This project seeks imidazole-pyrrole polyamides to be used as topical antiviral agents for the treatment of human papillomavirus (HPV). HPV, especially in its sexually-transmitted forms, presents a major public health problem throughout the world. Current treatments, which include surgery, freezing, noxious agents, and =biological response modifiers,"""""""" are primitive or non-specific. One reason for the lack of treatment alternatives is the small size of the viral genome, and the corresponding lack of antivirai targets. For this reason, the alternative approach of targeting HPV DNA using sequence-specific DNA binding agents is being taken. The HPV origin of replication (on) contains binding sites for the viral-encoded replication proteins E1 and E2, which are required for viral replication and maintenance. Targeting the or/with sequence-specific DNA binding agents has the potential to block the action of E1 and E2, thereby disrupting processes required for maintenance in cells. Preliminary work with HPV31 has shown significant promise, lmidazole-pyrrole polyamides, designed to target the HPV31 E1 binding site, were found to potently reduce HPV31 episomal DNA levels in cells. We now request supped for the design, synthesis, and testing of compounds that target the commercially important HPV16 genotype. Similar to our preliminary studies with HPV31, we hypothesize that several compounds with antiviral activity will be found among a library of imidazole-pyrrole polyamides targeting the HPV16 E1 binding site. This Phase I study will establish a keratinocyte culture system that supports HPV16 episomal maintenance. Polyamides will be synthesized that target the HPV16 origin of replication (on), and tested for their ability to suppress episomal DNA levels. To meet these objectives, the following specific aims were identified:
Aim 1 : The viral origin or replication (ori) will be targeted via synthesis of a series of polyamides recognizing the specific sequence of the canonical E1 binding site associated with HPV16.
Aim 2 : The effects of polyamides on HPV16 replication and maintenance will be tested in cell culture.
Aim 3 : Positive results showing a decrease in HPV16 DNA levels will be further characterized, and conditions will be established for maximum antiviral effects in cell culture. Successful completion of these studies offers the promise of successful antiviral treatments for HPV. These studies are important because they provide an alternative to the vaccine approaches to HPV therapy. Such approaches have come to dominate the pharmaceutical industry, while offedng no hope to those people currently infected with the virus. In addition, these studies may identifyvaluable research tools for use in understanding important aspects of the HPV life cycle. Phase II studies will test the efficacy of active compounds in complex cell culture models (raft cultures) and animal models of HPV-related disease. In addition, bioavailability studies will focus on developing optimal topical treatment formulations and upon measuring systemic exposure following topical treatments. These studies will be required to guide toxicological studies prior to testing in humans. Ultimately, the project seeks to use polyamides targeting the most prevalent cancer causing virus (HPV16) as topical agents in a clinical setting.
