Murine norovirus (MNV) is emerging as a potential pathogen in mice. Initially, the virus appeared to cause morbidity and mortality only in immunocompromised mice while it did not cause any clinical signs of overt diseases in immunocompetent mice. However, we found that MNV infection can induce subtle changes in immune responses even in wild type mice and that the virus alters disease phenotypes in a mouse model of bacterially induced inflammatory bowel disease. Exacerbation of IBD by MNV was partly mediated by effects on dendritic cells. Additionally, we observed that MNV infection alters the production of several inflammatory cytokines in bone marrow derived macrophages. Thus, we suggest that MNV has potential to become a major interfering variable in research studies with rodents. Unfortunately, we do not have sufficient data to determine whether this virus should be eliminated from research facilities. For our proposed studies, we will focus on effects of MNV on mouse studies of IBD as we have significant experience with IBD research and we have evidence that MNV alters IBD development/progression. First, we will determine if and how MNV infection exacerbates IBD in three commonly used models of IBD. Next, we will determine if MNV alters antigen presentation and consequently immune responses to antigens in immunologically normal as well as immunologically deficient mice by altering DCs. Finally, we will determine if MNV alters immune responses by influencing DC and macrophage functions. Proposed studies in this application will fill the gap in current knowledge to determine whether the time and effort should be invested in elimination of MNV from the research facilities. Thus, our application is in line with the objective of current RFA to support investigation of the impact of murine norovirus infection on immune response.

Public Health Relevance

Murine norovirus is prevalent in research facilities across the United States. Our studies will investigate effects of MNV on murine models of IBD and provide information for determining whether the research facilities should be maintained MNV-free to reduce variability in studies of murine models of human diseases.

Agency
National Institute of Health (NIH)
Institute
Office of The Director, National Institutes of Health (OD)
Type
Research Project (R01)
Project #
5R01OD011149-05
Application #
8843059
Study Section
Special Emphasis Panel (ZRR1)
Program Officer
Moro, Manuel H
Project Start
2011-08-05
Project End
2017-04-30
Budget Start
2015-05-01
Budget End
2017-04-30
Support Year
5
Fiscal Year
2015
Total Cost
Indirect Cost
Name
University of Washington
Department
Veterinary Sciences
Type
Schools of Medicine
DUNS #
605799469
City
Seattle
State
WA
Country
United States
Zip Code
98195
Hsu, Charlie C; Meeker, Stacey M; Escobar, Sabine et al. (2018) Murine norovirus inhibits B cell development in the bone marrow of STAT1-deficient mice. Virology 515:123-133
Seamons, Audrey; Treuting, Piper M; Meeker, Stacey et al. (2018) Obstructive Lymphangitis Precedes Colitis in Murine Norovirus-Infected Stat1-Deficient Mice. Am J Pathol 188:1536-1554
Hsu, C C; Piotrowski, S L; Meeker, S M et al. (2016) Histologic Lesions Induced by Murine Norovirus Infection in Laboratory Mice. Vet Pathol 53:754-63
Hsu, Charlie C; Paik, Jisun; Treuting, Piper M et al. (2014) Infection with murine norovirus 4 does not alter Helicobacter-induced inflammatory bowel disease in Il10(-/-) mice. Comp Med 64:256-63