Technological advances have greatly improved our knowledge of myelopoiesis,for example,with the discovery of granulocyte‒monocyte‒dendritic cell(DC)progenitors(GMDPs),monocyte‒DC progenitors(MDPs),common DC progenitor...Technological advances have greatly improved our knowledge of myelopoiesis,for example,with the discovery of granulocyte‒monocyte‒dendritic cell(DC)progenitors(GMDPs),monocyte‒DC progenitors(MDPs),common DC progenitors(CDPs)and common monocyte progenitors(cMoPs)on the basis of flow cytometry approaches.Concomitantly,some progress has been made in characterizing the very early phases of human neutropoiesis with the description of novel CD66b^(+)progenitors,including eNePs,PMs w/o eNePs,ProNeus,and PreNeus.More recently,we identified four SSC^(lo)Lin^(-)CD66b^(-)CD45^(dim)CD34^(+)/CD34^(dim/-)CD64^(dim)CD115^(-)cells as the earliest precursors specifically committed to the neutrophil lineage present in human bone marrow(BM),which we called neutrophil-committed progenitors(NCPs,from NCP1s to NCP4s).In this study,we report the isolation and characterization of two new SSC^(hi)CD66b^(-)CD64^(dim)CD115^(-)NCPs that,by phenotypic,transcriptomic,maturation and immunohistochemistry properties,as well as by flow cytometric side-scattered light(SSC),stand after NCP4s but precede promyelocytes during the neutropoiesis cascade.Similar to SSC^(lo)CD45RA^(+)NCP2s/NCP3s and SSC^(lo)CD45RA^(-)NCP1s/NCP4s,these cells exhibit phenotypic differences in CD45RA expression levels and,therefore,were named SSC^(hi)CD45RA^(+)NCP5s and SSC^(hi)CD45RA^(-)NCP6s.Moreover,NCP5s were more immature than NCP6s,as determined by cell differentiation and proliferative potential,as well as by transcriptomic and phenotypical features.Finally,by examining whether NCPs and all other CD66b^(+)neutrophil precursors are altered in representative hematological malignancies,we found that,in patients with chronic-phase chronic myeloid leukemia(CP-CML),but not with systemic mastocytosis(SM),there is an increased frequency of BM NCP4s,NCP6s,and all downstream CD45RA-negative neutrophil progenitors,suggesting their expansion in CML pathogenesis.Taken together,our data advance our knowledge of human neutropoiesis.展开更多
基金funding from Associazione Italiana per la Ricerca sul Cancro(AIRC,IG-27613 to MAC,IG-29348 and 5x1000 no.22757 to AS)Ministero dellistruzione,dellUniversita e della Ricerca(PRIN 20227YR8AW and PRIN2022W839FM to MAC and NT,respectively)+1 种基金University of Verona(RIBA2022 to PS)supported by the European Cooperation in Science and Technology(COST)Action CA20117 Mye-InfoBank(www.mye-infobank.eu).
文摘Technological advances have greatly improved our knowledge of myelopoiesis,for example,with the discovery of granulocyte‒monocyte‒dendritic cell(DC)progenitors(GMDPs),monocyte‒DC progenitors(MDPs),common DC progenitors(CDPs)and common monocyte progenitors(cMoPs)on the basis of flow cytometry approaches.Concomitantly,some progress has been made in characterizing the very early phases of human neutropoiesis with the description of novel CD66b^(+)progenitors,including eNePs,PMs w/o eNePs,ProNeus,and PreNeus.More recently,we identified four SSC^(lo)Lin^(-)CD66b^(-)CD45^(dim)CD34^(+)/CD34^(dim/-)CD64^(dim)CD115^(-)cells as the earliest precursors specifically committed to the neutrophil lineage present in human bone marrow(BM),which we called neutrophil-committed progenitors(NCPs,from NCP1s to NCP4s).In this study,we report the isolation and characterization of two new SSC^(hi)CD66b^(-)CD64^(dim)CD115^(-)NCPs that,by phenotypic,transcriptomic,maturation and immunohistochemistry properties,as well as by flow cytometric side-scattered light(SSC),stand after NCP4s but precede promyelocytes during the neutropoiesis cascade.Similar to SSC^(lo)CD45RA^(+)NCP2s/NCP3s and SSC^(lo)CD45RA^(-)NCP1s/NCP4s,these cells exhibit phenotypic differences in CD45RA expression levels and,therefore,were named SSC^(hi)CD45RA^(+)NCP5s and SSC^(hi)CD45RA^(-)NCP6s.Moreover,NCP5s were more immature than NCP6s,as determined by cell differentiation and proliferative potential,as well as by transcriptomic and phenotypical features.Finally,by examining whether NCPs and all other CD66b^(+)neutrophil precursors are altered in representative hematological malignancies,we found that,in patients with chronic-phase chronic myeloid leukemia(CP-CML),but not with systemic mastocytosis(SM),there is an increased frequency of BM NCP4s,NCP6s,and all downstream CD45RA-negative neutrophil progenitors,suggesting their expansion in CML pathogenesis.Taken together,our data advance our knowledge of human neutropoiesis.
