DEVELOPING AND TESTING IN VIVO MODELS TO EXAMINE THE EFFECT OF INFLAMMATION AND BARRIER FUNCTION IN THE FEMALE GENITAL TRACT IN THE CONTEXT OF SEXUALLY TRANSMITTED VIRUSES

Abstract

A number of factors including epithelial barrier function, mucosal inflammation and HSV-2 infection are known to affect the early events of HIV transmission and pathogenesis in the female genital tract (FGT). We previously demonstrated that curcumin, a highly pleiotropic anti-inflammatory natural compound, can inhibit cytokine and chemokine production, epithelial barrier disruption and HSV-2 replication in vitro. Thus, the goal of the present study was to investigate the in vitro to in vivo translatability of the aforementioned study and the ability of curcumin to prevent mucosal inflammation and HSV-2 replication in a mouse model. The second objective of this study was to further our understanding of the genital epithelial barrier in vivo and develop an assay system that would allow for the experimental determination of in vivo genital barrier function. The work summarized in this thesis has furthered our understanding of the genital microenvironment and its relevance to HIV infection. Our results show that while crude curcumin decreased HSV-2 infection, it was most likely due to a physical barrier effect. Further examination with curcumin nanoformulations demonstrated that it was able to potently decrease TLR-induced inflammation in the FGT, particularly with direct application to the genital tissue, but not HSV-2 infection. We also established a simple, reliable and reproducible method to functionally assess changes in genital barrier function by measuring concentrations of dye in the blood following vaginal delivery. Using this system, we have demonstrated that Depo-Provera, a widely used progestin-based hormonal contraceptive that has been linked to HIV risk, severely reduces genital barrier function in vivo. This work emphasizes that inflammation and barrier function are critical avenues that should be explored in the development of more effective prevention and treatment strategies for HIV infection. Understanding causes of inflammation and barrier breakdown will also prove valuable in guiding the use of safer hormonal contraceptives and vaginal healthcare products in high risk women.