Expression of Plus- and Minus-strand Viral RNA in Coxsackievirus B3-Infected A/J Mice

In order to investigate the implication of viral replication in acute, subacute, and chronic infections of coxsackievirus B3 (CVB3), we examined the histopathological changes and plus- and minus-strand viral RNA dynamics in heart, pancreas, brain, and liver of CVB3-infected A/J mice. Mice were inoculated intraperitoneally with CVB3 and sacrificed on 1, 2, 3, 4, 7, 10, 14, 21, 30, 60, and 90 days post infection (p.i.). Plus- and minus-strand viral RNAs in the organs were quantitated and the organs were additionally evaluated histopathologically for inflammation. No inflammatory infiltrates were observed in the liver, brain, and heart. In contrast, massive lymphocyte infiltration and fat replacement were shown in the pancreas with loss of acinar cells. Both plus- and minus-strand viral RNA levels were detected by 21 days p.i. in heart, 90 days p.i. in pancreas, 4 days p.i. in liver, and 10 days p.i. in brain. The plus-strand RNA was found at least fifty fold higher than the minus-strand RNA by 4 days p.i. in heart and pancreas and by 3 days p.i. in liver. The plus- to minus-strand RNA ratio in brain was found less than 1:20. Our data indicate that viral replication was actively occurred in heart, pancreas, and liver during acute CVB3 infection, whereas viral replication was limited in brain. Furthermore, chronic persistent viral RNA was observed in pancreas. In conclusion, CVB3 at low dose of virus induces severe pancreatitis but marginal or no inflammatory changes in the heart, liver, and brain.

Characterization of Enteroviruses Isolated from Patients with Aseptic Meningitis

Enteroviruses (EVs) are human pathogens that cause a wide variety of clinical illnesses. The spectrum of the diseases ranges from a mild febrile illness to severe diseases such as meningitis or myocarditis. In the present study, we have used a reverse transcription-polymerase chain reaction method to detect EVs from patients with aseptic meningitis followed by typing of the EVs after HeLa cell culture isolation. In addition, twelve reference strains and the six clinical isolates of EVs were infected to neonatal rat cardiocytes and the viability of infected cells was measured by MTT assay. Marked inhibition of cell proliferation was observed in the cardiocytes cultures infected with coxsackievirus (CV) B1, CVB4, and CVB5, and two wild strains, whereas mild inhibition was observed from those infected with CVB2, CVB3, echoviruses 6, 7, 11, 22, 25, and 30. Recombinant plasmid containing full-length cDNA genome of the cardiovirulent wild strain was successfully constructed and its complete nucleotide sequence was determined. The genome showed characteristics of enteroviruses. The RNA genome was 7,391 nucleotides in length, with a 5'-nontranslating region (742 nucleotides) followed by an open reading frame (encoding a 2,182 amino acid polyprotein) and a 3'-nontranslating region (100 nucleotides) and polyadenylated tail. The predicted amino acid sequences of the polyprotein showed 89~95% homology with those of reference coxsackievirus strains (CVB1-5).

Sequence Varation of 5(1) Nontranslating Region of Enterovirus Isolated from Patients with Aseptic Meningitis

No abstract available.