Enteroviruses, type 1 diabetes and hygiene: a complex relationship

Authors

  • S. Tracy,

    Corresponding author
    1. Department of Pathology and Microbiology, University of Nebraska Medical Center, 986495 Nebraska Medical Center, Omaha NE 68198-6495, USA
    • Department of Pathology and Microbiology, University of Nebraska Medical Center, 986495 Nebraska Medical Center, Omaha NE 68198-6495, USA.
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  • K. M. Drescher,

    1. Department of Medical Microbiology and Immunology, Creighton University School of Medicine, 2500 California Plaza, Omaha NE 68178, USA
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  • J. D. Jackson,

    1. Department of Pathology and Microbiology, University of Nebraska Medical Center, 986495 Nebraska Medical Center, Omaha NE 68198-6495, USA
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  • K. Kim,

    1. Department of Pathology and Microbiology, University of Nebraska Medical Center, 986495 Nebraska Medical Center, Omaha NE 68198-6495, USA
    2. Department of Influenza and Respiratory Viruses, Center for Infectious Diseases, National Institute of Health, KCDC, Seoul 122-701, Korea
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  • K. Kono

    1. Department of Pathology and Microbiology, University of Nebraska Medical Center, 986495 Nebraska Medical Center, Omaha NE 68198-6495, USA
    2. The Eppley Institute, University of Nebraska Medical Center, Omaha NE 68198-7696, USA
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Abstract

Type 1 diabetes (T1D) is an autoimmune disease in which the immune system mounts an attack on the host's insulin-producing β cells. Because most cases of T1D cannot be attributed only to individual genetics, it is strongly inferred that there is a significant environmental contribution, such as infection, impacting disease development. The human enteroviruses (HEV) are common picornaviruses often implicated as triggers of human T1D, although precisely which of the numerous HEV may be involved in human T1D development is unknown. Experiments using non-obese diabetic (NOD) mice, commonly used to model T1D, show that induction of T1D by HEV infection in NOD mice is a multifactorial process involving both the virus and the host. Interestingly, results demonstrate that HEV infection of NOD mice can also induce long-term protection from T1D under certain conditions, suggesting that a similar mechanism may occur in humans. Based upon both experimental animal and observational human studies, we postulate that HEV have a dual role in T1D development and can either cause or prevent autoimmune disease. Whichever outcome occurs depends upon multiple variables in the host-virus equation, many of which can be deduced from results obtained from NOD mouse studies. We propose that the background to the sharply rising T1D incidences observed in the 20th century correlates with increased levels of hygiene in human societies. Viewing T1D in this perspective suggests that potential preventative options could be developed. Copyright © 2009 John Wiley & Sons, Ltd.

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