DOI
https://doi.org/10.25772/A7Y4-3J80
Author ORCID Identifier
orcid.org/0000-0001-7208-7692
Defense Date
2017
Document Type
Thesis
Degree Name
Master of Science
Department
Microbiology & Immunology
First Advisor
Francine Marciano-Cabral
Second Advisor
Melissa Jamerson
Third Advisor
Kimberly Jefferson
Abstract
Naegleria fowleri is a free-living amoeba found in freshwater lakes and ponds that is the causative agent of Primary Amoebic Meningoencephalitis (PAM). Matrix metalloproteinases (MMPs) have been described in protozoa, such as Plasmodium falciparum, Trypanosoma brucei, and Balamuthia mandrillaris, and have been linked to their increased motility and invasive capability by degrading components of the extracellular matrix (ECM). In addition, MMPs are often upregulated in tumorigenic cells and have been attributed as responsible for the metastasis of certain cancers. In the present study, in vitro experiments indicated that MMPs are linked functionally to the ECM degradation process. Gelatin zymography demonstrated protease activity in N. fowleri whole cell lysates, conditioned media, and media collected from in vitro invasion assays. Western immunoblotting confirmed the presence of the metalloproteinases MMP-2, -9, and -14. The highly virulent mouse-passaged amoebae expressed higher levels of MMPs than the weakly virulent axenically grown amoebae. The functional relevance of MMPs found in media in degradation of ECM components was confirmed through the use of MMP inhibitors. The collective in vitro results suggest that MMPs may play a critical role in the invasion of the CNS. Furthermore, the expression of select metalloproteinases may serve as amenable targets for therapeutic manipulation of expansive PAM.
Rights
© The Author
Is Part Of
VCU University Archives
Is Part Of
VCU Theses and Dissertations
Date of Submission
7-18-2017