Maurizio Gentile - Academia.edu (original) (raw)

Papers by Maurizio Gentile

Annals of the New York Academy of Sciences, Nov 1, 2011

Adaptive co-evolution of mammals and bacteria has led to the establishment of complex commensal c... more Adaptive co-evolution of mammals and bacteria has led to the establishment of complex commensal communities on mucosal surfaces. In spite of having available a wealth of immunesensing and effector mechanisms capable of triggering inflammation in response to microbial intrusion, mucosal immune cells establish an intimate dialogue with microbes to generate a state of hyporesponsiveness against commensals and active readiness against pathogens. A key component of this homeostatic balance is IgA, a noninflammatory antibody isotype produced by mucosal B cells through class switching. This process involves activation of B cells by IgAinducing signals originating from mucosal T cells, dendritic cells, and epithelial cells. Here, we review the mechanisms by which mucosal B cells undergo IgA diversification and production and discuss how the study of primary immunodeficiencies facilitates better understanding of mucosal IgA responses in humans.

The Journal of Immunology

The splenic marginal zone (MZ) generates prompt antibody responses to blood-borne antigens throug... more The splenic marginal zone (MZ) generates prompt antibody responses to blood-borne antigens through a unique subset of innate-like B cells that closely interact with poorly characterized stromal cells. We found that human MZ contained fibroblast-like marginal reticular cells (MRCs) that expressed MAdCAM-1 along with the stromal molecules Thy-1, thrombomodulin, ICAM-1 and VCAM-1, but lacked the endothelial molecules CD31, CD34 and von Willebrand factor. Similar to stromal lymphoid tissue organizers, MRCs up-regulated the adhesion molecules ICAM-1 and VCAM-1 in response to LT and TNF. Moreover, MRCs exposed to microbial TLR ligands, released the B cell-stimulating factors BAFF, APRIL and IL-6, which delivered survival, proliferation, class switching and plasma cell differentiation signals to MZ B cells. Plasma cells emerging from this pathway showed either T cell-dependent or T cell-independent ontogenetic features, and released IgM antibodies to conserved carbohydrate and lipid antige...

The Journal of Immunology, 2019

In the published version of Fig. 6A, the FACS dotplot shown for the stimulation of DG75-COex at 2... more In the published version of Fig. 6A, the FACS dotplot shown for the stimulation of DG75-COex at 25 mg in the presence of IL-21 was inadvertently duplicated from the 5 mg/IL-21 panel. The indicated frequency of 5% of CD38 high CD20 low B cells, however, is correct. This correct value of 5% was used in Fig. 6B, so the error in Fig. 6A did not influence the interpretation of the results and conclusions of this work. Fig. 6A has now been corrected with the correct dotplot for stimulation of DG75-COex at 25 mg in the presence of IL-21. The corrected version of Fig. 6 is shown below. The figure legend was correct as published and is shown below for reference. Fig. 6 has also been corrected in the online version of the article, which now differs from the print version originally published.

Thrombosis and Haemostasis, 2008

SummaryThrombin is a multifunctional serine protease generated at the site of vascular injury tha... more SummaryThrombin is a multifunctional serine protease generated at the site of vascular injury that transforms fibrinogen into fibrin, activates blood platelets and elicits multiple effects on a variety of cell types including endothelial cells, vascular smooth muscle cells (VSMC), monocytes,T lymphocytes and fibroblasts. Cellular effects of thrombin are mediated by protease-activated receptors (PARs), members of the G protein-coupled receptors that carry their own ligand which remains cryptic until unmasked by proteolytic cleavage. Thrombin signalling in platelets contributes to haemostasis and thrombosis. In normal arteries PARs are mainly expressed in endothelial cells, while their expression in VSMC is limited. Endothelial PARs participate in the regulation of vascular tone, vascular permeability and endothelial secretory activity while in VSMC they mediate contraction, migration, proliferation, hypertrophy and production of extra-cellular matrix. PARs contribute to the pro-infla...

Arteriosclerosis, Thrombosis, and Vascular Biology, 2011

Objective— Our aim was to analyze the regulation of CC Chemokine ligand 20 (CCL20) by LDL in huma... more Objective— Our aim was to analyze the regulation of CC Chemokine ligand 20 (CCL20) by LDL in human vascular smooth muscle cells (VSMC). Methods and Results— In asymptomatic subjects, circulating CCL20 levels were higher in patients with hypercholesterolemia (18.5±3.2 versus 9.1±1.3 pg/mL; P <0.01). LDL induced the expression of CCL20 in VSMC in a dose- and time-dependent manner. Increased levels of CCL20 secreted by LDL-treated VSMC significantly induced human lymphocyte migration, an effect reduced by CCL20 silencing. The upregulation of CCL20 by LDL was dependent on the activation of kinase signaling pathways and NF-κB. By site-directed mutagenesis, electrophoretic mobility shift assay, and chromatin immunoprecipitation, we identified a NF-κB site (−80/−71) in CCL20 promoter critical for LDL responsiveness. Lysophosphatidic acid mimicked the upregulation of CCL20 induced by LDL, and minimal oxidation of LDL increased the ability of LDL to induce CCL20 through a mechanism that i...

Frontiers in Bioscience, 2008

Introduction 3. NOR-1 in the vascular wall 3.1. Structure of NOR-1 and regulation of transcriptio... more Introduction 3. NOR-1 in the vascular wall 3.1. Structure of NOR-1 and regulation of transcriptional activity 3.2. Regulation of NOR-1 by extracellular stimuli in vascular cells 3.2.1. Regulation of NOR-1 in VSMC 3.2.2. Regulation of NOR-1 in endothelial cells 3.3. Modulation of NOR-1 transcription by CREB in vascular cells 3.4. Pathophysiological roles of NOR-1 in the vascular wall 4. Modulation of endothelial function by thrombin 4.1. Endothelial functions modulated by thrombin via PAR-1 4.2. NOR-1 is induced by thrombin and mediates endothelial cell growth 4.2.1. Thrombin induces NOR-1 in endothelial cells via PAR-1 4.2.2. CREB activation is critical in NOR-1 induction by thrombin 4.2.3. NOR-1 modulates thrombin-induced DNA synthesis and cell growth 5. Summary and perspectives 6. Acknowledgements 7. References

full#ref-list-1 , 21 of which you can access for free at: cites 51 articles This article average ... more full#ref-list-1 , 21 of which you can access for free at: cites 51 articles This article average * 4 weeks from acceptance to publication Fast Publication! • Every submission reviewed by practicing scientists No Triage! • from submission to initial decision Rapid Reviews! 30 days* • Submit online.

Science, 2013

Guardian of the Gut The intestine is able to tolerate continual exposure to large amounts of comm... more Guardian of the Gut The intestine is able to tolerate continual exposure to large amounts of commensal bacteria and foreign food antigens without triggering an inappropriate inflammatory immune response. In the large intestine, this immunological tolerance is thought to occur via a physical separation between environment and host imposed by a continuous mucous layer built up from the secreted mucin protein, MUC2. However, in the small intestine, this mucous layer is porous, necessitating an additional layer of immune control. Shan et al. (p. 447 , published online 26 September; see the Perspective by Belkaid and Grainger ) now report that in the small intestine, MUC2 plays an active role in immunological tolerance by activating a transcription factor in resident dendritic cells, thereby selectively blocking their ability to launch an inflammatory response. This work identifies MUC2 as a central mediator of immune tolerance to maintain homeostasis in the gut and possibly at other muc...

Nature Immunology, 2014

Innate lymphoid cells (ILCs) regulate stromal, epithelial and immune cells, but their impact on B... more Innate lymphoid cells (ILCs) regulate stromal, epithelial and immune cells, but their impact on B cells remains unclear. We identified RORγt + ILCs nearby the marginal zone (MZ), a splenic compartment containing innate-like B cells that respond to circulating T cell-independent (TI) antigens. Spenic ILCs established a bidirectional crosstalk with MAdCAM-1 + marginal reticular cells by providing tumor necrosis factor (TNF) and lymphotoxin, and activated MZ B cells via BAFF, CD40 ligand and the Notch ligand, Delta-like 1. Splenic ILCs further helped MZ B cells and their plasma cell progeny by co-opting neutrophils through the release of GM-CSF. Users may view, print, copy, download and text and data-mine the content in such documents, for the purposes of academic research, subject always to the full Conditions of use:

Nature Immunology, 2014

In the version of this article originally posted online, the units in the text referring to Figur... more In the version of this article originally posted online, the units in the text referring to Figure 1a were incorrect. The correct unit is "μm" and the correct text is " the receptor depicted would measure about 3 μm, compared with a resting B lymphocyte, with an average diameter of about 7 μm. " The error has been corrected in this file as of

Journal of Virology, 2011

An HIV-1 vaccine remains elusive, in part because various factors limit the quantity and quality ... more An HIV-1 vaccine remains elusive, in part because various factors limit the quantity and quality of the antibodies raised against the viral envelope glycoprotein complex (Env). We hypothesized that targeting Env vaccines directly to B cells, by fusing them to molecules that bind and activate these cells, would improve Env-specific antibody responses. Therefore, we fused trimeric Env gp140 to A PRoliferation-Inducing Ligand (APRIL), B-cell Activating Factor (BAFF), and CD40 Ligand (CD40L). The Env-APRIL, Env-BAFF, and Env-CD40L gp140 trimers all enhanced the expression of activation-induced cytidine deaminase (AID), the enzyme responsible for inducing somatic hypermutation, antibody affinity maturation, and antibody class switching. They also triggered IgM, IgG, and IgA secretion from human B cells in vitro . The Env-APRIL trimers induced higher anti-Env antibody responses in rabbits, including neutralizing antibodies against tier 1 viruses. The enhanced Env-specific responses were n...

Journal of Clinical Investigation, 2013

Common variable immune deficiency (CVID) is an assorted group of primary diseases that clinically... more Common variable immune deficiency (CVID) is an assorted group of primary diseases that clinically manifest with antibody deficiency, infection susceptibility, and autoimmunity. Heterozygous mutations in the gene encoding the tumor necrosis factor receptor superfamily member TACI are associated with CVID and autoimmune manifestations, whereas two mutated alleles prevent autoimmunity. To assess how the number of TACI mutations affects B cell activation and tolerance checkpoints, we analyzed healthy individuals and CVID patients carrying one or two TACI mutations. We found that TACI interacts with the cleaved, mature forms of TLR7 and TLR9 and plays an important role during B cell activation and the central removal of autoreactive B cells in healthy donors and CVID patients. However, only subjects with a single TACI mutation displayed a breached immune tolerance and secreted antinuclear antibodies (ANAs). These antibodies were associated with the presence of circulating B cell lymphoma 6-expressing T follicular helper (Tfh) cells, likely stimulating autoreactive B cells. Thus, TACI mutations may favor CVID by altering B cell activation with coincident impairment of central B cell tolerance, whereas residual B cell responsiveness in patients with one, but not two, TACI mutations enables autoimmune complications. Conflict of interest: The authors have declared that no conflict of interest exists.

Nature Immunology, 2011

Users may view, print, copy, download and text and data-mine the content in such documents, for t... more Users may view, print, copy, download and text and data-mine the content in such documents, for the purposes of academic research, subject always to the full Conditions of use:

Molecular and Cellular Biology, 2009

Introducción. La leptina es una hormona secretada por los adipocitos que se ha relacionado con el... more Introducción. La leptina es una hormona secretada por los adipocitos que se ha relacionado con el proceso de la transición de epitelio a mesénquima (Epithelial-Mesenchymal Transition, EMT). Promueve la migración e invasión de las células del epitelio mamario mediante la activación de las cinasas FAK y Src, un complejo regulador de vías de señalización que favorecen la expresión de las proteínas relacionadas con la formación de estructuras proteolíticas implicadas en la invasión y progresión del cáncer. Recientemente, se ha descrito que la sobreexpresión y activación de la proteína Hic-5 durante el mencionado proceso de transición, favorece la formación de los puntos de actina (indicativa de la formación y funcionalidad de los invadopodios), lo cual promueve la degradación local de los componentes de la matriz extracelular y la metástasis del cáncer. Objetivos. Evaluar el papel de las cinasas FAK y Src sobre la expresión y localización subcelular de Hic-5 y la formación de puntos de actina inducida por la leptina en la línea celular MCF10A de epitelio mamario no tumoral. Materiales y métodos. Se utilizaron los inhibidores específicos de la FAK (PF-573228) y la Src (PP2) para evaluar el papel de ambas cinasas en los niveles de expresión y localización subcelular de la proteína Hic-5 mediante Western blot e inmunofluorescencia, así como la formación de puntos de actina mediante la tinción con faloidina-TRITC en células MCF10A estimuladas con leptina. Resultados. La leptina indujo el incremento en la expresión de Hic-5 y la formación de puntos de actina. El tratamiento previo con los inhibidores de las cinasas FAK (PF-573228) y Src (PP2), promovió la disminución en la expresión de Hic-5 y de los puntos de actina en la línea celular MCF10A de epitelio mamario no tumoral. Conclusión. La leptina indujo la expresión y la localización perinuclear de Hic-5 y la formación de puntos de actina mediante un mecanismo dependiente de la actividad de las cinasas FAK y Src en las células MCF10A. Palabras clave: leptina; neoplasias; metástasis de la neoplasia; actinas; transición de epitelio a mesénquima. Leptin induced Hic-5 expression and actin puncta formation by the FAK/Src-dependent pathway in MCF10A mammary epithelial cells. Introduction: Leptin is a hormone secreted by adipocytes that has been associated with the epithelial-mesenchymal transition (EMT). Additionally, leptin promotes the migration and invasion of mammary epithelial cells through the activation of FAK and Src kinases, which are part of a regulatory complex of signaling pathways that promotes the expression of proteins related to the formation of proteolytic structures involved in the invasion and progression of cancer. Recently, overexpression and activation of Hic-5 during the EMT have been shown to induce the formation of actin puncta; these structures are indicative of the formation and functionality of invadopodia, which promote the local degradation of extracellular matrix components and cancer metastasis. Objective: To evaluate the role of FAK and Src kinases in the expression of Hic-5 during the epithelial-mesenchymal transition induced by leptin in MCF10A cells. Materials and methods: We used specific inhibitors of FAK (PF-573228) and Src (PP2) to evaluate Hic-5 expression and subcellular localization by Western blot and immunofluorescence assays and to investigate the formation of actin puncta by epifluorescence in MCF10A cells stimulated with leptin. Results: Leptin induced an increase in Hic-5 expression and the formation of actin puncta. Pretreatment with inhibitors of FAK (PF-573228) and Src (PP2) promoted a decrease in Hic-5 expression and actin puncta formation in the non-tumorigenic mammary epithelial cell line MCF10A.

Adaptive co-evolution of mammals and bacteria has led to the establishment of complex commensal c... more Adaptive co-evolution of mammals and bacteria has led to the establishment of complex commensal communities on mucosal surfaces. In spite of having available a wealth of immunesensing and effector mechanisms capable of triggering inflammation in response to microbial intrusion, mucosal immune cells establish an intimate dialogue with microbes to generate a state of hyporesponsiveness against commensals and active readiness against pathogens. A key component of this homeostatic balance is IgA, a noninflammatory antibody isotype produced by mucosal B cells through class switching. This process involves activation of B cells by IgAinducing signals originating from mucosal T cells, dendritic cells, and epithelial cells. Here, we review the mechanisms by which mucosal B cells undergo IgA diversification and production and discuss how the study of primary immunodeficiencies facilitates better understanding of mucosal IgA responses in humans.

Nature communications, Nov 13, 2017

Mechanistic target of rapamycin (mTOR) enhances immunity in addition to orchestrating metabolism.... more Mechanistic target of rapamycin (mTOR) enhances immunity in addition to orchestrating metabolism. Here we show that mTOR coordinates immunometabolic reconfiguration of marginal zone (MZ) B cells, a pre-activated lymphocyte subset that mounts antibody responses to T-cell-independent antigens through a Toll-like receptor (TLR)-amplified pathway involving transmembrane activator and CAML interactor (TACI). This receptor interacts with mTOR via the TLR adapter MyD88. The resulting mTOR activation instigates MZ B-cell proliferation, immunoglobulin G (IgG) class switching, and plasmablast differentiation through a rapamycin-sensitive pathway that integrates metabolic and antibody-inducing transcription programs, including NF-κB. Disruption of TACI-mTOR interaction by rapamycin, truncation of the MyD88-binding domain of TACI, or B-cell-conditional mTOR deficiency interrupts TACI signaling via NF-κB and cooperation with TLRs, thereby hampering IgG production to T-cell-independent antigens b...

Nature Immunology, 2011

Neutrophils utilize immunoglobulins (Igs) to clear antigen, but their role in Ig production is un... more Neutrophils utilize immunoglobulins (Igs) to clear antigen, but their role in Ig production is unknown. Here we identified neutrophils around the marginal zone (MZ) of the spleen, a B cell area specialized in T-independent Ig responses to circulating antigen. Neutrophils colonized peri-MZ areas after post-natal mucosal colonization by microbes and enhanced their B-helper function upon receiving reprogramming signals from splenic sinusoidal endothelial cells, including interleukin 10 (IL-10). Splenic neutrophils induced Ig class switching, somatic hypermutation and antibody production by activating MZ B cells through a mechanism involving the cytokines BAFF, APRIL and IL-21. Neutropenic patients had fewer and hypomutated MZ B cells and less preimmune Igs to T-independent antigens, which indicates that neutrophils generate an innate layer of antimicrobial Ig defense by interacting with MZ B cells.

Annals of the New York Academy of Sciences, Nov 1, 2011

Adaptive co-evolution of mammals and bacteria has led to the establishment of complex commensal c... more Adaptive co-evolution of mammals and bacteria has led to the establishment of complex commensal communities on mucosal surfaces. In spite of having available a wealth of immunesensing and effector mechanisms capable of triggering inflammation in response to microbial intrusion, mucosal immune cells establish an intimate dialogue with microbes to generate a state of hyporesponsiveness against commensals and active readiness against pathogens. A key component of this homeostatic balance is IgA, a noninflammatory antibody isotype produced by mucosal B cells through class switching. This process involves activation of B cells by IgAinducing signals originating from mucosal T cells, dendritic cells, and epithelial cells. Here, we review the mechanisms by which mucosal B cells undergo IgA diversification and production and discuss how the study of primary immunodeficiencies facilitates better understanding of mucosal IgA responses in humans.

The Journal of Immunology

The splenic marginal zone (MZ) generates prompt antibody responses to blood-borne antigens throug... more The splenic marginal zone (MZ) generates prompt antibody responses to blood-borne antigens through a unique subset of innate-like B cells that closely interact with poorly characterized stromal cells. We found that human MZ contained fibroblast-like marginal reticular cells (MRCs) that expressed MAdCAM-1 along with the stromal molecules Thy-1, thrombomodulin, ICAM-1 and VCAM-1, but lacked the endothelial molecules CD31, CD34 and von Willebrand factor. Similar to stromal lymphoid tissue organizers, MRCs up-regulated the adhesion molecules ICAM-1 and VCAM-1 in response to LT and TNF. Moreover, MRCs exposed to microbial TLR ligands, released the B cell-stimulating factors BAFF, APRIL and IL-6, which delivered survival, proliferation, class switching and plasma cell differentiation signals to MZ B cells. Plasma cells emerging from this pathway showed either T cell-dependent or T cell-independent ontogenetic features, and released IgM antibodies to conserved carbohydrate and lipid antige...

The Journal of Immunology, 2019

In the published version of Fig. 6A, the FACS dotplot shown for the stimulation of DG75-COex at 2... more In the published version of Fig. 6A, the FACS dotplot shown for the stimulation of DG75-COex at 25 mg in the presence of IL-21 was inadvertently duplicated from the 5 mg/IL-21 panel. The indicated frequency of 5% of CD38 high CD20 low B cells, however, is correct. This correct value of 5% was used in Fig. 6B, so the error in Fig. 6A did not influence the interpretation of the results and conclusions of this work. Fig. 6A has now been corrected with the correct dotplot for stimulation of DG75-COex at 25 mg in the presence of IL-21. The corrected version of Fig. 6 is shown below. The figure legend was correct as published and is shown below for reference. Fig. 6 has also been corrected in the online version of the article, which now differs from the print version originally published.

Thrombosis and Haemostasis, 2008

SummaryThrombin is a multifunctional serine protease generated at the site of vascular injury tha... more SummaryThrombin is a multifunctional serine protease generated at the site of vascular injury that transforms fibrinogen into fibrin, activates blood platelets and elicits multiple effects on a variety of cell types including endothelial cells, vascular smooth muscle cells (VSMC), monocytes,T lymphocytes and fibroblasts. Cellular effects of thrombin are mediated by protease-activated receptors (PARs), members of the G protein-coupled receptors that carry their own ligand which remains cryptic until unmasked by proteolytic cleavage. Thrombin signalling in platelets contributes to haemostasis and thrombosis. In normal arteries PARs are mainly expressed in endothelial cells, while their expression in VSMC is limited. Endothelial PARs participate in the regulation of vascular tone, vascular permeability and endothelial secretory activity while in VSMC they mediate contraction, migration, proliferation, hypertrophy and production of extra-cellular matrix. PARs contribute to the pro-infla...

Arteriosclerosis, Thrombosis, and Vascular Biology, 2011

Objective— Our aim was to analyze the regulation of CC Chemokine ligand 20 (CCL20) by LDL in huma... more Objective— Our aim was to analyze the regulation of CC Chemokine ligand 20 (CCL20) by LDL in human vascular smooth muscle cells (VSMC). Methods and Results— In asymptomatic subjects, circulating CCL20 levels were higher in patients with hypercholesterolemia (18.5±3.2 versus 9.1±1.3 pg/mL; P <0.01). LDL induced the expression of CCL20 in VSMC in a dose- and time-dependent manner. Increased levels of CCL20 secreted by LDL-treated VSMC significantly induced human lymphocyte migration, an effect reduced by CCL20 silencing. The upregulation of CCL20 by LDL was dependent on the activation of kinase signaling pathways and NF-κB. By site-directed mutagenesis, electrophoretic mobility shift assay, and chromatin immunoprecipitation, we identified a NF-κB site (−80/−71) in CCL20 promoter critical for LDL responsiveness. Lysophosphatidic acid mimicked the upregulation of CCL20 induced by LDL, and minimal oxidation of LDL increased the ability of LDL to induce CCL20 through a mechanism that i...

Frontiers in Bioscience, 2008

Introduction 3. NOR-1 in the vascular wall 3.1. Structure of NOR-1 and regulation of transcriptio... more Introduction 3. NOR-1 in the vascular wall 3.1. Structure of NOR-1 and regulation of transcriptional activity 3.2. Regulation of NOR-1 by extracellular stimuli in vascular cells 3.2.1. Regulation of NOR-1 in VSMC 3.2.2. Regulation of NOR-1 in endothelial cells 3.3. Modulation of NOR-1 transcription by CREB in vascular cells 3.4. Pathophysiological roles of NOR-1 in the vascular wall 4. Modulation of endothelial function by thrombin 4.1. Endothelial functions modulated by thrombin via PAR-1 4.2. NOR-1 is induced by thrombin and mediates endothelial cell growth 4.2.1. Thrombin induces NOR-1 in endothelial cells via PAR-1 4.2.2. CREB activation is critical in NOR-1 induction by thrombin 4.2.3. NOR-1 modulates thrombin-induced DNA synthesis and cell growth 5. Summary and perspectives 6. Acknowledgements 7. References

full#ref-list-1 , 21 of which you can access for free at: cites 51 articles This article average ... more full#ref-list-1 , 21 of which you can access for free at: cites 51 articles This article average * 4 weeks from acceptance to publication Fast Publication! • Every submission reviewed by practicing scientists No Triage! • from submission to initial decision Rapid Reviews! 30 days* • Submit online.

Science, 2013

Guardian of the Gut The intestine is able to tolerate continual exposure to large amounts of comm... more Guardian of the Gut The intestine is able to tolerate continual exposure to large amounts of commensal bacteria and foreign food antigens without triggering an inappropriate inflammatory immune response. In the large intestine, this immunological tolerance is thought to occur via a physical separation between environment and host imposed by a continuous mucous layer built up from the secreted mucin protein, MUC2. However, in the small intestine, this mucous layer is porous, necessitating an additional layer of immune control. Shan et al. (p. 447 , published online 26 September; see the Perspective by Belkaid and Grainger ) now report that in the small intestine, MUC2 plays an active role in immunological tolerance by activating a transcription factor in resident dendritic cells, thereby selectively blocking their ability to launch an inflammatory response. This work identifies MUC2 as a central mediator of immune tolerance to maintain homeostasis in the gut and possibly at other muc...

Nature Immunology, 2014

Innate lymphoid cells (ILCs) regulate stromal, epithelial and immune cells, but their impact on B... more Innate lymphoid cells (ILCs) regulate stromal, epithelial and immune cells, but their impact on B cells remains unclear. We identified RORγt + ILCs nearby the marginal zone (MZ), a splenic compartment containing innate-like B cells that respond to circulating T cell-independent (TI) antigens. Spenic ILCs established a bidirectional crosstalk with MAdCAM-1 + marginal reticular cells by providing tumor necrosis factor (TNF) and lymphotoxin, and activated MZ B cells via BAFF, CD40 ligand and the Notch ligand, Delta-like 1. Splenic ILCs further helped MZ B cells and their plasma cell progeny by co-opting neutrophils through the release of GM-CSF. Users may view, print, copy, download and text and data-mine the content in such documents, for the purposes of academic research, subject always to the full Conditions of use:

Nature Immunology, 2014

In the version of this article originally posted online, the units in the text referring to Figur... more In the version of this article originally posted online, the units in the text referring to Figure 1a were incorrect. The correct unit is "μm" and the correct text is " the receptor depicted would measure about 3 μm, compared with a resting B lymphocyte, with an average diameter of about 7 μm. " The error has been corrected in this file as of

Journal of Virology, 2011

An HIV-1 vaccine remains elusive, in part because various factors limit the quantity and quality ... more An HIV-1 vaccine remains elusive, in part because various factors limit the quantity and quality of the antibodies raised against the viral envelope glycoprotein complex (Env). We hypothesized that targeting Env vaccines directly to B cells, by fusing them to molecules that bind and activate these cells, would improve Env-specific antibody responses. Therefore, we fused trimeric Env gp140 to A PRoliferation-Inducing Ligand (APRIL), B-cell Activating Factor (BAFF), and CD40 Ligand (CD40L). The Env-APRIL, Env-BAFF, and Env-CD40L gp140 trimers all enhanced the expression of activation-induced cytidine deaminase (AID), the enzyme responsible for inducing somatic hypermutation, antibody affinity maturation, and antibody class switching. They also triggered IgM, IgG, and IgA secretion from human B cells in vitro . The Env-APRIL trimers induced higher anti-Env antibody responses in rabbits, including neutralizing antibodies against tier 1 viruses. The enhanced Env-specific responses were n...

Journal of Clinical Investigation, 2013

Common variable immune deficiency (CVID) is an assorted group of primary diseases that clinically... more Common variable immune deficiency (CVID) is an assorted group of primary diseases that clinically manifest with antibody deficiency, infection susceptibility, and autoimmunity. Heterozygous mutations in the gene encoding the tumor necrosis factor receptor superfamily member TACI are associated with CVID and autoimmune manifestations, whereas two mutated alleles prevent autoimmunity. To assess how the number of TACI mutations affects B cell activation and tolerance checkpoints, we analyzed healthy individuals and CVID patients carrying one or two TACI mutations. We found that TACI interacts with the cleaved, mature forms of TLR7 and TLR9 and plays an important role during B cell activation and the central removal of autoreactive B cells in healthy donors and CVID patients. However, only subjects with a single TACI mutation displayed a breached immune tolerance and secreted antinuclear antibodies (ANAs). These antibodies were associated with the presence of circulating B cell lymphoma 6-expressing T follicular helper (Tfh) cells, likely stimulating autoreactive B cells. Thus, TACI mutations may favor CVID by altering B cell activation with coincident impairment of central B cell tolerance, whereas residual B cell responsiveness in patients with one, but not two, TACI mutations enables autoimmune complications. Conflict of interest: The authors have declared that no conflict of interest exists.

Nature Immunology, 2011

Users may view, print, copy, download and text and data-mine the content in such documents, for t... more Users may view, print, copy, download and text and data-mine the content in such documents, for the purposes of academic research, subject always to the full Conditions of use:

Molecular and Cellular Biology, 2009

Introducción. La leptina es una hormona secretada por los adipocitos que se ha relacionado con el... more Introducción. La leptina es una hormona secretada por los adipocitos que se ha relacionado con el proceso de la transición de epitelio a mesénquima (Epithelial-Mesenchymal Transition, EMT). Promueve la migración e invasión de las células del epitelio mamario mediante la activación de las cinasas FAK y Src, un complejo regulador de vías de señalización que favorecen la expresión de las proteínas relacionadas con la formación de estructuras proteolíticas implicadas en la invasión y progresión del cáncer. Recientemente, se ha descrito que la sobreexpresión y activación de la proteína Hic-5 durante el mencionado proceso de transición, favorece la formación de los puntos de actina (indicativa de la formación y funcionalidad de los invadopodios), lo cual promueve la degradación local de los componentes de la matriz extracelular y la metástasis del cáncer. Objetivos. Evaluar el papel de las cinasas FAK y Src sobre la expresión y localización subcelular de Hic-5 y la formación de puntos de actina inducida por la leptina en la línea celular MCF10A de epitelio mamario no tumoral. Materiales y métodos. Se utilizaron los inhibidores específicos de la FAK (PF-573228) y la Src (PP2) para evaluar el papel de ambas cinasas en los niveles de expresión y localización subcelular de la proteína Hic-5 mediante Western blot e inmunofluorescencia, así como la formación de puntos de actina mediante la tinción con faloidina-TRITC en células MCF10A estimuladas con leptina. Resultados. La leptina indujo el incremento en la expresión de Hic-5 y la formación de puntos de actina. El tratamiento previo con los inhibidores de las cinasas FAK (PF-573228) y Src (PP2), promovió la disminución en la expresión de Hic-5 y de los puntos de actina en la línea celular MCF10A de epitelio mamario no tumoral. Conclusión. La leptina indujo la expresión y la localización perinuclear de Hic-5 y la formación de puntos de actina mediante un mecanismo dependiente de la actividad de las cinasas FAK y Src en las células MCF10A. Palabras clave: leptina; neoplasias; metástasis de la neoplasia; actinas; transición de epitelio a mesénquima. Leptin induced Hic-5 expression and actin puncta formation by the FAK/Src-dependent pathway in MCF10A mammary epithelial cells. Introduction: Leptin is a hormone secreted by adipocytes that has been associated with the epithelial-mesenchymal transition (EMT). Additionally, leptin promotes the migration and invasion of mammary epithelial cells through the activation of FAK and Src kinases, which are part of a regulatory complex of signaling pathways that promotes the expression of proteins related to the formation of proteolytic structures involved in the invasion and progression of cancer. Recently, overexpression and activation of Hic-5 during the EMT have been shown to induce the formation of actin puncta; these structures are indicative of the formation and functionality of invadopodia, which promote the local degradation of extracellular matrix components and cancer metastasis. Objective: To evaluate the role of FAK and Src kinases in the expression of Hic-5 during the epithelial-mesenchymal transition induced by leptin in MCF10A cells. Materials and methods: We used specific inhibitors of FAK (PF-573228) and Src (PP2) to evaluate Hic-5 expression and subcellular localization by Western blot and immunofluorescence assays and to investigate the formation of actin puncta by epifluorescence in MCF10A cells stimulated with leptin. Results: Leptin induced an increase in Hic-5 expression and the formation of actin puncta. Pretreatment with inhibitors of FAK (PF-573228) and Src (PP2) promoted a decrease in Hic-5 expression and actin puncta formation in the non-tumorigenic mammary epithelial cell line MCF10A.

Adaptive co-evolution of mammals and bacteria has led to the establishment of complex commensal c... more Adaptive co-evolution of mammals and bacteria has led to the establishment of complex commensal communities on mucosal surfaces. In spite of having available a wealth of immunesensing and effector mechanisms capable of triggering inflammation in response to microbial intrusion, mucosal immune cells establish an intimate dialogue with microbes to generate a state of hyporesponsiveness against commensals and active readiness against pathogens. A key component of this homeostatic balance is IgA, a noninflammatory antibody isotype produced by mucosal B cells through class switching. This process involves activation of B cells by IgAinducing signals originating from mucosal T cells, dendritic cells, and epithelial cells. Here, we review the mechanisms by which mucosal B cells undergo IgA diversification and production and discuss how the study of primary immunodeficiencies facilitates better understanding of mucosal IgA responses in humans.

Nature communications, Nov 13, 2017

Mechanistic target of rapamycin (mTOR) enhances immunity in addition to orchestrating metabolism.... more Mechanistic target of rapamycin (mTOR) enhances immunity in addition to orchestrating metabolism. Here we show that mTOR coordinates immunometabolic reconfiguration of marginal zone (MZ) B cells, a pre-activated lymphocyte subset that mounts antibody responses to T-cell-independent antigens through a Toll-like receptor (TLR)-amplified pathway involving transmembrane activator and CAML interactor (TACI). This receptor interacts with mTOR via the TLR adapter MyD88. The resulting mTOR activation instigates MZ B-cell proliferation, immunoglobulin G (IgG) class switching, and plasmablast differentiation through a rapamycin-sensitive pathway that integrates metabolic and antibody-inducing transcription programs, including NF-κB. Disruption of TACI-mTOR interaction by rapamycin, truncation of the MyD88-binding domain of TACI, or B-cell-conditional mTOR deficiency interrupts TACI signaling via NF-κB and cooperation with TLRs, thereby hampering IgG production to T-cell-independent antigens b...

Nature Immunology, 2011

Neutrophils utilize immunoglobulins (Igs) to clear antigen, but their role in Ig production is un... more Neutrophils utilize immunoglobulins (Igs) to clear antigen, but their role in Ig production is unknown. Here we identified neutrophils around the marginal zone (MZ) of the spleen, a B cell area specialized in T-independent Ig responses to circulating antigen. Neutrophils colonized peri-MZ areas after post-natal mucosal colonization by microbes and enhanced their B-helper function upon receiving reprogramming signals from splenic sinusoidal endothelial cells, including interleukin 10 (IL-10). Splenic neutrophils induced Ig class switching, somatic hypermutation and antibody production by activating MZ B cells through a mechanism involving the cytokines BAFF, APRIL and IL-21. Neutropenic patients had fewer and hypomutated MZ B cells and less preimmune Igs to T-independent antigens, which indicates that neutrophils generate an innate layer of antimicrobial Ig defense by interacting with MZ B cells.