480 research outputs found
Pension communication, knowledge, and behaviour
Many recent pension reforms require individuals to make more decisions on supplementary savings, investment choices, etc. Governments and the pension industry try to assist individuals through pension communication but little is known about the effectiveness of such policies. This paper uses Dutch longitudinal data to analyse the causal links between communication, pension knowledge, and conscious pension decision-making. A robust finding is that pension knowledge has a positive causal effect on active pension decision-making. Providing an annual pension statement might have a small positive effect on pension knowledge, but this result is sensitive to the identifying assumptions
TCR-engineered T cells: a model of inducible TCR expression to dissect the interrelationship between two TCRs
TCR gene-modified T cells for adoptive therapy simultaneously express the transgenic (tg) TCR and the endogenous TCR which might lead to mispaired TCRs with harmful unknown specificity and to a reduced function of TCR-tg T cells. We generated dual TCR T cells in two settings in which either TCR was constitutively expressed by a retroviral promoter while the second TCR expression was regulable by a tet-on system. Constitutively expressed TCR molecules were reduced on the cell surface depending on the induced TCR expression leading to strongly hampered function. Besides that, using fluorescence resonance energy transfer (FRET) we detected mispaired TCR dimers and different pairing behaviors of individual TCR chains with a mutual influence on TCR chain expression. The loss of function and mispairing could not be avoided by changing the TCR expression level or by introduction of an additional cysteine bridge. However, in polyclonal T cells, optimized TCR formats (cysteineization, codon optimization) enhanced correct pairing and function. We conclude from our data that (i) the level of mispairing depends on the individual TCRs and is not reduced by increasing the level of one TCR, and (ii) modifications (cysteineization, codon optimization) improve correct pairing but do not completely exclude mispairing (cysteineization)
TCR-engineered T cells: a model of inducible TCR expression to dissect the interrelationship between two TCRs
TCR gene-modified T cells for adoptive therapy simultaneously express the transgenic (tg) TCR and the endogenous TCR which might lead to mispaired TCRs with harmful unknown specificity and to a reduced function of TCR-tg T cells. We generated dual TCR T cells in two settings in which either TCR was constitutively expressed by a retroviral promoter while the second TCR expression was regulable by a tet-on system. Constitutively expressed TCR molecules were reduced on the cell surface depending on the induced TCR expression leading to strongly hampered function. Besides that, using fluorescence resonance energy transfer (FRET) we detected mispaired TCR dimers and different pairing behaviors of individual TCR chains with a mutual influence on TCR chain expression. The loss of function and mispairing could not be avoided by changing the TCR expression level or by introduction of an additional cysteine bridge. However, in polyclonal T cells, optimized TCR formats (cysteineization, codon optimization) enhanced correct pairing and function. We conclude from our data that (i) the level of mispairing depends on the individual TCRs and is not reduced by increasing the level of one TCR, and (ii) modifications (cysteineization, codon optimization) improve correct pairing but do not completely exclude mispairing (cysteineization)
Mitotic Recombination Accelerates Adaptation in the Fungus Aspergillus nidulans
Understanding the prevalence of sexual reproduction in eukaryotes is a hard problem. At least two aspects still defy a fully satisfactory explanation, the functional significance of genetic recombination and the great variation among taxa in the relative lengths of the haploid and diploid phases in the sexual cycle. We have performed an experimental study to explore the specific advantages of haploidy or diploidy in the fungus Aspergillus nidulans. Comparing the rate of adaptation to a novel environment between haploid and isogenic diploid strains over 3,000 mitotic generations, we demonstrate that diploid strains, which during the experiment have reverted to haploidy following parasexual recombination, reach the highest fitness. This is due to the accumulation of recessive deleterious mutations in diploid nuclei, some of which show their combined beneficial effect in haploid recombinants. Our findings show the adaptive significance of mitotic recombination combined with flexibility in the timing of ploidy level transition if sign epistasis is an important determinant of fitness
Interspecies virus transfer via protoplast fusions between Fusarium poae and black Aspergillus strains
Similarities between the genome organisation of dsRNA mycoviruses and dsRNA patterns in different fungal species suggest a relatedness between these viruses, which could be the result of co-evolved infections or of interspecies transfer. Such interspecies transfer between species is suggested by our observation of transfer and maintenance of mycoviral dsRNAs between Fusarium and Aspergillus via protoplast fusion
Expression of cytokines and their receptors by psoriatic fibroblasts I. Altered IL-6 synthesis
T cells expressing a TCR-like antibody selected against the heteroclitic variant of a shared MAGE-A epitope do not recognise the cognate epitope
Antibodies-recognising peptides bound to the major histocompatibility complex (pMHC) represent potentially valuable and promising targets for chimeric antigen receptor (CAR) T cells to treat patients with cancer. Here, a human phage-Fab library has been selected using HLA-A2 complexed with a heteroclitic peptide variant from an epitope shared among multiple melanoma-associated antigens (MAGEs). DNA restriction analyses and phage ELISAs confirmed selection of unique antibody clones that specifically bind to HLA-A2 complexes or HLA-A2-positive target cells loaded with native or heteroclitic peptide. Antibodies selected against heteroclitic peptide, in contrast to native peptide, demonstrated significantly lower to even negligible binding towards native peptide or tumour cells that naturally expressed peptides. The binding to native peptide was not rescued by phage panning with antigen-positive tumour cells. Importantly, when antibodies directed against heteroclitic peptides were engineered into CARs and expressed by T cells, binding to native peptides and tumour cells was minimal to absent. In short, TCR-like antibodies, when isolated from a human Fab phage library using heteroclitic peptide, fail to recognise its native peptide. We therefore argue that peptide modifications to improve antibody selections should be performed with caution as resulting antibodies, either used directly or as CARs, may lose activity towards endogenously presented tumour epitopes
Quantification of pharmacokinetic profiles of PD-1/PD-L1 antibodies by validated ELISAs
Immunotherapy has changed the paradigm of cancer treatments. In this way, several
combinatorial strategies based on monoclonal antibodies (mAb) such as anti (a)-PD-1 or anti (a)-PD-L1
are often reported to yield promising clinical benefits. However, the pharmacokinetic (PK) behavior
of these mAbs is a critical issue that requires selective analytical techniques. Indeed, few publications
report data on a-PD1/a-PD-L1 exposure and its relationship with therapeutic or toxic effects. In this
regard, preclinical assays allow the time profiles of antibody plasma concentrations to be characterized
rapidly and easily, which may help to increase PK knowledge. In this study, we have developed
and validated two in-house ELISAs to quantify a-PD-1 and a-PD-L1 in plasma collected from
tumor-bearing mice. The linear range for the a-PD-1 assay was 2.5–125 ng/mL and 0.11–3.125 ng/mL
for the a-PD-L1 assay, whereas the intra-and inter-day precision was lower than 20% for both analytes.
The PK characterization revealed a significant decrease in drug exposure after administration of
multiple doses. Plasma half-life for a-PD-1 was slightly shorter (22.3 h) than for a-PD-L1 (46.7 h).
To our knowledge, this is the first reported preclinical ELISA for these immune checkpoint inhibitors,
which is sufficiently robust to be used in different preclinical models. These methods can help to
understand the PK behavior of these antibodies under different scenarios and the relationship with
response, thus guiding the choice of optimal doses in clinical settings
Targeting melanoma with immunoliposomes coupled to anti-MAGEAI TCR-like single-chain antibody
Therapy of melanoma using T-cells with genetically introduced T-cell receptors (TCRs) directed against a tumor-selective cancer testis antigen (CTA) NY-ESO1 demonstrated clear antitumor responses in patients without side effects. Here, we exploited the concept of TCR-mediated targeting through introduction of single-chain variable fragment (scFv) antibodies that mimic TCRs in binding major histocompatibility complex-restricted CTA. We produced scFv antibodies directed against Melanoma AntiGEn A1 (MAGE A1) presented by human leukocyte antigen A1 (HLA-A1), in short M1/A1, and coupled these TCR-like antibodies to liposomes to achieve specific melanoma targeting. Two anti-M1/A1 antibodies with different ligand-binding affinities were derived from a phage-display library and reformatted into scFvs with an added cysteine at their carboxyl termini. Protein production conditions, ie, bacterial strain, temperature, time, and compartments, were optimized, and following production, scFv proteins were purified by immobilized metal ion affinity chromatography. Batches of pure scFvs were validated for specific binding to M1/A1-positive B-cells by flow cytometry. Coupling of scFvs to liposomes was conducted by employing different conditions, and an optimized procedure was achieved. In vitro experiments with immunoliposomes demonstrated binding of M1/A1-positive B-cells as well as M1/A1-positive melanoma cells and internalization by these cells using flow cyt
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