RESUMO
Spleen marginal zone (MZ) B cells are important for antibody responses against blood-borne antigens. The signals they use to detect exposure to blood are not well defined. Here, using intravital two-photon microscopy in mice, we observe transient contacts between MZ B cells and red blood cells that are in flow. We show that MZ B cells use adhesion G-protein-coupled receptor ADGRE5 (CD97) for retention in the spleen. CD97 function in MZ B cells depends on its ability to undergo autoproteolytic cleavage and signaling via Gα13 and ARHGEF1. Red blood cell expression of the CD97 ligand CD55 is required for MZ B cell homeostasis. Applying a pulling force on CD97-transfected cells using an optical C-trap and CD55+ beads leads to accumulation of active RhoA and membrane retraction. Finally, we show that CD97 deficiency leads to a reduced T cell-independent IgM response. Thus, our studies provide evidence that MZ B cells use mechanosensing to position in a manner that enhances antibody responses against blood-borne antigens.
Assuntos
Linfócitos B , Tecido Linfoide , Camundongos , Animais , Baço/metabolismo , Transdução de Sinais , Antígenos CD55/metabolismo , EritrócitosRESUMO
While intestinal Th17 cells are critical for maintaining tissue homeostasis, recent studies have implicated their roles in the development of extra-intestinal autoimmune diseases including multiple sclerosis. However, the mechanisms by which tissue Th17 cells mediate these dichotomous functions remain unknown. Here, we characterized the heterogeneity, plasticity, and migratory phenotypes of tissue Th17 cells in vivo by combined fate mapping with profiling of the transcriptomes and TCR clonotypes of over 84,000 Th17 cells at homeostasis and during CNS autoimmune inflammation. Inter- and intra-organ single-cell analyses revealed a homeostatic, stem-like TCF1+ IL-17+ SLAMF6+ population that traffics to the intestine where it is maintained by the microbiota, providing a ready reservoir for the IL-23-driven generation of encephalitogenic GM-CSF+ IFN-γ+ CXCR6+ T cells. Our study defines a direct in vivo relationship between IL-17+ non-pathogenic and GM-CSF+ and IFN-γ+ pathogenic Th17 populations and provides a mechanism by which homeostatic intestinal Th17 cells direct extra-intestinal autoimmune disease.
Assuntos
Autoimunidade , Intestinos/imunologia , Células-Tronco/metabolismo , Células Th17/imunologia , Animais , Movimento Celular , Células Clonais , Encefalomielite Autoimune Experimental/imunologia , Fator Estimulador de Colônias de Granulócitos e Macrófagos/metabolismo , Homeostase , Humanos , Interferon gama/metabolismo , Interleucina-17/metabolismo , Camundongos Endogâmicos C57BL , Especificidade de Órgãos , RNA/metabolismo , RNA-Seq , Receptores de Antígenos de Linfócitos T/metabolismo , Receptores CXCR6/metabolismo , Receptores de Interleucina/metabolismo , Reprodutibilidade dos Testes , Família de Moléculas de Sinalização da Ativação Linfocitária/metabolismo , Análise de Célula Única , Baço/metabolismoRESUMO
Re-activation and clonal expansion of tumor-specific antigen (TSA)-reactive T cells are critical to the success of checkpoint blockade and adoptive transfer of tumor-infiltrating lymphocyte (TIL)-based therapies. There are no reliable markers to specifically identify the repertoire of TSA-reactive T cells due to their heterogeneous composition. We introduce FucoID as a general platform to detect endogenous antigen-specific T cells for studying their biology. Through this interaction-dependent labeling approach, intratumoral TSA-reactive CD4+, CD8+ T cells, and TSA-suppressive CD4+ T cells can be detected and separated from bystander T cells based on their cell-surface enzymatic fucosyl-biotinylation. Compared to bystander TILs, TSA-reactive TILs possess a distinct T cell receptor (TCR) repertoire and unique gene features. Although exhibiting a dysfunctional phenotype, TSA-reactive CD8+ TILs possess substantial capabilities of proliferation and tumor-specific killing. Featuring genetic manipulation-free procedures and a quick turnover cycle, FucoID should have the potential of accelerating the pace of personalized cancer treatment.
Assuntos
Antígenos de Neoplasias/metabolismo , Comunicação Celular , Fucose/metabolismo , Linfócitos T/imunologia , Linfócitos T/patologia , Adulto , Sequência de Aminoácidos , Animais , Biomarcadores Tumorais/metabolismo , Biotinilação , Efeito Espectador/imunologia , Linfócitos T CD8-Positivos/imunologia , Membrana Celular/metabolismo , Células Dendríticas/metabolismo , Modelos Animais de Doenças , Feminino , Fucosiltransferases/metabolismo , Perfilação da Expressão Gênica , Regulação Neoplásica da Expressão Gênica , Helicobacter pylori/enzimologia , Humanos , Imunidade , Linfócitos do Interstício Tumoral/imunologia , Melanoma Experimental/genética , Melanoma Experimental/imunologia , Melanoma Experimental/patologia , Camundongos Endogâmicos C57BL , Peptídeos/química , Fenótipo , Receptor de Morte Celular Programada 1/metabolismo , Baço/metabolismoRESUMO
The brain is a site of relative immune privilege. Although CD4 T cells have been reported in the central nervous system, their presence in the healthy brain remains controversial, and their function remains largely unknown. We used a combination of imaging, single cell, and surgical approaches to identify a CD69+ CD4 T cell population in both the mouse and human brain, distinct from circulating CD4 T cells. The brain-resident population was derived through in situ differentiation from activated circulatory cells and was shaped by self-antigen and the peripheral microbiome. Single-cell sequencing revealed that in the absence of murine CD4 T cells, resident microglia remained suspended between the fetal and adult states. This maturation defect resulted in excess immature neuronal synapses and behavioral abnormalities. These results illuminate a role for CD4 T cells in brain development and a potential interconnected dynamic between the evolution of the immunological and neurological systems. VIDEO ABSTRACT.
Assuntos
Encéfalo/citologia , Linfócitos T CD4-Positivos/metabolismo , Feto/citologia , Microglia/citologia , Microglia/metabolismo , Sinapses/metabolismo , Adulto , Animais , Antígenos CD/metabolismo , Antígenos de Diferenciação de Linfócitos T/metabolismo , Escala de Avaliação Comportamental , Células Sanguíneas/citologia , Células Sanguíneas/metabolismo , Encéfalo/embriologia , Encéfalo/metabolismo , Criança , Feminino , Feto/embriologia , Humanos , Lectinas Tipo C/metabolismo , Pulmão/citologia , Pulmão/metabolismo , Masculino , Camundongos , Camundongos Endogâmicos C57BL , Camundongos Knockout , Pessoa de Meia-Idade , Neurogênese/genética , Parabiose , Células Piramidais/metabolismo , Células Piramidais/fisiologia , Análise de Célula Única , Baço/citologia , Baço/metabolismo , Sinapses/imunologia , TranscriptomaRESUMO
Current approaches to reducing the latent HIV reservoir entail first reactivating virus-containing cells to become visible to the immune system. A critical second step is killing these cells to reduce reservoir size. Endogenous cytotoxic T-lymphocytes (CTLs) may not be adequate because of cellular exhaustion and the evolution of CTL-resistant viruses. We have designed a universal CAR-T cell platform based on CTLs engineered to bind a variety of broadly neutralizing anti-HIV antibodies. We show that this platform, convertibleCAR-T cells, effectively kills HIV-infected, but not uninfected, CD4 T cells from blood, tonsil, or spleen and only when armed with anti-HIV antibodies. convertibleCAR-T cells also kill within 48 h more than half of the inducible reservoir found in blood of HIV-infected individuals on antiretroviral therapy. The modularity of convertibleCAR-T cell system, which allows multiplexing with several anti-HIV antibodies yielding greater breadth and control, makes it a promising tool for attacking the latent HIV reservoir.
Assuntos
Anticorpos Anti-Idiotípicos/farmacologia , Infecções por HIV/terapia , Imunoterapia Adotiva , Replicação Viral/genética , Animais , Anticorpos Anti-Idiotípicos/imunologia , Células HEK293 , Infecções por HIV/genética , Infecções por HIV/imunologia , Infecções por HIV/virologia , HIV-1/imunologia , HIV-1/patogenicidade , Humanos , Camundongos , Tonsila Palatina/imunologia , Tonsila Palatina/metabolismo , Cultura Primária de Células , Baço/imunologia , Baço/metabolismo , Linfócitos T Citotóxicos/imunologia , Latência Viral/imunologia , Replicação Viral/imunologiaRESUMO
Fasting is associated with improved outcomes in cancer. Here, we investigated the impact of fasting on natural killer (NK) cell anti-tumor immunity. Cyclic fasting improved immunity against solid and metastatic tumors in an NK cell-dependent manner. During fasting, NK cells underwent redistribution from peripheral tissues to the bone marrow (BM). In humans, fasting also reduced circulating NK cell numbers. NK cells in the spleen of fasted mice were metabolically rewired by elevated concentrations of fatty acids and glucocorticoids, augmenting fatty acid metabolism via increased expression of the enzyme CPT1A, and Cpt1a deletion impaired NK cell survival and function in this setting. In parallel, redistribution of NK cells to the BM during fasting required the trafficking mediators S1PR5 and CXCR4. These cells were primed by an increased pool of interleukin (IL)-12-expressing BM myeloid cells, which improved IFN-γ production. Our findings identify a link between dietary restriction and optimized innate immune responses, with the potential to enhance immunotherapy strategies.
Assuntos
Jejum , Células Matadoras Naturais , Camundongos Endogâmicos C57BL , Animais , Células Matadoras Naturais/imunologia , Células Matadoras Naturais/metabolismo , Camundongos , Humanos , Neoplasias/imunologia , Medula Óssea/imunologia , Medula Óssea/metabolismo , Camundongos Knockout , Interferon gama/metabolismo , Interferon gama/imunologia , Baço/imunologia , Baço/metabolismo , Imunidade Inata/imunologia , Interleucina-12/metabolismo , Interleucina-12/imunologia , Receptores CXCR4/metabolismoRESUMO
Visceral adipose tissue (VAT) hosts a population of regulatory T (Treg) cells, with a unique phenotype, that controls local and systemic inflammation and metabolism. Generation of a T cell receptor transgenic mouse line, wherein VAT Tregs are highly enriched, facilitated study of their provenance, dependencies, and activities. We definitively established a role for T cell receptor specificity, uncovered an unexpected function for the primordial Treg transcription-factor, Foxp3, evidenced a cell-intrinsic role for interleukin-33 receptor, and ordered these dependencies within a coherent scenario. Genesis of the VAT-Treg phenotype entailed a priming step in the spleen, permitting them to exit the lymphoid organs and surveil nonlymphoid tissues, and a final diversification process within VAT, in response to microenvironmental cues. Understanding the principles of tissue-Treg biology is a prerequisite for precision-targeting strategies.
Assuntos
Gordura Intra-Abdominal/metabolismo , Receptores de Antígenos de Linfócitos T/genética , Linfócitos T Reguladores/metabolismo , Animais , Montagem e Desmontagem da Cromatina , Fatores de Transcrição Forkhead/metabolismo , Proteína 1 Semelhante a Receptor de Interleucina-1/genética , Proteína 1 Semelhante a Receptor de Interleucina-1/metabolismo , Gordura Intra-Abdominal/imunologia , Macrófagos/citologia , Macrófagos/imunologia , Macrófagos/metabolismo , Masculino , Camundongos , Camundongos Endogâmicos C57BL , Camundongos Transgênicos , PPAR gama/genética , PPAR gama/metabolismo , Fenótipo , RNA/química , RNA/isolamento & purificação , RNA/metabolismo , Receptores de Antígenos de Linfócitos T/metabolismo , Receptores de Interleucina/metabolismo , Análise de Célula Única , Baço/imunologia , Baço/metabolismo , Linfócitos T Reguladores/citologia , Linfócitos T Reguladores/imunologia , TranscriptomaRESUMO
Located within red pulp cords, splenic red pulp macrophages (RPMs) are constantly exposed to the blood flow, clearing senescent red blood cells (RBCs) and recycling iron from hemoglobin. Here, we studied the mechanisms underlying RPM homeostasis, focusing on the involvement of stromal cells as these cells perform anchoring and nurturing macrophage niche functions in lymph nodes and liver. Microscopy revealed that RPMs are embedded in a reticular meshwork of red pulp fibroblasts characterized by the expression of the transcription factor Wilms' Tumor 1 (WT1) and colony stimulating factor 1 (CSF1). Conditional deletion of Csf1 in WT1+ red pulp fibroblasts, but not white pulp fibroblasts, drastically altered the RPM network without altering circulating CSF1 levels. Upon RPM depletion, red pulp fibroblasts transiently produced the monocyte chemoattractants CCL2 and CCL7, thereby contributing to the replenishment of the RPM network. Thus, red pulp fibroblasts anchor and nurture RPM, a function likely conserved in humans.
Assuntos
Fibroblastos/metabolismo , Fator Estimulador de Colônias de Macrófagos/metabolismo , Macrófagos/imunologia , Baço/citologia , Proteínas WT1/metabolismo , Animais , Quimiocina CCL2/metabolismo , Quimiocina CCL7/metabolismo , Regulação da Expressão Gênica , Humanos , Imunidade Inata/imunologia , Ferro/metabolismo , Fator Estimulador de Colônias de Macrófagos/genética , Camundongos , Camundongos Endogâmicos C57BL , Camundongos Knockout , Monócitos/imunologia , Ratos , Transdução de Sinais/imunologia , Baço/metabolismoRESUMO
Central memory CD8+ T cells (Tcm) control systemic secondary infections and can protect from chronic infection and cancer as a result of their stem-cell-like capacity to expand, differentiate, and self-renew. Central memory is generally thought to emerge following pathogen clearance and to form based on the de-differentiation of cytolytic effector cells. Here, we uncovered rare effector-phase CD8+ T cells expressing high amounts of the transcription factor Tcf7 (Tcf1) that showed no evidence of prior cytolytic differentiation and that displayed key hallmarks of Tcm cells. These effector-phase Tcf7hi cells quantitatively yielded Tcm cells based on lineage tracing. Mechanistically, Tcf1 counteracted the differentiation of Tcf7hi cells and sustained the expression of conserved adult stem-cell genes that were critical for CD8+ T cell stemness. The discovery of stem-cell-like CD8+ T cells during the effector response to acute infection provides an opportunity to optimize Tcm cell formation by vaccination.
Assuntos
Linfócitos T CD8-Positivos/imunologia , Linfócitos T CD8-Positivos/metabolismo , Diferenciação Celular/imunologia , Citotoxicidade Imunológica , Fator 1-alfa Nuclear de Hepatócito/metabolismo , Memória Imunológica , Fator 1 de Transcrição de Linfócitos T/metabolismo , Animais , Linfócitos T CD8-Positivos/citologia , Diferenciação Celular/genética , Montagem e Desmontagem da Cromatina , Citotoxicidade Imunológica/genética , Imunofluorescência , Expressão Gênica , Fator 1-alfa Nuclear de Hepatócito/química , Fator 1-alfa Nuclear de Hepatócito/genética , Humanos , Imunização , Memória Imunológica/genética , Imunofenotipagem , Camundongos , Camundongos Endogâmicos C57BL , Camundongos Knockout , Modelos Moleculares , Conformação Proteica , Baço/imunologia , Baço/metabolismo , Relação Estrutura-Atividade , Fator 1 de Transcrição de Linfócitos T/química , Fator 1 de Transcrição de Linfócitos T/genéticaRESUMO
Lymphocyte homeostasis and immune surveillance require that T and B cells continuously recirculate between secondary lymphoid organs. Here, we used intravital microscopy to define lymphocyte trafficking routes within the spleen, an environment of open blood circulation and shear forces unlike other lymphoid organs. Upon release from arterioles into the red pulp sinuses, T cells latched onto perivascular stromal cells in a manner that was independent of the chemokine receptor CCR7 but sensitive to Gi protein-coupled receptor inhibitors. This latching sheltered T cells from blood flow and enabled unidirectional migration to the bridging channels and then to T zones, entry into which required CCR7. Inflammatory responses modified the chemotactic cues along the perivascular homing paths, leading to rapid block of entry. Our findings reveal a role for vascular structures in lymphocyte recirculation through the spleen, indicating the existence of separate entry and exit routes and that of a checkpoint located at the gate to the T zone.
Assuntos
Movimento Celular/imunologia , Receptores CCR7/imunologia , Baço/imunologia , Linfócitos T/imunologia , Animais , Linfócitos B/citologia , Linfócitos B/imunologia , Linfócitos B/metabolismo , Humanos , Vigilância Imunológica/imunologia , Microscopia Intravital , Proteínas Luminescentes/genética , Proteínas Luminescentes/metabolismo , Linfócitos/citologia , Linfócitos/imunologia , Linfócitos/metabolismo , Camundongos Endogâmicos C57BL , Camundongos Transgênicos , Receptores CCR7/genética , Receptores CCR7/metabolismo , Transdução de Sinais/imunologia , Baço/citologia , Baço/metabolismo , Linfócitos T/citologia , Linfócitos T/metabolismoRESUMO
Splenic red pulp macrophages (RPMs) contribute to erythrocyte homeostasis and are required for iron recycling. Heme induces the expression of SPIC transcription factor in monocyte-derived macrophages and promotes their differentiation into RPM precursors, pre-RPMs. However, the requirements for differentiation into mature RPMs remain unknown. Here, we have demonstrated that interleukin (IL)-33 associated with erythrocytes and co-cooperated with heme to promote the generation of mature RPMs through activation of the MyD88 adaptor protein and ERK1/2 kinases downstream of the IL-33 receptor, IL1RL1. IL-33- and IL1RL1-deficient mice showed defective iron recycling and increased splenic iron deposition. Gene expression and chromatin accessibility studies revealed a role for GATA transcription factors downstream of IL-33 signaling during the development of pre-RPMs that retained full potential to differentiate into RPMs. Thus, IL-33 instructs the development of RPMs as a response to physiological erythrocyte damage with important implications to iron recycling and iron homeostasis.
Assuntos
Proteína 1 Semelhante a Receptor de Interleucina-1/imunologia , Interleucina-33/imunologia , Ferro/metabolismo , Macrófagos/imunologia , Transdução de Sinais/imunologia , Baço/metabolismo , Animais , Eritrócitos/imunologia , Eritrócitos/metabolismo , Heme/imunologia , Heme/metabolismo , Homeostase/imunologia , Proteína 1 Semelhante a Receptor de Interleucina-1/genética , Proteína 1 Semelhante a Receptor de Interleucina-1/metabolismo , Interleucina-33/genética , Interleucina-33/metabolismo , Macrófagos/metabolismo , Camundongos Knockout , Proteína Quinase 1 Ativada por Mitógeno/imunologia , Proteína Quinase 1 Ativada por Mitógeno/metabolismo , Proteína Quinase 3 Ativada por Mitógeno/imunologia , Proteína Quinase 3 Ativada por Mitógeno/metabolismo , Fator 88 de Diferenciação Mieloide/imunologia , Fator 88 de Diferenciação Mieloide/metabolismo , Baço/citologiaRESUMO
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
Non-lymphoid tissues (NLTs) harbor a pool of adaptive immune cells with largely unexplored phenotype and development. We used single-cell RNA-seq to characterize 35,000 CD4+ regulatory (Treg) and memory (Tmem) T cells in mouse skin and colon, their respective draining lymph nodes (LNs) and spleen. In these tissues, we identified Treg cell subpopulations with distinct degrees of NLT phenotype. Subpopulation pseudotime ordering and gene kinetics were consistent in recruitment to skin and colon, yet the initial NLT-priming in LNs and the final stages of NLT functional adaptation reflected tissue-specific differences. Predicted kinetics were recapitulated using an in vivo melanoma-induction model, validating key regulators and receptors. Finally, we profiled human blood and NLT Treg and Tmem cells, and identified cross-mammalian conserved tissue signatures. In summary, we describe the relationship between Treg cell heterogeneity and recruitment to NLTs through the combined use of computational prediction and in vivo validation.
Assuntos
Adaptação Fisiológica/imunologia , Análise de Célula Única/métodos , Linfócitos T Reguladores/imunologia , Transcriptoma/imunologia , Adaptação Fisiológica/genética , Animais , Linhagem Celular Tumoral , Movimento Celular/genética , Movimento Celular/imunologia , Colo/imunologia , Colo/metabolismo , Humanos , Memória Imunológica/genética , Memória Imunológica/imunologia , Tecido Linfoide/imunologia , Tecido Linfoide/metabolismo , Camundongos Transgênicos , Neoplasias Experimentais/genética , Neoplasias Experimentais/imunologia , Neoplasias Experimentais/patologia , Pele/imunologia , Pele/metabolismo , Baço/imunologia , Baço/metabolismo , Linfócitos T Reguladores/metabolismoRESUMO
Dendritic cells (DCs) can initiate immune responses by presenting exogenous antigens to T cells via both major histocompatibility complex (MHC) class I pathways and MHC class II pathways. Lysosomal activity has an important role in modulating the balance between these two pathways. The transcription factor TFEB regulates lysosomal function by inducing lysosomal activation. Here we report that TFEB expression inhibited the presentation of exogenous antigen by MHC class I while enhancing presentation via MHC class II. TFEB promoted phagosomal acidification and protein degradation. Furthermore, we found that the activation of TFEB was regulated during DC maturation and that phagosomal acidification was impaired in DCs in which the gene encoding TFEB was silenced. Our data indicate that TFEB is a key participant in the differential regulation of the presentation of exogenous antigens by DCs.
Assuntos
Apresentação de Antígeno/imunologia , Antígenos/imunologia , Fatores de Transcrição de Zíper de Leucina e Hélice-Alça-Hélix Básicos/imunologia , Transdução de Sinais/imunologia , Animais , Fatores de Transcrição de Zíper de Leucina e Hélice-Alça-Hélix Básicos/genética , Fatores de Transcrição de Zíper de Leucina e Hélice-Alça-Hélix Básicos/metabolismo , Células Cultivadas , Chlorocebus aethiops , Apresentação Cruzada/imunologia , Citometria de Fluxo , Células HEK293 , Antígenos de Histocompatibilidade Classe II/imunologia , Humanos , Concentração de Íons de Hidrogênio , Camundongos Endogâmicos C57BL , Microscopia Confocal , Fagossomos/imunologia , Fagossomos/metabolismo , Proteólise , Interferência de RNA/imunologia , Baço/citologia , Baço/imunologia , Baço/metabolismo , Células VeroRESUMO
Despite the importance of signaling lipids, many questions remain about their function because few tools are available for charting lipid gradients in vivo. Here we generated a sphingosine 1-phosphate (S1P) reporter mouse and used this mouse to define the distribution of S1P in the spleen. Unexpectedly, the presence of blood did not serve as a predictor of the concentration of signaling-available S1P. Large areas of the red pulp had low concentrations of S1P, while S1P was sensed by cells inside the white pulp near the marginal sinus. The lipid phosphate phosphatase LPP3 maintained low S1P concentrations in the spleen and enabled efficient shuttling of marginal zone B cells. The exquisitely tight regulation of S1P availability might explain how a single lipid can simultaneously orchestrate the movements of many cells of the immune system.
Assuntos
Lisofosfolipídeos/metabolismo , Esfingosina/análogos & derivados , Baço/metabolismo , Animais , Antígenos de Diferenciação/metabolismo , Linfócitos B/metabolismo , Linhagem Celular , Proteínas de Fluorescência Verde/genética , Proteínas de Fluorescência Verde/metabolismo , Proteínas Luminescentes/genética , Proteínas Luminescentes/metabolismo , Macrófagos/metabolismo , Camundongos Knockout , Camundongos Transgênicos , Microscopia Confocal , Proteínas Mutantes/genética , Proteínas Mutantes/metabolismo , Fosfatidato Fosfatase/genética , Fosfatidato Fosfatase/metabolismo , Receptores de Lisoesfingolipídeo/genética , Receptores de Lisoesfingolipídeo/metabolismo , Lectina 1 Semelhante a Ig de Ligação ao Ácido Siálico/metabolismo , Esfingosina/metabolismo , Receptores de Esfingosina-1-Fosfato , Baço/citologia , Proteína Vermelha FluorescenteRESUMO
There is a growing body of research on the neural control of immunity and inflammation. However, it is not known whether the nervous system can regulate the production of inflammatory myeloid cells from hematopoietic progenitor cells in disease conditions. Myeloid cell numbers in diabetic patients were strongly correlated with plasma concentrations of norepinephrine, suggesting the role of sympathetic neuronal activation in myeloid cell production. The spleens of diabetic patients and mice contained higher numbers of tyrosine hydroxylase (TH)-expressing leukocytes that produced catecholamines. Granulocyte macrophage progenitors (GMPs) expressed the ß2 adrenergic receptor, a target of catecholamines. Ablation of splenic sympathetic neuronal signaling using surgical, chemical, and genetic approaches diminished GMP proliferation and myeloid cell development. Finally, mice lacking TH-producing leukocytes had reduced GMP proliferation, resulting in diminished myelopoiesis. Taken together, our study demonstrates that catecholamines produced by leukocytes and sympathetic nerve termini promote GMP proliferation and myeloid cell development.
Assuntos
Diabetes Mellitus/fisiopatologia , Células Progenitoras de Granulócitos e Macrófagos/citologia , Células Progenitoras de Granulócitos e Macrófagos/metabolismo , Mielopoese , Neuroimunomodulação , Sistema Nervoso Simpático/metabolismo , Antagonistas de Receptores Adrenérgicos beta 2/farmacologia , Animais , Proliferação de Células/efeitos dos fármacos , Diabetes Mellitus/sangue , Modelos Animais de Doenças , Feminino , Humanos , Leucócitos/enzimologia , Leucócitos/metabolismo , Masculino , Camundongos , Células Mieloides/citologia , Mielopoese/efeitos dos fármacos , Neuroimunomodulação/efeitos dos fármacos , Norepinefrina/sangue , Transdução de Sinais/efeitos dos fármacos , Baço/citologia , Baço/inervação , Baço/metabolismo , Sistema Nervoso Simpático/efeitos dos fármacosRESUMO
The differentiation of follicular dendritic cells (FDC) is essential to the remarkable microanatomic plasticity of lymphoid follicles. Here we show that FDC arise from ubiquitous perivascular precursors (preFDC) expressing platelet-derived growth factor receptor ß (PDGFRß). PDGFRß-Cre-driven reporter gene recombination resulted in FDC labeling, whereas conditional ablation of PDGFRß(+)-derived cells abolished FDC, indicating that FDC originate from PDGFRß(+) cells. Lymphotoxin-α-overexpressing prion protein (PrP)(+) kidneys developed PrP(+) FDC after transplantation into PrP(-) mice, confirming that preFDC exist outside lymphoid organs. Adipose tissue-derived PDGFRß(+) stromal-vascular cells responded to FDC maturation factors and, when transplanted into lymphotoxin ß receptor (LTßR)(-) kidney capsules, differentiated into Mfge8(+)CD21/35(+)FcγRIIß(+)PrP(+) FDC capable of trapping immune complexes and recruiting B cells. Spleens of lymphocyte-deficient mice contained perivascular PDGFRß(+) FDC precursors whose expansion required both lymphoid tissue inducer (LTi) cells and lymphotoxin. The ubiquity of preFDC and their strategic location at blood vessels may explain the de novo generation of organized lymphoid tissue at sites of lymphocytic inflammation.
Assuntos
Vasos Sanguíneos/citologia , Células Dendríticas Foliculares/citologia , Baço/citologia , Células-Tronco/citologia , Animais , Linfócitos B/imunologia , Células Dendríticas Foliculares/imunologia , Células Dendríticas Foliculares/metabolismo , Centro Germinativo/citologia , Centro Germinativo/imunologia , Centro Germinativo/metabolismo , Inflamação/patologia , Células Matadoras Naturais/imunologia , Camundongos , Receptor beta de Fator de Crescimento Derivado de Plaquetas/metabolismo , Organismos Livres de Patógenos Específicos , Baço/metabolismoRESUMO
BACKGROUND: Inflammation is pathogenically implicated in pulmonary arterial hypertension; however, it has not been adequately targeted therapeutically. We investigated whether neuromodulation of an anti-inflammatory neuroimmune pathway involving the splenic nerve using noninvasive, focused ultrasound stimulation of the spleen (sFUS) can improve experimental pulmonary hypertension. METHODS: Pulmonary hypertension was induced in rats either by Sugen 5416 (20 mg/kg SQ) injection, followed by 21 (or 35) days of hypoxia (sugen/hypoxia model), or by monocrotaline (60 mg/kg IP) injection (monocrotaline model). Animals were randomized to receive either 12-minute-long sessions of sFUS daily or sham stimulation for 14 days. Catheterizations, echocardiography, indices of autonomic function, lung and heart histology and immunohistochemistry, spleen flow cytometry, and lung single-cell RNA sequencing were performed after treatment to assess the effects of sFUS. RESULTS: Splenic denervation right before induction of pulmonary hypertension results in a more severe disease phenotype. In both sugen/hypoxia and monocrotaline models, sFUS treatment reduces right ventricular systolic pressure by 25% to 30% compared with sham treatment, without affecting systemic pressure, and improves right ventricular function and autonomic indices. sFUS reduces wall thickness, apoptosis, and proliferation in small pulmonary arterioles, suppresses CD3+ and CD68+ cell infiltration in lungs and right ventricular fibrosis and hypertrophy and lowers BNP (brain natriuretic peptide). Beneficial effects persist for weeks after sFUS discontinuation and are more robust with early and longer treatment. Splenic denervation abolishes sFUS therapeutic benefits. sFUS partially normalizes CD68+ and CD8+ T-cell counts in the spleen and downregulates several inflammatory genes and pathways in nonclassical and classical monocytes and macrophages in the lung. Differentially expressed genes in those cell types are significantly enriched for human pulmonary arterial hypertension-associated genes. CONCLUSIONS: sFUS causes dose-dependent, sustained improvement of hemodynamic, autonomic, laboratory, and pathological manifestations in 2 models of experimental pulmonary hypertension. Mechanistically, sFUS normalizes immune cell populations in the spleen and downregulates inflammatory genes and pathways in the lung, many of which are relevant in human disease.
Assuntos
Hipertensão Pulmonar , Baço , Animais , Baço/metabolismo , Masculino , Ratos , Hipertensão Pulmonar/terapia , Hipertensão Pulmonar/metabolismo , Ratos Sprague-Dawley , Modelos Animais de Doenças , Ondas UltrassônicasRESUMO
There is considerable interest in therapeutically engaging human γδ T cells. However, due to the unique TCRs of human γδ T cells, studies from animal models have provided limited directly applicable insights, and human γδ T cells from key immunological tissues remain poorly characterized. In this study, we investigated γδ T cells from human spleen tissue. Compared to blood, where Vδ2+Vγ9+ T cells are the dominant subset, splenic γδ T cells included a variety of TCR types, with Vδ1+ T cells typically being the most frequent. Intracellular cytokine staining revealed that IFN-γ was produced by a substantial fraction of splenic γδ T cells, IL-17A by a small fraction, and IL-4 was minimal. Primary splenic γδ T cells frequently expressed NKG2D (NK group 2 member D) and CD16, whereas expression of DNAM-1 (DNAX accessory molecule 1), CD28, PD-1, TIGIT, and CD94 varied according to subset, and there was generally little expression of natural cytotoxicity receptors, TIM-3, LAG-3, or killer Ig-like receptors. In vitro expansion was associated with marked changes in expression of these activating and inhibitory receptors. Analysis of functional responses of spleen-derived Vδ2+Vγ9+, Vδ1+Vγ9+, and Vδ1+Vγ9- T cell lines to recombinant butyrophilin BTN2A1 and BTN3A1 demonstrated that both Vδ2+Vγ9+ and Vδ1+Vγ9+ T cells were capable of responding to the extracellular domain of BTN2A1, whereas the addition of BTN3A1 only markedly enhanced the responses of Vδ2+Vγ9+ T cells. Conversely, Vδ1+Vγ9+ T cells appeared more responsive than Vδ2+Vγ9+ T cells to TCR-independent NKG2D stimulation. Thus, despite shared recognition of BTN2A1, differential effects of BTN3A1 and coreceptors may segregate target cell responses of Vδ2+Vγ9+ and Vδ1+Vγ9+ T cells.
Assuntos
Receptores de Antígenos de Linfócitos T gama-delta , Baço , Animais , Humanos , Baço/metabolismo , Butirofilinas , Subfamília K de Receptores Semelhantes a Lectina de Células NK , Linfócitos T , Antígenos CDRESUMO
Aberrant levels of the asparaginyl endopeptidase legumain have been linked to inflammation, neurodegeneration, and cancer, yet our understanding of this protease is incomplete. Systematic attempts to identify legumain substrates have been previously confined to in vitro studies, which fail to mirror physiological conditions and obscure biologically relevant cleavage events. Using high-field asymmetric waveform ion mobility spectrometry (FAIMS), we developed a streamlined approach for proteome and N-terminome analyses without the need for N-termini enrichment. Compared to unfractionated proteomic analysis, we demonstrate FAIMS fractionation improves N-termini identification by >2.5 fold, resulting in the identification of >2882 unique N-termini from limited sample amounts. In murine spleens, this approach identifies 6366 proteins and 2528 unique N-termini, with 235 cleavage events enriched in WT compared to legumain-deficient spleens. Among these, 119 neo-N-termini arose from asparaginyl endopeptidase activities, representing novel putative physiological legumain substrates. The direct cleavage of selected substrates by legumain was confirmed using in vitro assays, providing support for the existence of physiologically relevant extra-lysosomal legumain activity. Combined, these data shed critical light on the functions of legumain and demonstrate the utility of FAIMS as an accessible method to improve depth and quality of N-terminomics studies.