University of Louisville
Development of a Next-Generation Topical Pre-Exposure Prophylactic (PrEP) Technology Using SiRNA-Encapsulated, Surface-Modified Nanoparticles
Institution
University of Louisville
Faculty Advisor/ Mentor
Jill M. Steinbach
Abstract
Despite recent advances in our understanding of human immunodeficiency virus (HIV), HIV continues to spread at an alarming rate, with 2 million people newly infected in 2014. To manage this HIV pandemic, topical PrEP technologies − defined as active agents that prevent infection by inactivating or neutralizing pathogens − are being developed as vaccine alternatives. Current PrEP technologies are challenged with the safe delivery of active agents, specifically biologicals, for prolonged durations in the unique microenvironment of the female reproductive tract (FRT). Toward this challenge, our long-term goal is to develop short interfering RNA (siRNA) poly(lactic-co-glycolic acid) (PLGA) nanoparticles (NPs) to provide prolonged protection against HIV via multiple stages of infection. We hypothesize that delivery of siRNA NPs will inhibit the expression of the HIV-1 host cell receptor, C-C chemokine receptor type 5 (CCR5), and prevent one of the initial stages of virus infection, cell entry. Furthermore, we hypothesize that surface modifying siCCR5 NPs with Griffithsin (GRFT), a potent antiviral lectin that binds to and inactivates HIV; or MPG, a cell penetrating peptide (CPP) to enable enhanced uptake of siRNA-encapsulated NPs, will confer more temporally efficacious protection against HIV infection. The experiments conducted thus far aim to characterize and determine the efficacy of surface-modified siCCR5 PLGA NPs to achieve CCR5 knockdown (KD) and corresponding HIV inhibition in vitro. Preliminary data demonstrated that unmodified siCCR5 NPs achieved the highest CCR5 KD among the three surface modifications (37%) while CCR5 expression in cells treated with MPG siCCR5 NPs exhibited significantly lower expression (roughly 2-fold less). GRFT-modified NPs showed negligible CCR5 KD. We are currently optimizing dosage to provide more efficacious KD.
Development of a Next-Generation Topical Pre-Exposure Prophylactic (PrEP) Technology Using SiRNA-Encapsulated, Surface-Modified Nanoparticles
Despite recent advances in our understanding of human immunodeficiency virus (HIV), HIV continues to spread at an alarming rate, with 2 million people newly infected in 2014. To manage this HIV pandemic, topical PrEP technologies − defined as active agents that prevent infection by inactivating or neutralizing pathogens − are being developed as vaccine alternatives. Current PrEP technologies are challenged with the safe delivery of active agents, specifically biologicals, for prolonged durations in the unique microenvironment of the female reproductive tract (FRT). Toward this challenge, our long-term goal is to develop short interfering RNA (siRNA) poly(lactic-co-glycolic acid) (PLGA) nanoparticles (NPs) to provide prolonged protection against HIV via multiple stages of infection. We hypothesize that delivery of siRNA NPs will inhibit the expression of the HIV-1 host cell receptor, C-C chemokine receptor type 5 (CCR5), and prevent one of the initial stages of virus infection, cell entry. Furthermore, we hypothesize that surface modifying siCCR5 NPs with Griffithsin (GRFT), a potent antiviral lectin that binds to and inactivates HIV; or MPG, a cell penetrating peptide (CPP) to enable enhanced uptake of siRNA-encapsulated NPs, will confer more temporally efficacious protection against HIV infection. The experiments conducted thus far aim to characterize and determine the efficacy of surface-modified siCCR5 PLGA NPs to achieve CCR5 knockdown (KD) and corresponding HIV inhibition in vitro. Preliminary data demonstrated that unmodified siCCR5 NPs achieved the highest CCR5 KD among the three surface modifications (37%) while CCR5 expression in cells treated with MPG siCCR5 NPs exhibited significantly lower expression (roughly 2-fold less). GRFT-modified NPs showed negligible CCR5 KD. We are currently optimizing dosage to provide more efficacious KD.