Year of Publication

2014

Degree Name

Master of Science in Medical Sciences (MSMS)

Document Type

Master's Thesis

College

Medicine

Department

Microbiology, Immunology, and Molecular Genetics

First Advisor

Dr. Sarah D'Orazio

Abstract

The invasive pathways, InlA- and InB-mediated uptake and M cell transcytosis, that Listeria monocytogenes uses to invade the intestine have mainly been studied using infection models that do not truly replicate what occurs during a natural infection. Recently, our lab has developed an oral infection model that is more physiolocally relevant to what occurs during food borne listeriosis. We have sought to evaluate the relative roles of the previously defined invasive pathways, in our oral model of infection. We have done this by utilizing an InlAmCG Lm strain that is able to bind murine E-cadherin, knockout Lm strains, ΔinlA Lm, and ΔinlAΔinlB Lm. We also took advantage of a knockout mice strain CD137-/-that has M cells that are deficient in M cell transcytosis. We were able to show that these invasive pathways are relevant in our oral infection model, that M cell transcytosis is a compensatory pathway for InlA-mediated uptake, and that there might be another mechanism that L. monocytogenes uses to invade the intestines. To confirm this, it is necessary though that the M cell transcytosis deficiency be confirmed in the CD137-/- mice.