RESUMO
BACKGROUND: Fluorine-18 fluorodeoxyglucose (FDG) with positron emission tomography (PET) is the standard for detecting myocardial inflammation in cardiac sarcoidosis, requiring preparation with the ketogenic diet (KD) to achieve myocardial glucose suppression. Despite this, incomplete myocardial glucose suppression remains a significant issue, and strategies to reduce myocardial glucose uptake (MGU) and identify incomplete myocardial glucose suppression are required. This study sought to understand the relationship between point-of-care beta-hydroxybutyrate (BHB) and different patterns of MGU and between KD and fasting duration with MGU in patients undergoing evaluation for cardiac sarcoidosis. METHODS: We prospectively included 471 outpatients who underwent FDG-PET for cardiac sarcoidosis evaluation, followed the KD for 1 (n=100), 2 (n=29), and ≥3 days (n=342), fasted for at least 12 hours, and had BHB levels measured immediately before FDG injection. Images were classified as (1) no MGU (negative), (2) focal/multifocal (positive), (3) diffuse (nondiagnostic), or (4) nonspecific uptake (NS-MGU). RESULTS: Cardiac FDG-PET scans were interpreted as the following: 376 (79.83%) negative; 61 (12.95%) positive; 14 (2.97%) diffuse; and 20 (4.25%) NS-MGU. There was a strong negative relationship between BHB levels and MGU (P<0.0001). BHB levels increased significantly with KD duration (P<0.0001) and fasting time (P=0.0067). The combined rate of diffuse, NS-MGU, and positive scans (34%, 28%, 16%) decreased inversely with KD duration (1, 2, and ≥3 days, respectively). However, MGU was not different across different fasting times (P=0.6). Blood glucose levels were not associated with MGU (P=0.17) and only weakly associated with BHB levels (R2=0.03; P<0.001). CONCLUSIONS: We observed a strong inverse relationship between ketosis and patterns of MGU. Longer KD and fasting durations are associated with higher ketosis. However, only KD duration was associated with lower rates of MGU. Measurement of BHB levels before FDG-PET using point-of-care testing is feasible and may facilitate the management of patients referred for myocardial inflammation.
RESUMO
We examined antibody and memory B cell responses longitudinally for â¼9-10 months after primary 2-dose SARS-CoV-2 mRNA vaccination and 3 months after a 3rd dose. Antibody decay stabilized between 6 and 9 months, and antibody quality continued to improve for at least 9 months after 2-dose vaccination. Spike- and RBD-specific memory B cells remained durable over time, and 40%-50% of RBD-specific memory B cells simultaneously bound the Alpha, Beta, Delta, and Omicron variants. Omicron-binding memory B cells were efficiently reactivated by a 3rd dose of wild-type vaccine and correlated with the corresponding increase in neutralizing antibody titers. In contrast, pre-3rd dose antibody titers inversely correlated with the fold-change of antibody boosting, suggesting that high levels of circulating antibodies may limit the added protection afforded by repeat short interval boosting. These data provide insight into the quantity and quality of mRNA-vaccine-induced immunity over time through 3 or more antigen exposures.
Assuntos
Vacinas contra COVID-19 , COVID-19 , Anticorpos Neutralizantes , Anticorpos Antivirais , COVID-19/prevenção & controle , Humanos , RNA Mensageiro , SARS-CoV-2 , Vacinas Sintéticas , Vacinas de mRNARESUMO
Despite a clear role in protective immunity, the durability and quality of antibody and memory B cell responses induced by mRNA vaccination, particularly by a 3 rd dose of vaccine, remains unclear. Here, we examined antibody and memory B cell responses in a cohort of individuals sampled longitudinally for â¼9-10 months after the primary 2-dose mRNA vaccine series, as well as for â¼3 months after a 3 rd mRNA vaccine dose. Notably, antibody decay slowed significantly between 6- and 9-months post-primary vaccination, essentially stabilizing at the time of the 3 rd dose. Antibody quality also continued to improve for at least 9 months after primary 2-dose vaccination. Spike- and RBD-specific memory B cells were stable through 9 months post-vaccination with no evidence of decline over time, and â¼40-50% of RBD-specific memory B cells were capable of simultaneously recognizing the Alpha, Beta, Delta, and Omicron variants. Omicron-binding memory B cells induced by the first 2 doses of mRNA vaccine were boosted significantly by a 3rd dose and the magnitude of this boosting was similar to memory B cells specific for other variants. Pre-3 rd dose memory B cell frequencies correlated with the increase in neutralizing antibody titers after the 3 rd dose. In contrast, pre-3 rd dose antibody titers inversely correlated with the fold-change of antibody boosting, suggesting that high levels of circulating antibodies may limit reactivation of immunological memory and constrain further antibody boosting by mRNA vaccines. These data provide a deeper understanding of how the quantity and quality of antibody and memory B cell responses change over time and number of antigen exposures. These data also provide insight into potential immune dynamics following recall responses to additional vaccine doses or post-vaccination infections.
RESUMO
Dendritic cells (DCs) and monocytes develop from a series of bone-marrow-resident progenitors in which lineage potential is regulated by distinct transcription factors. Zeb2 is an E-box-binding protein associated with epithelial-mesenchymal transition and is widely expressed among hematopoietic lineages. Previously, we observed that Zeb2 expression is differentially regulated in progenitors committed to classical DC (cDC) subsets in vivo. Using systems for inducible gene deletion, we uncover a requirement for Zeb2 in the development of Ly-6Chi monocytes but not neutrophils, and we show a corresponding requirement for Zeb2 in expression of the M-CSF receptor in the bone marrow. In addition, we confirm a requirement for Zeb2 in development of plasmacytoid DCs but find that Zeb2 is not required for cDC2 development. Instead, Zeb2 may act to repress cDC1 progenitor specification in the context of inflammatory signals.
Assuntos
Células Dendríticas/citologia , Regulação da Expressão Gênica , Monócitos/citologia , Homeobox 2 de Ligação a E-box com Dedos de Zinco/genética , Homeobox 2 de Ligação a E-box com Dedos de Zinco/fisiologia , Animais , Medula Óssea/metabolismo , Linfócitos T CD8-Positivos/citologia , Linhagem da Célula , Citoplasma/metabolismo , Feminino , Citometria de Fluxo , Deleção de Genes , Perfilação da Expressão Gênica , Inflamação , Integrases/metabolismo , Masculino , Camundongos , Neutrófilos/citologia , Neutrófilos/metabolismoRESUMO
Both classical DCs (cDCs) and monocyte-derived DCs (Mo-DCs) are capable of cross-priming CD8(+) T cells in response to cell-associated antigens. We found that Ly-6C(hi)TREML4(-) monocytes can differentiate into Zbtb46(+) Mo-DCs in response to granulocyte-macrophage colony-stimulating factor (GM-CSF) and interleukin-4 (IL-4) but that Ly-6C(hi)TREML4(+) monocytes were committed to differentiate into Ly-6C(lo)TREML4(+) monocytes. Differentiation of Zbtb46(+) Mo-DCs capable of efficient cross-priming required both GM-CSF and IL-4 and was accompanied by the induction of Batf3 and Irf4. However, monocytes require IRF4, but not BATF3, to differentiate into Zbtb46(+) Mo-DCs capable of cross-priming CD8(+) T cells. Instead, Irf4(-/-) monocytes differentiate into macrophages in response to GM-CSF and IL-4. Thus, cDCs and Mo-DCs require distinct transcriptional programs of differentiation in acquiring the capacity to prime CD8(+) T cells. These differences may be of consideration in the use of therapeutic DC vaccines based on Mo-DCs.
Assuntos
Apresentação Cruzada/genética , Células Dendríticas/imunologia , Monócitos/citologia , Transcrição Gênica , Animais , Células Apresentadoras de Antígenos/citologia , Células Apresentadoras de Antígenos/efeitos dos fármacos , Células Apresentadoras de Antígenos/metabolismo , Antígenos/metabolismo , Fatores de Transcrição de Zíper de Leucina Básica/deficiência , Fatores de Transcrição de Zíper de Leucina Básica/metabolismo , Linfócitos T CD8-Positivos/imunologia , Diferenciação Celular/efeitos dos fármacos , Linhagem da Célula/efeitos dos fármacos , Apresentação Cruzada/efeitos dos fármacos , Células Dendríticas/citologia , Células Dendríticas/efeitos dos fármacos , Feminino , Fator Estimulador de Colônias de Granulócitos e Macrófagos/farmacologia , Fatores Reguladores de Interferon/metabolismo , Interleucina-4/metabolismo , Masculino , Camundongos Endogâmicos C57BL , Camundongos Knockout , Membro 1 do Grupo A da Subfamília 4 de Receptores Nucleares/metabolismo , Receptores Imunológicos/metabolismo , Proteínas Repressoras/deficiência , Proteínas Repressoras/metabolismo , Transdução de Sinais/efeitos dos fármacos , Transcrição Gênica/efeitos dos fármacosRESUMO
The transcription factors Batf3 and IRF8 are required for the development of CD8α(+) conventional dendritic cells (cDCs), but the basis for their actions has remained unclear. Here we identified two progenitor cells positive for the transcription factor Zbtb46 that separately generated CD8α(+) cDCs and CD4(+) cDCs and arose directly from the common DC progenitor (CDP). Irf8 expression in CDPs required prior autoactivation of Irf8 that was dependent on the transcription factor PU.1. Specification of the clonogenic progenitor of CD8α(+) cDCs (the pre-CD8 DC) required IRF8 but not Batf3. However, after specification of pre-CD8 DCs, autoactivation of Irf8 became Batf3 dependent at a CD8α(+) cDC-specific enhancer with multiple transcription factor AP1-IRF composite elements (AICEs) within the Irf8 superenhancer. CDPs from Batf3(-/-) mice that were specified toward development into pre-CD8 DCs failed to complete their development into CD8α(+) cDCs due to decay of Irf8 autoactivation and diverted to the CD4(+) cDC lineage.
Assuntos
Fatores de Transcrição de Zíper de Leucina Básica/imunologia , Células Dendríticas/imunologia , Fatores Reguladores de Interferon/imunologia , Proteínas Repressoras/imunologia , Células-Tronco/imunologia , Animais , Sequência de Bases , Fatores de Transcrição de Zíper de Leucina Básica/genética , Fatores de Transcrição de Zíper de Leucina Básica/metabolismo , Células da Medula Óssea/imunologia , Células da Medula Óssea/metabolismo , Antígeno CD24/imunologia , Antígeno CD24/metabolismo , Antígenos CD8/imunologia , Antígenos CD8/metabolismo , Células Cultivadas , Células Clonais/imunologia , Células Clonais/metabolismo , Células Dendríticas/metabolismo , Citometria de Fluxo , Fatores Reguladores de Interferon/genética , Fatores Reguladores de Interferon/metabolismo , Camundongos da Linhagem 129 , Camundongos Endogâmicos C57BL , Camundongos Knockout , Camundongos Transgênicos , Dados de Sequência Molecular , Análise de Sequência com Séries de Oligonucleotídeos , Ligação Proteica , Receptores Imunológicos/imunologia , Receptores Imunológicos/metabolismo , Proteínas Repressoras/genética , Proteínas Repressoras/metabolismo , Homologia de Sequência do Ácido Nucleico , Células-Tronco/metabolismo , Transcriptoma/genética , Transcriptoma/imunologiaRESUMO
Splenic red pulp macrophages (RPM) degrade senescent erythrocytes and recycle heme-associated iron. The transcription factor SPI-C is selectively expressed by RPM and is required for their development, but the physiologic stimulus inducing Spic is unknown. Here, we report that Spic also regulated the development of F4/80(+)VCAM1(+) bone marrow macrophages (BMM) and that Spic expression in BMM and RPM development was induced by heme, a metabolite of erythrocyte degradation. Pathologic hemolysis induced loss of RPM and BMM due to excess heme but induced Spic in monocytes to generate new RPM and BMM. Spic expression in monocytes was constitutively inhibited by the transcriptional repressor BACH1. Heme induced proteasome-dependent BACH1 degradation and rapid Spic derepression. Furthermore, cysteine-proline dipeptide motifs in BACH1 that mediate heme-dependent degradation were necessary for Spic induction by heme. These findings are the first example of metabolite-driven differentiation of a tissue-resident macrophage subset and provide new insights into iron homeostasis.
Assuntos
Diferenciação Celular , Proteínas de Ligação a DNA/metabolismo , Heme/metabolismo , Ferro/metabolismo , Monócitos/metabolismo , Animais , Fatores de Transcrição de Zíper de Leucina Básica/metabolismo , Células da Medula Óssea/citologia , Células da Medula Óssea/metabolismo , Proteínas de Ligação a DNA/genética , Feminino , Macrófagos/metabolismo , Masculino , Camundongos , Camundongos da Linhagem 129 , Camundongos Endogâmicos C57BL , Células Mieloides/metabolismo , Baço/citologia , Baço/metabolismoRESUMO
The transcription factors c-Myc and N-Myc--encoded by Myc and Mycn, respectively--regulate cellular growth and are required for embryonic development. A third paralogue, Mycl1, is dispensable for normal embryonic development but its biological function has remained unclear. To examine the in vivo function of Mycl1 in mice, we generated an inactivating Mycl1(gfp) allele that also reports Mycl1 expression. We find that Mycl1 is selectively expressed in dendritic cells (DCs) of the immune system and controlled by IRF8, and that during DC development, Mycl1 expression is initiated in the common DC progenitor concurrent with reduction in c-Myc expression. Mature DCs lack expression of c-Myc and N-Myc but maintain L-Myc expression even in the presence of inflammatory signals such as granulocyte-macrophage colony-stimulating factor. All DC subsets develop in Mycl1-deficient mice, but some subsets such as migratory CD103(+) conventional DCs in the lung and liver are greatly reduced at steady state. Importantly, loss of L-Myc by DCs causes a significant decrease in in vivo T-cell priming during infection by Listeria monocytogenes and vesicular stomatitis virus. The replacement of c-Myc by L-Myc in immature DCs may provide for Myc transcriptional activity in the setting of inflammation that is required for optimal T-cell priming.
Assuntos
Apresentação Cruzada/imunologia , Células Dendríticas/imunologia , Células Dendríticas/metabolismo , Regulação da Expressão Gênica , Proteínas Proto-Oncogênicas c-myc/metabolismo , Linfócitos T/imunologia , Animais , Antígenos CD/metabolismo , Divisão Celular , Células Dendríticas/citologia , Feminino , Fator Estimulador de Colônias de Granulócitos e Macrófagos/metabolismo , Inflamação/imunologia , Inflamação/metabolismo , Cadeias alfa de Integrinas/metabolismo , Fatores Reguladores de Interferon/metabolismo , Listeria monocytogenes/imunologia , Fígado/citologia , Fígado/imunologia , Pulmão/citologia , Pulmão/imunologia , Masculino , Camundongos , Proteínas Proto-Oncogênicas c-myc/deficiência , Transcrição Gênica , Vesiculovirus/imunologiaRESUMO
Defense against attaching-and-effacing bacteria requires the sequential generation of interleukin 23 (IL-23) and IL-22 to induce protective mucosal responses. Although CD4(+) and NKp46(+) innate lymphoid cells (ILCs) are the critical source of IL-22 during infection, the precise source of IL-23 is unclear. We used genetic techniques to deplete mice of specific subsets of classical dendritic cells (cDCs) and analyzed immunity to the attaching-and-effacing pathogen Citrobacter rodentium. We found that the signaling receptor Notch2 controlled the terminal stage of cDC differentiation. Notch2-dependent intestinal CD11b(+) cDCs were an obligate source of IL-23 required for survival after infection with C. rodentium, but CD103(+) cDCs dependent on the transcription factor Batf3 were not. Our results demonstrate a nonredundant function for CD11b(+) cDCs in the response to pathogens in vivo.
Assuntos
Citrobacter rodentium/imunologia , Células Dendríticas/imunologia , Células Dendríticas/metabolismo , Mucosa Intestinal/imunologia , Mucosa Intestinal/metabolismo , Receptor Notch2/metabolismo , Animais , Antígenos CD/metabolismo , Antígeno CD11b/metabolismo , Diferenciação Celular/genética , Diferenciação Celular/imunologia , Células Dendríticas/citologia , Infecções por Enterobacteriaceae/imunologia , Infecções por Enterobacteriaceae/microbiologia , Infecções por Enterobacteriaceae/mortalidade , Interações Hospedeiro-Patógeno/genética , Interações Hospedeiro-Patógeno/imunologia , Interleucina-23/metabolismo , Mucosa Intestinal/microbiologia , Lectinas Tipo C/metabolismo , Receptor beta de Linfotoxina/genética , Receptor beta de Linfotoxina/metabolismo , Camundongos , Camundongos Transgênicos , Antígenos de Histocompatibilidade Menor , Receptor Notch2/deficiência , Receptores de Superfície Celular/metabolismo , Transdução de Sinais , Baço/imunologia , Fatores de Transcrição/genética , Fatores de Transcrição/metabolismo , Cicatrização/genética , Cicatrização/imunologiaRESUMO
Bcl11a is a transcription factor known to regulate lymphoid and erythroid development. Recent bioinformatic analysis of global gene expression patterns has suggested a role for Bcl11a in the development of dendritic cell (DC) lineages. We tested this hypothesis by analyzing the development of DC and other lineages in Bcl11a (-/-) mice. We found that Bcl11a was required for expression of IL-7 receptor (IL-7R) and Flt3 in early hematopoietic progenitor cells. In addition, we found severely decreased numbers of plasmacytoid dendritic cells (pDCs) in Bcl11a (-/-) fetal livers and in the bone marrow of Bcl11a (-/-) fetal liver chimeras. Moreover, Bcl11a (-/-) cells showed severely impaired in vitro development of Flt3L-derived pDCs and classical DCs (cDCs). In contrast, we found normal in vitro development of DCs from Bcl11a (-/-) fetal liver cells treated with GM-CSF. These results suggest that the persistent cDC development observed in Bcl11a (-/-) fetal liver chimeras reflects derivation from a Bcl11a- and Flt3-independent pathway in vivo.
Assuntos
Proteínas de Transporte/genética , Células Dendríticas/metabolismo , Regulação da Expressão Gênica , Células-Tronco Hematopoéticas/metabolismo , Proteínas Nucleares/genética , Tirosina Quinase 3 Semelhante a fms/genética , Animais , Proteínas de Transporte/metabolismo , Diferenciação Celular , Linhagem da Célula/efeitos dos fármacos , Linhagem da Célula/genética , Proteínas de Ligação a DNA , Células Dendríticas/citologia , Células Dendríticas/efeitos dos fármacos , Regulação da Expressão Gênica/efeitos dos fármacos , Fator Estimulador de Colônias de Granulócitos e Macrófagos/metabolismo , Fator Estimulador de Colônias de Granulócitos e Macrófagos/farmacologia , Células-Tronco Hematopoéticas/citologia , Células-Tronco Hematopoéticas/efeitos dos fármacos , Imunofenotipagem , Células Progenitoras Linfoides/citologia , Células Progenitoras Linfoides/efeitos dos fármacos , Células Progenitoras Linfoides/metabolismo , Proteínas de Membrana/metabolismo , Proteínas de Membrana/farmacologia , Camundongos , Camundongos Knockout , Proteínas Nucleares/metabolismo , Receptores de Interleucina-7/genética , Receptores de Interleucina-7/metabolismo , Proteínas Repressoras , Tirosina Quinase 3 Semelhante a fms/metabolismoRESUMO
The AP1 transcription factor Batf3 is required for homeostatic development of CD8α(+) classical dendritic cells that prime CD8 T-cell responses against intracellular pathogens. Here we identify an alternative, Batf3-independent pathway in mice for CD8α(+) dendritic cell development operating during infection with intracellular pathogens and mediated by the cytokines interleukin (IL)-12 and interferon-γ. This alternative pathway results from molecular compensation for Batf3 provided by the related AP1 factors Batf, which also functions in T and B cells, and Batf2 induced by cytokines in response to infection. Reciprocally, physiological compensation between Batf and Batf3 also occurs in T cells for expression of IL-10 and CTLA4. Compensation among BATF factors is based on the shared capacity of their leucine zipper domains to interact with non-AP1 factors such as IRF4 and IRF8 to mediate cooperative gene activation. Conceivably, manipulating this alternative pathway of dendritic cell development could be of value in augmenting immune responses to vaccines.
Assuntos
Fatores de Transcrição de Zíper de Leucina Básica/metabolismo , Células Dendríticas/citologia , Células Dendríticas/metabolismo , Fatores Reguladores de Interferon/metabolismo , Animais , Apresentação de Antígeno , Antígenos CD/metabolismo , Fatores de Transcrição de Zíper de Leucina Básica/química , Fatores de Transcrição de Zíper de Leucina Básica/deficiência , Fatores de Transcrição de Zíper de Leucina Básica/genética , Linfócitos T CD4-Positivos/citologia , Linfócitos T CD4-Positivos/imunologia , Antígenos CD8/imunologia , Antígenos CD8/metabolismo , Antígeno CTLA-4/metabolismo , Diferenciação Celular , Linhagem Celular Tumoral , Linhagem da Célula , Células Dendríticas/imunologia , Feminino , Fibrossarcoma/imunologia , Fibrossarcoma/metabolismo , Fibrossarcoma/patologia , Regulação da Expressão Gênica , Cadeias alfa de Integrinas/metabolismo , Fatores Reguladores de Interferon/deficiência , Fatores Reguladores de Interferon/genética , Interleucina-10/metabolismo , Interleucina-12/imunologia , Interleucina-12/metabolismo , Zíper de Leucina , Masculino , Camundongos , Camundongos Endogâmicos C57BL , Transplante de Neoplasias , Proteína Oncogênica p65(gag-jun)/metabolismo , Ligação Proteica , Estrutura Terciária de Proteína , Proteínas Repressoras/deficiência , Proteínas Repressoras/genética , Linfócitos T Auxiliares-Indutores/citologia , Linfócitos T Auxiliares-Indutores/imunologia , Linfócitos T Auxiliares-Indutores/metabolismo , Toxoplasma/imunologiaRESUMO
Myeloid ecotropic viral integration site 1 (Meis1) forms a heterodimer with Pbx1 that augments Hox-dependent gene expression and is associated with leukemogenesis and HSC self-renewal. Here we identified 2 independent actions of Meis1 in hematopoietic development: one regulating cellular proliferation and the other involved in megakaryocyte lineage development. First, we found that endogenous Mesp1 indirectly induces Meis1 and Meis2 in endothelial cells derived from embryonic stem cells. Overexpression of Meis1 and Meis2 greatly enhanced the formation of hematopoietic colonies from embryonic stem cells, with the exception of erythroid colonies, by maintaining hematopoietic progenitor cells in a state of proliferation. Second, overexpression of Meis1 repressed the development of early erythroid progenitors, acting in vivo at the megakaryocyte-erythroid progenitor stage to skew development away from erythroid generation and toward megakaryocyte development. This previously unrecognized action of Meis1 may explain the embryonic lethality observed in Meis1(-/-) mice that arises from failure of lymphatic-venous separation and can result as a consequence of defective platelet generation. These results show that Meis1 exerts 2 independent functions, with its role in proliferation of hematopoietic progenitors acting earlier in development from its influence on the fate choice at the megakaryocyte-erythroid progenitor between megakaryocytic and erythroid development.
Assuntos
Células Precursoras Eritroides/citologia , Células Precursoras Eritroides/fisiologia , Células-Tronco Hematopoéticas/citologia , Células-Tronco Hematopoéticas/fisiologia , Proteínas de Homeodomínio/fisiologia , Proteínas de Neoplasias/fisiologia , Animais , Fatores de Transcrição Hélice-Alça-Hélice Básicos/genética , Fatores de Transcrição Hélice-Alça-Hélice Básicos/fisiologia , Linhagem Celular , Linhagem da Célula/genética , Linhagem da Célula/fisiologia , Proliferação de Células , Ensaio de Unidades Formadoras de Colônias , Eritropoese/genética , Eritropoese/fisiologia , Regulação da Expressão Gênica no Desenvolvimento , Hematopoese/genética , Hematopoese/fisiologia , Proteínas de Homeodomínio/genética , Megacariócitos/citologia , Megacariócitos/fisiologia , Camundongos , Camundongos Knockout , Proteína Meis1 , Proteínas de Neoplasias/deficiência , Proteínas de Neoplasias/genética , Isoformas de Proteínas/genética , Isoformas de Proteínas/fisiologia , Transdução de SinaisRESUMO
Distinguishing dendritic cells (DCs) from other cells of the mononuclear phagocyte system is complicated by the shared expression of cell surface markers such as CD11c. In this study, we identified Zbtb46 (BTBD4) as a transcription factor selectively expressed by classical DCs (cDCs) and their committed progenitors but not by plasmacytoid DCs (pDCs), monocytes, macrophages, or other lymphoid or myeloid lineages. Using homologous recombination, we replaced the first coding exon of Zbtb46 with GFP to inactivate the locus while allowing detection of Zbtb46 expression. GFP expression in Zbtb46(gfp/+) mice recapitulated the cDC-specific expression of the native locus, being restricted to cDC precursors (pre-cDCs) and lymphoid organ- and tissue-resident cDCs. GFP(+) pre-cDCs had restricted developmental potential, generating cDCs but not pDCs, monocytes, or macrophages. Outside the immune system, Zbtb46 was expressed in committed erythroid progenitors and endothelial cell populations. Zbtb46 overexpression in bone marrow progenitor cells inhibited granulocyte potential and promoted cDC development, and although cDCs developed in Zbtb46(gfp/gfp) (Zbtb46 deficient) mice, they maintained expression of granulocyte colony-stimulating factor and leukemia inhibitory factor receptors, which are normally down-regulated in cDCs. Thus, Zbtb46 may help enforce cDC identity by restricting responsiveness to non-DC growth factors and may serve as a useful marker to identify rare cDC progenitors and distinguish between cDCs and other mononuclear phagocyte lineages.
Assuntos
Linhagem da Célula/imunologia , Células Dendríticas/imunologia , Fatores de Transcrição/genética , Fatores de Transcrição/imunologia , Animais , Sequência de Bases , Células da Medula Óssea/citologia , Células da Medula Óssea/metabolismo , Diferenciação Celular/imunologia , Células Dendríticas/citologia , Células Endoteliais/metabolismo , Regulação da Expressão Gênica , Fator Estimulador de Colônias de Granulócitos , Proteínas de Fluorescência Verde/genética , Proteínas de Fluorescência Verde/metabolismo , Recombinação Homóloga , Tecido Linfoide/citologia , Tecido Linfoide/imunologia , Tecido Linfoide/metabolismo , Macrófagos/metabolismo , Camundongos , Camundongos Endogâmicos C57BL , Camundongos Mutantes , Dados de Sequência Molecular , Células Mieloides/metabolismo , Receptores de OSM-LIF , Células-Tronco/fisiologia , Fatores de Transcrição/metabolismoRESUMO
Dendritic cells (DCs) subsets differ in precursor cell of origin, functional properties, requirements for growth factors, and dependence on transcription factors. Lymphoid-tissue resident CD8α(+) conventional DCs (cDCs) and CD11b(low/-)CD103(+) non-lymphoid DCs are developmentally related, each being dependent on FMS-like tyrosine kinase 3 ligand (Flt3L), and requiring the transcription factors Batf3, Irf8, and Id2 for development. It was recently suggested that granulocyte/macrophage colony stimulating factor (GM-CSF) was required for the development of dermal CD11b(low/-)Langerin(+)CD103(+) DCs, and that this dermal DC subset was required for priming autoreactive T cells in experimental autoimmune encephalitis (EAE). Here, we compared development of peripheral tissue DCs and susceptibility to EAE in GM-CSF receptor deficient (Csf2rb(-/-)) and Batf3(-/-) mice. We find that Batf3-dependent dermal CD11b(low/-)Langerin(+) DCs do develop in Csf2rb(-/-) mice, but that they express reduced, but not absent, levels of CD103. Further, Batf3(-/-) mice lacking all peripheral CD11b(low/-) DCs show robust Th cell priming after subcutaneous immunization and are susceptible to EAE. Our results suggest that defective T effector priming and resistance to EAE exhibited by Csf2rb(-/-) mice does not result from the absence of dermal CD11b(low/-)Langerin(+)CD103(+) DCs.
Assuntos
Fatores de Transcrição de Zíper de Leucina Básica/metabolismo , Antígeno CD11b/metabolismo , Apresentação Cruzada/efeitos dos fármacos , Células Dendríticas/imunologia , Fator Estimulador de Colônias de Granulócitos e Macrófagos/farmacologia , Imunização , Proteínas Repressoras/metabolismo , Linfócitos T Auxiliares-Indutores/imunologia , Animais , Antígenos CD/metabolismo , Antígenos de Superfície/metabolismo , Antígenos CD8/metabolismo , Subunidade beta Comum dos Receptores de Citocinas/deficiência , Células Dendríticas/efeitos dos fármacos , Derme/imunologia , Derme/patologia , Suscetibilidade a Doenças , Encefalomielite Autoimune Experimental/imunologia , Encefalomielite Autoimune Experimental/patologia , Cadeias alfa de Integrinas/metabolismo , Lectinas Tipo C/metabolismo , Linfonodos/efeitos dos fármacos , Linfonodos/imunologia , Lectinas de Ligação a Manose/metabolismo , Camundongos , Camundongos Endogâmicos C57BL , Proteínas da Mielina/imunologia , Glicoproteína Mielina-Oligodendrócito , Transdução de Sinais/efeitos dos fármacos , Baço/efeitos dos fármacos , Baço/imunologia , Tela Subcutânea/efeitos dos fármacos , Tela Subcutânea/imunologia , Linfócitos T Auxiliares-Indutores/efeitos dos fármacosRESUMO
Dendritic cells (DCs) are a heterogeneous population within the mononuclear phagocyte system (MPS) that derive from bone marrow precursors. Commitment and specification of hematopoietic progenitors to the DC lineage is critical for the proper induction of both immunity and tolerance. This review summarizes the important cytokines and transcription factors required for differentiation of the DC lineage as well as further diversification into specific DC subsets. We highlight recent advances in the characterization of immediate DC precursors arising from the common myeloid progenitor (CMP). Particular emphasis is placed on the corresponding temporal expression of relevant factors involved in regulating developmental options.
Assuntos
Diferenciação Celular , Células Dendríticas/citologia , Fatores de Transcrição/metabolismo , Linhagem da Célula , Humanos , Modelos BiológicosRESUMO
CD8α(+) dendritic cells (DCs) prime cytotoxic T lymphocytes during viral infections and produce interleukin-12 in response to pathogens. Although the loss of CD8α(+) DCs in Batf3(-/-) mice increases their susceptibility to several pathogens, we observed that Batf3(-/-) mice exhibited enhanced resistance to the intracellular bacterium Listeria monocytogenes. In wild-type mice, Listeria organisms, initially located in the splenic marginal zone, migrated to the periarteriolar lymphoid sheath (PALS) where they grew exponentially and induced widespread lymphocyte apoptosis. In Batf3(-/-) mice, however, Listeria organisms remain trapped in the marginal zone, failed to traffic into the PALS, and were rapidly cleared by phagocytes. In addition, Batf3(-/-) mice, which lacked the normal population of hepatic CD103(+) peripheral DCs, also showed protection from liver infection. These results suggest that Batf3-dependent CD8α(+) and CD103(+) DCs provide initial cellular entry points within the reticuloendothelial system by which Listeria establishes productive infection.
Assuntos
Células Dendríticas/metabolismo , Listeria monocytogenes/fisiologia , Listeriose/imunologia , Linfonodos/metabolismo , Baço/metabolismo , Animais , Antígenos CD/biossíntese , Apoptose/genética , Fatores de Transcrição de Zíper de Leucina Básica/genética , Antígenos CD8/biossíntese , Células Dendríticas/imunologia , Células Dendríticas/microbiologia , Células Dendríticas/patologia , Imunidade Inata/genética , Cadeias alfa de Integrinas/biossíntese , Listeria monocytogenes/patogenicidade , Listeriose/microbiologia , Linfonodos/imunologia , Linfonodos/microbiologia , Linfonodos/patologia , Linfócitos/patologia , Camundongos , Camundongos Endogâmicos , Camundongos Knockout , Fagocitose/genética , Proteínas Repressoras/genética , Baço/imunologia , Baço/microbiologia , Baço/patologia , VirulênciaRESUMO
Although CD103-expressing dendritic cells (DCs) are widely present in nonlymphoid tissues, the transcription factors controlling their development and their relationship to other DC subsets remain unclear. Mice lacking the transcription factor Batf3 have a defect in the development of CD8alpha+ conventional DCs (cDCs) within lymphoid tissues. We demonstrate that Batf3(-/-) mice also lack CD103+CD11b- DCs in the lung, intestine, mesenteric lymph nodes (MLNs), dermis, and skin-draining lymph nodes. Notably, Batf3(-/-) mice displayed reduced priming of CD8 T cells after pulmonary Sendai virus infection, with increased pulmonary inflammation. In the MLNs and intestine, Batf3 deficiency resulted in the specific lack of CD103+CD11b- DCs, with the population of CD103+CD11b+ DCs remaining intact. Batf3(-/-) mice showed no evidence of spontaneous gastrointestinal inflammation and had a normal contact hypersensitivity (CHS) response, despite previous suggestions that CD103+ DCs were required for immune homeostasis in the gut and CHS. The relationship between CD8alpha+ cDCs and nonlymphoid CD103+ DCs implied by their shared dependence on Batf3 was further supported by similar patterns of gene expression and their shared developmental dependence on the transcription factor Irf8. These data provide evidence for a developmental relationship between lymphoid organ-resident CD8alpha+ cDCs and nonlymphoid CD103+ DCs.
Assuntos
Antígenos CD/metabolismo , Antígenos CD8/metabolismo , Células Dendríticas/citologia , Células Dendríticas/metabolismo , Cadeias alfa de Integrinas/metabolismo , Animais , Antígenos de Superfície/genética , Fatores de Transcrição de Zíper de Leucina Básica/genética , Células Dendríticas/imunologia , Dermatite de Contato/imunologia , Dermatite de Contato/patologia , Dinitrofluorbenzeno/imunologia , Feminino , Expressão Gênica/genética , Expressão Gênica/imunologia , Fatores Reguladores de Interferon/genética , Mucosa Intestinal/citologia , Mucosa Intestinal/imunologia , Pulmão/citologia , Pulmão/imunologia , Linfonodos/citologia , Linfonodos/imunologia , Masculino , Mesentério/citologia , Mesentério/imunologia , Camundongos , Camundongos Endogâmicos C3H , Camundongos Endogâmicos C57BL , Camundongos Knockout , Camundongos Mutantes , Análise de Sequência com Séries de Oligonucleotídeos , Receptor de Fator Estimulador de Colônias de Macrófagos/genética , Proteínas Repressoras/genética , Infecções por Respirovirus/imunologia , Vírus Sendai/imunologia , Pele/citologia , Pele/imunologia , Linfócitos T/imunologia , Fatores de Transcrição/genética , Tirosina Quinase 3 Semelhante a fms/genéticaRESUMO
Susceptibility to Crohn's disease, a complex inflammatory disease involving the small intestine, is controlled by over 30 loci. One Crohn's disease risk allele is in ATG16L1, a gene homologous to the essential yeast autophagy gene ATG16 (ref. 2). It is not known how ATG16L1 or autophagy contributes to intestinal biology or Crohn's disease pathogenesis. To address these questions, we generated and characterized mice that are hypomorphic for ATG16L1 protein expression, and validated conclusions on the basis of studies in these mice by analysing intestinal tissues that we collected from Crohn's disease patients carrying the Crohn's disease risk allele of ATG16L1. Here we show that ATG16L1 is a bona fide autophagy protein. Within the ileal epithelium, both ATG16L1 and a second essential autophagy protein ATG5 are selectively important for the biology of the Paneth cell, a specialized epithelial cell that functions in part by secretion of granule contents containing antimicrobial peptides and other proteins that alter the intestinal environment. ATG16L1- and ATG5-deficient Paneth cells exhibited notable abnormalities in the granule exocytosis pathway. In addition, transcriptional analysis revealed an unexpected gain of function specific to ATG16L1-deficient Paneth cells including increased expression of genes involved in peroxisome proliferator-activated receptor (PPAR) signalling and lipid metabolism, of acute phase reactants and of two adipocytokines, leptin and adiponectin, known to directly influence intestinal injury responses. Importantly, Crohn's disease patients homozygous for the ATG16L1 Crohn's disease risk allele displayed Paneth cell granule abnormalities similar to those observed in autophagy-protein-deficient mice and expressed increased levels of leptin protein. Thus, ATG16L1, and probably the process of autophagy, have a role within the intestinal epithelium of mice and Crohn's disease patients by selective effects on the cell biology and specialized regulatory properties of Paneth cells.