Photophysiology of the haploid form of the cryptophyte Teleaulax amphioxeia.

Cryptophytes are abundant and ubiquitous microalgae that constitute a major plastid source for kleptoplastidic ciliates and dinoflagellates. Despite their ecological significance, the understanding of their light preferences and photophysiology remains limited. Here, we provide a comprehensive study of the response of the haploid strain Teleaulax amphioxeia (Cr10EHU) to varying light irradiance.

Evaluation of Torque Teno Virus DNA Load as a Predictive Biomarker in Kidney Transplant Recipients Converted from Calcineurin Inhibitors to Belatacept.

Introduction: Belatacept is a relevant alternative to calcineurin inhibitors (CNIs) after kidney transplantation (KT). Circulating Torque Teno virus (TTV) DNA load is correlated to infections and rejection risks post-KT in patients treated with CNIs. The aim of this study was to assess the TTV DNA load profile in kidney transplant recipients converted from CNIs to belatacept and explore its use as a predictive biomarker.

Interaction Studies of Hexameric and Pentameric IgMs with Serum-Derived C1q and Recombinant C1q Mimetics.

The interaction between IgM and C1q represents the first step of the classical pathway of the complement system in higher vertebrates. To identify the significance of particular IgM/C1q interactions, recombinant IgMs were used in both hexameric and pentameric configurations and with two different specificities, along with C1q derived from human serum (sC1q) and two recombinant single-chain variants of the trimeric globular region of C1q. Interaction and complement activation assays were performed using the ELISA format, and bio-layer interferometry measurements to study kinetic behavior.

Chemo-enzymatic synthesis of tetrasaccharide linker peptides to study the divergent step in glycosaminoglycan biosynthesis.

Glycosaminoglycans are extended linear polysaccharides present on cell surfaces and within the extracellular matrix that play crucial roles in various biological processes. Two prominent glycosaminoglycans, heparan sulfate and chondroitin sulfate, are covalently linked to proteoglycan core proteins through a common tetrasaccharide linker comprising glucuronic acid, galactose, galactose, and xylose moities. This tetrasaccharide linker is meticulously assembled step by step by four Golgi-localized glycosyltransferases.

Development of a New Off-the-Shelf Plasmacytoid Dendritic Cell-Based Approach for the Expansion and Characterization of SARS-CoV-2-Specific T Cells.

Global vaccination against COVID-19 has been widely successful; however, there is a need for complementary immunotherapies in severe forms of the disease and in immunocompromised patients. Cytotoxic CD8+ T cells have a crucial role in disease control, but their function can be dysregulated in severe forms of the disease. We report here a cell-based approach using a plasmacytoid dendritic cell line (PDC*line) to expand in vitro specific CD8+ responses against COVID-19 Ags.

Cytomegalovirus detection is associated with ICU admission in non-AIDS and AIDS patients with Pneumocystis jirovecii pneumonia.

Objectives: Cytomegalovirus (CMV) is frequently detected in lung and/or blood samples of patients with Pneumocystis jirovecii pneumonia (PJP), although this co-detection is not precisely understood. We aimed to determine whether PJP was more severe in case of CMV detection.

Methods: We retrospectively included all patients with a diagnosis of PJP between 2009 and 2020 in our centre and with a measure of CMV viral load in blood and/or bronchoalveolar lavage (BAL).

The regulation of bacterial two-partner secretion systems.

Two-partner secretion (TPS) systems, also known as Type Vb secretion systems, allow the translocation of effector proteins across the outer membrane of Gram-negative bacteria. By secreting different classes of effectors, including cytolysins and adhesins, TPS systems play important roles in bacterial pathogenesis and host interactions. Here, we review the current knowledge on TPS systems regulation and highlight specific and common regulatory mechanisms across TPS functional classes.

Using Small-angle X-ray Scattering to Characterize Biological Systems: A General Overview and Practical Tips.

Small-angle X-ray Scattering (SAXS) is a versatile and powerful technique with applications in a wide range of fields. The continuous improvements in hardware, data analysis software, and standards for validation significantly contributed to increase its popularity and, nowadays, SAXS is a well-established method. SAXS allows to study flexible and dynamic systems (e.

Screening of Buffers and Additives for Protein Stabilization by Thermal Shift Assay: A Practical Approach.

Thermal shift assay (TSA), also commonly designed by differential scanning fluorimetry (DSF) or ThermoFluor, is a technique relatively easy to implement and perform, useful in a myriad of applications. In addition to versatility, it is also rather inexpensive, making it suitable for high-throughput approaches. TSA uses a fluorescent dye to monitor the thermal denaturation of the protein under study and determine its melting temperature (T).

Virological Markers in Epstein-Barr Virus-Associated Diseases.

Epstein-Barr virus (EBV) is an oncogenic virus infecting more than 95% of the world's population. After primary infection-responsible for infectious mononucleosis in young adults-the virus persists lifelong in the infected host, especially in memory B cells. Viral persistence is usually without clinical consequences, although it can lead to EBV-associated cancers such as lymphoma or carcinoma.

Fatal HSV-2 primary infection most likely acquired by kidney transplantation: A case report.

Herpes simplex virus 2 (HSV-2) rarely causes severe disease, even in solid organ transplant recipients. This paper describes a fatal case of HSV-2 infection, probably transmitted from a donor to a kidney transplant recipient. The donor was seropositive for HSV-2 but not for HSV-1, whereas the recipient was seronegative for both viruses before transplantation, suggesting that the graft was the source of infection.

IFNγ binding to extracellular matrix prevents fatal systemic toxicity.

Interferon-γ (IFNγ) is an important mediator of cellular immune responses, but high systemic levels of this cytokine are associated with immunopathology. IFNγ binds to its receptor (IFNγR) and to extracellular matrix (ECM) via four positively charged C-terminal amino acids (KRKR), the ECM-binding domain (EBD). Across evolution, IFNγ is not well conserved, but the EBD is highly conserved, suggesting a critical function.

Structure of the human heparan sulfate polymerase complex EXT1-EXT2.

Heparan sulfates are complex polysaccharides that mediate the interaction with a broad range of protein ligands at the cell surface. A key step in heparan sulfate biosynthesis is catalyzed by the bi-functional glycosyltransferases EXT1 and EXT2, which generate the glycan backbone consisting of repeating N-acetylglucosamine and glucuronic acid units. The molecular mechanism of heparan sulfate chain polymerization remains, however, unknown.

Letermovir use to treat complex cytomegalovirus reactivations in two heart transplant recipients.

Letermovir, an anti-cytomegalovirus (CMV) drug, is recommended as a prophylactic agent in patients at risk of CMV infection/reactivation after allogeneic hematopoietic stem cell transplant. We report the curative and pre-emptive use of letermovir in two heart transplant recipients. In one patient with ganciclovir-resistant CMV, letermovir was successfully used to treat CMV colitis.

Use of RT-PCR thermocycling program for the quantification of DNA viruses in a single run with RNA viruses: Example of Altona RealStar® HSV or VZV PCR kits.

Real-time PCR plays a key role in the diagnosis of viral infections. Multiple kits can detect or quantify genomes of various viruses with the same thermocycling program. Detection of RNA viruses includes an additional step of reverse transcription and challenge their detection in a single run with DNA viruses.

DltC acts as an interaction hub for AcpS, DltA and DltB in the teichoic acid D-alanylation pathway of Lactiplantibacillus plantarum.

Teichoic acids (TA) are crucial for the homeostasis of the bacterial cell wall as well as their developmental behavior and interplay with the environment. TA can be decorated by different modifications, modulating thus their biochemical properties. One major modification consists in the esterification of TA by D-alanine, a process known as D-alanylation.

Biophysical Characterization of the Oligomeric States of Recombinant Immunoglobulins Type-M and Their C1q-Binding Kinetics by Biolayer Interferometry.

Immunoglobulins type-M (IgMs) are one of the first antibody classes mobilized during immune responses against pathogens and tumor cells. Binding to specific target antigens enables the interaction with the C1 complex which strongly activates the classical complement pathway. This biological function is the basis for the huge therapeutic potential of IgMs.

Alix is required for activity-dependent bulk endocytosis at brain synapses.

In chemical synapses undergoing high frequency stimulation, vesicle components can be retrieved from the plasma membrane via a clathrin-independent process called activity-dependent bulk endocytosis (ADBE). Alix (ALG-2-interacting protein X/PDCD6IP) is an adaptor protein binding to ESCRT and endophilin-A proteins which is required for clathrin-independent endocytosis in fibroblasts. Alix is expressed in neurons and concentrates at synapses during epileptic seizures.

Identification of a two-component regulatory system involved in antimicrobial peptide resistance in Streptococcus pneumoniae.

Two-component regulatory systems (TCS) are among the most widespread mechanisms that bacteria use to sense and respond to environmental changes. In the human pathogen Streptococcus pneumoniae, a total of 13 TCS have been identified and many of them have been linked to pathogenicity. Notably, TCS01 strongly contributes to pneumococcal virulence in several infection models.

The core and accessory Hfq interactomes across Pseudomonas aeruginosa lineages.

The major RNA-binding protein Hfq interacts with mRNAs, either alone or together with regulatory small noncoding RNAs (sRNAs), affecting mRNA translation and degradation in bacteria. However, studies tend to focus on single reference strains and assume that the findings may apply to the entire species, despite the important intra-species genetic diversity known to exist. Here, we use RIP-seq to identify Hfq-interacting RNAs in three strains representing the major phylogenetic lineages of Pseudomonas aeruginosa.