178 research outputs found
Review of "Cancer Nanotechnology: Methods and Protocols (Methods in Molecular Biology)" by Stephen R. Grobmyer (Editor), Brij M. Moudgil (Editor)
Cancer remains one of the leading causes of death. Research and resulting technologies have contributed to rising numbers of cancer survivors. Cancer nanotechnology is a novel and burgeoning field with the promise to open the door for the development of improved cancer therapies and detection methods. Cancer nanotechnology has the potential to become clinical reality
Linear and multivalent PEGylation of the tobacco mosaic virus and the effects on its biological properties
Plant virus-based nanoparticles (VNPs) offer a bioinspired approach to the delivery of drugs and imaging agents. The chemical addressability, biocompatibility, and scalable manufacturability of VNPs make them a promising alternative to synthetic delivery platforms. However, VNPs, just like other proteinaceous or synthetic nanoparticles (NPs), are readily recognized and cleared by the immune system and mechanisms such as opsonization and phagocytosis. Shielding strategies, such as PEGylation, are commonly used to mitigate premature NP clearance. Here, we investigated polyethylene glycol (PEG) coatings on the tobacco mosaic virus (TMV), which was used as a model nanocarrier system. Specifically, we evaluated the effects of linear and multivalent PEG coatings at varying chain lengths on serum protein adsorption, antibody recognition, and macrophage uptake. Linear and multivalent PEGs of molecular weights 2,000 and 5,000 Da were successfully grafted onto the TMV at ≈ 20%–60% conjugation efficiencies, and the degree of cross-linking as a function of PEG valency and length was determined. PEGylation resulted in the modulation of TMV–macrophage interactions and reduced corona formation as well as antibody recognition. Linear and multivalent PEG 5,000 formulations (but not PEG 2,000 formulations) reduced α-TMV antibody recognition, whereas shorter, multivalent PEG coatings significantly reduced α-PEG recognition—this highlights an interesting interplay between the NP and the PEG itself in potential antigenicity and should be an important consideration in PEGylation strategies. This work provides insight into the PEGylation of VNPs, which may improve the possibility of their implementation in clinical applications
COVID-19 vaccines based on viral nanoparticles displaying a conserved B-cell epitope show potent immunogenicity and a long-lasting antibody response
The COVID-19 pandemic caused by SARS-CoV-2 sparked intensive research into the development of effective vaccines, 50 of which have been approved thus far, including the novel mRNA-based vaccines developed by Pfizer and Moderna. Although limiting the severity of the disease, the mRNA-based vaccines presented drawbacks, such as the cold chain requirement. Moreover, antibody levels generated by these vaccines decline significantly after 6 months. These vaccines deliver mRNA encoding the full-length spike (S) glycoprotein of SARS-CoV-2, but must be updated as new strains and variants of concern emerge, creating a demand for adjusted formulations and booster campaigns. To overcome these challenges, we have developed COVID-19 vaccine candidates based on the highly conserved SARS CoV-2, 809-826 B-cell peptide epitope (denoted 826) conjugated to cowpea mosaic virus (CPMV) nanoparticles and bacteriophage Qβ virus-like particles, both platforms have exceptional thermal stability and facilitate epitope delivery with inbuilt adjuvant activity. We evaluated two administration methods: subcutaneous injection and an implantable polymeric scaffold. Mice received a prime–boost regimen of 100 μg per dose (2 weeks apart) or a single dose of 200 μg administered as a liquid formulation, or a polymer implant. Antibody titers were evaluated longitudinally over 50 weeks. The vaccine candidates generally elicited an early Th2-biased immune response, which stimulates the production of SARS-CoV-2 neutralizing antibodies, followed by a switch to a Th1-biased response for most formulations. Exceptionally, vaccine candidate 826-CPMV (administered as prime-boost, soluble injection) elicited a balanced Th1/Th2 immune response, which is necessary to prevent pulmonary immunopathology associated with Th2 bias extremes. While the Qβ-based vaccine elicited overall higher antibody titers, the CPMV-induced antibodies had higher avidity. Regardless of the administration route and formulation, our vaccine candidates maintained high antibody titers for more than 50 weeks, confirming a potent and durable immune response against SARS-CoV-2 even after a single dose
Generation of Mutants from the 57B Region of Drosophila melanogaster
The 57B region of Drosophila melanogaster includes a cluster of the three homeobox genes
orthopedia (otp), Drosophila Retinal homeobox (DRx), and homeobrain (hbn). In an attempt to isolate mu tants for these genes, we performed an EMS mutagenesis and isolated lethal mutants from the 57B
region, among them mutants for otp, DRx, and hbn. With the help of two newly generated deletions
from the 57B region, we mapped additional mutants to specific chromosomal intervals and identi fied several of these mutants from the 57B region molecularly. In addition, we generated mutants
for CG15651 and RIC-3 by gene targeting and mutants for the genes CG9344, CG15649, CG15650,
and ND-B14.7 using the CRISPR/Cas9 system. We determined the lethality period during develop ment for most isolated mutants. In total, we analysed alleles from nine different genes from the 57B
region of Drosophila, which could now be used to further explore the functions of the corresponding
genes in the future
Neoadjuvant in situ vaccination with cowpea mosaic virus as a novel therapy against canine inflammatory mammary cancer
BackgroundInflammatory mammary cancer (IMC), the counterpart of human inflammatory breast cancer (IBC), is the deadliest form of canine mammary tumors. IMC patients lack specific therapy and have poor outcomes. This proof-of-principle preclinical study evaluated the efficacy, safety, and effect on survival of neoadjuvant intratumoral (in situ) empty cowpea mosaic virus (eCPMV) immunotherapy in companion dogs diagnosed with IMC.MethodsTen IMC-bearing dogs were enrolled in the study. Five dogs received medical therapy, and five received weekly neoadjuvant in situ eCPMV immunotherapy (0.2–0.4 mg per injection) and medical therapy after the second eCPMV injection. Efficacy was evaluated by reduction of tumor growth; safety by hematological and biochemistry changes in blood and plasma; and patient outcome by survival analysis. eCPMV-induced immune changes in blood cells were analyzed by flow cytometry; changes in the tumor microenvironment were evaluated by CD3 (T lymphocytes), CD20 (B lymphocytes), FoxP3 (Treg lymphocytes), myeloperoxidase (MPO; neutrophils), Ki-67 (proliferation index, PI; tumor cell proliferation), and Cleaved Caspase-3 (CC-3; apoptosis) immunohistochemistry.ResultsTwo neoadjuvant in situ eCPMV injections resulted in tumor shrinkage in all patients by day 14 without systemic adverse events. Although surgery for IMC is generally not an option, reduction in tumor size allowed surgery in two IMC patients. In peripheral blood, in situ eCPMV immunotherapy was associated with a significant decrease of Treg/CD8 ratio and changes in CD8Granzyme B T cells, which behave as a lagging predictive biomarker. In the TME, higher neutrophilic infiltration and MPO expression, lower tumor Ki-67 PI, increase in CD3 lymphocytes, decrease in FoxP3/CD3 ratio (p<0.04 for all comparisons), and no changes in CC-3 immunostainings were observed in post-treatment tumor tissues when compared with pretreatment tumor samples. eCPMV-treated IMC patients had a statistically significant (p=0.033) improved overall survival than patients treated with medical therapy.ConclusionsNeoadjuvant in situ eCPMV immunotherapy demonstrated anti-tumor efficacy and improved survival in IMC patients without systemic adverse effects. eCPMV-induced changes in immune cells point to neutrophils as a driver of immune response. Neoadjuvant in situ eCPMV immunotherapy could be a groundbreaking immunotherapy for canine IMC and a potential future immunotherapy for human IBC patients
Unleashing the potential of cell membrane-based nanoparticles for COVID-19 treatment and vaccination
Introduction: Severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) is a particular coronavirus strain responsible for the coronavirus disease 2019 (COVID-19), accounting for more than 3.1 million deaths worldwide. Several health-related strategies have been successfully developed to contain the rapidly-spreading virus across the globe, toward reduction of both disease burden and infection rates. Particularly, attention has been focused on either the development of novel drugs and vaccines, or by adapting already-existing drugs for COVID-19 treatment, mobilizing huge efforts to block disease progression and to overcome the shortage of effective measures available at this point. Areas covered: This perspective covers the breakthrough of multifunctional biomimetic cell membrane-based nanoparticles as next-generation nanosystems for cutting-edge COVID-19 therapeutics and vaccination, specifically cell membrane-derived nanovesicles and cell membrane-coated nanoparticles, both tailorable cell membrane-based nanosystems enriched with the surface repertoire of native cell membranes, toward maximized biointerfacing, immune evasion, cell targeting and cell-mimicking properties. Expert opinion: Nano-based approaches have received widespread interest regarding enhanced antigen delivery, prolonged blood circulation half-life and controlled release of drugs. Cell membrane-based nanoparticles comprise interesting antiviral multifunctional nanoplatforms for blocking SARS-CoV-2 binding to host cells, reducing inflammation through cytokine neutralization and improving drug delivery toward COVID-19 treatment
Neoadjuvant Intratumoral Immunotherapy with Cowpea Mosaic Virus Induces Local and Systemic Antitumor Efficacy in Canine Mammary Cancer Patients
The lack of optimal models to evaluate novel agents is delaying the development of effective immunotherapies against human breast cancer (BC). In this prospective open label study, we applied neoadjuvant intratumoral immunotherapy with empty cowpea mosaic virus-like particles (eCPMV) to 11 companion dogs diagnosed with canine mammary cancer (CMC), a spontaneous tumor resembling human BC. We found that two neoadjuvant intratumoral eCPMV injections resulted in tumor reduction in injected tumors in all patients and in noninjected tumors located in the ipsilateral and contralateral mammary chains of injected dogs. Tumor reduction was independent of clinical stage, tumor size, histopathologic grade, and tumor molecular subtype. RNA-seq-based analysis of injected tumors indicated a decrease in DNA replication activity and an increase in activated dendritic cell infiltration in the tumor microenvironment. Immunohistochemistry analysis demonstrated significant intratumoral increases in neutrophils, T and B lymphocytes, and plasma cells. eCPMV intratumoral immunotherapy demonstrated antitumor efficacy without any adverse effects. This novel immunotherapy has the potential for improving outcomes for human BC patients
The Seventh Data Release of the Sloan Digital Sky Survey
This paper describes the Seventh Data Release of the Sloan Digital Sky Survey
(SDSS), marking the completion of the original goals of the SDSS and the end of
the phase known as SDSS-II. It includes 11663 deg^2 of imaging data, with most
of the roughly 2000 deg^2 increment over the previous data release lying in
regions of low Galactic latitude. The catalog contains five-band photometry for
357 million distinct objects. The survey also includes repeat photometry over
250 deg^2 along the Celestial Equator in the Southern Galactic Cap. A
coaddition of these data goes roughly two magnitudes fainter than the main
survey. The spectroscopy is now complete over a contiguous area of 7500 deg^2
in the Northern Galactic Cap, closing the gap that was present in previous data
releases. There are over 1.6 million spectra in total, including 930,000
galaxies, 120,000 quasars, and 460,000 stars. The data release includes
improved stellar photometry at low Galactic latitude. The astrometry has all
been recalibrated with the second version of the USNO CCD Astrograph Catalog
(UCAC-2), reducing the rms statistical errors at the bright end to 45
milli-arcseconds per coordinate. A systematic error in bright galaxy photometr
is less severe than previously reported for the majority of galaxies. Finally,
we describe a series of improvements to the spectroscopic reductions, including
better flat-fielding and improved wavelength calibration at the blue end,
better processing of objects with extremely strong narrow emission lines, and
an improved determination of stellar metallicities. (Abridged)Comment: 20 pages, 10 embedded figures. Accepted to ApJS after minor
correction
The Eighth Data Release of the Sloan Digital Sky Survey: First Data from SDSS-III
The Sloan Digital Sky Survey (SDSS) started a new phase in August 2008, with
new instrumentation and new surveys focused on Galactic structure and chemical
evolution, measurements of the baryon oscillation feature in the clustering of
galaxies and the quasar Ly alpha forest, and a radial velocity search for
planets around ~8000 stars. This paper describes the first data release of
SDSS-III (and the eighth counting from the beginning of the SDSS). The release
includes five-band imaging of roughly 5200 deg^2 in the Southern Galactic Cap,
bringing the total footprint of the SDSS imaging to 14,555 deg^2, or over a
third of the Celestial Sphere. All the imaging data have been reprocessed with
an improved sky-subtraction algorithm and a final, self-consistent photometric
recalibration and flat-field determination. This release also includes all data
from the second phase of the Sloan Extension for Galactic Understanding and
Evolution (SEGUE-2), consisting of spectroscopy of approximately 118,000 stars
at both high and low Galactic latitudes. All the more than half a million
stellar spectra obtained with the SDSS spectrograph have been reprocessed
through an improved stellar parameters pipeline, which has better determination
of metallicity for high metallicity stars.Comment: Astrophysical Journal Supplements, in press (minor updates from
submitted version
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