The small molecule inhibitor BX-795 uncouples IL-2 production from inhibition of Th2 inflammation and induces CD4+ T cells resembling iTreg

BackgroundTreg cells have been shown to be an important part of immune-homeostasis and IL-2 which is produced upon T cell receptor (TCR)-dependent activation of T lymphocytes has been demonstrated to critically participate in Treg development.ObjectiveTo evaluate small molecule inhibitors (SMI) for the identification of novel IL-2/Treg enhancing compounds.Materials and methodsWe used TCR-dependent and allergen-specific cytokine secretion of human and mouse T cells, next generation messenger ribonucleic acid sequencing (RNA-Seq) and two different models of allergic airway inflammation to examine lead SMI-compounds.ResultsWe show here that the reported 3-phosphoinositide dependent kinase-1 (PDK1) SMI BX-795 increased IL-2 in culture supernatants of Jurkat E6-1 T cells, human peripheral blood mononuclear cells (hPBMC) and allergen-specific mouse T cells upon TCR-dependent and allergen-specific stimulation while concomitantly inhibiting Th2 cytokine secretion. RNA-Seq revealed that the presence of BX-795 during allergen-specific activation of T cells induces a bona fide Treg cell type highly similar to iTreg but lacking Foxp3 expression. When applied in mugwort pollen and house dust mite extract-based models of airway inflammation, BX-795 significantly inhibited Th2 inflammation including expression of Th2 signature transcription factors and cytokines and influx into the lungs of type 2-associated inflammatory cells such as eosinophils.ConclusionsBX-795 potently uncouples IL-2 production from Th2 inflammation and induces Th-IL-2 cells, which highly resemble induced (i)Tregs. Thus, BX-795 may be a useful new compound for the treatment of allergic diseases

A multi-country test of brief reappraisal interventions on emotions during the COVID-19 pandemic.

The COVID-19 pandemic has increased negative emotions and decreased positive emotions globally. Left unchecked, these emotional changes might have a wide array of adverse impacts. To reduce negative emotions and increase positive emotions, we tested the effectiveness of reappraisal, an emotion-regulation strategy that modifies how one thinks about a situation. Participants from 87 countries and regions (n = 21,644) were randomly assigned to one of two brief reappraisal interventions (reconstrual or repurposing) or one of two control conditions (active or passive). Results revealed that both reappraisal interventions (vesus both control conditions) consistently reduced negative emotions and increased positive emotions across different measures. Reconstrual and repurposing interventions had similar effects. Importantly, planned exploratory analyses indicated that reappraisal interventions did not reduce intentions to practice preventive health behaviours. The findings demonstrate the viability of creating scalable, low-cost interventions for use around the world

Immunology Letters / The making and function of CAR cells

Genetically engineered T cells expressing chimeric antigen receptors (CAR) present a new treatment option for patients with cancer. Recent clinical trials of B cell leukemia have demonstrated a response rate of up to 90%. However, CAR cell therapy is frequently accompanied by severe side effects such as cytokine release syndrome and the development of target cell resistance. Consequently, further optimization of CARs to obtain greater long-term efficacy and increased safety is urgently needed. Here we high-light the various efforts of adjusting the intracellular signaling domains of CARs to these major requirements to eventually obtain high-level target cell cytotoxicity paralleled by the establishment of longevity of the CAR expressing cell types to guarantee for extended tumor surveillance over prolonged periods of time. We are convinced that it will be crucial to identify the molecular pathways and signaling requirements utilized by such ‘efficient CARs in order to provide a rational basis for their further hypothesis-based improvement. Furthermore, we here discuss timely attempts of how to: i) control ‘on-tumor off-target effects; ii) introduce Signal 3 (cytokine responsiveness of CAR cells) as an important building-block into the CAR concept; iii) most efficiently eliminate CAR cells once full remission has been obtained. We also argue that universal systems for the variable and pharmacokinetically-controlled attachment of extracellular ligand recognition domains of choice along with the establishment of ‘off-the-shelf cell preparations with suitability for all patients in need of a highly-potent cellular therapy may become future mainstays of CAR cell therapy. Such therapies would have the attraction to work independent of the patients histocompatibility make-up and the availability of functionally intact patients cells. Finally, we summarize the evidence that CAR cells may obtain a prominent place in the treatment of non-malignant and auto-reactive T and B lymphocyte expansions in the near future, e.g., for the alleviation of autoimmune diseases and allergies. After the introduction of red blood cell transfusions, which were made possible by the landmark discoveries of the ABO blood groups by Karl Landsteiner, and the establishment of bone marrow transplantation by E. Donnall Thomas to exchange the entire hematopoietic system of a patient suffering from leukemia, the introduction of patient-tailored cytotoxic cellular populations to eradicate malignant cell populations in vivo pioneered by Carl H. June, represents the third major and broadly applicable milestone in the development of human cellular therapies within the rapidly developing field of applied biomedical research of the last one hundred years.(VLID)490349

Art v 1 IgE epitopes of patients and humanized mice are conformational

Background: Worldwide, pollen of the weed mugwort (Artemisia vulgaris) is a major cause of severe respiratory allergy, with its major allergen, Art v 1, being the key pathogenic molecule for millions of patients. Humanized mice transgenic for a human T-cell receptor specific for the major Art v 1 T-cell epitope and the corresponding HLA have been made. Objective: We sought to characterize IgE epitopes of Art v 1–sensitized patients and humanized mice for molecular immunotherapy of mugwort allergy. Methods: Four overlapping peptides incorporating surface-exposed amino acids representing the full-length Art v 1 sequence were synthesized and used to search for IgE reactivity to sequential epitopes. For indirect mapping, peptide-specific rabbit antibodies were raised to block IgE against surface-exposed epitopes on folded Art v 1. IgE reactivity and basophil activation studies were performed in clinically defined mugwort-allergic patients. Secondary structure of recombinant (r) Art v 1 and peptides was determined by circular dichroism spectroscopy. Results: Mugwort-allergic patients and humanized mice sensitized by allergen inhalation showed IgE reactivity and/or basophil activation mainly to folded, complete Art v 1 but not to unfolded, sequential peptide epitopes. Blocking of allergic patients’ IgE with peptide-specific rabbit antisera identified a hitherto unknown major conformational IgE binding site in the C-terminal Art v 1 domain. Conclusions: Identification of the new major conformational IgE binding site on Art v 1, which can be blocked with IgG raised against non-IgE reactive Art v 1 peptides, is an important basis for the development of a hypoallergenic peptide vaccine for mugwort allergy

Protein kinase/phosphatase balance mediates the effects of increased late sodium current on ventricular calcium cycling

Increased late sodium current (late I-Na) is an important arrhythmogenic trigger in cardiac disease. It prolongs cardiac action potential and leads to an increased SR Ca2+ leak. This study investigates the contribution of Ca2+/Calmodulin-dependent kinase II (CaMKII), protein kinase A (PKA) and conversely acting protein phosphatases 1 and 2A (PP1, PP2A) to this subcellular crosstalk. Augmentation of late I-Na (ATX-II) in murine cardiomyocytes led to an increase of diastolic Ca2+ spark frequency and amplitudes of Ca2+ transients but did not affect SR Ca2+ load. Interestingly, inhibition of both, CaMKII and PKA, attenuated the late I-Na-dependent induction of the SR Ca2+ leak. PKA inhibition additionally reduced the amplitudes of systolic Ca2+ transients. FRET-measurements revealed increased levels of cAMP upon late I-Na augmentation, which could be prevented by simultaneous inhibition of Na+/Ca2+-exchanger (NCX) suggesting that PKA is activated by Ca2+-dependent cAMP-production. Whereas inhibition of PP2A showed no effect on late I-Na-dependent alterations of Ca2+ cycling, additional inhibition of PP1 further increased the SR Ca2+ leak. In line with this, selective activation of PP1 yielded a strong reduction of the late I-Na-induced SR Ca2+ leak and did not affect systolic Ca2+ release. This study indicates that phosphatase/kinase-balance is perturbed upon increased Na+ influx leading to disruption of ventricular Ca2+ cycling via CaMKII- and PKA-dependent pathways. Importantly, an activation of PP1 at RyR2 may represent a promising new toehold to counteract pathologically increased kinase activity