Minute Virus of Mice: Antibody Response, Viral Shedding, and Persistence of Viral DNA in Multiple Strains of Mice

摘要

Minutevirusofmice(MVM)isamajorconcernforlaboratoryanimalfacilitiesbecauseitremainswithconsiderablyhighprevalencedespitestrictbarriersystems.TheaimofthisstudywastoelucidatepotentialrisksassociatedwithMVMinfectionbyinvestigatingtheroleofthegeneticbackgroundonantibodyproductionandpersistenceaswellasviralshedding.MiceofvariousstrainsandstockswereinoculatedoronasallywiththeimmunosuppressivestrainMVMi;inaddition,naturalinfectionwasmodeledthroughcontactexposure.Asdeterminedbyserology,seroconversionandserumlevelsofIgGdifferedconsiderablyamongstrainsandstocks,especiallyinthecontact-exposedgroup.Forexample,C57BL/6JmicerespondedwelltoexposureincontrasttoFVB/N,NMRI,ICR,andC3H/HeNmice.Titrationstudiesindicatedthattheviraldosenecessarytoinduceseroconversionwasstrain-dependent.ExperimentstodissecttheroleofthemajorhistocompatibilitycomplexhaplotypeintheresponsetoMVMigaveinconclusiveresults.Todetectviralpersistence,spleensandfeceswereanalyzedbyPCRat16wkafterexposure,andtheinfectivityofPCR-positivespleenswasinvestigatedbyIPandoronasalinoculationofnaivemice.AlthoughDNAwasdetectedinthespleensofsomemice,fecesremainednegative,andnaivemicewerenotinfectedbyinoculation.Inaddition,viralsheddingdeclinedrapidlyafterday20postinoculation.Insummary,thedatashowthatseroconversionandantibodyresponsetoMVMiinfectiondependonthegeneticbackgroundofmice,withtheinfectivedosebeingacriticalfactor.TheroleofviralDNAinchronicallyinfectedmicewillrequirefurtherelucidation.