A developmental study of murine epidermal Langerhans cells☆

[摘要] Prospectiveskinpriortoinvasionbyneuralcrestcellswasdissectedfrom10.5-daymouseembryosandcultivatedinchickembryohosts.Thegrafttissuewaspreparedforthedemonstrationofbothmouseandchickcells,pigmentcells,andLangerhanscells.Chickcellswerenotfoundinthegraftmouseepidermis;however,ATPase-positiveandosmiumiodide-positivecellswerepresent.Electronmicroscopicexaminationrevealedthat,inyoungergrafts,onlyindeterminatecellscouldbefoundamongthekeratinocytes.Inoldergrafts,bothindeterminatecellsandLangerhanscellswithgranuleswereseen.TheevidenceaffirmsthatepidermalLangerhanscellsarenotrelatedtopigmentcells.BasedonthedevelopmentalnatureofBirbeck(Langerhans)granulesfromthecytomembrane,itisproposedthatthegranulenolongerbeconsideredasspecifictoandcharacteristicofepidermalLangerhanscells.Rather,LangerhanscellsshouldbedefinedasATPase-positive,desmosome-freecellswithinstratifiedsquamous,potentiallykeratinizing,epithelia.Thusepidermal,ATPase-positiveindeterminatecellsandsuchcellswithBirbeckgranulesbothshouldbeconsideredascomponentsoftheLangerhanscellseries.NormalchickskindoesnotshowATPase-positivecells.However,when10.5-daymouseembryoectodermwasinsertedundertheectodermofchickembryos,theresultingchimericepidermispossessedATPase-positivecells.ItisproposedthatepidermalLangerhanscellsareofectodermalorigin.

[学科分类] 生物科学（综合）