The CD27/CD70 pathway negatively regulates visceral adipose tissue-resident Th2 cells and controls metabolic homeostasis.

Adipose tissue homeostasis relies on the interplay between several regulatory lineages, such as type 2 innate lymphoid cells (ILC2s), T helper 2 (Th2) cells, regulatory T cells, eosinophils, and type 2 macrophages. Among them, ILC2s are numerically the dominant source of type 2 cytokines and are considered as major regulators of adiposity. Despite the overlap in immune effector molecules and sensitivity to alarmins (thymic stromal lymphopoietin and interleukin-33) between ILC2s and resident memory Th2 lymphocytes, the role of the adaptive axis of type 2 immunity remains unclear.

Chronic CD27-CD70 costimulation promotes type 1-specific polarization of effector Tregs.

Introduction: Most T lymphocytes, including regulatory T cells, express the CD27 costimulatory receptor in steady state conditions. There is evidence that CD27 engagement on conventional T lymphocytes favors the development of Th1 and cytotoxic responses in mice and humans, but the impact on the regulatory lineage is unknown.

Methods: In this report, we examined the effect of constitutive CD27 engagement on both regulatory and conventional CD4 T cells , in the absence of intentional antigenic stimulation.

PHD2 Constrains Antitumor CD8+ T-cell Activity.

The prolyl hydroxylase domain/hypoxia-inducible factor (PHD/HIF) pathway has been implicated in a wide range of immune and inflammatory processes, including in the oxygen-deprived tumor microenvironment. To examine the effect of HIF stabilization in antitumor immunity, we deleted Phd2 selectively in T lymphocytes using the cre/lox system. We show that the deletion of PHD2 in lymphocytes resulted in enhanced regression of EG7-OVA tumors, in a HIF-1α-dependent manner.

Inhaled dry powder cisplatin increases antitumour response to anti-PD1 in a murine lung cancer model.

Despite advances in targeted therapies and immunotherapy in lung cancer, chemotherapy remains the backbone of treatment in most patients at different stages of the disease. Inhaled chemotherapy is a promising strategy to target lung tumours and to limit the induced severe systemic toxicities. Cisplatin dry powder for inhalation (CIS-DPI) was tested as an innovative way to deliver cisplatin locally via the pulmonary route with minimal systemic toxicities.

Agonistic anti-CD27 antibody ameliorates EAE by suppressing IL-17 production.

CD27/CD70 costimulation enhances T-cell survival, memory formation and Th1-cell differentiation and effector function. In addition to promoting Th1 responses, CD27 signaling has been shown to exert a negative regulatory role on IL-17 production, resulting in increased sensitivity of CD27 KO mice to EAE. By inducing EAE in full CD27 KO mice, and in a novel, T-cell specific CD27 KO mouse strain (CD4-Cre x CD27 ), we demonstrate herein that CD27 engagement by its natural ligand (CD70) suppresses IL-17 production in a cell autonomous fashion.

The oxygen sensor prolyl hydroxylase domain 2 regulates the in vivo suppressive capacity of regulatory T cells.

The oxygen sensor prolyl hydroxylase domain 2 (PHD2) plays an important role in cell hypoxia adaptation by regulating the stability of HIF proteins (HIF1α and HIF2α) in numerous cell types, including T lymphocytes. The role of oxygen sensor on immune cells, particularly on regulatory T cell (Treg) function, has not been fully elucidated. The purpose of our study was to evaluate the role of PHD2 in the regulation of Treg phenotype and function.

Adenosine Diphosphate and the P2Y13 Receptor Are Involved in the Autophagic Protection of Ex Vivo Perfused Livers From Fasted Rats: Potential Benefit for Liver Graft Preservation.

Studies on how to protect livers perfused ex vivo can help design strategies for hepatoprotection and liver graft preservation. The protection of livers isolated from 24-hour versus 18-hour starved rats has been previously attributed to autophagy, which contributes to the energy-mobilizing capacity ex vivo. Here, we explored the signaling pathways responsible for this protection.

Long-term T cell fitness and proliferation is driven by AMPK-dependent regulation of reactive oxygen species.

The AMP-activated kinase (AMPK) is a major energy sensor metabolic enzyme that is activated early during T cell immune responses but its role in the generation of effector T cells is still controversial. Using both in vitro and in vivo models of T cell proliferation, we show herein that AMPK is dispensable for early TCR signaling and short-term proliferation but required for sustained long-term T cell proliferation and effector/memory T cell survival. In particular, AMPK promoted accumulation of effector/memory T cells in competitive homeostatic proliferation settings.

Multiple Environmental Signaling Pathways Control the Differentiation of RORγt-Expressing Regulatory T Cells.

RORγt-expressing Tregs form a specialized subset of intestinal CD4 Foxp3 cells which is essential to maintain gut homeostasis and tolerance to commensal microbiota. Recently, c-Maf emerged as a critical factor in the regulation of RORγt expression in Tregs. However, aside from c-Maf signaling, the signaling pathways involved in the differentiation of RORγt Tregs and their possible interplay with c-Maf in this process are largely unknown.

HO-1 mitigates acute kidney injury and subsequent kidney-lung cross-talk.

Ischemia-reperfusion injury (IRI) is a leading cause of acute kidney injury (AKI), which contributes to the development of chronic kidney disease (CKD). IRI-induced AKI releases proinflammatory cytokines (e.g.

Protection in a model of liver injury is parallel to energy mobilization capacity under distinct nutritional status.

Objective: Dietary and energetic restrictions are endowed with protection against experimental injuries. However, a drop in cell energetic status under a critical threshold may prevent protection, as previously observed for livers isolated from rat donors undergoing 18-h fasting versus feeding. The aim of this study was to further explore, in the latter model, links between nutritional status, energy availability, and protection through lengthening of rat fasting to 24 h and withdrawal of energy sources from perfusions.

Dual effect of hemin on renal ischemia-reperfusion injury.

Acute kidney injury (AKI) is a major public health concern, which is contributing to serious hospital complications, chronic kidney disease (CKD) and even death. Renal ischemia-reperfusion injury (IRI) remains a leading cause of AKI. The stress-responsive enzyme, heme oxygenase-1 (HO-1) mediates protection against renal IRI and may be preventively induced using hemin prior to renal insult.

Activation of the endoplasmic reticulum stress sensor IRE1α by the vaccine adjuvant AS03 contributes to its immunostimulatory properties.

The oil-in-water emulsion Adjuvant System 03 (AS03) is one of the few adjuvants used in licensed vaccines. Previous work indicates that AS03 induces a local and transient inflammatory response that contributes to its adjuvant effect. However, the molecular mechanisms involved in its immunostimulatory properties are ill-defined.

A Flow Cytometry-Based Protocol to Measure Lymphocyte Viability Upon Metabolic Stress.

Distinct lymphocyte subpopulations display discrete metabolic profiles and are differently affected by metabolic resource variations, making the analysis of lymphocyte survival in a complex tissue in response to metabolic stress highly challenging. Here we describe a flow cytometry-based method allowing simultaneous cell identification and viable cell counting in mixed lymphocyte populations without extensive cell subset purification procedures. The example provided herein illustrates the role of AMPK in T lymphocyte survival in response to the mitochondrial poison oligomycin.

Regulatory T cells constrain the TCR repertoire of antigen-stimulated conventional CD4 T cells.

To analyze the potential role of Tregs in controlling the TCR repertoire breadth to a non-self-antigen, a TCRβ transgenic mouse model (EF4.1) expressing a limited, yet polyclonal naïve T-cell repertoire was used. The response of EF4.

Cyclophosphamide treatment regulates the balance of functional/exhausted tumor-specific CD8 T cells.

An important question is how chemotherapy may (re-)activate tumor-specific immunity. In this study, we provide a phenotypic, functional and genomic analysis of tumor-specific CD8 T cells in tumor (P815)-bearing mice, treated or not with cyclophosphamide. Our data show that chemotherapy favors the development of effector-type lymphocytes in tumor bed, characterized by higher KLRG-1 expression, lower PD-1 expression and increased cytotoxicity.

The Transcription Factor c-Maf Promotes the Differentiation of Follicular Helper T Cells.

Follicular helper T cells (Tfh) have been identified as the primary cell subpopulation regulating B cell responses in germinal centers, thus supporting high-affinity antibody production. Among the transcription factors orchestrating Tfh cell differentiation and function, the role played by the proto-oncogene c-Maf remains poorly characterized. We report herein that selective loss of c-Maf expression in the T cell compartment results in defective development of Tfh cells in response to both antigen/adjuvant vaccinations and commensal intestinal bacteria.

Nicotinamide Phosphoribosyltransferase in Smooth Muscle Cells Maintains Genome Integrity, Resists Aortic Medial Degeneration, and Is Suppressed in Human Thoracic Aortic Aneurysm Disease.

Rationale: The thoracic aortic wall can degenerate over time with catastrophic consequences. Vascular smooth muscle cells (SMCs) can resist and repair artery damage, but their capacities decline with age and stress. Recently, cellular production of nicotinamide adenine dinucleotide (NAD) via nicotinamide phosphoribosyltransferase (Nampt) has emerged as a mediator of cell vitality.

Specific expression of heme oxygenase-1 by myeloid cells modulates renal ischemia-reperfusion injury.

Renal ischemia-reperfusion injury (IRI) is a major risk factor for delayed graft function in renal transplantation. Compelling evidence exists that the stress-responsive enzyme, heme oxygenase-1 (HO-1) mediates protection against IRI. However, the role of myeloid HO-1 during IRI remains poorly characterized.

Vaccine development: From concept to early clinical testing.

In the 21st century, an array of microbiological and molecular allow antigens for new vaccines to be specifically identified, designed, produced and delivered with the aim of optimising the induction of a protective immune response against a well-defined immunogen. New knowledge about the functioning of the immune system and host pathogen interactions has stimulated the rational design of vaccines. The design toolbox includes vaccines made from whole pathogens, protein subunits, polysaccharides, pathogen-like particles, use of viral/bacterial vectors, plus adjuvants and conjugation technology to increase and broaden the immune response.

Antigen-presenting cell-derived IL-6 restricts the expression of GATA3 and IL-4 by follicular helper T cells.

Follicular helper T cells (Tfh) support high-affinity Ab production by germinal center B cells through both membrane interactions and secretion of IL-4 and -21, two major cytokines implicated in B-cell survival and Ab class switch. Tfh-2 cells recently emerged in humans as a strong IL-4 producer Tfh cell subset implicated in both autoimmune and allergic diseases. Although the molecular mechanisms governing Tfh cell differentiation from naive T cells have been widely described, much less is known about the regulation of cytokine secretion by mouse Tfh-2 cells.

Reassessing the role of NAD as a prosurvival factor.

The mechanisms regulating the choice of cell demise remain largely unknown. NAD(+), a key metabolite with well-known roles in cell metabolism, has been shown to counteract apoptosis while promoting necroptosis, a form of proinflammatory cell death. This observation identifies NAD(+) availability as an important parameter with contrasting roles in the regulation of distinct regulated cell death programs.

Complex role of nicotinamide adenine dinucleotide in the regulation of programmed cell death pathways.

Over the past few years, a growing body of experimental observations has led to the identification of novel and alternative programs of regulated cell death. Recently, autophagic cell death and controlled forms of necrosis have emerged as major alternatives to apoptosis, the best characterized form of regulated cell demise. These recently identified, caspase-independent, forms of cell death appear to play a role in the response to several forms of stress, and their importance in different pathological conditions such as ischemia, infection and inflammation has been recognized.

Type I interferons regulate eomesodermin expression and the development of unconventional memory CD8(+) T cells.

CD8(+) T-cell memory phenotype and function are acquired after antigen-driven activation. Memory-like cells may also arise in absence of antigenic exposure in the thymus or in the periphery. Eomesodermin (Eomes) is a key transcription factor for the development of these unconventional memory cells.