This Project will study the efficacy of two novel carrageenan-based formulations, zinc- carrageenan (Zn-carrageenan) and lignosulfonic acid (LSA) carrageenan (LSA-carrageenan). Preliminary results indicate that these formulations are significantly more efficacious than carrageenan in blocking HIV in vitro and herpes simplex-2 (HSV -2) infection in mice. Since there is no known assay that is predictive of a microbicide's efficacy, the applicant proposes to utilize a number of different in vitro assays and animal systems. In vitro assays will involve a peripheral blood mononuclear cells (PBMC) assay and another assay that employs an established epithelial cell line derived from the human cervix. Because there is a variety of different HIV strains that are sexually transmitted, as well as the fact that the viral genome is constantly changing, the formulations will be assayed for activity against a number of different strains and clades of HIV. Additionally, formulations will be evaluated in a number of animal systems. The HSV-2/mouse system has proven to be a straightforward and consistently reproducible method for evaluating several parameters. Formulations will be evaluated in this system for vaginal and rectal anti-viral activity, duration of activity, and efficacy in protecting against pre- and post-viral challenge. Another system, developed by the PL, has shown that lymphocytes and macrophages can traffic from the vaginal vault and subsequently be detected in lymph nodes and spleen. This finding supports the concept that HIV -infected mononuclear cells in semen may infect women by study by Masurier et al. (J. Virol. 1998:72:7822-7829), which presented evidence that when active or inactivated virus is instilled into the vagina of a mouse, it can subsequently be detected by RT -PCR in the lymph nodes. The applicant will utilize his modified HIV/Mouse system and the Cell Trafficking system to compare Zn-carrageenan, LSA-carrageenan, and the carrageenan-only formulation, Carraguard for efficacy in preventing HIV transport and cell trafficking from the vaginal vault. The applicant feels that the proposed in vitro assays and animal systems in conjunction with the proposed research of our co-investigators is the most well rounded approach to the pre-clinical development of novel microbicide against HIV.
