Linear ubiquitination is a newly discovered posttranslational modification that is currently restricted to a small number of known protein substrates. The linear ubiquitination assembly complex (LUBAC), consisting of HOIL-1L, HOIP, and Sharpin, has been reported to activate NF-κB–mediated transcription in response to receptor signaling by ligating linear ubiquitin chains to Nemo and Rip1. Despite recent advances, the detailed roles of LUBAC in immune cells remain elusive. We demonstrate a novel HOIL-1L function as an essential regulator of the activation of the NLRP3/ASC inflammasome in primary bone marrow–derived macrophages (BMDMs) independently of NF-κB activation. Mechanistically, HOIL-1L is required for assembly of the NLRP3/ASC inflammasome and the linear ubiquitination of ASC, which we identify as a novel LUBAC substrate. Consequently, we find that HOIL-1L−/− mice have reduced IL-1β secretion in response to in vivo NLRP3 stimulation and survive lethal challenge with LPS. Together, these data demonstrate that linear ubiquitination is required for NLRP3 inflammasome activation, defining the molecular events of NLRP3 inflammasome activation and expanding the role of LUBAC as an innate immune regulator. Furthermore, our observation is clinically relevant because patients lacking HOIL-1L expression suffer from pyogenic bacterial immunodeficiency, providing a potential new therapeutic target for enhancing inflammation in immunodeficient patients.
Abstract Looking back on it, it seems almost incredible that so many equally educated, equally sincere compatriots and contemporaries, all drawing from the same limited stock of evidence, should have reached so many totally different conclusions—and always with complete certainty.
<p>JNJ-61186372 recovered in serum from cynomolgus monkeys treated with JNJ-61186372 inhibited ligand-induced phosphorylation of both EGFR and cMet in a lung cancer cell line.</p>
Replication protein A (RP-A) is a complex of three polypeptides of molecular mass 70, 32, and 14 kDa, which is absolutely required for simian virus 40 DNA replication in vitro. We have isolated a cDNA coding for the 32-kDa subunit of RP-A. An oligonucleotide probe was constructed based upon a tryptic peptide sequence derived from whole RP-A, and clones were isolated from a lambda gt11 library containing HeLa cDNA inserts. The amino acid sequence predicted from the cDNA contains the peptide sequence obtained from whole RP-A along with two sequences obtained from tryptic peptides derived from sodium dodecyl sulfate-polyacrylamide gel-purified 32-kDa subunit. The coding sequence predicts a protein of 29,228 daltons, in good agreement with the electrophoretically determined molecular mass of the 32-kDa subunit. No significant homology was found with any of the sequences in the GenBank data base. The protein predicted from the cDNA has an N-terminal region rich in glycine and serine along with two acidic and two basic segments. Monoclonal antibodies have been raised against the 70- and 32-kDa subunits of RP-A. The cloned cDNA has been overexpressed in bacteria using an inducible T7 expression system. The protein made in bacteria is recognized by a monoclonal antibody that is specific for the 32-kDa subunit of RP-A. This monoclonal antibody against the 32-kDa subunit inhibits DNA replication in vitro.
We have examined the early events of cellular attachment and spreading (10-30 min) by allowing chick embryonic fibroblasts transformed by Rous sarcoma virus to interact with fibronectin immobilized on matrix beads. The binding activity of cells to fibronectin beads was sensitive to both the mAb JG22E and the GRGDS peptide, which inhibit the interaction between integrin and fibronectin. The precise distribution of cytoskeleton components and integrin was determined by immunocytochemistry of frozen thin sections. In suspended cells, the distribution of talin was diffuse in the cytoplasm and integrin was localized at the cell surface. Within 10 min after binding of cells and fibronectin beads at 22 degrees C or 37 degrees C, integrin and talin aggregated at the membrane adjacent to the site of bead attachment. In addition, an internal pool of integrin-positive vesicles accumulated. The mAb ES238 directed against the extracellular domain of the avian beta 1 integrin subunit, when coupled to beads, also induced the aggregation of talin at the membrane, whereas ES186 directed against the intracellular domain of the beta 1 integrin subunit did not. Cells attached and spread on Con A beads, but neither integrin nor talin aggregated at the membrane. After 30 min, when many of the cells were at a more advanced stage of spreading around beads or phagocytosing beads, alpha-actinin and actin, but not vinculin, form distinctive aggregates at sites along membranes associated with either fibronectin or Con A beads. Normal cells also rapidly formed aggregates of integrin and talin after binding to immobilized fibronectin in a manner that was similar to the transformed cells, suggesting that the aggregation process is not dependent upon activity of the pp60v-src tyrosine kinase. Thus, the binding of cells to immobilized fibronectin caused integrin-talin coaggregation at the sites of membrane-ECM contact, which can initiate the cytoskeletal events necessary for cell adhesion and spreading.
The promoter of the human thymidine kinase gene was defined by DNA sequence and genetic analyses. Mutant plasmids with deletions extending into the promoter region from both the 5' and 3' directions were constructed. The mutants were tested in a gene transfer system for the ability to transform TK- cells to the TK+ phenotype. This analysis delimited the functional promoter to within an 83-base-pair region upstream of the mRNA cap site. This region contains sequences common to other eucaryotic promoters including G X C-rich hexanucleotides, a CAAT box, and an A X T-rich region. The CAAT box is in an inverted orientation and is part of a 9-base-pair sequence repeated twice in the promoter region. Comparison of the genomic sequence with the cDNA sequence defined the first exon of the thymidine kinase gene.
Proc Amer Assoc Cancer Res, Volume 47, 2006
4636
Hematopoietic malignancies are associated with recurrent molecular abnormalities that confer or contribute to cellular transformation. Among the associated mutations, point mutations in signaling molecules and balanced translocations involving transcription factors are among the most common and specific. Immortalized cell lines with such aberrations are widely used in the laboratory to model different aspects of both leukemogenesis and lymphomagenesis. We reasoned that specific mutations should be associated with discrete profiles of drug sensitivities. To test this hypothesis, we developed a sensitive proliferation assay suitable for high-throughput screening using Alamar blue reduction as an indicator of cellular viability. The assay was miniaturized and validated for 384-well microtiter plates. We have begun screening established leukemia and lymphoma cell lines against the Sloan-Kettering Institute small molecule library which includes 200,000 compounds from both synthetic and natural origins. Our results indicate that several of the tested cell types can be distinguished by their sensitivity to specific classes of small molecules. We are now extending our screening to an expanded repertoire of cell lines representing several different types of leukemia and lymphoma. We expect this approach will aid in the development of tailored treatment strategies and novel drug discovery for these common hematopoietic malignancies.
Abstract CAR T-cell therapy related neurotoxicity (NT) is common and can lead to fatalities. Early recognition may improve its management and treatment. METHODS Twenty-six patients with relapsed/refractory diffuse large B cell lymphoma who received commercial CAR T-cell therapy (25 axicabtagene ciloleucel [Yescarta®], 1 tisagenlecleucel [Kymriah®]) between December 2017 and September 2018 were assessed for NT based on CARTOX-10 score and Common Terminology Criteria for Adverse Events (CTCAE) version 4. RESULTS Twenty-three of 26 (88%) of patients developed NT, which was severe (Grade III-IV) in 8/26 (31%). Severe NT was associated with complete remission compared to progressive disease by both CTCAE (2.4 ±1.1 vs. 1.4 ± 1.3, p = 0.050) and CARTOX-10 score (8.3 ± 1.6 vs. 9.4 ± 1.5, p = 0.040). CARTOX-10 scores were lower for those transferred to the ICU compared to those transferred, respectively, on Days 8 (2.71 ± 4.78 vs. 9.28 ± 2.31, p = 0.010), 9 (2.71 ± 3.96 vs. 9.06 ± 2.50, p = 0.003) and 10 (2.86 ± 4.27 vs. 8.83 ± 3.37, p = 0.002). Depression was associated with poor overall survival (deceased 67% vs. alive 20%, p = 0.00004) and severe NT (severe NT 63% vs. non-severe NT 20%, p = 0.040). EEG findings of frontal intermittent rhythmic delta activity (FIRDA) in 22% (2/9) and triphasic waves in 33% (3/9) were exclusive found in severe NT. Tremulousness was present in 100% of severe NT compared to 67% of non-severe NT patients (p = 0.060). Delirium occurred in 2 patients, both of whom expired with severe NT. CONCLUSION Depression, tremor, delirium, encephalopathy, and EEG features of FIRDA and triphasic waves may represent early clinical signs that predict the development of severe NT in off-protocol CAR T-cell therapy. Paradoxically, severe NT is positively correlated with progression free survival and may indicate effective therapeutic response.
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