PR01 Molecular Pathogenesis of Rickettsioses and Development of Anti- Rickettsial Treatment by Combinatorial Peptide-Based Libraries

摘要

The purpose of this study is to utilize adaptein libraries coded within pantropic retroviral vectors that confer protection against rickettsial pathogens and to study the molecular pathogenesis of rickettsioses. The following specific aims were proposed: (1) To establish heterogeneous cell populations, with each cell expressing a unique member of a complex combinatorial peptide-based (e.g., adaptein) library and challenge with R. prowazekii, R. rickettsii, and O. tsutsugamushi; (2) To determine the role of NF- kB, cytokines, ROS and NO in intracellular killing of rickettsia-infected monolayers containing adapteins and (3) To characterize signal transduction pathways modulating the cytoskeletal events responsible for the increased vascular permeability. During the fourth year of the project, rickettsial challenges performed with SV-HCEC cells were continued and expansion of the resistant colonies was not possible. We are currently conducting experiments with a murine and a human monocytic cell line that grow in suspension. Both cell lines have been infected with pantropic retroviruses and challenging experiments are underway. Experiments with SVHCEC cells have elucidated the role of rickettsiae and cytokines in modulating permeability across infected monolayers. Confocal microscopy studies also suggest that these changes might in part be due to changes in p120 distribution in adherens junctions. The role of nitric oxide and its derivative peroxinitrite in increased permeability across infected monolayers has also been elucidated.