The C3 protein is the central molecule within the complement system and undergoes proteolytic activation to C3b in the presence of pathogens. Pattern-independent activation of C3 also occurs via hydrolysis, resulting in C3(HO), but the structural details of C3 hydrolysis remain elusive. Here we show that the conformation of the C3(HO) analog, C3MA, is indistinguishable from C3b.
View Article and Find Full Text PDFIn our drug discovery campaigns to target the oncogenic drivers of cancers, the demand for a chemoselective, stereoselective and economical synthesis of chiral benzylamines drove the development of a catalytic zirconium hydride reduction. This methodology uses the inexpensive, bench stable zirconocene dichloride, and a novel tetrabutylammonium fluoride activation tactic to catalytically generate a metal hydride under ambient conditions. The diastereo- and chemoselectivity of this reaction was tested with the preparation of key intermediates from our discovery programs and in the scope of sulfinyl ketimines and carbonyls relevant to medicinal chemistry and natural product synthesis.
View Article and Find Full Text PDFImmune checkpoint blockade has changed the treatment paradigm for advanced solid tumors, but the overall response rates are still limited. The combination of checkpoint blockade with anti-4-1BB antibodies to stimulate tumor-infiltrating T cells has shown anti-tumor activity in human trials. However, the further clinical development of these antibodies has been hampered by significant off-tumor toxicities.
View Article and Find Full Text PDFThe glycosylphosphatidylinositol (GPI)-anchored protein cluster of differentiation 109 (CD109) is expressed on many human cell types and modulates the transforming growth factor β (TGF-β) signaling network. CD109 belongs to the alpha-macroglobulin family of proteins, known for their protease-triggered conformational changes. However, the effect of proteolysis on CD109 and its conformation are unknown.
View Article and Find Full Text PDFThe H1047R mutation of is highly prevalent in breast cancers and other solid tumors. Selectively targeting PI3Kα over PI3Kα is crucial due to the role that PI3Kα plays in normal cellular processes, including glucose homeostasis. Currently, only one PI3Kα-selective inhibitor has progressed into clinical trials, while three pan mutant (H1047R, H1047L, H1047Y, E542K, and E545K) selective PI3Kα inhibitors have also reached the clinical stage.
View Article and Find Full Text PDFObjective: To evaluate the impact of the recent changes to the urology residency application process on the criteria utilized by residency program directors (PDs) for interview invitations and their perspectives concerning these changes.
Methods: One hundred thirty-seven urology residency PDs were invited to participate in an anonymous survey to explore interview selection criteria and the impact of the increase in preference signals (PS) per applicant.
Results: Fifty-eight PDs (42.
Chiral amine synthesis remains a significant challenge in accelerating the design cycle of drug discovery programs. A zirconium hydride, due to its high oxophilicity and lower reactivity, gave highly chemo- and stereoselective reductions of sulfinyl ketimines. The development of this zirconocene-mediated reduction helped to accelerate our drug discovery efforts and is applicable to several motifs commonly used in medicinal chemistry.
View Article and Find Full Text PDFNon-tuberculous mycobacteria (NTM) are ubiquitous environmental organisms that can cause significant disease in both immunocompromised and immunocompetent individuals. The incidence of NTM pulmonary disease (NTM-PD) is rising globally. Diagnostic challenges persist and treatment efficacy is variable.
View Article and Find Full Text PDFProtease inhibitors of the alpha-macroglobulin family (αM) have a unique mechanism that allows them to trap proteases that is dependent not on the protease's class, but rather on its cleavage specificity. Proteases trigger a conformational change in the αM protein by cleaving within a "bait region," resulting in the sequestering of the protease inside the αM molecule. This nonspecific inhibitory mechanism appears to have arisen early in the αM family, and the broad protease-trapping capacity that it allows may play a role in pathogen defense.
View Article and Find Full Text PDFAdministration of neutralizing antibodies (nAbs) has proved to be effective by providing immediate protection against SARS-CoV-2. However, dual strategies combining virus neutralization and immune response stimulation to enhance specific cytotoxic T cell responses, such as dendritic cell (DC) cross-priming, represent a promising field but have not yet been explored. Here, a broadly nAb, TN , are first generated by grafting an anti-RBD biparatopic tandem nanobody onto a trimerbody scaffold.
View Article and Find Full Text PDFObjective: To assess the rationale behind the choice of programs for preference signaling (PS) and subinternships by urology applicants in the 2023 cycle.
Methods: We emailed an anonymous, multiple-choice survey to the 403 prospective candidates who applied to our institution for the 2023 Urology Residency Match.
Results: 121 applicants (30.
Immune checkpoint blockade (ICB) with antibodies has shown durable clinical responses in a wide range of cancer types, but the overall response rate is still limited. Other effective therapeutic modalities to increase the ICB response rates are urgently needed. New bispecific antibody (bsAb) formats combining the ICB effect and a direct action on cancer cells could improve the efficacy of current immunotherapies.
View Article and Find Full Text PDFThe enzymes of microorganisms that live in cold environments must be able to function at ambient temperatures. Cold-adapted enzymes generally have less ordered structures that convey a higher catalytic rate, but at the cost of lower thermodynamic stability. In this study, we characterized P355, a novel intracellular subtilisin protease (ISP) derived from the genome of Or1, which is a bacterium metabolically active down to -25°C.
View Article and Find Full Text PDFBackground: The ward round is an integral part of everyday surgical practice. It is a complex clinical activity that requires both sound clinical management and communication skills. This study reports the results of a consensus-building exercise on the common aspects of the general surgical ward rounds.
View Article and Find Full Text PDFSyst Pract Action Res
November 2022
This study offers a conceptual explanation of a holistic methodology that has utility in how we engage with complex situations. This is the VIPLAN Methodology developed by Raul Espejo and first published in 1988. A case is presented that evaluates whether this methodology has impact when tacitly embedded in a postgraduate research methods course.
View Article and Find Full Text PDFCostimulation of tumor-infiltrating T lymphocytes by anti-4-1BB monoclonal antibodies (mAbs) has shown anti-tumor activity in human trials, but can be associated with significant off-tumor toxicities involving FcγR interactions. Here, we introduce albumin-fused mouse and human bispecific antibodies with clinically favorable pharmacokinetics designed to confine 4-1BB costimulation to the tumor microenvironment. These Fc-free 4-1BB agonists consist of an EGFR-specific V antibody, a 4-1BB-specific scFv, and a human albumin sequence engineered for high FcRn binding connected in tandem (LiTCo-Albu).
View Article and Find Full Text PDFThe protease inhibitor α-macroglobulin (A2M) is a member of the ancient α-macroglobulin superfamily (A2MF), which also includes structurally related proteins, such as complement factor C3. A2M and other A2MF proteins undergo an extensive conformational change upon cleavage of their bait region by proteases. However, the mechanism whereby cleavage triggers the change has not yet been determined.
View Article and Find Full Text PDFChimeric antigen receptor (CAR)-modified T cells have revolutionized the treatment of CD19-positive hematologic malignancies. Although anti-CD19 CAR-engineered autologous T cells can induce remission in patients with B-cell acute lymphoblastic leukemia, a large subset relapse, most of them with CD19-positive disease. Therefore, new therapeutic strategies are clearly needed.
View Article and Find Full Text PDFRetargeting of T lymphocytes toward cancer cells by bispecific antibodies has demonstrated its therapeutic potential, with one such antibody approved for the treatment of acute lymphoblastic leukemia (blinatumomab) and several other in clinical trials. However, improvement of their efficacy and selectivity for solid tumors is still required. Here, we describe a novel tandem T-cell recruiting trispecific antibody for the treatment of colorectal cancer (CRC).
View Article and Find Full Text PDFHuman α-macroglobulin (A2M) is an abundant protease inhibitor in plasma, which regulates many proteolytic processes and is involved in innate immunity. A2M's unique protease-trapping mechanism of inhibition is initiated when a protease cleaves within the exposed and highly susceptible "bait region." As the wild-type bait region is permissive to cleavage by most human proteases, A2M is accordingly a broad-spectrum protease inhibitor.
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