Critical role for thymic CD19+CD5+CD1dhiIL‐10+ regulatory B cells in immune homeostasis

[摘要] Thisstudytestedthehypothesisthatbesidesthespleen,LNs,peripheralblood,andthymuscontainaregulatoryIL‐10‐producingCD19+CD5+CD1dhighBcellsubsetthatmayplayacriticalroleinthemaintenanceofimmunehomeostasis.Indeed,thispopulationwasidentifiedinthemurinethymus,andfurthermore,whencoculturedwithCD4+Tcells,thispopulationofBcellssupportedthemaintenanceofCD4+Foxp3+Tregsinvitro,inpart,viatheCD5–CD72interaction.MicehomozygousforCd19Cre(CD19−/−)expressBcellswithimpairedsignalingandhumoralresponses.Strikingly,CD19−/−miceproducefewerCD4+Foxp3+TregsandagreaterpercentageofCD4+CD8−andCD4−CD8+Tcells.Consistentwiththeseresults,transferofthymicCD19+CD5+CD1dhiBcellsintoCD19−/−miceresultedinsignificantlyup‐regulatednumbersofCD4+Foxp3+TregswithaconcomitantreductioninCD4+CD8−andCD4−CD8+Tcellpopulationsinthethymus,spleen,andLNsbutnotintheBMofrecipientmice.Inaddition,thymicCD19+CD5+CD1dhiBcellssignificantlysuppressedautoimmuneresponsesinlupus‐likemiceviaup‐regulationofCD4+Foxp3+TregsandIL‐10‐producingBregs.ThisstudysuggeststhatthymicCD19+CD5+CD1dhiIL‐10+Bregsplayacriticalroleinthemaintenanceofimmunehomeostasis...

[学科分类] 生理学

[关键词] regulatory T cells;Foxp3;CD72