The Immune Response in Inbred and Outbred Strains of Mice before and after Bone Marrow Transplantation

Abstract

Abstract:Understanding the immune response is critical to evaluate the response to infection and vaccines, particularly in bone marrow transplant (BMT) recipients who may exhibit an altered immune system. Such studies have relied upon inbred mouse models due to genetic consistency and experimental reproducibility. Recent studies suggest that inbred mice vary substantially from outbred counterparts in terms of immune responses. These experiments quantified differences in immune responses of inbred and outbred mice before and after BMT. Inbred and outbred adult mice were lethally irradiated and syngeneic bone marrow transplants performed. 6-9weeksafterengraftment,themicewereimmunizedwithallogeneiccells.Immunecellchangeswereanalyzedbyflowcytometry. Immunizationresultedinsignificantleukocyteincreasesinallgroups.Bcellsonlyvariedfortransplantedinbredmice.Outbredmice hadsignificantlygreaterbaselineTcellsduetoincreasedCD4+Tcells.CD8+ T cell numbers were comparable between the strains and groups.Interestingly,inoutbredmicebothCD4andCD8TcellsrespondedequallywhileininbredmiceCD8Tcellswere predominant. Outbredmicehadpeakresponseslaterandmoreprolongedthaninbredmice.Thus,inbredmicemaynotbeanaccuratemodelfor testing immune responses in humans, especially after BMT.