Microbiome methods in experimental autoimmune encephalomyelitis.

Abstract

Abstract Multiple Sclerosis (MS) is an autoimmune disease that affects the central nervous system (CNS) via neuroinflammation and demyelination. The exact triggers, subsets and effector mechanisms that contribute to disease progression are still largely unknown. Recent studies of healthy vs MS human stool samples indicated an altered microbiome, dysbiosis, which could lead to inflammation and disease. Experimental autoimmune encephalomyelitis (EAE) is a model used for the study of MS and can be induced in multiple non-rodent and rodent species. It is critical to control the environment of both the animal facility and experimental housing conditions in microbiome studies. We compared commercial vendors, Envigo and Jackson Laboratory, C57BL/6 female mice. Fecal samples were collected at Day 0, 14, and 21 for DNA extraction and sequencing of the ribosomal DNA (rDNA) to analyze the gut microbiome composition prior to and after induction of EAE. There was a significant difference between sources with Jackson Laboratory mice having an increased severity index compared to Envigo mice (p < 0.01) and a decreased survival rate of 20% when compared to 85% for Envigo mice. Our results suggest different sources of EAE mouse models have critical impacts on microbiome composition and levels of disease severity. Furthermore, this highlights the importance of consistent and controlled conditions from the animal model source, and throughout the experiment, when inducing EAE in mice and other animal models of disease. This project was sponsored by NIH grant R15 NS107743.