title: Presence of Minute virus of mice in immunocompetent mice despite the onset of host immunity.
abstract: Infections with the autonomous parvovirus Minute virus of mice (MVM) are generally characterized as acute and self-limiting. However, MVM remains with considerably high prevalence rates in laboratory mouse colonies impeding rodent based research. The objective of this study was to assess whether the immunosuppressive variant of MVM (MVMi) establishes a persistent infection in immunocompetent adult mice. Therefore, we approached the question whether replicating and/or infectious virus is present in mice after the decline of viral shedding and whether immunosuppression might modify the infection. Dissection or induction of immunosuppression of individually housed mice was performed at 8 weeks post inoculation after fecal samples tested negative for viral DNA for at least 2 subsequent weeks as determined by weekly PCR analyses. MVMi mRNA was detected by both, RT-PCR and in situ RT-PCR in spleens at 8 weeks post inoculation with positive cells resembling lymphocytes and macrophages. These findings and the use of explant cultures strongly indicated the presence of replicating virus in spleens at 8 weeks post inoculation. Following immunosuppression (by irradiation), an induction of viral shedding was observed. Additionally, an increase in the amount of viral DNA was detected by real-time qPCR in mesenteric lymph nodes after irradiation. In summary, our data support the notion that MVMi persists in lymphoid tissue of immunocompetent adult mice despite the onset of host immunity.
authors.affiliation: Institute for Laboratory Animal Science, Hannover Medical School, Hannover, Germany.
authors.forename: Lydia M
authors.initials: LM
authors.lastname: Janus
authors.forename: Anna
authors.initials: A
authors.lastname: Smoczek
authors.forename: Anne
authors.initials: A
authors.lastname: Jörns
authors.forename: Hans-J
authors.initials: HJ
authors.lastname: Hedrich
authors.forename: Andre
authors.initials: A
authors.lastname: Bleich
mesh_terms: D056704:Adaptive Immunity / Q000276:immunology; D000818:Animals; D004279:DNA, Viral / Q000032:analysis; D019084:Fluorescent Antibody Technique, Indirect / Q000662:veterinary; D008297:Male; D051379:Mice; D008915:Minute Virus of Mice / Q000276:immunology* / Q000472:pathogenicity; D010322:Parvoviridae Infections / Q000276:immunology / Q000662:veterinary* / Q000821:virology; D012333:RNA, Messenger / Q000032:analysis; D020133:Reverse Transcriptase Polymerase Chain Reaction / Q000662:veterinary; D012376:Rodent Diseases / Q000276:immunology / Q000821:virology*; D013154:Spleen / Q000821:virology; D017201:Virus Shedding / Q000276:immunology
chemical_list: D004279:DNA, Viral; D012333:RNA, Messenger