HIV is adept at avoiding naturally generated T cell responses; therefore, there is a need to develop HIV-specific T cells with greater potency for use in HIV cure strategies. Starting with a ...CD4-based chimeric antigen receptor (CAR) that was previously used without toxicity in clinical trials, we optimized the vector backbone, promoter, HIV targeting moiety, and transmembrane and signaling domains to determine which components augmented the ability of T cells to control HIV replication. This re-engineered CAR was at least 50-fold more potent in vitro at controlling HIV replication than the original CD4 CAR, or a TCR-based approach, and substantially better than broadly neutralizing antibody-based CARs. A humanized mouse model of HIV infection demonstrated that T cells expressing optimized CARs were superior at expanding in response to antigen, protecting CD4 T cells from infection, and reducing viral loads compared to T cells expressing the original, clinical trial CAR. Moreover, in a humanized mouse model of HIV treatment, CD4 CAR T cells containing the 4-1BB costimulatory domain controlled HIV spread after ART removal better than analogous CAR T cells containing the CD28 costimulatory domain. Together, these data indicate that potent HIV-specific T cells can be generated using improved CAR design and that CAR T cells could be important components of an HIV cure strategy.
Despite the ability of antiretroviral therapy to minimize human immunodeficiency virus type 1 (HIV-1) replication and increase the duration and quality of patients’ lives, the health consequences and ...financial burden associated with the lifelong treatment regimen render a permanent cure highly attractive. Although T cells play an important role in controlling virus replication, they are themselves targets of HIV-mediated destruction. Direct genetic manipulation of T cells for adoptive cellular therapies could facilitate a functional cure by generating HIV-1–resistant cells, redirecting HIV-1–specific immune responses, or a combination of the two strategies. In contrast to a vaccine approach, which relies on the production and priming of HIV-1–specific lymphocytes within a patient's own body, adoptive T-cell therapy provides an opportunity to customize the therapeutic T cells prior to administration. However, at present, it is unclear how to best engineer T cells so that sustained control over HIV-1 replication can be achieved in the absence of antiretrovirals. This review focuses on T-cell gene-engineering and gene-editing strategies that have been performed in efforts to inhibit HIV-1 replication and highlights the requirements for a successful gene therapy–mediated functional cure.
Antimicrobial peptides are an important component of the molecular arsenal employed by hosts against bacteria. Many bacteria in turn possess pathways that provide protection against these compounds. ...In Escherichia coli and related bacteria, the PhoQ/PhoP signalling system is a key regulator of this antimicrobial peptide defence. Here we show that treating E. coli with sublethal concentrations of antimicrobial peptides causes cells to filament, and that this division block is controlled by the PhoQ/PhoP system. The filamentation results from increased expression of QueE, an enzyme that is part of a tRNA modification pathway but that, as we show here, also affects cell division. We also find that a functional YFP-QueE fusion localizes to the division septum in filamentous cells, suggesting QueE blocks septation through interaction with the divisome. Regulation of septation by PhoQ/PhoP may protect cells from antimicrobial peptide-induced stress or other conditions associated with high-level stimulation of this signalling system.
HIV infection preferentially depletes HIV-specific CD4+ T cells, thereby impairing antiviral immunity. In this study, we explored the therapeutic utility of adoptively transferred CD4+ T cells ...expressing an HIV-specific chimeric antigen receptor (CAR4) to restore CD4+ T cell function to the global HIV-specific immune response. We demonstrated that CAR4 T cells directly suppressed in vitro HIV replication and eliminated virus-infected cells. Notably, CAR4 T cells containing intracellular domains (ICDs) derived from the CD28 receptor family (ICOS and CD28) exhibited superior effector functions compared to the tumor necrosis factor receptor (TNFR) family ICDs (CD27, OX40, and 4-1BB). However, despite demonstrating limited in vitro efficacy, only HIV-resistant CAR4 T cells expressing the 4-1BBζ ICD exhibited profound expansion, concomitant with reduced rebound viremia after antiretroviral therapy (ART) cessation and protection of CD4+ T cells (CAR−) from HIV-induced depletion in humanized mice. Moreover, CAR4 T cells enhanced the in vivo persistence and efficacy of HIV-specific CAR-modified CD8+ T cells expressing the CD28ζ ICD, which alone exhibited poor survival. Collectively, these studies demonstrate that HIV-resistant CAR4 T cells can directly control HIV replication and augment the virus-specific CD8+ T cell response, highlighting the therapeutic potential of engineered CD4+ T cells to engender a functional HIV cure.
Display omitted
HIV infects CD4+ T cells, resulting in the impairment of antiviral immunity and susceptibility to opportunistic diseases. Maldini and colleagues investigated the therapeutic utility of gene-engineered, HIV-resistant/specific CD4+ T cells to directly combat infection and restore T cell help that is lost due to HIV-mediated destruction of endogenous CD4+ T cells.
Enterococcus faecalis is a common Gram-positive commensal bacterium of the metazoan gastrointestinal tract capable of biofilm formation and an opportunistic pathogen of increasing clinical concern. ...Dogma has held that biofilms are slow-growing structures, often taking days to form mature microcolonies. Here we report that extracellular DNA (eDNA) is an integral structural component of early E. faecalis biofilms (≤4 h postinoculation). Combining cationic dye-based biofilm matrix stabilization techniques with correlative immuno-scanning electron microscopy (SEM) and fluorescent techniques, we demonstrate that--in early E. faecalis biofilms--eDNA localizes to previously undescribed intercellular filamentous structures, as well as to thick mats of extruded extracellular matrix material. Both of these results are consistent with previous reports that early biofilms are exquisitely sensitive to exogenous DNase treatment. High-resolution SEM demonstrates a punctate labeling pattern in both structures, suggesting the presence of an additional, non-DNA constituent. Notably, the previously described fratricidal or lytic mechanism reported as the source of eDNA in older (≥24 h) E. faecalis biofilms does not appear to be at work under these conditions; extensive visual examination by SEM revealed a striking lack of lysed cells, and bulk biochemical assays also support an absence of significant lysis at these early time points. In addition, some cells demonstrated eDNA labeling localized at the septum, suggesting the possibility of DNA secretion from metabolically active cells. Overall, these data are consistent with a model in which a subpopulation of viable E. faecalis cells secrete or extrude DNA into the extracellular matrix.
This paper reports the production of extracellular DNA during early biofilm formation in Enterococcus faecalis. The work is significant because the mechanism of eDNA (extracellular DNA) production is independent of cell lysis and the DNA is confined to well-defined structures, suggesting a novel form of DNA secretion by viable cells. Previous models of biofilm formation in enterococci and related species propose cell lysis as the mechanism of DNA release.
Background and objectivesLiterature review using search engines results in a list of manuscripts but does not provide the content contained in the manuscripts. Our goal was to evaluate user ...performance-based criteria of concept retrieval accuracy and efficiency using a new database system that contained information extracted from 1000 COVID-19 articles.MethodsA sample of 17 students from the University of Vermont were randomly assigned to use the COVID-19 publication database or their usual preferred search methods to research eight prompts about COVID-19. The relevance and accuracy of the evidence found for each prompt were graded. A Cox proportional hazards’ model with a sandwich estimator and Kaplan-Meier plots were used to analyse these data in a time-to-correct answer context.ResultsOur findings indicate that students using the new information management system answered significantly more prompts correctly and, in less time, than students using conventional research methods. Bivariate models for demographic factors indicated that previous research experience conferred an advantage in study performance, though it was found to be independent from the assigned research method.ConclusionsThe results from this pilot randomised trial present a potential tool for more quickly and thoroughly navigating the literature on expansive topics such as COVID-19.
JEWISH OBJECTS AND JEWISH AFFECTS EICHLER-LEVINE, JODI; GROSS, RACHEL B.; LEIBMAN, LAURA A. ...
Cross currents (New Rochelle, N.Y.),
03/2021, Letnik:
71, Številka:
1
Journal Article
Recenzirano
A roundtable discussion participated by authors Jodi Eichler-Levine, Rachel B. Gross, Laura A. Leibman and Laura S. Levitt is presented. Among other things, they talk about their recent books and ...share why and how they study the Jewish objects and affects.
Plants rely on innate immunity to perceive and ward off microbes and pests, and are able to overcome the majority of invading microorganisms. Even so, specialized pathogens overcome plant defenses, ...posing a persistent threat to crop and food security worldwide, raising the need for agricultural products with broad, efficient resistance. Here we report a specific mutation in a tomato (S. lycopersicum) helper nucleotide-binding domain leucine-rich repeat H-NLR, SlNRC4a, which results in gain of function constitutive basal defense activation, in absence of PRR activation. Knockout of the entire NRC4 clade in tomato was reported to compromise Rpi-blb2 mediated immunity. The SlNRC4a mutant reported here possesses enhanced immunity and disease resistance to a broad-spectrum of pathogenic fungi, bacteria and pests, while lacking auto-activated HR or negative effects on plant growth and crop yield, providing promising prospects for agricultural adaptation in the war against plant pathogens that decrease productivity.
BackgroundGlycoprotein-A repetitions predominant (GARP) is expressed on regulatory T-cells and modulates release of active transforming growth factor β1 (TGFβ1), an immunosuppressive cytokine. ...ABBV-151 is a first-in-class monoclonal antibody (mAb) that binds to the GARP-TGFβ1 complex, blocking the release of active TGFβ1. Preclinical data demonstrate that blocking GARP-TGFβ1 and programmed cell death protein-1 (PD-1) improves antitumor efficacy compared with anti–PD-1 alone. Combining ABBV-151 with the anti–PD-1 mAb budigalimab may enable increased antitumor efficacy by reducing the immunosuppressive effects of TGFβ1. Herein, we report preliminary safety, efficacy, and pharmacokinetic (PK) results from a first-in-human, phase 1 study (NCT03821935) assessing ABBV-151 ± budigalimab in adult patients (≥18 years) with locally advanced/metastatic solid tumors. Results from the all-comer dose escalation (ESC) phase and two cohorts from the dose expansion (EXP) phase are available: anti-PD-1/PD-ligand (L)1 naïve hepatocellular carcinoma (HCC) and anti-PD-1/PD-L1 relapsed/refractory urothelial cancer (UC).MethodsESC patients must be refractory/intolerant to existing effective therapies; EXP cohorts have tumor-specific eligibility requirements. The primary ESC endpoint is the recommended phase II dose of ABBV-151 ± budigalimab. The primary EXP endpoint is preliminary efficacy of ABBV-151 + budigalimab, assessed by objective response rate per Response Evaluation Criteria in Solid Tumors (RECIST) version 1.1.ResultsAs of June 2022, 157 patients have been enrolled, 57 in ESC (23 ABBV-151 monotherapy; 34 combination therapy) and 100 in EXP (including 36 UC; 12 HCC). As of January 2022, safety data were available for 129 patients. Any-grade adverse events (AEs) were reported in 119/129 (92%) patients. Most commonly: fatigue (28%), pruritus (27%), and nausea (22%). Grade 3-4 AEs occurred in 66/129 (51%) patients, with drug-related grade 3-4 AEs in 18/129 (14%) patients. ABBV-151 showed dose proportional PK. No antitumor responses were reported for the ABBV-151 monotherapy ESC cohorts. In the combination ESC cohorts, there were 4 confirmed responses, 1 unconfirmed response, and 4 patients had stable disease (SD) ≥6 months. In the anti-PD-1/PD-L1 relapsed/refractory UC EXP cohort, there were 5 confirmed responses, 1 unconfirmed response, and 5 patients had a best response of SD. In the anti-PD-1/PD-L1 naïve HCC EXP cohort, there were 5 confirmed responses, including one response per immune RECIST, and 3 patients had a best response of SD.ConclusionsABBV-151 ± budigalimab showed a manageable safety profile in patients with advanced solid tumors. Preliminary efficacy results demonstrate durable antitumor activity with ABBV-151 + budigalimab, including in anti-PD-1 relapsed/refractory UC and in anti-PD-1 naïve HCC.AcknowledgementsAbbVie and the authors thank all the trial investigators and the patients who participated in this clinical trial. Medical writing support was provided by Rebecca L. Crepeau, PhD, from Aptitude Health, Atlanta, GA, USA and funded by AbbVie.Trial RegistrationNCT03821935Ethics ApprovalThe study was approved by the Advarra Ethics Board, under the license number IRB00000971.
This thesis project aimed to develop chimeric antigen receptors (CARs) capable of durably suppressing the Human Immunodeficiency Virus Type 1 (HIV) replication, by building upon a previous CD4-based ...CAR that was employed in several clinical trials. We applied lessons learned from cancer-targeting CARs to optimize the CAR vector backbone, promoter, HIV targeting moiety, and transmembrane and signaling domains, in an effort to determine which components augmented the ability of CD8 T cells to control HIV replication. CD8 T cells expressing the optimized CARs were at least 50-fold more potent in vitro at controlling HIV replication than the original CD4 CAR or TCR-based approaches and substantially better than broadly neutralizing antibody-based CARs. We then utilized a humanized mouse model of HIV infection to demonstrate superior control over HIV replication, better protection of CD4 T cells, and greater CAR T cell expansion with the optimized vectors compared to the original clinical trial vector. Compared to optimized CD4 CARs containing the CD28 costimulatory domain, CARs containing 4-1BB expanded better in vivo in the absence of antigen and resulted in greater control over HIV replication. We found that the CD4 CAR promoted infection of transduced CD8 T cells and employed CCR5 zinc finger nucleases (ZFNs) or a GP41-based fusion inhibitor to protect the CAR T cells. We employed ZFN-pretreated, CAR-transduced CD8 T cells in our mouse models and saw an enrichment of the disrupted alleles in HIV-infected mice compared to mock controls. In humans, a functional cure will require CAR T cells to prevent the spread of HIV following virus reactivation from the latent reservoir. We modeled this scenario in vitro using ART patient T cells and latency reversing agents (LRAs). Preliminary data suggest that CD4 CAR T cells can respond to low levels of antigen produced by resting ART patient cells in the presence of LRAs. Together, these data indicate that potent HIV-specific T cells can be generated using improved CAR design and provide optimism that CAR T cells could help achieve a functional cure.
PDF
