Viral Infection Associated With Autoimmune Diabetes in Rats
Study links rat CMV to diabetes; simultaneous and sequential inoculation of viruses affects outcome
MONDAY, Jan. 11 (HealthDay News) -- Certain viruses -- including Kilham rat virus (KRV) and rat cytomegalovirus (RCMV) -- are associated with autoimmune diabetes in rats, according to research published in the January issue of Diabetes.
Rebecca S. Tirabassi, Ph.D., of BioMedical Research Models in Worcester, Mass., and colleagues analyzed data from LEW.1WR1 rats, about 2 percent of which spontaneously develop autoimmune disease.
The researchers found that inoculations of KRV and RCMV were associated with diabetes in up to 60 percent of rats. H-1 parvovirus did not induce diabetes however, nor did Coxsackie B4. Simultaneously inoculating groups of rats with KRV and RCMV led to diabetes in 50 to 100 percent of animals, and sequential inoculation with RCMV followed by KRV days later increased diabetes penetrance to 90 percent. Treating rats with poly I:C, an activator of innate immunity, before KRV inoculation led to diabetes in 100 percent and increased the penetrance of diabetes after vaccinia or Coxsackie B4 inoculation.
"The data document that viral diabetogenicity is a complex phenotype with epidemiological characteristics that may help explain why it has been difficult to prove a role for infection in human diabetes pathogenesis and identify the relevant mechanisms," the authors write. "In keeping with previous analyses of both rodents and humans, the connection between infections and autoimmunity is multifaceted and complex."