The impact of transforming growth factor beta 1 on dendritic cell development and subset specification

Dendritic cells (DC) are bone marrow-derived antigen presenting cells that are crucial for inducing adaptive immune responses and maintaining T cell tolerance. An increasingly precise picture of DC development from bone marrow progenitors is emerging, including the discovery of a DC lineage restricted common DC progenitor (CDP). The molecular mechanisms determining DC commitment of CDP and their further specification into DC subsets remained, however, less clear. This is partly due to the lack of genetic tools and/or culture model systems that would allow the developmental stage-specific analysis of the impact of single factors, like transcription factors and cytokines, on DC development. In this study, I have developed a culture system that reproduces CDP in vitro and addressed the molecular mechanisms behind DC commitment of CDP from multipotent progenitors (MPP). The in vitro amplified CDP recapitulate the function, surface marker and gene expression profile of in vivo CDP, therefore providing a valuable model system for studying DC development. Gene expression analysis by DNA microarrays showed that CDP exhibit a DC-primed transcription profile that includes the upregulation of DC-poietin receptors and DC specific transcription profiles upon differentiation from MPP. Consistent with their capacity to generate both conventional DC (cDC) and plasmacytoid DC (pDC), CDP express pan-DC genes as well as genes specific for either DC subset. Concomitantly with lineage specification, hematopoietic cells cease proliferating and undergo cell cycle arrest. In line with the loss of self-renewal capacity and multilineage potential, CDP differentiation from MPP is accompanied by downregulation of stem/progenitor cell associated gene expression. In addition, this thesis addressed the impact of transforming growth factor-b1 (TGF-b1) on DC differentiation. DNA microarray analysis showed that TGF-b1 pushed the CDP transcription profile towards DC within 24 h, indicating that TGF-b1 accelerates DC differentiation from CDP. This was accompanied with upregulation of genes involved in DC differentiation and/or function and downregulation of proliferation associated genes. Most importantly, TGF-b1 directed DC subset specification towards cDC. TGF-b1 treated CDP acquired a cDC affiliated transcription factor repertoire, with the induction of cDC differentiation instructing transcriptional regulators, including interferon regulatory factor-4 (IRF-4) and several members of the nuclear factor-kB (NF-kB) family. Concurrently, TGF-b1 induced transcription factors that inhibit pDC differentiation, such as inhibitor of DNA binding/differentiation 2 (Id2) and interferon regulatory factor-1 (IRF-1). Taken together, this study describes an in vitro system for studying the consecutive development of MPP towards CDP and their further differentiation into DC subsets. Employing the culture system, the molecular mechanisms instructing DC commitment and subset specification were analysed. For the first time, TGF-b1 was identified as a determining factor that regulates DC subset specification and directs DC differentiation towards cDC

The impact of transforming growth factor beta 1 on dendritic cell development and subset specification

Dendritic cells (DC) are bone marrow-derived antigen presenting cells that are crucial for inducing adaptive immune responses and maintaining T cell tolerance. An increasingly precise picture of DC development from bone marrow progenitors is emerging, including the discovery of a DC lineage restricted common DC progenitor (CDP). The molecular mechanisms determining DC commitment of CDP and their further specification into DC subsets remained, however, less clear. This is partly due to the lack of genetic tools and/or culture model systems that would allow the developmental stage-specific analysis of the impact of single factors, like transcription factors and cytokines, on DC development. In this study, I have developed a culture system that reproduces CDP in vitro and addressed the molecular mechanisms behind DC commitment of CDP from multipotent progenitors (MPP). The in vitro amplified CDP recapitulate the function, surface marker and gene expression profile of in vivo CDP, therefore providing a valuable model system for studying DC development. Gene expression analysis by DNA microarrays showed that CDP exhibit a DC-primed transcription profile that includes the upregulation of DC-poietin receptors and DC specific transcription profiles upon differentiation from MPP. Consistent with their capacity to generate both conventional DC (cDC) and plasmacytoid DC (pDC), CDP express pan-DC genes as well as genes specific for either DC subset. Concomitantly with lineage specification, hematopoietic cells cease proliferating and undergo cell cycle arrest. In line with the loss of self-renewal capacity and multilineage potential, CDP differentiation from MPP is accompanied by downregulation of stem/progenitor cell associated gene expression. In addition, this thesis addressed the impact of transforming growth factor-b1 (TGF-b1) on DC differentiation. DNA microarray analysis showed that TGF-b1 pushed the CDP transcription profile towards DC within 24 h, indicating that TGF-b1 accelerates DC differentiation from CDP. This was accompanied with upregulation of genes involved in DC differentiation and/or function and downregulation of proliferation associated genes. Most importantly, TGF-b1 directed DC subset specification towards cDC. TGF-b1 treated CDP acquired a cDC affiliated transcription factor repertoire, with the induction of cDC differentiation instructing transcriptional regulators, including interferon regulatory factor-4 (IRF-4) and several members of the nuclear factor-kB (NF-kB) family. Concurrently, TGF-b1 induced transcription factors that inhibit pDC differentiation, such as inhibitor of DNA binding/differentiation 2 (Id2) and interferon regulatory factor-1 (IRF-1). Taken together, this study describes an in vitro system for studying the consecutive development of MPP towards CDP and their further differentiation into DC subsets. Employing the culture system, the molecular mechanisms instructing DC commitment and subset specification were analysed. For the first time, TGF-b1 was identified as a determining factor that regulates DC subset specification and directs DC differentiation towards cDC

За кадры. 1999. № 11 (3011)

И кто придумал сдавать сессию летом?Цифры и факты / С. Дараева11 мая, в день 103-летия ТПУ, состоялся торжественный Ученый Совет, посвященный Дню УниверситетаПесня всех объединила / С. ФедоровНовости политехнического. Мы уже сообщали[Совет ветеранов] / А. В. АстафуровПолитехническому отдано 36 лет / В. Ф. КуцепаленкоНовости политехнического. Весной 1999 года / Е. В. АрляповаНовости политехнического. Итоги нового общеуниверситетского конкурса / Л. М. ЗольниковаНовости политехнического. Уважаемые товарищи! / Г. С. Бухановская, И. Н. Савельева, Е. И. АлибасоваНовости политехнического. Три дня в ТПУНовости политехнического. В числе пяти проектовМеждународное сотрудничествоСильный помогает слабому / С. МазуровГород вздрогнул... / Я. АнечкинаНе успевает тот, кто не торопится / Е. ЕфстифееваКогда изучать экологию? / Е. Т. ПротасевичГазовый факел озарил всю область / [беседа с] С. А. ЖвачкинОгни общежитий. Смотр-конкурсОгни общежитий. Мойдодыры политехническогоОгни общежитий. Праздник немецкой культуры в Томске / А. А. ФрицлерЭто сильно / И. ЮневаВыбор между жизнью и смертью - за вами!"Полигон" - чемпион!" / В. Прибаукин"Друзья, прекрасен наш союз!" / П. Веников"Нужно самим работать.." / И. БасалаеваКоролевские призерыСпартакиада есть! Спартакиада будет! / Б. Л. БайгуловПраздник, посвященный 103-летию ТПУ / А. СидороffВаш пропуск в XXI век200-летие поэта - достойный повод для "открытий чудных" / Л. И. ВласоваДядь, дай семьдесят копеек! / А. ГригорьевОбратная связ

Dendritic cell lineage commitment is instructed by distinct cytokine signals

AbstractDendritic cells (DC) develop from hematopoietic stem cells, which is guided by instructive signals through cytokines. DC development progresses from multipotent progenitors (MPP) via common DC progenitors (CDP) into DC. Flt3 ligand (Flt3L) signaling via the Flt3/Stat3 pathway is of pivotal importance for DC development under steady state conditions. Additional factors produced during steady state or inflammation, such as TGF-β1 or GM-CSF, also influence the differentiation potential of MPP and CDP. Here, we studied how gp130, GM-CSF and TGF-β1 signaling influence DC lineage commitment from MPP to CDP and further into DC. We observed that activation of gp130 signaling promotes expansion of MPP. Additionally, gp130 signaling inhibited Flt3L-driven DC differentiation, but had little effect on GM-CSF-driven DC development. The inflammatory cytokine GM-CSF induces differentiation of MPP into inflammatory DC and blocks steady state DC development. Global transcriptome analysis revealed a GM-CSF-driven gene expression repertoire that primes MPP for differentiation into inflammatory DC. Finally, TGF-β1 induces expression of DC-lineage affiliated genes in MPP, including Flt3, Irf-4 and Irf-8. Under inflammatory conditions, however, the effect of TGF-β1 is altered: Flt3 is not upregulated, indicating that an inflammatory environment inhibits steady state DC development. Altogether, our data indicate that distinct cytokine signals produced during steady state or inflammation have a different outcome on DC lineage commitment and differentiation