Introduction: The future of human space missions relies on the ability to provide adequate food resources for astronauts and also to reduce stress due to the environment (microgravity and cosmic radiation). In this context, microgreens have been proposed for the astronaut diet because of their fast-growing time and their high levels of bioactive compounds and nutrients (vitamins, antioxidants, minerals, etc.), which are even higher than mature plants, and are usually consumed as ready-to-eat vegetables.
View Article and Find Full Text PDFIntroduction: Future long-term space missions will focus to the solar system exploration, with the Moon and Mars as leading goals. Plant cultivation will provide fresh food as a healthy supplement to astronauts' diet in confined and unhealthy outposts. Ionizing radiation (IR) are a main hazard in outer space for their capacity to generate oxidative stress and DNA damage.
View Article and Find Full Text PDFSoilless cultivation of saffron () in a controlled environment represents an interesting alternative to field cultivation, in order to obtain a standardized high-quality product and to optimize yields. In particular, pharma-grade saffron is fundamental for therapeutic applications of this spice, whose efficacy has been demonstrated in the treatment of macular diseases, such as Age-related Macular Degeneration (AMD). In this work, a hydroponic cultivation system was developed, specifically designed to meet the needs of plant.
View Article and Find Full Text PDFMonoclonal antibodies are considered to be highly effective therapeutic tools for the treatment of mild to moderate COVID-19 patients. In the present work, we describe the production of two SARS-CoV-2 human IgG1 monoclonal antibodies recognizing the spike protein receptor-binding domain (RBD) and endowed with neutralizing activity (nAbs) in plants. The first one, mAbJ08-MUT, was previously isolated from a COVID-19 convalescent patient and Fc-engineered to prolong the half-life and reduce the risk of antibody-dependent enhancement.
View Article and Find Full Text PDFPlant cultivation on spacecraft or planetary outposts is a promising and actual perspective both for food and bioactive molecules production. To this aim, plant response to ionizing radiations, as an important component of space radiation, must be assessed through on-ground experiments due to the potentially fatal effects on living systems. Hereby, we investigated the effects of X-rays and γ-rays exposure on tomato "hairy root" cultures (HRCs), which represent a solid platform for the production of pharmaceutically relevant molecules, including metabolites and recombinant proteins.
View Article and Find Full Text PDFBackground: A better understanding of locally advanced cervical cancer (LACC) is mandatory for further improving the rates of disease control, since a significant proportion of patients still fail to respond or undergo relapse after concurrent chemoradiation treatment (CRT), and survival for these patients has generally remained poor.
Methods: To identify specific markers of CRT response, we compared pretreatment biopsies from LACC patients with pathological complete response (sensitive) with those from patients showing macroscopic residual tumor (resistant) after neoadjuvant CRT, using a proteomic approach integrated with gene expression profiling. The study of the underpinning mechanisms of chemoradiation response was carried out through in vitro models of cervical cancer.
Static magnetic fields created by superconducting magnets have been proposed as an effective solution to protect spacecrafts and planetary stations from cosmic radiations. This shield can deflect high-energy particles exerting injurious effects on living organisms, including plants. In fact, plant systems are becoming increasingly interesting for space adaptation studies, being useful not only as food source but also as sink of bioactive molecules in future bioregenerative life-support systems (BLSS).
View Article and Find Full Text PDFUnlabelled: To shed light on the molecular mechanisms associated with aberrant accumulation of c-Myb in chronic myeloid leukemia, comparative proteomic analysis was performed on c-myb RNAi-specifically silenced K562 cells, sampled on a time-course basis. 2D-DIGE technology highlighted 37 differentially-represented proteins that were further characterized by nLC-ESI-LIT-MS/MS and validated by western blotting and qRT-PCR analysis. Most of the deregulated proteins were related to protein folding, energy/primary metabolism, transcription/translation regulation and oxidative stress response.
View Article and Find Full Text PDFThe Flavivirus genus includes widespread and severe human pathogens like the four serotypes of dengue virus (DENV1 to DENV4), yellow fever virus, Japanese encephalitis virus and West Nile virus. Domain III (ED3) of the viral envelope protein interacts with cell receptors and contains epitopes recognized by virus neutralizing antibodies. Its structural, antigenic and immunogenic properties have been thoroughly studied contrary to its physico-chemical properties.
View Article and Find Full Text PDFWe previously described the expression of a tumour-targeting antibody (mAb H10) in Nicotiana benthamiana by vacuum-agro-infiltration and the remarkable yields of highly pure protein achieved. The objective of the present work was to investigate different strategies for transient overexpression of the mAb H10 in which glycan configuration was modulated and assess how these strategies affect the accumulation yield and stability of the antibody. To this aim, three procedures have been assayed: (1) Site-directed mutagenesis to abolish the glycosylation site; (2) endoplasmic reticulum retention (C-terminal SEKDEL fusion) to ensure predominantly high-mannose type glycans; and (3) expression in a N.
View Article and Find Full Text PDFWe have recently described an efficient transient expression system mediated by Agrobacterium tumefaciens for the production of HIV-1 Nef protein in Nicotiana benthamiana plants. In order to enhance the yield of recombinant protein we assayed the effect of three gene-silencing viral suppressor proteins (P25 of Potato Virus X, P19 of Artichoke Mottled Crinckle virus and Tomato Bushy Stunt virus) on Nef expression levels. Results demonstrated that AMCV-P19 gave the highest Nef yield (1.
View Article and Find Full Text PDFCucumber mosaic virus (CMV), a member of the Cucumovirus genus, is the causal agent of several plant diseases in a wide range of host species, causing important economic losses in agriculture. Because of the lack of natural resistance genes in most crops, different genetic engineering strategies have been adopted to obtain virus-resistant plants. In a previous study, we described the engineering of transgenic tomato plants expressing a single-chain variable fragment antibody (scFv G4) that are specifically protected from CMV infection.
View Article and Find Full Text PDFIt was previously demonstrated that the tumour-targeting antibody mAb H10 can be transiently expressed and purified at high levels in Nicotiana benthamiana by using a vacuum-agroinfiltration system boosted by the use of a virus silencing suppressor protein. Scope of this work was to analyse different steps of protein extraction from agroinfiltrated leaves to optimise the purification process of the secretory mAb H10 providing new insights in the field of large-scale plant production. Two different extraction procedures (mechanical shearing/homogenisation and recovery of intercellular fluids -IFs-) were evaluated and compared in terms of purified antibody yields, antibody degradation and total phenolic compounds content.
View Article and Find Full Text PDFBackground: In recent years, different HIV antigens have been successfully expressed in plants by either stable transformation or transient expression systems. Among HIV proteins, Nef is considered a promising target for the formulation of a multi-component vaccine due to its implication in the first steps of viral infection. Attempts to express Nef as a single protein product (not fused to a stabilizing protein) in transgenic plants resulted in disappointingly low yields (about 0.
View Article and Find Full Text PDFThe expression of exogenous antibodies in plant is an effective strategy to confer protection against viral infection or to produce molecules with pharmaceutical interest. However, the acceptance of the transgenic technology to obtain self-protecting plants depends on the assessment of their substantial equivalence compared to non-modified crops with an established history of safe use. In fact, the possibility exists that the introduction of transgenes in plants may alter expression of endogenous genes and/or normal production of metabolites.
View Article and Find Full Text PDFThe aims of this work were to obtain a human antibody against the tumour-associated antigen tenascin-C (TNC) and to compare the yield and quality of plant-produced antibody in either stable transgenics or using a transient expression system. To this end, the characterization of a full-sized human immunoglobulin G (IgG) [monoclonal antibody H10 (mAb H10)], derived from a selected single-chain variable fragment (scFv) and produced in plants, is presented. The human mAb gene was engineered for plant expression, and Nicotiana tabacum transgenic lines expressing both heavy (HC) and light (LC) chain were obtained and evaluated for antibody expression levels, in vivo assembly and functionality.
View Article and Find Full Text PDFThe murine single-chain variable fragment F8 (scFv(F8)) is endowed with high intrinsic thermodynamic stability and can be functionally expressed in the reducing environment of both prokaryotic and eukaryotic cytoplasm. The stability and intracellular functionality of this molecule can be ascribed mostly to its framework regions and are essentially independent of the specific sequence and structure of the supported antigen-binding site. Therefore, the scFv(F8) represents a suitable scaffold to construct stable scFv chimeric molecules against different antigens by in vitro evolution or antigen-binding site grafting.
View Article and Find Full Text PDFWe have previously generated a semi-synthetic single-chain variable fragments (scFv) phage display library built on a thermodynamically stable single-framework scaffold. All scFv antibodies selected from this repertoire showed high thermodynamic stability and were expressed as soluble molecules in bacterial cytoplasm. In this work, two complementary methodologies have been adopted to assess the functionality of library-derived scFvs as intracellular antibodies and to verify the possibility to directly use this repertoire for the selection of antibodies able to function in a reducing environment.
View Article and Find Full Text PDFImmunomodulation by the ectopic expression of intracellular antibodies ('intrabodies') has a great potential for interfering with physiological or pathological functions in vivo in a highly specific manner. One of the major obstacles of this technology is the inability of most antibodies to properly fold and function in the reducing environment of the cytoplasm, which prevents the formation of essential disulfide bonds. We wished to assess the intracellular performance of antibodies derived from a semi-synthetic single-chain variable fragment (scFv) phage display library ('F8 library') built on a thermodynamically stable single-framework scaffold.
View Article and Find Full Text PDFProc Natl Acad Sci U S A
April 2005
The function of the virion-associated protein (VAP) of cauliflower mosaic virus (CaMV) has long been only poorly understood. VAP is associated with the virion but is dispensable for virus morphogenesis and replication. It mediates virus transmission by aphids through simultaneous interaction with both the aphid transmission factor and the virion.
View Article and Find Full Text PDFMany attempts have been made to develop antibody fragments that can be expressed in the cytoplasm ("intrabodies") in a stable and functional form. The recombinant antibody fragment scFv(F8) is characterised by peculiarly high in vitro stability and functional folding in both prokaryotic and eukaryotic cytoplasm. To dissect the relative contribution of different scFv(F8) regions to cytoplasmic stability and specificity we designed and constructed five chimeric molecules (scFv-P1 to P5) in which several groups of residues important for antigen binding in the poorly stable anti-hen egg lysozyme (HEL) scFv(D1.
View Article and Find Full Text PDFThe potent antitumor activity of certain cytokines is often achieved at the expense of unacceptable toxicity. One avenue to improve the therapeutic index of cytokines in cancer therapy consists of fusing them to monoclonal antibodies capable of a selective localization at the tumor site. We have constructed fusion proteins of interleukin-12 (IL-12) and tumor necrosis factor (TNF-alpha) with L19, an antibody fragment specific to the extradomain B of fibronectin which has been shown to target tumors in animal models and in patients with cancer.
View Article and Find Full Text PDFA major problem of antibody-based targeting of solid tumors is the poor penetration of antibodies into tumor tissue. Vasoactive immunoconjugates have been proposed as a means of increasing antibody uptake in tumors. In principle, VEGF (also known as vascular permeability factor) could selectively alter vascular permeability, leading to improved tumor targeting.
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