In contrast to previous efforts to incorporate fluorescent proteins into the AAV2 capsid, the isolated mCherry mutant maintains native infectivity while displaying robust fluorescence. Collectively, these results demonstrate that the pAAV2_RaPID platform library can be used to create fully infectious AAV vectors carrying large functional protein domains on the capsid.
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    Tunable Protease-Activatable Virus Nanonodes
    (American Chemical Society, 2014) Judd, Justin; Ho, Michelle L.; Tiwari, Abhinav; Gomez, Eric J.; Dempsey, Christopher; Vliet, Kim Van; Igoshin, Oleg A.; Silberg, Jonathan J.; Agbandje-McKenna, Mavis; Suh, Junghae; Bioengineering; Biosciences
    We explored the unique signal integration properties of the self-assembling 60-mer protein capsid of adeno-associated virus (AAV), a clinically proven human gene therapy vector, by engineering proteolytic regulation of virusﾖreceptor interactions such that processing of the capsid by proteases is required for infection. We find the transfer function of our engineered protease-activatable viruses (PAVs), relating the degree of proteolysis (input) to PAV activity (output), is highly nonlinear, likely due to increased polyvalency. By exploiting this dynamic polyvalency, in combination with the self-assembly properties of the virus capsid, we show that mosaic PAVs can be constructed that operate under a digital AND gate regime, where two different protease inputs are required for virus activation. These results show viruses can be engineered as signal-integrating nanoscale nodes whose functional properties are regulated by multiple proteolytic signals with easily tunable and predictable response surfaces, a promising development toward advanced control of gene delivery.