Mechanisms of Cbl-Mediated Ubiquitination of Proteins in T and Natural Killer Cells and Effects on Immune Cell Functions.

Post-translational ubiquitination is an essential mechanism for the regulation of protein stability and function, which contributes to the regulation of the immune system. Cbl, an E3 ubiquitin ligase, is particularly well-characterized in the context of T and NK cell signaling, where it serves as a key regulator of receptor downstream signaling events and as a modulator of cell activation. Cbl promotes the proteasomal degradation of TCR/CD3 subunits as well as the protein kinases Fyn and Lck in T cells.

Cupin-1.1 Adsorption Layers at the Surface of 8 M Urea Solutions.

The adsorption layers of cupin-1.1, one of the two evolutionary conserved β-barrel domains of vicilin─the garden pea storage globulin─at the liquid-gas interface were studied by a few methods of the surface chemistry. The kinetic dependencies of the surface pressure of cupin-1.

Dynamic properties of the layers of cupin-1.1 aggregates at the air/water interface.

Spread layers of amorphous aggregates of the structural domain of plant protein vicilin, cupin-1.1, at the water - air interface were studied by the surface tensiometry, dilational surface rheology, Brewster angle and atomic force microscopy. The layer properties differed strongly from the results for the layers of previously studied proteins.

The Peptidyl-Prolyl isomerase, Pin1, associates with Protein Kinase C θ a critical Phospho-Thr-Pro motif in the V3 regulatory domain.

Protein kinase C-θ (PKCθ) is a member of the novel PKC subfamily known for its selective and predominant expression in T lymphocytes where it regulates essential functions required for T cell activation and proliferation. Our previous studies provided a mechanistic explanation for the recruitment of PKCθ to the center of the immunological synapse (IS) by demonstrating that a proline-rich (PR) motif within the V3 region in the regulatory domain of PKCθ is necessary and sufficient for PKCθ IS localization and function. Herein, we highlight the importance of Thr-Pro residue in the PR motif, the phosphorylation of which is key in the activation of PKCθ and its subsequent IS localization.

The role of AMPK in cancer metabolism and its impact on the immunomodulation of the tumor microenvironment.

Adenosine monophosphate-activated protein kinase (AMPK) is a key metabolic sensor that is pivotal for the maintenance of cellular energy homeostasis. AMPK contributes to diverse metabolic and physiological effects besides its fundamental role in glucose and lipid metabolism. Aberrancy in AMPK signaling is one of the determining factors which lead to the development of chronic diseases such as obesity, inflammation, diabetes, and cancer.

Termination of TCR-mediated activation signals is regulated by CrkII-dependent Cbl-mediated ubiquitination and degradation of C3G.

Crk adaptor proteins are key players in signal transduction from multiple cell surface receptors, including the T cell antigen receptor (TCR). The involvement of CrkII in the early stages of T cell activation is well documented, but little is known about its role during the termination of the activation response. We substantiated findings showing that CrkII utilizes its SH3N and SH2 domains to constitutively associate with C3G and transiently with Cbl in resting and TCR/CD3-stimulated T cells, respectively.

Cyclophilin A associates with and regulates the activity of ZAP70 in TCR/CD3-stimulated T cells.

The ZAP70 protein tyrosine kinase (PTK) couples stimulated T cell antigen receptors (TCRs) to their downstream signal transduction pathways and is sine qua non for T cell activation and differentiation. TCR engagement leads to activation-induced post-translational modifications of ZAP70, predominantly by kinases, which modulate its conformation, leading to activation of its catalytic domain. Here, we demonstrate that ZAP70 in TCR/CD3-activated mouse spleen and thymus cells, as well as human Jurkat T cells, is regulated by the peptidyl-prolyl cis-trans isomerase (PPIase), cyclophilin A (CypA) and that this regulation is abrogated by cyclosporin A (CsA), a CypA inhibitor.

Decoupling the role of RORγt in the differentiation and effector function of T17 cells.

RORγt is known to instruct the differentiation of T helper 17 (T17) cells that mediate the pathogenesis of autoimmune diseases. However, it remains unknown whether RORγt plays a distinct role in the differentiation and effector function of T17 cells. Here, we show that mutation of RORγt lysine-256, a ubiquitination site, to arginine (K256R) separates the RORγt role in these two functions.

Corrigendum: Blockade of uttroside B-induced autophagic pro-survival signals augments its chemotherapeutic efficacy against hepatocellular carcinoma.

[This corrects the article DOI: 10.3389/fonc.2022.

Steroid nuclear receptor coactivator 2 controls immune tolerance by promoting induced T differentiation via up-regulating Nr4a2.

Steroid nuclear receptor coactivator 2 (SRC2) is a member of a family of transcription coactivators. While SRC1 inhibits the differentiation of regulatory T cells (T) critical for establishing immune tolerance, we show here that SRC2 stimulates T differentiation. SRC2 is dispensable for the development of thymic T, whereas naive CD4 T cells from mice deficient of SRC2 specific in T () display defective T differentiation.

Blockade of Uttroside B-Induced Autophagic Pro-Survival Signals Augments Its Chemotherapeutic Efficacy Against Hepatocellular Carcinoma.

Our previous study has demonstrated that Uttroside B (Utt-B), a saponin isolated from the leaves of Linn induces apoptosis in hepatic cancer cells and exhibits a remarkable growth inhibition of Hepatocellular Carcinoma (HCC). Our innovation has been granted a patent from the US (US 2019/0160088A1), Canada (3,026,426.), Japan (JP2019520425) and South Korea (KR1020190008323) and the technology have been transferred commercially to Q Biomed, a leading US-based Biotech company.

Histocompatibility and Reproduction: Lessons from the Anglerfish.

Reproduction in certain deep-sea anglerfishes involves the permanent attachment of dwarf males to much larger females and fusion of their tissues leading to the establishment of a shared circulatory system. This unusual phenomenon of sexual parasitism enables anglerfishes to maximize reproductive success in the vast and deep oceans, where females and males otherwise rarely meet. An even more surprising phenomenon relates to the observation that joining of genetically disparate male and female anglerfishes does not evoke a strong anti-graft immune rejection response, which occurs in vertebrates following allogeneic parabiosis.

Unraveling the hidden role of a uORF-encoded peptide as a kinase inhibitor of PKCs.

Approximately 40% of human messenger RNAs (mRNAs) contain upstream open reading frames (uORFs) in their 5' untranslated regions. Some of these uORF sequences, thought to attenuate scanning ribosomes or lead to mRNA degradation, were recently shown to be translated, although the function of the encoded peptides remains unknown. Here, we show a uORF-encoded peptide that exhibits kinase inhibitory functions.

A watchful waiting approach for newly diagnosed Crohn's disease patients with an inflammatory phenotype.

Background: An early treat-to-target approach in Crohn's disease (CD) patients is recommended to avoid complications. However, CD may not always progress despite lack of treatment, thus exposing some patients to unnecessary side effects. We aimed to examine whether newly diagnosed CD patients with an inflammatory phenotype can benefit from a watchful waiting approach.

Protein kinase C eta is activated in reactive astrocytes of an Alzheimer's disease mouse model: Evidence for its immunoregulatory function in primary astrocytes.

Alzheimer's disease (AD) is the primary cause of age-related dementia. Pathologically, AD is characterized by synaptic loss, the accumulation of β-amyloid peptides and neurofibrillary tangles, glial activation, and neuroinflammation. Whereas extensive studies focused on neurons and activation of microglia in AD, the role of astrocytes has not been well-characterized.

Higher Maintenance Adalimumab Trough Levels are Associated With Achievement of Advanced Remission Targets in Patients With Inflammatory Bowel Disease.

Background: Biomarker normalization and endoscopic remission are superior to clinical remission in achieving improved long-term clinical outcomes in patients with inflammatory bowel diseases.

Goal: To study whether higher maintenance adalimumab levels are associated with clinical remission, biomarker normalization, and endoscopic remission.

Study: Data were collected retrospectively from the patients' medical records.

Vedolizumab is effective and safe in elderly inflammatory bowel disease patients: a binational, multicenter, retrospective cohort study.

Background: Immune modulating therapies are associated with an increased risk of infections and malignancies. This is of particular concern in elderly inflammatory bowel disease patients. This study aims to compare the safety and efficacy of vedolizumab between young and elderly inflammatory bowel disease patients.

[Radiation-induced meningiomas: analysis of 33 cases].

Background: Development of meningiomas correlating with irradiation has been described in the last century. Different biological features of radiation-induced meningiomas depending on dose and type of irradiation have been observed in recent years.

Material And Methods: There were 8848 patients (women - 74.

PICOT binding to chromatin-associated EED negatively regulates cyclin D2 expression by increasing H3K27me3 at the CCND2 gene promoter.

Protein kinase C (PKC)-interacting cousin of thioredoxin (PICOT; also termed glutaredoxin 3 (Grx3; Glrx3)) is a ubiquitous protein that can interact with the embryonic ectoderm development (EED) protein via each of its two C-terminal PICOT/Grx homology domains. Since EED is a Polycomb-Group protein and a core component of the polycomb repressive complex 2 (PRC2), we tested the involvement of PICOT in the regulation of PRC2-mediated H3 lysine 27 trimethylation (H3K27me3), transcription and translation of selected PRC2 target genes. A fraction of the cellular PICOT protein was found in the nuclei of leukemia cell lines, where it was associated with the chromatin.

PICOT (GLRX3) is a positive regulator of stress-induced DNA-damage response.

Protein kinase C (PKC)-interacting cousin of thioredoxin (PICOT; also termed glutaredoxin 3 (Glrx3)) is a ubiquitously expressed protein that possesses an N-terminal monothiol thioredoxin (Trx) domain and two C-terminal tandem copies of a monothiol Glrx domain. It has an overall highly conserved amino acid sequence and is encoded by a unique gene, both in humans and mice, without having other functional gene homologs in the entire genome. Despite being discovered almost two decades ago, the biological function of PICOT remains largely ill-defined and its ramifications are underestimated considering the fact that PICOT-deficiency in mice results in embryonic lethality.

PICOT binding to the polycomb group protein, EED, alters H3K27 methylation at the MYT1 PRC2 target gene.

PICOT is a ubiquitous protein that has no functional redundant ortholog and is critical for mouse embryonic development. It is involved in the regulation of signal transduction in T lymphocytes and cardiac muscle, and in cellular iron metabolism and biogenesis of Fe/S proteins. However, very little is known about the physiological role of PICOT and its mechanism of action, and on its upstream regulators or downstream target molecules.

Dietary arachidonic acid affects immune function and fatty acid composition in cultured rabbitfish Siganus rivulatus.

The marbled spinefoot rabbitfish (Siganus rivulatus) is an economically valuable fish species that has potential for commercial production in aquaculture. To overcome challenges in its sustainable production, a formulated diet is required for imparting health and robustness. This study evaluates the effect of dietary supplementation with arachidonic acid (ARA; 20:4n-6) on growth, survival, immune function and fatty acid composition of red blood cells (RBCs) in rabbitfish.