Innate acting memory Th1 cells modulate heterologous diseases.

Through immune memory, infections have a lasting effect on the host. While memory cells enable accelerated and enhanced responses upon rechallenge with the same pathogen, their impact on susceptibility to unrelated diseases is unclear. We identify a subset of memory T helper 1 (Th1) cells termed innate acting memory T (TIA) cells that originate from a viral infection and produce IFN-γ with innate kinetics upon heterologous challenge in vivo. Activation of memory TIA cells is induced in response to IL-12 in combination with IL-18 or IL-33 but is TCR independent. Rapid IFN-γ production by memory TIA cells is protective in subsequent heterologous challenge with the bacterial pathogen Legionella pneumophila. In contrast, antigen-independent reactivation of CD4+ memory TIA cells accelerates disease onset in an autoimmune model of multiple sclerosis. Our findings demonstrate that memory Th1 cells can acquire additional TCR-independent functionality to mount rapid, innate-like responses that modulate susceptibility to heterologous challenges.

Host succinate inhibits influenza virus infection through succinylation and nuclear retention of the viral nucleoprotein.

Influenza virus infection causes considerable morbidity and mortality, but current therapies have limited efficacy. We hypothesized that investigating the metabolic signaling during infection may help to design innovative antiviral approaches. Using bronchoalveolar lavages of infected mice, we here demonstrate that influenza virus induces a major reprogramming of lung metabolism. We focused on mitochondria-derived succinate that accumulated both in the respiratory fluids of virus-challenged mice and of patients with influenza pneumonia. Notably, succinate displays a potent antiviral activity in vitro as it inhibits the multiplication of influenza A/H1N1 and A/H3N2 strains and strongly decreases virus-triggered metabolic perturbations and inflammatory responses. Moreover, mice receiving succinate intranasally showed reduced viral loads in lungs and increased survival compared to control animals. The antiviral mechanism involves a succinate-dependent posttranslational modification, that is, succinylation, of the viral nucleoprotein at the highly conserved K87 residue. Succinylation of viral nucleoprotein altered its electrostatic interactions with viral RNA and further impaired the trafficking of viral ribonucleoprotein complexes. The finding that succinate efficiently disrupts the influenza replication cycle opens up new avenues for improved treatment of influenza pneumonia.

Osteohistology of the hyperelongate hemispinous processes of Amargasaurus cazaui (Dinosauria: Sauropoda): Implications for soft tissue reconstruction and functional significance.

Dicraeosaurid sauropods are iconically characterized by the presence of elongate hemispinous processes in presacral vertebrae. These hemispinous processes can show an extreme degree of elongation, such as in the Argentinean forms Amargasaurus cazaui, Pilmatueia faundezi and Bajadasaurus pronuspinax. These hyperelongated hemispinous processes have been variably interpreted as a support structure for a padded crest/sail as a display, a bison-like hump or as the internal osseous cores of cervical horns. With the purpose to test these hypotheses, here we analyze, for the first time, the external morphology, internal microanatomy and bone microstructure of the hemispinous processes from the holotype of Amargasaurus, in addition to a second dicraeosaurid indet. (also from the La Amarga Formatin; Lower Cretaceous, Argentina). Transverse thin-sections sampled from the proximal, mid and distal portions of both cervical and dorsal hemispinous processes reveal that the cortical bone is formed by highly vascularized fibrolamellar bone interrupted with cyclical growth marks. Obliquely oriented Sharpey's fibres are mostly located in the medial and lateral portions of the cortex. Secondary remodelling is evidenced by the presence of abundant secondary osteons irregularly distributed within the cortex. Both anatomical and histological evidence does not support the presence of a keratinized sheath (i.e. horn) covering the hyperelongated hemispinous processes of Amargasaurus, and either, using a parsimonious criterium, in other dicraeosaurids with similar vertebral morphology. The spatial distribution and relative orientation of the Sharpey's fibres suggest the presence of an important system of interspinous ligaments that possibly connect successive hemispinous processes in Amargasaurus. These ligaments were distributed along the entirety of the hemispinous processes. The differential distribution of secondary osteons indicates that the cervical hemispinous processes of Amargasaurus were subjected to mechanical forces that generated higher compression strain on the anterior side of the elements. Current data support the hypothesis for the presence of a 'cervical sail' in Amargasaurus and other dicraeosaurids.

Secukinumab for the treatment of psoriasis, psoriatic arthritis, and axial spondyloarthritis: Physical and pharmacological properties underlie the observed clinical efficacy and safety.

Psoriasis, psoriatic arthritis, and axial spondyloarthritis are systemic inflammatory diseases, each commonly manifesting as a spectrum of symptoms, complications, and comorbidities that arise differently in individual patients. Drugs targeting inflammatory cytokines common to the pathogenesis of each of these conditions have been developed, although their specific actions in the different tissues involved are variable. For a drug to be effective, it must be efficiently delivered to and locally bioactive in disease-relevant tissues. Detailed clinical data shed light on the therapeutic effects of individual biologics on specific domains or clinical manifestations of disease and assist in guiding treatment decisions. Pharmacologic, molecular, and functional properties of drugs strongly impact their observed safety and efficacy, and an understanding of these properties provides complementary insight. Secukinumab, a fully human monoclonal IgG1/κ antibody selectively targeting interleukin (IL)-17A, has been in clinical use for >6 years in the treatment of moderate to severe psoriasis, psoriatic arthritis, and both radiographic (also known as ankylosing spondylitis) and nonradiographic axial spondyloarthritis. In this review, we discuss pharmacokinetic and pharmacodynamic data for secukinumab to introduce clinicians to the pharmacological properties of this widely used drug. Understanding how these properties affect the observed clinical efficacy, safety, and tolerability of this drug in the treatment of IL-17A-mediated systemic inflammatory diseases is important for all physicians treating these conditions.

Effect of ofatumumab on pregnancy, parturition, and lactation in cynomolgus monkeys.

Knowledge of the impacts of the anti-CD20 monoclonal antibody ofatumumab on the developing immune system is limited. This study examined the effects of intravenous ofatumumab on pregnancy, parturition, and lactation, and on pre- and postnatal survival and development in cynomolgus monkeys, an established model for developmental toxicity assessment. Pregnant cynomolgus monkeys (n = 42) were randomized to receive vehicle only (control group; n = 14), low-dose ofatumumab (n = 14), or high-dose ofatumumab (n = 14). Survival, clinical outcomes, and clinical pathology investigations were evaluated regularly until lactation day (maternal animals) and postnatal day 180±1 (infants). Anatomic pathology was investigated in euthanized infants and unscheduled terminations of maternal animals and infants. Ofatumumab treatment was not associated with maternal toxicity or embryotoxicity and had no effect on the growth and development of offspring. As expected, B-cell depletion occurred in maternal animals and their offspring, with a reduced humoral immune response in infants of mothers on high-dose ofatumumab. Both effects were reversible. In the high-dose group, perinatal deaths of 3 infants were attributed to infections, potentially secondary to pharmacologically induced immunosuppression. The no-observed adverse-effect level for initial/maintenance ofatumumab doses was 100/20 mg, and 10/3 mg/kg for pharmacological effects in infant animals, which are associated with exposures significantly higher than those following therapeutic doses in humans. In this study with cynomolgus monkeys, ofatumumab treatment was not associated with maternal toxicity or embryotoxicity and had no effect on the growth and development of offspring.

Metabolic and immunomodulatory control of type 1 diabetes via orally delivered bile-acid-polymer nanocarriers of insulin or rapamycin.

Oral formulations of insulin are typically designed to improve its intestinal absorption and increase its blood bioavailability. Here we show that polymerized ursodeoxycholic acid, selected from a panel of bile-acid polymers and formulated into nanoparticles for the oral delivery of insulin, restored blood-glucose levels in mice and pigs with established type 1 diabetes. The nanoparticles functioned as a protective insulin carrier and as a high-avidity bile-acid-receptor agonist, increased the intestinal absorption of insulin, polarized intestinal macrophages towards the M2 phenotype, and preferentially accumulated in the pancreas of the mice, binding to the islet-cell bile-acid membrane receptor TGR5 with high avidity and activating the secretion of glucagon-like peptide and of endogenous insulin. In the mice, the nanoparticles also reversed inflammation, restored metabolic functions and extended animal survival. When encapsulating rapamycin, they delayed the onset of diabetes in mice with chemically induced pancreatic inflammation. The metabolic and immunomodulatory functions of ingestible bile-acid-polymer nanocarriers may offer translational opportunities for the prevention and treatment of type 1 diabetes.

Overcoming Obstacles in the Development of Antigen-Specific Immunotherapies for Type 1 Diabetes.

Antigen-specific immunotherapy (ASI) holds great promise for type 1 diabetes (T1D). Preclinical success for this approach has been demonstrated in vivo, however, clinical translation is still pending. Reasons explaining the slow progress to approve ASI are complex and span all stages of research and development, in both academic and industry environments. The basic four hurdles comprise a lack of translatability of pre-clinical research to human trials; an absence of robust prognostic and predictive biomarkers for therapeutic outcome; a need for a clear regulatory path addressing ASI modalities; and the limited acceptance to develop therapies intervening at the pre-symptomatic stages of disease. The core theme to address these challenges is collaboration-early, transparent, and engaged interactions between academic labs, pharmaceutical research and clinical development teams, advocacy groups, and regulatory agencies to drive a fundamental shift in how we think and treat T1D.

Mass Cytometry of CSF Identifies an MS-Associated B-cell Population.

OBJECTIVE: To identify an MS-specific immune cell population by deep immune phenotyping and relate it to soluble signaling molecules in CSF. METHODS: We analyzed surface expression of 22 markers in paired blood/CSF samples from 39 patients using mass cytometry (cytometry by time of flight). We also measured the concentrations of 296 signaling molecules in CSF using proximity extension assay. Results were analyzed using highly automated unsupervised algorithmic informatics. RESULTS: Mass cytometry objectively identified a B-cell population characterized by the expression of CD49d, CD69, CD27, CXCR3, and human leukocyte antigen (HLA)-DR as clearly associated with MS. Concentrations of the B cell-related factors, notably FCRL2, were increased in MS CSF, especially in early stages of the disease. The B-cell trophic factor B cell activating factor (BAFF) was decreased in MS. Proteins involved in neural plasticity were also reduced in MS. CONCLUSION: When analyzed without a priori assumptions, both the soluble and the cellular compartments of the CSF in MS were characterized by markers related to B cells, and the strongest candidate for an MS-specific cell type has a B-cell phenotype.

The Emerging Jamboree of Transformative Therapies for Autoimmune Diseases.

Standard treatments for autoimmune and autoinflammatory disorders rely mainly on immunosuppression. These are predominantly symptomatic remedies that do not affect the root cause of the disease and are associated with multiple side effects. Immunotherapies are being developed during the last decades as more specific and safer alternatives to small molecules with broad immunosuppressive activity, but they still do not distinguish between disease-causing and protective cell targets and thus, they still have considerable risks of increasing susceptibility to infections and/or malignancy. Antigen-specific approaches inducing immune tolerance represent an emerging trend carrying the potential to be curative without inducing broad immunosuppression. These therapies are based on antigenic epitopes derived from the same proteins that are targeted by the autoreactive T and B cells, and which are administered to patients together with precise instructions to induce regulatory responses capable to restore homeostasis. They are not personalized medicines, and they do not need to be. They are precision therapies exquisitely targeting the disease-causing cells that drive pathology in defined patient populations. Immune tolerance approaches are truly transformative options for people suffering from autoimmune diseases.

Imaging Mass Cytometry and Single-Cell Genomics Reveal Differential Depletion and Repletion of B-Cell Populations Following Ofatumumab Treatment in Cynomolgus Monkeys.

Ofatumumab is the first, fully human, anti-CD20 monoclonal antibody in Phase 3 development for multiple sclerosis (MS). The study focused on changes in lymphocyte subsets in blood and lymphoid tissues and on potential novel biomarkers as a result of anti-CD20 antibody action in Cynomolgus monkeys treated with human equivalent doses of subcutaneous (s.c.) ofatumumab on Days 0, 7, and 14. Axillary lymph nodes (LNs) and blood samples were collected at various time points until Day 90. Lymphocyte subsets were quantified by flow cytometry, while morphological and immune cell changes were assessed by imaging mass cytometry (IMC), immunohistochemistry (IHC), in situ hybridization (ISH), and transcriptome analyses using single-cell methodology. Ofatumumab treatment resulted in a potent and rapid reduction of B cells along with a simultaneous drop in CD20+ T cell counts. At Day 21, IHC revealed B-cell depletion in the perifollicular and interfollicular area of axillary LNs, while only the core of the germinal center was depleted of CD20+CD21+ cells. By Day 62, the perifollicular and interfollicular areas were abundantly infiltrated by CD21+ B cells and this distribution returned to the baseline cytoarchitecture by Day 90. By IMC CD20+CD3+CD8+ cells could be identified at the margin of the follicles, with a similar pattern of distribution at Day 21 and 90. Single-cell transcriptomics analysis showed that ofatumumab induced reversible changes in t-distributed stochastic neighbor embedding (t-SNE) defined B-cell subsets that may serve as biomarkers for drug action. In summary, low dose s.c. ofatumumab potently depletes both B cells and CD20+ T cells but apparently spares marginal zone (MZ) B cells in the spleen and LN. These findings add to our molecular and tissue-architectural understanding of ofatumumab treatment effects on B-cell subsets.

Taming autoimmunity: Translating antigen-specific approaches to induce immune tolerance.

José M. Carballido, Executive Director at Novartis Institutes for BioMedical Research, and Pere Santamaria, Professor of Immunology at the University of Calgary and Founder of Parvus Therapeutics Inc., discuss the opportunities and challenges of translating antigen-specific approaches for autoimmunity with an emphasis on the need for scientific rigor in the preclinical stage.

Fingerprints of CD8+ T cells on human pre-plasma and memory B cells.

Differentiation of B cells is a stringently controlled multi-step process, which is still incompletely understood. Here we identify and characterize a rare population of human B cells, which surprisingly carry CD8AB on their surface. Existence of such cells was demonstrated both in tonsils and in human apheresis material. Gene expression profiling and real time PCR detected however no CD8A or CD8B message in these cells. Instead, we found that surface CD8 was hijacked from activated CD8+ T cells by a transfer process that required direct cell-to-cell contact. A focused transcriptome analysis at single cell level allowed the dissection of the CD8 positive B cell population. We found that the affected cells are characteristically of the CD27+CD200- phenotype, and consist of two discrete late-stage subpopulations that carry signatures of activated memory B like cells, and early plasmablasts. Thus, there is only a restricted time window in the differentiation process during which B cells can intimately interact with CD8+ T cells. The findings point to a novel link between the T and B arms of the adaptive immune system, and suggest that CD8+ T cells have the capability to directly shape the global antibody repertoire.

Succinate receptor deficiency attenuates arthritis by reducing dendritic cell traffic and expansion of Th17 cells in the lymph nodes.

Rheumatoid arthritis is a chronic inflammatory disease that leads to significant changes in metabolic activity. Succinate, an intermediate of the tricarboxylic acid cycle, has emerged as a metabolic mediator of the innate immune response. However, the involvement of succinate in the generation of the adaptive immune response and establishment of autoimmune response has not been addressed thus far. Here we demonstrated that the succinate-sensing receptor (Sucnr1/GPR91) plays a critical role in the development of immune-mediated arthritis. We found that Sucnr1 acts as a chemotactic gradient sensor that guides dendritic cells (DCs) into the lymph nodes, orchestrating the expansion of the T helper (Th)17-cell population and the development of experimental antigen-induced arthritis. Sucnr1-/- mice show reduced articular hyperalgesia, neutrophil infiltration and inflammatory cytokines in the joint, and reduced frequency of Th17 cells in draining lymph nodes. Adoptive transfer of wild-type (WT) DCs into Sucnr1-/- mice restored the development of arthritis. Moreover, DC-depleted mice transferred with Sucnr1-/- DCs developed less arthritis than mice transferred with WT DCs. In contrast, succinate given together with the immunization boosted the recruitment of DCs and the frequency of Th17 cells in draining lymph nodes, increasing arthritis severity. Therefore, the blockade of Sucnr1 may represent a novel therapeutic target of arthritis.-Saraiva, A. L., Veras, F. P., Peres, R. S., Talbot, J., de Lima, K. A., Luiz, J. P., Carballido, J. M., Cunha, T. M., Cunha, F. Q., Ryffel, B., Alves-Filho, J. C. Succinate receptor deficiency attenuates arthritis by reducing dendritic cell traffic and expansion of Th17 cells in the lymph nodes.

The T-cell fingerprint of MALT1 paracaspase revealed by selective inhibition.

Mucosa-associated lymphoid tissue lymphoma translocation protein 1 (MALT1) is essential for immune responses triggered by antigen receptors but the contribution of its paracaspase activity is not fully understood. Here, we studied how MALT1 proteolytic function regulates T-cell activation and fate after engagement of the T-cell receptor pathway. We show that MLT-827, a potent and selective MALT1 paracaspase inhibitor, does not prevent the initial phase of T-cell activation, in contrast to the pan-protein kinase C inhibitor AEB071. However, MLT-827 strongly impacted cell expansion after activation. We demonstrate this is the consequence of profound inhibition of IL-2 production as well as reduced expression of the IL-2 receptor alpha subunit (CD25), resulting from defective canonical NF-κB activation and accelerated mRNA turnover mechanisms. Accordingly, MLT-827 revealed a unique transcriptional fingerprint of MALT1 protease activity, providing evidence for broad control of T-cell signaling pathways. Altogether, this first report with a potent and selective inhibitor elucidates how MALT1 paracaspase activity integrates several T-cell activation pathways and indirectly controls gamma-chain receptor dependent survival, to impact on T-cell expansion.

A natural ligand for the orphan receptor GPR15 modulates lymphocyte recruitment to epithelia.

GPR15 is an orphan G protein-coupled receptor (GPCR) that is found in lymphocytes. It functions as a co-receptor of simian immunodeficiency virus and HIV-2 and plays a role in the trafficking of T cells to the lamina propria in the colon and to the skin. We describe the purification from porcine colonic tissue extracts of an agonistic ligand for GPR15 and its functional characterization. In humans, this ligand, which we named GPR15L, is encoded by the gene C10ORF99 and has some features similar to the CC family of chemokines. GPR15L was found in some human and mouse epithelia exposed to the environment, such as the colon and skin. In humans, GPR15L was also abundant in the cervix. In skin, GPR15L was readily detected after immunologic challenge and in human disease, for example, in psoriatic lesions. Allotransplantation of skin from Gpr15l-deficient mice onto wild-type mice resulted in substantial graft protection, suggesting nonredundant roles for GPR15 and GPR15L in the generation of effector T cell responses. Together, these data identify a receptor-ligand pair that is required for immune homeostasis at epithelia and whose modulation may represent an alternative approach to treating conditions affecting the skin such as psoriasis.

A new giant titanosaur sheds light on body mass evolution among sauropod dinosaurs.

Titanosauria was the most diverse and successful lineage of sauropod dinosaurs. This clade had its major radiation during the middle Early Cretaceous and survived up to the end of that period. Among sauropods, this lineage has the most disparate values of body mass, including the smallest and largest sauropods known. Although recent findings have improved our knowledge on giant titanosaur anatomy, there are still many unknown aspects about their evolution, especially for the most gigantic forms and the evolution of body mass in this clade. Here we describe a new giant titanosaur, which represents the largest species described so far and one of the most complete titanosaurs. Its inclusion in an extended phylogenetic analysis and the optimization of body mass reveals the presence of an endemic clade of giant titanosaurs inhabited Patagonia between the Albian and the Santonian. This clade includes most of the giant species of titanosaurs and represents the major increase in body mass in the history of Titanosauria.

Data on the mechanisms underlying succinate-induced aortic contraction.

We describe the mechanisms underlying the vascular contraction induced by succinate. The data presented here are related to the article entitled "Pharmacological characterization of the mechanisms underlying the vascular effects of succinate" (L.N. Leite, N.A. Gonzaga, J.A. Simplicio, G.T. Vale, J.M. Carballido, J.C. Alves-Filho, C.R. Tirapelli, 2016) [1]. Succinate acts as a signaling molecule by binding to a G-protein-coupled receptor termed GPR91, "Citric acid cycle intermediates as ligands for orphan G-protein-coupled receptors" (W. He, F.J. Miao, D.C. Lin, R.T. Schwandner, Z. Wang, J. Gao, J.L. Chen, H. Tian, L. Ling, 2004) [2]. Here we include data on the contractile effect of succinate in the aorta. Succinate contracted both endothelium-intact and endothelium-denuded aortic rings isolated from male Wistar rats or C57BL/6 mice. Succinate was less effective at inducing contraction in arteries isolated from GPR91-deficient mice, when compared to its vascular effect in aortas from wild type mice. SB203508 (p38MAK inhibitor), SP600125 (JNK inhibitor) and Y27632 (Rho-kinase inhibitor) reduced succinate-induced contraction in both endothelium-intact and endothelium-denuded rat aortic rings, while PD98059 (ERK1/2 inhibitor) did not affect succinate-induced contraction. The contractile response induced by succinate on endothelium-intact and endothelium-denuded rat aortic rings was reduced by indomethacin (non-selective cyclooxygenase inhibitor), H7 (protein kinase C inhibitor), verapamil (Ca(2+) channel blocker) and tiron (superoxide anion scavenger).

Pharmacological characterization of the mechanisms underlying the vascular effects of succinate.

We investigated the mechanisms underlying the vascular effects of succinate. Vascular reactivity experiments were performed in aortic rings isolated from male Wistar rats and C57BL/6 wild type (WT) or GPR91(-/-) mice. Nitrate/nitrite (NOx) was measured colorimetrically whereas 6-keto-prostaglandin F1α (stable product of prostacyclin) was measured by enzyme immunoassay (EIA). Phosphorylation of endothelial nitric oxide synthase (eNOS) was assessed by western immunoblotting. Functional assays revealed that the direct effect of succinate in the vasculature is biphasic. At lower concentrations succinate induced relaxation while at higher concentrations succinate induced vascular contraction. Succinate concentration dependently relaxed rat aortic rings with intact endothelium. Endothelial removal reduced, but not abolished succinate-induced relaxation. Similarly, succinate relaxed endothelium-intact and endothelium-denuded aortas isolated from both C57BL/6 and GPR91(-/-) mice. Pre-incubation of endothelium-intact, but not endothelium-denuded rat aortic rings with l-NAME, indomethacin and tetraethylammonium (TEA) reduced succinate-induced relaxation. In endothelium-intact rings, succinate-induced relaxation was attenuated by ODQ, haemoglobin, Rp-8-Br-Pet-cGMPS, thapsigargin, wortmannin and SC-560. Blockade of K(+) channels with 4-aminopyridine, apamin and charybdotoxin reduced succinate-induced relaxation. Succinate increased the concentration of NOx and 6-keto-prostaglandin F1α as well as eNOS phosphorylation at ser(1177) residue. CaCl2-induced contraction of endothelium-intact or endothelium-denuded aortas was not affected by succinate. The major finding of our study is that it first demonstrates a direct effect of succinate in the vasculature. Succinate displays a biphasic and concentration-dependent effect. The vascular relaxation induced by succinate is partially mediated by endothelial GPR91 receptors via the NO-cGMP pathway, a vasodilator cyclooxygenase (COX) product(s) and the opening of K(+) channels.