Postoperative atrial fibrillation: The role of the inflammatory response Ishii, Yosuke, MD, PhD; Schuessler, Richard B., PhD; Gaynor, Sydney L., MD ...
Journal of thoracic and cardiovascular surgery/The Journal of thoracic and cardiovascular surgery/The journal of thoracic and cardiovascular surgery,
06/2017, Letnik:
153, Številka:
6
Journal Article
Recenzirano
Odprti dostop
Abstract Objective Abnormal atrial conduction has been shown to be a substrate for postoperative atrial fibrillation (POAF). This study aimed to determine the relationship between the location of the ...atrial reentry responsible for POAF, and degree of atrial inflammation. Methods Normal mongrel dogs (n = 18) were divided into 3 groups: anesthesia alone (anesthesia), lateral right atriotomy (atriotomy), and lateral right atriotomy with anti-inflammatory therapy (steroid). Conduction properties of the right and left atria (RA and LA) were examined 3 days postoperatively by mapping. Activation was observed during burst pacing–induced AF. The RA and LA myeloperoxidase activity was measured to quantitate the degree of inflammation. Results Sustained AF (>2 minutes) was induced in 5 of 6 animals in the atriotomy group, but in none in the anesthesia or steroid groups. All sustained AF originated from around the RA incision. Three of these animals had an incisional reentrant tachycardia around the right atriotomy and 2 had a focal activation arising from the RA during AF. The LA activations in these animals were passive from the RA activation. The RA activation of the atriotomy group was more inhomogeneous than that of the anesthesia group (inhomogeneity index: 2.0 ± 0.2 vs 1.0 ± 0.1, P < .01). Steroid therapy significantly normalized the RA activation after the atriotomy (1.2 ± 0.1, P < .01). The inhomogeneity of the atrial conduction correlated with the myeloperoxidase activity ( r = 0.774, P < .001). Conclusions Reentrant circuits responsible for POAF are dependent on the degree of inflammation and rotate around the atriotomy. Anti-inflammatory therapy decreased the risk of postoperative AF.
The nuclear factor (NF)-κB pathway is important for the expression of a wide variety of genes that are involved in the control of the host immune and inflammatory response, and in the regulation of ...cellular proliferation and survival. The constitutive activation of this pathway is associated with inflammatory and autoimmune diseases, such as asthma, rheumatoid arthritis and inflammatory bowel disease, in addition to atherosclerosis, Alzheimer's disease, cancer and diabetes. One of the key steps in activating the NF-κB pathway is the stimulation of the IκB (inhibitor of κB) kinases. Recent data indicate that these kinases activate the NF-κB pathway through distinct steps that are operative in both the cytoplasm and the nucleus. A better understanding of the mechanisms that activate this pathway provides the potential for defining new therapeutic targets that might prevent the aberrant activation of NF-κB in a variety of human diseases.
Neoantigens arise from mutations in cancer cells and are important targets of T cell-mediated anti-tumor immunity. Here, we report the first open-label, phase Ib clinical trial of a personalized ...neoantigen-based vaccine, NEO-PV-01, in combination with PD-1 blockade in patients with advanced melanoma, non-small cell lung cancer, or bladder cancer. This analysis of 82 patients demonstrated that the regimen was safe, with no treatment-related serious adverse events observed. De novo neoantigen-specific CD4+ and CD8+ T cell responses were observed post-vaccination in all of the patients. The vaccine-induced T cells had a cytotoxic phenotype and were capable of trafficking to the tumor and mediating cell killing. In addition, epitope spread to neoantigens not included in the vaccine was detected post-vaccination. These data support the safety and immunogenicity of this regimen in patients with advanced solid tumors (Clinicaltrials.gov: NCT02897765).
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•The personalized neoantigen vaccine Neo-PV-01 plus nivolumab is feasible and safe•NEO-PV-01 plus nivolumab stimulates durable neoantigen-specific T cell reactivity•NEO-PV-01-specific T cells have cytotoxic potential and can traffic to the tumor•NEO-PV-01 induces epitope spreading consistent with vaccine-mediated tumor cytotoxicity
In a phase Ib clinical trial, Ott et al. demonstrate feasibility, safety, and immunogenicity of the combination of personalized neoantigen vaccines and PD-1 inhibition in patients with advanced solid tumors. Vaccine-induced T cells persist over time, exhibit cytotoxic potential, and can migrate to tumors. Epitope spread and major pathologic tumor responses were detected following vaccination.
The ongoing COVID-19 pandemic has created an urgency to identify novel vaccine targets for protective immunity against SARS-CoV-2. Early reports identify protective roles for both humoral and ...cell-mediated immunity for SARS-CoV-2.
We leveraged our bioinformatics binding prediction tools for human leukocyte antigen (HLA)-I and HLA-II alleles that were developed using mass spectrometry-based profiling of individual HLA-I and HLA-II alleles to predict peptide binding to diverse allele sets. We applied these binding predictors to viral genomes from the Coronaviridae family and specifically focused on T cell epitopes from SARS-CoV-2 proteins. We assayed a subset of these epitopes in a T cell induction assay for their ability to elicit CD8
T cell responses.
We first validated HLA-I and HLA-II predictions on Coronaviridae family epitopes deposited in the Virus Pathogen Database and Analysis Resource (ViPR) database. We then utilized our HLA-I and HLA-II predictors to identify 11,897 HLA-I and 8046 HLA-II candidate peptides which were highly ranked for binding across 13 open reading frames (ORFs) of SARS-CoV-2. These peptides are predicted to provide over 99% allele coverage for the US, European, and Asian populations. From our SARS-CoV-2-predicted peptide-HLA-I allele pairs, 374 pairs identically matched what was previously reported in the ViPR database, originating from other coronaviruses with identical sequences. Of these pairs, 333 (89%) had a positive HLA binding assay result, reinforcing the validity of our predictions. We then demonstrated that a subset of these highly predicted epitopes were immunogenic based on their recognition by specific CD8
T cells in healthy human donor peripheral blood mononuclear cells (PBMCs). Finally, we characterized the expression of SARS-CoV-2 proteins in virally infected cells to prioritize those which could be potential targets for T cell immunity.
Using our bioinformatics platform, we identify multiple putative epitopes that are potential targets for CD4
and CD8
T cells, whose HLA binding properties cover nearly the entire population. We also confirm that our binding predictors can predict epitopes eliciting CD8
T cell responses from multiple SARS-CoV-2 proteins. Protein expression and population HLA allele coverage, combined with the ability to identify T cell epitopes, should be considered in SARS-CoV-2 vaccine design strategies and immune monitoring.
Increasing evidence indicates CD4+ T cells can recognize cancer-specific antigens and control tumor growth. However, it remains difficult to predict the antigens that will be presented by human ...leukocyte antigen class II molecules (HLA-II), hindering efforts to optimally target them therapeutically. Obstacles include inaccurate peptide-binding prediction and unsolved complexities of the HLA-II pathway. To address these challenges, we developed an improved technology for discovering HLA-II binding motifs and conducted a comprehensive analysis of tumor ligandomes to learn processing rules relevant in the tumor microenvironment. We profiled >40 HLA-II alleles and showed that binding motifs were highly sensitive to HLA-DM, a peptide-loading chaperone. We also revealed that intratumoral HLA-II presentation was dominated by professional antigen-presenting cells (APCs) rather than cancer cells. Integrating these observations, we developed algorithms that accurately predicted APC ligandomes, including peptides from phagocytosed cancer cells. These tools and biological insights will enable improved HLA-II-directed cancer therapies.
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•Affinity-tagging protocol enables proteomic profiling of individual HLA-II alleles•Even in “hot” tumors, professional APCs—not cancer cells—drive HLA-II expression•Cellular localization influences which phagocytosed cancer proteins get presented•Machine-learning models for binding and processing improve HLA-II prediction
Despite their role in directing T cell responses, HLA-II epitopes remain difficult to predict, hindering their therapeutic potential. Abelin et al. develop proteomic strategies that resolve diverse HLA-II motifs and pinpoint tumor epitopes that are presented by professional APCs. These data enable improved HLA-II epitope prediction and therapeutic targeting.
T cell responses play an important role in protection against beta-coronavirus infections, including SARS-CoV-2, where they associate with decreased COVID-19 disease severity and duration. To enhance ...T cell immunity across epitopes infrequently altered in SARS-CoV-2 variants, we designed BNT162b4, an mRNA vaccine component that is intended to be combined with BNT162b2, the spike-protein-encoding vaccine. BNT162b4 encodes variant-conserved, immunogenic segments of the SARS-CoV-2 nucleocapsid, membrane, and ORF1ab proteins, targeting diverse HLA alleles. BNT162b4 elicits polyfunctional CD4+ and CD8+ T cell responses to diverse epitopes in animal models, alone or when co-administered with BNT162b2 while preserving spike-specific immunity. Importantly, we demonstrate that BNT162b4 protects hamsters from severe disease and reduces viral titers following challenge with viral variants. These data suggest that a combination of BNT162b2 and BNT162b4 could reduce COVID-19 disease severity and duration caused by circulating or future variants. BNT162b4 is currently being clinically evaluated in combination with the BA.4/BA.5 Omicron-updated bivalent BNT162b2 (NCT05541861).
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•BNT162b4 encodes conserved, immunogenic segments of the SARS-CoV-2 N, M, and ORF1ab antigens•Mass spectrometry detects BNT162b4 encoded peptides bound to diverse HLA-I alleles•BNT162b4 elicits non-spike T cell responses in mice while maintaining spike immunity•BNT162b4 protects animals from severe disease and enhances viral clearance by BNT162b2
Adding non-spike targeting components to mRNA vaccination elicits promising T cell responses against SARS-CoV-2 variant strains in rodent models of COVID-19.
NF-κB comprises a family of cellular transcription factors that are involved in the inducible expression of a variety of cellular genes that regulate the inflammatory response,. NF-κB is sequestered ...in the cytoplasm by inhibitory proteins, IκB, which are phosphorylated by a cellular kinase complex known as IKK. IKK is made up of two kinases, IKK-α and IKK-β, which phosphorylate IκB, leading to its degradation and translocation of NF-κB to the nucleus. IKK kinase activity is stimulated when cells are exposed to the cytokine TNF-α or by overexpression of the cellular kinases MEKK1 and NIK,. Here we demonstrate that the anti-inflammatory agents aspirin and sodium salicylate specifically inhibit IKK-β activity in vitro and in vivo. The mechanism of aspirin and sodium salicylate inhibition is due to binding of these agents to IKK-β to reduce ATP binding. Our results indicate that the anti-inflammatory properties of aspirin and salicylate are mediated in part by their specific inhibition of IKK-β, thereby preventing activation by NF-κB of genes involved in the pathogenesis of the inflammatory response.
Celotno besedilo
Dostopno za:
DOBA, IJS, IZUM, KILJ, NUK, PILJ, PNG, SAZU, SIK, UILJ, UKNU, UL, UM, UPUK
DNA-dependent RNA polymerase II (RNAP II) largest subunit RPB1 C-terminal domain (CTD) kinases, including CDK9, are serine/threonine kinases known to regulate transcriptional initiation and ...elongation by phosphorylating Ser 2, 5, and 7 residues on CTD. Given the reported dysregulation of these kinases in some cancers, we asked whether inhibiting CDK9 may induce stress response and preferentially kill tumor cells. Herein, we describe a potent CDK9 inhibitor, LY2857785, that significantly reduces RNAP II CTD phosphorylation and dramatically decreases MCL1 protein levels to result in apoptosis in a variety of leukemia and solid tumor cell lines. This molecule inhibits the growth of a broad panel of cancer cell lines, and is particularly efficacious in leukemia cells, including orthotopic leukemia preclinical models as well as in ex vivo acute myeloid leukemia and chronic lymphocytic leukemia patient tumor samples. Thus, inhibition of CDK9 may represent an interesting approach as a cancer therapeutic target, especially in hematologic malignancies.
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