Genomic differences between the diabetogenic and nondiabetogenic variants of encephalomyocarditis virus

Echovirus Epidemics, Autoimmunity, and Type 1 Diabetes

“…Note that EMC virus belongs to the picornavirus family and is classified as an animal cardiovirus. Interestingly, the two variants were antigenically indistinguishable but genome sequence analysis revealed 14 nucleotide differences between them (Bae et al, 1989). In a subsequent study, the analysis of several mutant viruses generated from the EMC-B and EMC-D variants, revealed that just one amino acid at position 776 (alanine) was responsible of the diabetogenic effects (Bae & Yoon, 1993).…”

A genetically determined host factor controlling susceptibility to encephalomyocarditis virus-induced diabetes in mice

“…Two hours after adsorption, the medium was removed and replaced with MEM without methionine but containing 5 % dialysed fetal bovine serum (FBS) and 20 gCi per ml of [3~S]methionine. Sixteen hours later, the labelled virus was harvested and purified as described previously (Bae et al, 1989;Eun et al, 1988;Yoon et al, 1988 ;Bae et al, 1990). Before applying the collagenase digestion method for the preparation of pancreatic beta cells, we tested to see whether the collagenase treatment itself would result in a decrease in viral attachment to cells by the loss or modification of cell receptors (McClintock et al, 1983).…”

“…As the first step in virus infection is binding of virus to cells, we attempted to determine the attachment rate of virus to freshly isolated beta cells, which are similar to beta cells in vivo. We previously established a method for isolating beta cells from mice by collagenase treatment (Yoon et al, 1984;Yoon & Notkins, 1976) and for labelling and purifying EMC virus (Bae et al, 1989;Eun et al, 1988;Yoon et al, 1988). Briefly, monolayers of L929 cells were adsorbed with EMC-D virus at an m.o.i, of 10.…”

“…Briefly, a portion of EMC-D viral cDNA (VPI-cDNA) (Bae et al, 1989;Eun et al, 1988) and rat pre-proinsulin cDNA (Cordell et al, 1979) without the poly(A) tail were radiolabelled with [3~P]dCTP by the oligonucleotide-primed synthesis method (Ausubel et al, 1987) and used for probing EMC-D viral RNA and insulin mRNA, respectively. Tail parts of pancreata were removed from SJL/J and C57BL/6J male mice (five mice per group) at 0, 12, 24, 48, 72 and 96 h after injection with EMC-D virus (3 × 10 ~ p.f.u./mouse).…”

“…Viruses were purified by sucrose and CsC1 gradient centrifugation from the supernatant of L929 cell cultures infected with plaque-purified EMC-D virus (Bae et al, 1989;Yoon et al, 1988). The diabetogenic activities of purified EMC-D virus were checked by injecting 30 SJL/J and 30 C57BL/6J male mice (The Jackson Laboratory) with EMC-D (3 × 105 p.f.u./mouse) (Yoon et al, 1980).…”