• MeSH
• Immunity MeSH
• Communicable Diseases immunology   MeSH
• Publication type
• Congress MeSH
• Collected Work MeSH
• News MeSH

• Conspectus
• Patologie. Klinická medicína
• NML Fields
• alergologie a imunologie
• infekční lékařství

Aberrant glycosylation, which impairs recognition capability of NK cells or modifies recognition pattern of target cells, is associated with cancer. Synthetic glycoconjugates (GCs), which modulate cell glycosylation, increase the sensitivity of tumor cells to therapy or boost anti-cancer immune response. In the current study, we employed N-acetyl-D-glucosamine-calix[4]arene (GN4C) as a modulator of cell glycosylation of NK cells represented by the NK-92 cell line and fresh human NK cells. For the first time, we have demonstrated that calix[4]arene-based GC down-regulated the expression of glycosyltransferases MGAT3 and MGAT5 in NK-92 and fresh NK cells. GN4C increased the susceptibility of tumor cells to cytotoxicity by purified fresh NK cells or NK-92 cells. This functional activation of NK cells and the NK-92 cell line correlated with an increased expression of NKG2D mRNA. In the NK-92 cell line, GN4C induced the synthesis of IL-2, IFN-gamma and tumor necrosis factor-alpha as well. Cellular signaling triggered by GN4C engaged PI3-kinase/ERK but not phospholipase C-gamma/JNK pathways. Simultaneously, in transformed NK-92 cells, GN4C reduced the rate of proliferation and down-regulated the c-MYC, EGF-receptor 1 and REL-A molecules. In conclusion, the modulation of glycosyltransferases MGAT3 and MGAT5 by synthetic GN4C correlated with the improvement of NK cell effector functions and the augmentation of tumor cells sensitivity to NK cell-mediated cytotoxicity.

• MeSH
• Acyltransferases immunology   metabolism   MeSH
• Lymphocyte Activation immunology   MeSH
• Cell Line MeSH
• HT29 Cells MeSH
• Killer Cells, Natural immunology   metabolism   MeSH
• Cytotoxicity, Immunologic genetics   immunology   MeSH
• Gene Expression MeSH
• Phosphatidylinositol 3-Kinases immunology   metabolism   MeSH
• Glycoconjugates immunology   metabolism   MeSH
• Glycosylation MeSH
• Humans MeSH
• RNA, Messenger analysis   MeSH
• N-Acetylglucosaminyltransferases immunology   metabolism   MeSH
• Neoplasms genetics   immunology   metabolism   MeSH
• Reverse Transcriptase Polymerase Chain Reaction MeSH
• Cell Proliferation MeSH
• Nerve Tissue Proteins immunology   metabolism   MeSH
• Flow Cytometry MeSH
• Gene Expression Regulation, Neoplastic MeSH
• Oligonucleotide Array Sequence Analysis MeSH
• Cell Separation MeSH
• Signal Transduction immunology   MeSH
• Check Tag
• Humans MeSH
• Publication type
• Journal Article MeSH
• Research Support, Non-U.S. Gov't MeSH

Cytokiny jsou významné informační a regulační molekuly přispívající k udržení homeostázy celého organismu. Mají společné buněčné zdroje (makrofágy, všechny typy buněk zpracovávající antigen (APC), subpopulace lymfocytů pomocných Th a cytotoxických Tc) a uplatňuje se buněčná pluralita tvorby cytokinů. Cytokiny vzájemně propojuje stále hlubší porozumění receptorové vazby a signalizačního převodu na genovou úroveň. Stejná signalizace provází vazbu růstového hormonu, prolaktinu, erytropoetinu, interleukinů i kolonie stimulujících faktorů. V závislosti na charakteru vazby, časové sekvenci i kvantitativních poměrech se mohou cytokiny projevovat buď vzájemnou podpůrnou - synergickou funkcí, nebo vzájemně se funkčně vytěsňovat – antagonizovat. Důsledkem všech uvedených faktorů, tj. buněčného zdroje, převodu signálu, výsledného synergického nebo antagonistického účinku, jsou funkční projevy vzájemného působení cytokinové sítě. Některé cytokiny podobně jako interleukiny mají vždy projevy prorůstové. Jsou to růstové faktory pojmenované podle zdroje a převážného působení na efektorové buňky, tj. epidermální, fibroblastové, nervové růstové faktory a další. Velká skupina cytokinů se účastní aktivace buněčných mechanismů imunity, děje, který vede k obranému zánětu. Teprve je-li za určitých podmínek např. nadměrná tvorba cytokinů, nebo jejich dysregulace, potom se projeví zánět tkáňovým poškozením, zánětem, který může vést až k šokovému stavu. Lokálně tvořené cytokiny a makrofágové peptidy zánětu působí nejen lokálně, ale přestupem do krevního oběhu mohou mít i vliv centrální na nervová centra hypotalamu.

Cytokines are important regulatory molecules which play a role in cell-cell interactions and homeostasis. Various cytokines can be produced by the same cell type, on the other hand a particular cytokine can be produced by different cell types, e.g. macrophages, all kinds of antigen presenting cells (APC), subpopulations of Th - helper and Tc - cytotoxic T-lymphocytes. Cytokines are interconnected by still deeper understanding of the cytokine-receptor signalling pathway. Similar signalling is applied in the binding of the growth factor, prolactin, erythropoetin, interleukins and of the colony stimulating factors. Depending on the character, the time-sequence and quantitative proportions of the cytokine-receptor interaction, cytokines can act together in synergistic function or be mutually functionally antagonistic. The consequences of the mentioned factors, i.e. cell source, signal transfer and the resulting synergistic or antagonistic effects are the functional manifestations of the interactions of the cytokine network. Some cytokines have significant growth effects and are therefore named growth factors and additionally according to the source and prevailing scope of action on effector cells, i.e. epidermal, fibroblast, nerve growth factors and others. A large group of cytokines is involved in activation of mechanisms of cell immunity, a process that leads to a protective inflammation. Under certain circumstances, such as excessive cytokine production or dysregulation of cytokine production, inflammation is manifested by a tissue damage, inflammation that can lead even to a shock state. The locally produced inflammatory cytokines and macrophage peptides act not only locally, but can influence the central nervous system of the hypothalamus by transfer into blood circulation.

• MeSH
• Chemokines physiology   immunology   classification   MeSH
• Cytokines physiology   immunology   classification   MeSH
• Hematopoietic Cell Growth Factors physiology   immunology   classification   MeSH
• Humans MeSH
• Nerve Growth Factors physiology   immunology   classification   MeSH
• Growth Substances physiology   immunology   classification   MeSH
• Transforming Growth Factors physiology   immunology   classification   MeSH
• Tumor Necrosis Factors physiology   immunology   MeSH
• Check Tag
• Humans MeSH
• Publication type
• Review MeSH

• Conspectus
• Biochemie. Molekulární biologie. Biofyzika
• NML Fields
• biochemie
• histologie

Cells have developed a unique set of molecular mechanisms that allows them to probe mechanical properties of the surrounding environment. These systems are based on deformable primary mechanosensors coupled to tension transmitting proteins and enzymes generating biochemical signals. This modular setup enables to transform a mechanical load into more versatile biochemical information. Src kinase appears to be one of the central components of the mechanotransduction network mediating force-induced signalling across multiple cellular contexts. In tight cooperation with primary sensors and the cytoskeleton, Src functions as an effector molecule necessary for transformation of mechanical stimuli into biochemical outputs executing cellular response and adaptation to mechanical cues.

• MeSH
• Adaptor Proteins, Signal Transducing genetics   metabolism   MeSH
• Mechanotransduction, Cellular genetics   MeSH
• Cytoskeleton metabolism   pathology   ultrastructure   MeSH
• Extracellular Matrix metabolism   pathology   ultrastructure   MeSH
• Integrins genetics   metabolism   MeSH
• Humans MeSH
• Stress, Mechanical MeSH
• Neoplasms genetics   metabolism   pathology   MeSH
• Protein Serine-Threonine Kinases genetics   metabolism   MeSH
• Gene Expression Regulation MeSH
• src-Family Kinases genetics   metabolism   MeSH
• Crk-Associated Substrate Protein genetics   metabolism   MeSH
• Transcription Factors genetics   metabolism   MeSH
• Receptor-Like Protein Tyrosine Phosphatases, Class 4 genetics   metabolism   MeSH
• Animals MeSH
• Check Tag
• Humans MeSH
• Animals MeSH
• Publication type
• Journal Article MeSH
• Research Support, Non-U.S. Gov't MeSH
• Review MeSH

UNLABELLED: Inhibitors targeting human glutamate carboxypeptidase II (GCPII) typically consist of a P1' glutamate-derived binding module, which warrants the high affinity and specificity, linked to an effector function that is positioned within the entrance funnel of the enzyme. Here we present a comprehensive structural and computational study aimed at dissecting the importance of the effector function for GCPII binding and affinity. To this end we determined crystal structures of human GCPII in complex with a series of phosphoramidate-based inhibitors harboring effector functions of diverse physicochemical characteristics. Our data show that higher binding affinities of phosphoramidates, compared to matching phosphonates, are linked to the presence of additional hydrogen bonds between Glu424 and Gly518 of the enzyme and the amide group of the phosphoramidate. While the positioning of the P1' glutamate-derived module within the S1' pocket of GCPII is invariant, interaction interfaces between effector functions and residues lining the entrance funnel are highly varied, with the positively charged arginine patch defined by Arg463, Arg534 and Arg536 being the only 'hot-spot' common to several studied complexes. This variability stems in part from the fact that the effector/GCPII interfaces generally encompass isolated areas of nonpolar residues within the entrance funnel and resulting van der Waals contacts lack the directionality typical for hydrogen bonding interactions. The presented data unravel a complexity of binding modes of inhibitors within non-prime site(s) of GCPII and can be exploited for the design of novel GCPII-specific compounds. PDB ID CODES: Atomic coordinates of the present structures together with the experimental structure factor amplitudes were deposited at the RCSB Protein Data Bank under accession codes 4P44 (complex with JRB-4-81), 4P45 (complex with JRB-4-73), 4P4B (complex with CTT54), 4P4D (complex with MP1C), 4P4E (complex with MP1D), 4P4F (complex with NC-2-40), 4P4I (complex with T33) and 4P4J (complex with T33D).

• MeSH
• Amides chemical synthesis   chemistry   pharmacology   MeSH
• Antigens, Surface metabolism   MeSH
• Glutamate Carboxypeptidase II antagonists & inhibitors   metabolism   MeSH
• Enzyme Inhibitors chemical synthesis   chemistry   pharmacology   MeSH
• Crystallography, X-Ray MeSH
• Phosphoric Acids chemical synthesis   chemistry   pharmacology   MeSH
• Humans MeSH
• Models, Molecular MeSH
• Molecular Structure MeSH
• Drug Design * MeSH
• Hydrogen Bonding MeSH
• Dose-Response Relationship, Drug MeSH
• Structure-Activity Relationship MeSH
• Check Tag
• Humans MeSH
• Publication type
• Journal Article MeSH
• Research Support, Non-U.S. Gov't MeSH

T cells are pivotal in the adaptive immune defense, necessitating a delicate balance between robust response against infections and self-tolerance. Their activation involves intricate cross-talk among signaling pathways triggered by the T-cell antigen receptors (TCR) and co-stimulatory or inhibitory receptors. The molecular regulation of these complex signaling networks is still incompletely understood. Here, we identify the adaptor protein ABIN1 as a component of the signaling complexes of GITR and OX40 co-stimulation receptors. T cells lacking ABIN1 are hyper-responsive ex vivo, exhibit enhanced responses to cognate infections, and superior ability to induce experimental autoimmune diabetes in mice. ABIN1 negatively regulates p38 kinase activation and late NF-κB target genes. P38 is at least partially responsible for the upregulation of the key effector proteins IFNG and GZMB in ABIN1-deficient T cells after TCR stimulation. Our findings reveal the intricate role of ABIN1 in T-cell regulation.

• MeSH
• Adaptor Proteins, Signal Transducing * metabolism   genetics   MeSH
• Lymphocyte Activation immunology   genetics   MeSH
• T-Lymphocytes, Cytotoxic * immunology   metabolism   MeSH
• Diabetes Mellitus, Type 1 immunology   genetics   metabolism   MeSH
• Glucocorticoid-Induced TNFR-Related Protein MeSH
• Interferon-gamma metabolism   MeSH
• Humans MeSH
• p38 Mitogen-Activated Protein Kinases metabolism   MeSH
• Mice, Inbred C57BL MeSH
• Mice, Knockout MeSH
• Mice MeSH
• NF-kappa B metabolism   MeSH
• Receptors, Antigen, T-Cell metabolism   MeSH
• Receptors, OX40 metabolism   genetics   MeSH
• Signal Transduction * MeSH
• Animals MeSH
• Check Tag
• Humans MeSH
• Mice MeSH
• Animals MeSH
• Publication type
• Journal Article MeSH

UNLABELLED: Deoxyribonucleoside regulator (DeoR) from Bacillus subtilis negatively regulates expression of enzymes involved in the catabolism of deoxyribonucleosides and deoxyribose. The DeoR protein is homologous to the sorbitol operon regulator family of metabolic regulators and comprises an N-terminal DNA-binding domain and a C-terminal effector-binding domain. We have determined the crystal structure of the effector-binding domain of DeoR (C-DeoR) in free form and in covalent complex with its effector deoxyribose-5-phosphate (dR5P). This is the first case of a covalently attached effector molecule captured in the structure of a bacterial transcriptional regulator. The dR5P molecule is attached through a Schiff base linkage to residue Lys141. The crucial role of Lys141 in effector binding was confirmed by mutational analysis and mass spectrometry of Schiff base adducts formed in solution. Structural analyses of the free and effector-bound C-DeoR structures provided a structural explanation for the mechanism of DeoR function as a molecular switch. DATABASES: Atomic coordinates and structure factors for crystal structures of free C-DeoR and the covalent Schiff base complex of C-DeoR with dR5P have been deposited in the Protein Data Bank with accession codes 4OQQ and 4OQP, respectively. STRUCTURED DIGITAL ABSTRACT: C-DeoR and C-DeoR bind by x-ray crystallography (View interaction) DeoR and DeoR bind by molecular sieving (1, 2).

• MeSH
• Bacillus subtilis * MeSH
• Bacterial Proteins chemistry   genetics   MeSH
• Crystallography, X-Ray MeSH
• Protein Structure, Quaternary MeSH
• Models, Molecular MeSH
• Protein Multimerization MeSH
• Mutagenesis, Site-Directed MeSH
• Repressor Proteins chemistry   genetics   MeSH
• Solutions MeSH
• Schiff Bases chemistry   MeSH
• Protein Structure, Secondary MeSH
• Amino Acid Sequence MeSH
• Structural Homology, Protein MeSH
• Amino Acid Substitution MeSH
• Protein Structure, Tertiary MeSH
• Protein Binding MeSH
• Binding Sites MeSH
• Hydrogen Bonding MeSH
• Publication type
• Journal Article MeSH
• Research Support, Non-U.S. Gov't MeSH

CD200/CD200R are highly conserved type I paired membrane glycoproteins that belong to the Ig superfamily containing a two immunoglobulin‑like domain (V, C). CD200 is broadly distributed in a variety of cell types, whereas CD200R is primarily expressed in myeloid and lymphoid cells. They fulfill multiple functions in regulating inflammation. The interaction between CD200/CD200R results in activation of the intracellular inhibitory pathway with RasGAP recruitment and thus contributes to effector cell inhibition. It was confirmed that the CD200R activation stimulates the differentiation of T cells to the Treg subset, upregulates indoleamine 2,3‑dioxygenase activity, modulates cytokine environment from a Th1 to a Th2 pattern, and facilitates an antiinflammatory IL‑10 and TGF‑β synthesis. CD200/CD200R are required for maintaining self‑tolerance. Many studies have demonstrated the importance of CD200 in controlling autoimmunity, inflammation, the development and spread of cancer, hypersensitivity, and spontaneous fetal loss.

• MeSH
• Antigens, Surface physiology   MeSH
• Antigens, CD physiology   MeSH
• Immunity physiology   MeSH
• Humans MeSH
• Receptors, Cell Surface physiology   MeSH
• Signal Transduction MeSH
• Inflammation physiopathology   MeSH
• Animals MeSH
• Check Tag
• Humans MeSH
• Animals MeSH
• Publication type
• Research Support, Non-U.S. Gov't MeSH
• Review MeSH

In Bacillus subtilis, the arabinose repressor AraR negatively controls the expression of genes in the metabolic pathway of arabinose-containing polysaccharides. The protein is composed of two domains of different phylogenetic origin and function: an N-terminal DNA-binding domain belonging to the GntR family and a C-terminal effector-binding domain that shows similarity to members of the GalR/LacI family. The crystal structure of the C-terminal effector-binding domain of AraR in complex with the effector L-arabinose has been determined at 2.2 Å resolution. The L-arabinose binding affinity was characterized by isothermal titration calorimetry and differential scanning fluorimetry; the K(d) value was 8.4 ± 0.4 µM. The effect of L-arabinose on the protein oligomeric state was investigated in solution and detailed analysis of the crystal identified a dimer organization which is distinctive from that of other members of the GalR/LacI family.

• MeSH
• Arabinose metabolism   MeSH
• Bacillus subtilis chemistry   metabolism   MeSH
• Bacterial Proteins chemistry   metabolism   MeSH
• Crystallography, X-Ray MeSH
• Models, Molecular MeSH
• Repressor Proteins chemistry   metabolism   MeSH
• Protein Structure, Tertiary MeSH
• Protein Binding MeSH
• Publication type
• Journal Article MeSH
• Research Support, Non-U.S. Gov't MeSH