title: Mutations in the 5' NTR and the Non-Structural Protein 3A of the Coxsackievirus B3 Selectively Attenuate Myocarditogenicity.
abstract: The 5' non-translated region (NTR) is an important molecular determinant that controls replication and virulence of coxsackievirus B (CVB)3. Previous studies have reported many nucleotide (nt) sequence differences in the Nancy strain of the virus, including changes in the 5' NTR with varying degrees of disease severity. In our studies of CVB3-induced myocarditis, we sought to generate an infectious clone of the virus for routine in vivo experimentation. By determining the viral nt sequence, we identified three new nt substitutions in the clone that differed from the parental virus strain: C97U in the 5' NTR; a silent mutation, A4327G, in non-structural protein 2C; and C5088U (resulting in P1449L amino acid change) in non-structural protein 3A of the virus leading us to evaluate the role of these changes in the virulence properties of the virus. We noted that the disease-inducing ability of the infectious clone-derived virus in three mouse strains was restricted to pancreatitis alone, and the incidence and severity of myocarditis were significantly reduced. We then reversed the mutations by creating three new clones, representing 1) U97C; 2) G4327A and U5088C; and 3) their combination together in the third clone. The viral titers obtained from all the clones were comparable, but the virions derived from the third clone induced myocarditis comparable to that induced by wild type virus; however, the pancreatitis-inducing ability remained unaltered, suggesting that the mutations described above selectively influence myocarditogenicity. Because the accumulation of mutations during passages is a continuous process in RNA viruses, it is possible that CVB3 viruses containing such altered nts may evolve naturally, thus favoring their survival in the environment.
authors.affiliation: School of Veterinary Medicine and Biomedical Sciences, University of Nebraska-Lincoln, Lincoln, Nebraska, United States of America.
authors.forename: Chandirasegaran
authors.initials: C
authors.lastname: Massilamany
authors.affiliation: School of Veterinary Medicine and Biomedical Sciences, University of Nebraska-Lincoln, Lincoln, Nebraska, United States of America.
authors.forename: Arunakumar
authors.initials: A
authors.lastname: Gangaplara
authors.affiliation: School of Veterinary Medicine and Biomedical Sciences, University of Nebraska-Lincoln, Lincoln, Nebraska, United States of America.
authors.forename: Rakesh H
authors.initials: RH
authors.lastname: Basavalingappa
authors.affiliation: School of Veterinary Medicine and Biomedical Sciences, University of Nebraska-Lincoln, Lincoln, Nebraska, United States of America.
authors.forename: Rajkumar A
authors.initials: RA
authors.lastname: Rajasekaran
authors.affiliation: School of Veterinary Medicine and Biomedical Sciences, University of Nebraska-Lincoln, Lincoln, Nebraska, United States of America.
authors.forename: Hiep
authors.initials: H
authors.lastname: Vu
authors.affiliation: Center for Biotechnology, University of Nebraska-Lincoln, Lincoln, Nebraska, United States of America.
authors.forename: Jean-Jack
authors.initials: JJ
authors.lastname: Riethoven
authors.affiliation: School of Veterinary Medicine and Biomedical Sciences, University of Nebraska-Lincoln, Lincoln, Nebraska, United States of America.
authors.forename: David
authors.initials: D
authors.lastname: Steffen
authors.affiliation: School of Veterinary Medicine and Biomedical Sciences, University of Nebraska-Lincoln, Lincoln, Nebraska, United States of America; Nebraska Center for Virology, University of Nebraska-Lincoln, Lincoln, Nebraska, United States of America.
authors.forename: Asit K
authors.initials: AK
authors.lastname: Pattnaik
authors.affiliation: School of Veterinary Medicine and Biomedical Sciences, University of Nebraska-Lincoln, Lincoln, Nebraska, United States of America.
authors.forename: Jay
authors.initials: J
authors.lastname: Reddy
mesh_terms: D020121:5' Untranslated Regions / Q000235:genetics*; D000596:Amino Acids; D000818:Animals; D003384:Coxsackievirus Infections / Q000821:virology; D029822:Enterovirus B, Human / Q000235:genetics*; D051379:Mice; D008807:Mice, Inbred BALB C; D008810:Mice, Inbred C57BL; D009154:Mutation / Q000235:genetics*; D009205:Myocarditis / Q000473:pathology* / Q000821:virology*; D032383:Myocytes, Cardiac / Q000821:virology; D010195:Pancreatitis / Q000821:virology; D012367:RNA, Viral / Q000235:genetics; D017361:Viral Nonstructural Proteins / Q000235:genetics*; D014774:Virulence / Q000235:genetics
chemical_list: D020121:5' Untranslated Regions; D000596:Amino Acids; D012367:RNA, Viral; D017361:Viral Nonstructural Proteins