158 research outputs found
A phase I randomized therapeutic MVA-B vaccination improves the magnitude and quality of the T cell immune responses in HIV-1-infected subjects on HAART
Trial Design
Previous studies suggested that poxvirus-based vaccines might be instrumental in the therapeutic
HIV field. A phase I clinical trial was conducted in HIV-1-infected patients on highly
active antiretroviral therapy (HAART), with CD4 T cell counts above 450 cells/mm3 and
undetectable viremia. Thirty participants were randomized (2:1) to receive either 3 intramuscular
injections of MVA-B vaccine (coding for clade B HIV-1 Env, Gag, Pol and Nef antigens)
or placebo, followed by interruption of HAART.
Methods
The magnitude, breadth, quality and phenotype of the HIV-1-specific T cell response were
assayed by intracellular cytokine staining (ICS) in 22 volunteers pre- and post-vaccination.
Results
MVA-B vaccine induced newly detected HIV-1-specific CD4 T cell responses and expanded
pre-existing responses (mostly against Gag, Pol and Nef antigens) that were high in magnitude,
broadly directed and showed an enhanced polyfunctionality with a T effector memory
(TEM) phenotype, while maintaining the magnitude and quality of the pre-existing HIV-1-
specific CD8 T cell responses. In addition, vaccination also triggered preferential CD8+ T
cell polyfunctional responses to the MVA vector antigens that increase in magnitude after
two and three booster doses
Drug discovery: Insights from the invertebrate Caenorhabditis elegans
Therapeutic drug development is a long, expensive, and complex process that usually takes 12–15 years. In the early phases of drug discovery, in particular, there is a growing need for animal models that ensure the reduction in both cost and time. Caenorhabditis elegans has been traditionally used to address fundamental aspects of key biological processes, such as apoptosis, aging, and gene expression regulation. During the last decade, with the advent of large-scale platforms for screenings, this invertebrate has also emerged as an essential tool in the pharmaceutical research industry to identify novel drugs and drug targets. In this review, we discuss the reasons why C. elegans has been positioned as an outstanding cost-effective option for drug discovery, highlighting both the advantages and drawbacks of this model. Particular attention is paid to the suitability of this nematode in large-scale genetic and pharmacological screenings. High-throughput screenings in C. elegans have indeed contributed to the breakthrough of a wide variety of candidate compounds involved in extensive fields including neurodegeneration, pathogen infections and metabolic disorders. The versatility of this nematode, which enables its instrumentation as a model of human diseases, is another attribute also herein underscored. As illustrative examples, we discuss the utility of C. elegans models of both human neurodegenerative diseases and parasitic nematodes in the drug discovery industry. Summing up, this review aims to demonstrate the impact of C. elegans models on the drug discovery pipeline.Fil: Giunti, Sebastián. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Bahía Blanca. Instituto de Investigaciones Bioquímicas de Bahía Blanca. Universidad Nacional del Sur. Instituto de Investigaciones Bioquímicas de Bahía Blanca; Argentina. Universidad Nacional del Sur. Departamento de Biología, Bioquímica y Farmacia; ArgentinaFil: Andersen, Natalia Denise. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Bahía Blanca. Instituto de Investigaciones Bioquímicas de Bahía Blanca. Universidad Nacional del Sur. Instituto de Investigaciones Bioquímicas de Bahía Blanca; Argentina. Universidad Nacional del Sur. Departamento de Biología, Bioquímica y Farmacia; ArgentinaFil: Rayes, Diego Hernán. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Bahía Blanca. Instituto de Investigaciones Bioquímicas de Bahía Blanca. Universidad Nacional del Sur. Instituto de Investigaciones Bioquímicas de Bahía Blanca; Argentina. Universidad Nacional del Sur. Departamento de Biología, Bioquímica y Farmacia; ArgentinaFil: de Rosa, Maria Jose. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Bahía Blanca. Instituto de Investigaciones Bioquímicas de Bahía Blanca. Universidad Nacional del Sur. Instituto de Investigaciones Bioquímicas de Bahía Blanca; Argentina. Universidad Nacional del Sur. Departamento de Biología, Bioquímica y Farmacia; Argentin
Molecular mechanisms of cell death: recommendations of the Nomenclature Committee on Cell Death 2018.
Over the past decade, the Nomenclature Committee on Cell Death (NCCD) has formulated guidelines for the definition and interpretation of cell death from morphological, biochemical, and functional perspectives. Since the field continues to expand and novel mechanisms that orchestrate multiple cell death pathways are unveiled, we propose an updated classification of cell death subroutines focusing on mechanistic and essential (as opposed to correlative and dispensable) aspects of the process. As we provide molecularly oriented definitions of terms including intrinsic apoptosis, extrinsic apoptosis, mitochondrial permeability transition (MPT)-driven necrosis, necroptosis, ferroptosis, pyroptosis, parthanatos, entotic cell death, NETotic cell death, lysosome-dependent cell death, autophagy-dependent cell death, immunogenic cell death, cellular senescence, and mitotic catastrophe, we discuss the utility of neologisms that refer to highly specialized instances of these processes. The mission of the NCCD is to provide a widely accepted nomenclature on cell death in support of the continued development of the field
Salmonella Typhi-specific multifunctional CD8+ T cells play a dominant role in protection from typhoid fever in humans.
BACKGROUND: Typhoid fever, caused by the human-restricted organism Salmonella Typhi (S. Typhi), is a major public health problem worldwide. Development of novel vaccines remains imperative, but is hampered by an incomplete understanding of the immune responses that correlate with protection.
METHODS: Recently, a controlled human infection model was re-established in which volunteers received ~10(3) cfu wild-type S. Typhi (Quailes strain) orally. Twenty-one volunteers were evaluated for their cell-mediated immune (CMI) responses. Ex vivo PBMC isolated before and up to 1 year after challenge were exposed to three S. Typhi-infected targets, i.e., autologous B lymphoblastoid cell-lines (B-LCL), autologous blasts and HLA-E restricted AEH B-LCL cells. CMI responses were evaluated using 14-color multiparametric flow cytometry to detect simultaneously five intracellular cytokines/chemokines (i.e., IL-17A, IL-2, IFN-g, TNF-a and MIP-1b) and a marker of degranulation/cytotoxic activity (CD107a).
RESULTS: Herein we provide the first evidence that S. Typhi-specific CD8+ responses correlate with clinical outcome in humans challenged with wild-type S. Typhi. Higher multifunctional S. Typhi-specific CD8+ baseline responses were associated with protection against typhoid and delayed disease onset. Moreover, following challenge, development of typhoid fever was accompanied by decreases in circulating S. Typhi-specific CD8+ T effector/memory (TEM) with gut homing potential, suggesting migration to the site(s) of infection. In contrast, protection against disease was associated with low or no changes in circulating S. Typhi-specific TEM.
CONCLUSIONS: These studies provide novel insights into the protective immune responses against typhoid disease that will aid in selection and development of new vaccine candidates
Summed squared distance error reduction by simultaneous multiprojections and applications
A parallel projection scheme in which projections are performed simultaneously on all constraints at each iteration is presented. It is a multiprojections scheme because different distance functions can be minimized for each projection as long as they are based on weighted L-2 norms. The use of multiple distance functions enables simplifications of the various projection operations, leading to an efficient implementation of this algorithm. This is true especially for constrained deconvolution type problems. Due to the inherent parallelism of the algorithm, projections onto more than two sets can be performed, even if one (or more) of the sets are nonconvex, maintaining a monotone decrease of a cost functional (with no further restrictions). This is in contrast to the serial projections onto convex sets (POCS) algorithm where no more than two sets can be treated if one of the sets is nonconvex. Our method is a special case of a multiprojections method proposed by Censor and Elfving where generalized distance functions of the Bregman type are used. The restriction to weighted L-2 norms leads to a simple and explicit form of this algorithm and allows relaxation and the use of nonconvex sets. (C) 2002 Elsevier Science Inc. All rights reserved.1264170015717
Dynamical wall-following for a wheeled robot using a passive tactile sensor
Abstract — Feedback from antennae – long, flexible tactile sensors – enables cockroaches and other arthropods to rapidly maneuver through poorly lit and cluttered environments. Inspired by their performance, we created a wall-following controller for a dynamic wheeled robot using tactile antenna feedback. We show this controller is stable for a wide range of control gains and robot system parameters. To test the controller, we constructed a two-link antenna that uses potentiometers and capacitive contact sensors. Experiments based on the prototype demonstrate that our controller robustly tracks unexpected corners ranging from −60 ◦ to +90 ◦. I
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