SKP1-CUL1-F-box protein (SCF) ubiquitin ligases are versatile protein complexes that mediate the ubiquitination of protein substrates. The direct substrate recognition relies on a large family of F-box-domain-containing subunits. One of these substrate receptors is FBXO38, which is encoded by a gene found mutated in families with early-onset distal motor neuronopathy. SCFFBXO38 ubiquitin ligase controls the stability of ZXDB, a nuclear factor associated with the centromeric chromatin protein CENP-B. Loss of FBXO38 in mice results in growth retardation and defects in spermatogenesis characterized by deregulation of the Sertoli cell transcription program and compromised centromere integrity. Moreover, it was reported that SCFFBXO38 mediates the degradation of PD-1, a key immune-checkpoint inhibitor in T cells. Here, we have re-addressed the link between SCFFBXO38 and PD-1 proteolysis. Our data do not support the notion that SCFFBXO38 directly or indirectly controls the abundance and stability of PD-1 in T cells.

• MeSH
• antigeny CD279 * metabolismus   genetika   MeSH
• F-box proteiny * metabolismus   genetika   MeSH
• lidé MeSH
• myši MeSH
• proteinligasy komplexu SCF metabolismus   genetika   MeSH
• proteolýza MeSH
• T-lymfocyty metabolismus   MeSH
• ubikvitinace MeSH
• zvířata MeSH
• Check Tag
• lidé MeSH
• mužské pohlaví MeSH
• myši MeSH
• zvířata MeSH
• Publikační typ
• časopisecké články MeSH

The PD-1/PD-L1 complex is an immune checkpoint responsible for regulating the natural immune response, but also allows tumors to escape immune surveillance. Inhibition of the PD-1/PD-L1 axis positively contributes to the efficacy of cancer treatment. The only available therapeutics targeting PD-1/PD-L1 are monoclonal antibody-based drugs, which have several limitations. Therefore, small molecule compounds are emerging as an attractive alternative that can potentially overcome the drawbacks of mAb-based therapy. In this article, we present a novel class of small molecule compounds based on the terphenyl scaffold that bind to PD-L1. The general architecture of the presented structures is characterized by axial symmetry and consists of three elements: an m-terphenyl core, an additional aromatic ring, and a solubilizing agent. Using molecular docking, we designed a series of final compounds, which were subsequently synthesized and tested in HTRF assay and NMR binding assay to evaluate their activity. In addition, we performed an in-depth analysis of the mutual arrangement of the phenyl rings of the terphenyl core within the binding pocket of PD-L1 and found several correlations between the plane angle values and the affinity of the compounds towards the protein.

• MeSH
• antigeny CD274 * antagonisté a inhibitory   metabolismus   chemie   MeSH
• antigeny CD279 * antagonisté a inhibitory   metabolismus   chemie   MeSH
• inhibitory kontrolních bodů chemie   farmakologie   MeSH
• knihovny malých molekul farmakologie   chemie   MeSH
• lidé MeSH
• molekulární struktura MeSH
• simulace molekulového dockingu * MeSH
• terfenylové sloučeniny * chemie   farmakologie   MeSH
• vazba proteinů * MeSH
• vazebná místa MeSH
• vztahy mezi strukturou a aktivitou MeSH
• Check Tag
• lidé MeSH
• Publikační typ
• časopisecké články MeSH

Monoclonal antibodies targeting immune checkpoints have revolutionized oncology. Yet, the effectiveness of these treatments varies significantly among patients, and they are associated with unexpected adverse events, including hyperprogression. The murine research model used in drug development fails to recapitulate both the functional human immune system and the population heterogeneity. Hence, a novel model is urgently needed to study the consequences of immune checkpoint blockade. Dogs appear to be uniquely suited for this role. Approximately 1 in 4 companion dogs dies from cancer, yet no antibodies are commercially available for use in veterinary oncology. Here we characterize two novel antibodies that bind canine PD-1 with sub-nanomolar affinity as measured by SPR. Both antibodies block the clinically crucial PD-1/PD-L1 interaction in a competitive ELISA assay. Additionally, the antibodies were tested with a broad range of assays including Western Blot, ELISA, flow cytometry, immunofluorescence and immunohistochemistry. The antibodies appear to bind two distinct epitopes as predicted by molecular modeling and peptide phage display. Our study provides new tools for canine oncology research and a potential veterinary therapeutic.

• MeSH
• antigeny CD274 imunologie   antagonisté a inhibitory   metabolismus   MeSH
• antigeny CD279 * imunologie   antagonisté a inhibitory   metabolismus   MeSH
• epitopy imunologie   MeSH
• inhibitory kontrolních bodů imunologie   farmakologie   MeSH
• lidé MeSH
• monoklonální protilátky * imunologie   MeSH
• nádory imunologie   veterinární   farmakoterapie   MeSH
• nemoci psů imunologie   farmakoterapie   MeSH
• psi MeSH
• vazba proteinů MeSH
• zvířata MeSH
• Check Tag
• lidé MeSH
• psi MeSH
• zvířata MeSH
• Publikační typ
• časopisecké články MeSH
• srovnávací studie MeSH

BACKGROUND: Programmed cell death 1 (PD-1) belongs to immune checkpoint proteins ensuring negative regulation of the immune response. In non-small cell lung cancer (NSCLC), the sensitivity to treatment with anti-PD-1 therapeutics, and its efficacy, mostly correlated with the increase of tumor infiltrating PD-1+ lymphocytes. Due to solid tumor heterogeneity of PD-1+ populations, novel low molecular weight anti-PD-1 high-affinity diagnostic probes can increase the reliability of expression profiling of PD-1+ tumor infiltrating lymphocytes (TILs) in tumor tissue biopsies and in vivo mapping efficiency using immune-PET imaging. METHODS: We designed a 13 kDa β-sheet Myomedin scaffold combinatorial library by randomization of 12 mutable residues, and in combination with ribosome display, we identified anti-PD-1 Myomedin variants (MBA ligands) that specifically bound to human and murine PD-1-transfected HEK293T cells and human SUP-T1 cells spontaneously overexpressing cell surface PD-1. RESULTS: Binding affinity to cell-surface expressed human and murine PD-1 on transfected HEK293T cells was measured by fluorescence with LigandTracer and resulted in the selection of most promising variants MBA066 (hPD-1 KD = 6.9 nM; mPD-1 KD = 40.5 nM), MBA197 (hPD-1 KD = 29.7 nM; mPD-1 KD = 21.4 nM) and MBA414 (hPD-1 KD = 8.6 nM; mPD-1 KD = 2.4 nM). The potential of MBA proteins for imaging of PD-1+ populations in vivo was demonstrated using deferoxamine-conjugated MBA labeled with 68Galium isotope. Radiochemical purity of 68Ga-MBA proteins reached values 94.7-99.3% and in vitro stability in human serum after 120 min was in the range 94.6-98.2%. The distribution of 68Ga-MBA proteins in mice was monitored using whole-body positron emission tomography combined with computerized tomography (PET/CT) imaging up to 90 min post-injection and post mortem examined in 12 mouse organs. The specificity of MBA proteins was proven by co-staining frozen sections of human tonsils and NSCLC tissue biopsies with anti-PD-1 antibody, and demonstrated their potential for mapping PD-1+ populations in solid tumors. CONCLUSIONS: Using directed evolution, we developed a unique set of small binding proteins that can improve PD-1 diagnostics in vitro as well as in vivo using PET/CT imaging.

• MeSH
• antigeny CD279 * metabolismus   MeSH
• HEK293 buňky MeSH
• lidé MeSH
• myši MeSH
• nádorové buněčné linie MeSH
• nádory plic diagnostické zobrazování   patologie   metabolismus   genetika   MeSH
• nemalobuněčný karcinom plic diagnostické zobrazování   patologie   metabolismus   MeSH
• pozitronová emisní tomografie * metody   MeSH
• proteinové inženýrství * MeSH
• sekvence aminokyselin MeSH
• zvířata MeSH
• Check Tag
• lidé MeSH
• myši MeSH
• zvířata MeSH
• Publikační typ
• časopisecké články MeSH
• práce podpořená grantem MeSH

Mucosal-associated invariant T-cells (MAIT) are unconventional T-cells with cytotoxic and pro-inflammatory properties. Previous research has reported contradictory findings on their role in cancerogenesis with data being even scarcer in haematological malignancies. Here, we report the results of a systematic analysis of MAIT cells in treatment-naïve patients with a broad range of haematological malignancies. We analysed peripheral blood of 204 patients and 50 healthy subjects. The pool of haematological patients had a statistically significant lower both the absolute value (median values, 0.01 × 109/L vs. 0.05 × 109/L) of MAIT cells and their percentage (median values 0.94% vs. 2.56%) among T-cells compared to the control group. Separate analysis showed that the decrease in the absolute number of MAIT cells is significant in patients with acute myeloid leukaemia, myeloproliferative neoplasms, plasma cell myeloma, B-cell non-Hodgkin lymphomas, otherwise not specified, diffuse large B-cell lymphoma, follicular lymphoma, mantle cell lymphoma, marginal zone lymphoma compared to the control population. Furthermore, in haematological malignancies, MAIT cells overexpress PD-1 (average values, 51.7% vs. 6.7%), HLA-DR (average values, 40.2% vs. 7%), CD38 (average values, 25.9% vs. 4.9%) and CD69 (average values, 40.2% vs. 9.2%). Similar results were obtained when comparing patients with individual malignancies to the control population. Our data show that the depletion of circulating MAIT cells is a common observation in a broad spectrum of haematological malignancies. In addition to their reduced numbers, MAIT cells acquire an activated/exhausted phenotype.

• MeSH
• antigeny CD279 * imunologie   metabolismus   MeSH
• antigeny CD38 metabolismus   imunologie   MeSH
• CD antigeny metabolismus   MeSH
• diferenciační antigeny T-lymfocytů metabolismus   MeSH
• dospělí MeSH
• hematologické nádory * imunologie   MeSH
• imunofenotypizace MeSH
• lektiny typu C MeSH
• lidé středního věku MeSH
• lidé MeSH
• MAIT buňky * imunologie   MeSH
• membránové glykoproteiny imunologie   MeSH
• mladý dospělý MeSH
• počet lymfocytů MeSH
• senioři nad 80 let MeSH
• senioři MeSH
• Check Tag
• dospělí MeSH
• lidé středního věku MeSH
• lidé MeSH
• mladý dospělý MeSH
• mužské pohlaví MeSH
• senioři nad 80 let MeSH
• senioři MeSH
• ženské pohlaví MeSH
• Publikační typ
• časopisecké články MeSH

Trichothecene mycotoxins have a strong immunosuppressive effect, which may even escape host immune surveillance and damage the immune repair to show an "immune evasion" effect. Increasing lines of evidence have shown that hypoxia and hypoxia-inducible factors (HIFs) are key mediators of trichothecenes, and these toxins appear to be closely related to the "immune evasion" mechanisms. Therefore, we used RAW264.7 cell model to explore the association of T-2 toxins with "immune evasion" process and hypoxia, as well as their cross-linking effects induced by T-2 toxin. Our results showed that HIF-1α is an important toxicity target of T-2 toxin, which could induce intracellular hypoxia. T-2 toxin induced an "immune evasion" process by activating the PD-1/PD-L1 signaling pathway. Interestingly, when HIF-1α activation was blocked, the "immune evasion" process regulated by PD-1/PD-L1 signaling was activated, resulting in the cells damage, suggesting that hypoxia induced by T-2 toxin plays a protective role for RAW264.7 cell damage. Thus, our work shows that HIF-1α inhibits T-2 toxin-mediated "immune evasion" process by negatively regulating PD-1/PD-L1signaling. This study contributes to a better understanding of the immunotoxicity mechanism of trichothecenes.

• MeSH
• antigeny CD274 metabolismus   MeSH
• antigeny CD279 metabolismus   MeSH
• faktor 1 indukovatelný hypoxií - podjednotka alfa farmakologie   MeSH
• hypoxie MeSH
• lidé MeSH
• T-2 toxin * toxicita   MeSH
• trichotheceny * toxicita   MeSH
• Check Tag
• lidé MeSH
• Publikační typ
• časopisecké články MeSH
• práce podpořená grantem MeSH

Cell surface expression of PD-1, PD-L1 and PD-L2 immune checkpoints on B and T cells obtained from patients with mantle cell lymphoma shows ambiguous results across many studies and creates obstacles for the implementation of immune checkpoint inhibitors into the therapy of mantle cell lymphoma. Using multiparameter flow cytometry we analysed surface expression of PD-1, PD-L1 and PD-L2 molecules on B and T cells of 31 newly diagnosed mantle cell lymphomas and compared it with the results of 26 newly diagnosed chronic lymphocytic leukaemias and 20 healthy volunteers. To gain insight into the age-dependent changes of surface expression of these immune checkpoints, flow cytometric subanalysis of 30 healthy volunteers of 25-93 years of age was conducted. Overall, we demonstrated weak surface expression of PD-1, PD-L1 and PD-L2 on B and T cells of mantle cell lymphoma patients (< 10 % when compared to healthy individuals). A significant age-dependent increase in the expression of PD-1 and its ligand PD-L2 was observed in healthy volunteers. Our results suggest that neither PD-1 nor its ligands represent relevant druggable targets for the therapy of mantle cell lymphoma. The observed age-dependent changes in healthy population could impact efficiency of immune checkpoint inhibitors and could be at least partly connected with increased incidence of cancer with age.

• MeSH
• antigeny CD273 metabolismus   MeSH
• antigeny CD274 metabolismus   MeSH
• antigeny CD279 metabolismus   MeSH
• B-lymfocyty MeSH
• dospělí MeSH
• lidé středního věku MeSH
• lidé MeSH
• lymfom z plášťových buněk metabolismus   MeSH
• senioři nad 80 let MeSH
• senioři MeSH
• studie případů a kontrol MeSH
• T-lymfocyty MeSH
• Check Tag
• dospělí MeSH
• lidé středního věku MeSH
• lidé MeSH
• senioři nad 80 let MeSH
• senioři MeSH
• Publikační typ
• časopisecké články MeSH

Esophageal and gastric cancers represent tumors with poor prognosis. Unfortunately, radiotherapy, chemotherapy, and targeted therapy have made only limited progress in recent years in improving the generally disappointing outcome. Immunotherapy with checkpoint inhibitors is a novel treatment approach that quickly entered clinical practice in malignant melanoma and renal cell cancer, but the role in esophageal and gastric cancer is still poorly defined. The principal prognostic/predictive biomarkers for immunotherapy efficacy currently considered are PD-L1 expression along with defects in mismatch repair genes resulting in microsatellite instability (MSI-H) phenotype. The new molecular classification of gastric cancer also takes these factors into consideration. Available reports regarding PD-1, PD-L1, PD-L2 expression and MSI status in gastric and esophageal cancer are reviewed to summarize the clinical prognostic and predictive role together with potential clinical implications. The most important recently published clinical trials evaluating checkpoint inhibitor efficacy in these tumors are also summarized.

• MeSH
• antigeny CD273 metabolismus   MeSH
• antigeny CD274 metabolismus   MeSH
• antigeny CD279 metabolismus   MeSH
• epitelo-mezenchymální tranzice MeSH
• exprese genu MeSH
• fenotyp MeSH
• imunita * MeSH
• imunoterapie * metody   MeSH
• kombinovaná terapie MeSH
• lidé MeSH
• mikrosatelitní nestabilita MeSH
• mikrosatelitní repetice MeSH
• nádory jícnu diagnóza   genetika   imunologie   terapie   MeSH
• nádory žaludku diagnóza   genetika   imunologie   terapie   MeSH
• únik nádoru z imunitní kontroly imunologie   MeSH
• zvířata MeSH
• Check Tag
• lidé MeSH
• zvířata MeSH
• Publikační typ
• časopisecké články MeSH
• přehledy MeSH

BACKGROUND: Human papillomavirus (HPV) type 16 infection is one of the most important etiological agents of oropharyngeal squamous cell carcinoma. Patients with HPV-associated carcinomas of the head and neck were reported to have a better clinical outcome than patients with HPV-negative tumors. Because HPV16 E6 and E7 oncoproteins are highly immunogenic and constitutively expressed, HPV-specific T cell immunity may play the key role in improving the prognosis of these patients. METHODS: Tumor-derived T cells were expanded in high levels of IL-2 and stimulated with HPV16 E6/E7 peptides in the presence or absence of anti-PD-1 monoclonal antibody nivolumab and soluble Tim-3. RESULTS: HPV16-specific tumor-infiltrating T cells were present in 73.1% of HPV-associated oropharyngeal tumors. HPV16 specific CD8+ TILs were able to produce IFNγ upon specific stimulation and predominantly expressed PD-1 but not Tim-3. Specific IFNγ production was further enhanced after a blockade of both PD-1 and Tim-3 pathways but not after a PD-1 blockade alone. Additionally, the specific stimulation of anti-HPV16 CD8+ T cells suppressed Tim-3 upregulation after the PD-1 blockade. CONCLUSION: Our data provide the rationale for combination cancer immunotherapy approaches, including the dual blockade of PD-1 and Tim-3 and, potentially, the use of HPV16-directed therapeutic vaccines.

• MeSH
• antigeny CD279 antagonisté a inhibitory   metabolismus   MeSH
• buněčný receptor 2 viru hepatitidy A metabolismus   MeSH
• CD8-pozitivní T-lymfocyty imunologie   MeSH
• cytokiny biosyntéza   MeSH
• dospělí MeSH
• lidé středního věku MeSH
• lidé MeSH
• lidský papilomavirus 16 izolace a purifikace   MeSH
• nádory orofaryngu farmakoterapie   imunologie   metabolismus   virologie   MeSH
• nivolumab terapeutické užití   MeSH
• protinádorové látky imunologicky aktivní terapeutické užití   MeSH
• senioři MeSH
• tumor infiltrující lymfocyty imunologie   MeSH
• únik nádoru z imunitní kontroly MeSH
• Check Tag
• dospělí MeSH
• lidé středního věku MeSH
• lidé MeSH
• mužské pohlaví MeSH
• senioři MeSH
• ženské pohlaví MeSH
• Publikační typ
• časopisecké články MeSH
• práce podpořená grantem MeSH

Adoptive cell therapy (ACT) is becoming a prominent alternative therapeutic treatment for cancer patients relapsing on traditional therapies. In parallel, antibodies targeting immune checkpoint molecules, such as cytotoxic-T-lymphocyte-associated antigen 4 (CTLA-4) and cell death protein 1 pathway (PD-1), are rapidly being approved for multiple cancer types, including as first line therapy for PD-L1-expressing non-small-cell lung cancer. The combination of ACT and checkpoint blockade could substantially boost the efficacy of ACT. In this study, we generated a novel self-delivering small interfering RNA (siRNA) (sdRNA) that knocked down PD-1 expression on healthy donor T cells as well as patient-derived tumor-infiltrating lymphocytes (TIL). We have developed an alternative chemical modification of RNA backbone for improved stability and increased efficacy. Our results show that T cells treated with sdRNA specific for PD-1 had increased interferon γ (IFN-γ) secreting capacity and that this modality of gene expression interference could be utilized in our rapid expansion protocol for production of TIL for therapy. TIL expanded in the presence of PD-1-specific sdRNA performed with increased functionality against autologous tumor as compared to control TIL. This method of introducing RNAi into T cells to modify the expression of proteins could easily be adopted into any ACT protocol and will lead to the exploration of new combination therapies.

• MeSH
• antigeny CD279 genetika   metabolismus   MeSH
• buněčná a tkáňová terapie metody   MeSH
• HeLa buňky MeSH
• imunoterapie adoptivní metody   MeSH
• interferon gama genetika   metabolismus   MeSH
• lidé MeSH
• melanom imunologie   metabolismus   terapie   MeSH
• nádory plic imunologie   metabolismus   terapie   MeSH
• průtoková cytometrie MeSH
• RNA interference fyziologie   MeSH
• T-lymfocyty metabolismus   MeSH
• Check Tag
• lidé MeSH
• Publikační typ
• časopisecké články MeSH
• práce podpořená grantem MeSH
• Research Support, N.I.H., Extramural MeSH