Scientists Elucidate Relation of Childhood Virus to Type 1 Diabetes

In their research published on March 27 in the journal PLOS Pathogens, scientists from the University of Melbourne in Australia have demonstrated the mechanism in mice by which infection with a common childhood virus may promote the onset of type 1 diabetes.

Rotavirus particles.

In children that are genetically predisposed to type 1 diabetes,  infection with rotavirus (a virus affecting the gastrointestinal system) is associated with increased immune responses to pancreatic islets. Pancreatic islets are parts of the pancreas that contain insulin-secreting cells, and when the body’s immune system mistakenly attacks these cells and prevents them from doing their job, type 1 diabetes ensues. The authors had previously found that infection with rotavirus in mice accelerated the onset of the disease. In the present study, the authors found that immune cells that recognize a piece of the virus called an antigen lead to the activation of B and T immune cells, which are involved in directly fighting infections. The antigen recognized by the immune cells is double-stranded RNA, a type of nucleic acid similar to DNA that is not found in humans in double-stranded form, which allows the immune system to recognize it as non-self. Some of the activated B and T cells may mistakenly be activated to recognize and destroy pancreatic islet immune cells, which causes accelerated diabetes in the mouse model used in this study.

Type 1 diabetes onset is usually seen in children, as it is a mostly genetic disorder and certain members of the population are more susceptible to the disease, depending on their unique genes. Now that the biological details have been elucidated in the relation between rotavirus infection and diabetes in mice, the next step will be to determine whether or not the same steps take place in humans. If this is found to be the case, then the unique mechanisms found in this research may be helpful in the development of possible preventative measures or therapeutics related to the rotavirus infection and its association with type 1 diabetes.

Article: Pane, J., Webster, N., Zufferey, C., & Coulson, B. (2014). Rotavirus Activates Lymphocytes from Non-Obese Diabetic Mice by Triggering Toll-Like Receptor 7 Signaling and Interferon Production in Plasmacytoid Dendritic Cells. PLOS Pathogens, DOI: 10.1371/journal.ppat.1003998

Link: http://www.plospathogens.org/article/info%3Adoi%2F10.1371%2Fjournal.ppat.1003998

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