Identification of the central tolerance checkpoint for autoreactive proteinase 3 B cells in human bone marrow.

Major target antigens of ANCA-associated vasculitis (AAV) are myeloperoxidase (MPO) and proteinase 3 (PR3). High-affinity MPO- and PR3-ANCA immunoglobulins are produced by antigen-experienced, class-switched autoreactive B cells. To prevent autoreactivity, B cells are subjected to several self-tolerance checkpoints, from the early immature stages in the bone marrow (BM), collectively called "central tolerance", to late mature stages, collectively called "peripheral tolerance"; the latter was recently elucidated for autoreactive PR3 B cells.

Immunogenicity of Outer Membrane Vesicles: Elucidation of Humoral Responses against OMV-Associated Antigens.

Outer membrane vesicles (OMVs) produced by Gram-negative bacteria have emerged as a novel and flexible vaccine platform. OMVs can be decorated with foreign antigens and carry potent immunostimulatory components. Therefore, after their purification from the culture supernatant, they are ready to be formulated for vaccine use.

Bacterial Outer Membrane Vesicles as a Platform for the Development of a Broadly Protective Human Papillomavirus Vaccine Based on the Minor Capsid Protein L2.

Human papillomaviruses (HPVs) are a large family of viruses with a capsid composed of the L1 and L2 proteins, which bind to receptors of the basal epithelial cells and promote virus entry. The majority of sexually active people become exposed to HPV and the virus is the most common cause of cervical cancer. Vaccines are available based on the L1 protein, which self-assembles and forms virus-like particles (VLPs) when expressed in yeast and insect cells.

Anti-Tumor Efficacy of In Situ Vaccination Using Bacterial Outer Membrane Vesicles.

In situ vaccination (ISV) is a promising cancer immunotherapy strategy that consists of the intratumoral administration of immunostimulatory molecules (adjuvants). The rationale is that tumor antigens are abundant at the tumor site, and therefore, to elicit an effective anti-tumor immune response, all that is needed is an adjuvant, which can turn the immunosuppressive environment into an immunologically active one. Bacterial outer membrane vesicles (OMVs) are potent adjuvants since they contain several microbe-associated molecular patterns (MAMPs) naturally present in the outer membrane and in the periplasmic space of Gram-negative bacteria.

Immunogenicity and pre-clinical efficacy of an OMV-based SARS-CoV-2 vaccine.

The vaccination campaign against SARS-CoV-2 relies on the world-wide availability of effective vaccines, with a potential need of 20 billion vaccine doses to fully vaccinate the world population. To reach this goal, the manufacturing and logistic processes should be affordable to all countries, irrespectively of economical and climatic conditions. Outer membrane vesicles (OMV) are bacterial-derived vesicles that can be engineered to incorporate heterologous antigens.

Autoreactive Plasmablasts After B Cell Depletion With Rituximab and Relapses in Antineutrophil Cytoplasmic Antibody-Associated Vasculitis.

Objective: Autoreactive B cells are responsible for antineutrophil cytoplasmic antibody (ANCA) production in ANCA-associated vasculitis (AAV). Rituximab (RTX) depletes circulating B cells, including autoreactive B cells. We aimed to evaluate changes and associations with relapse of the circulating autoreactive B cell pool following therapeutic B cell depletion in AAV.

Outer Membrane Vesicles From The Gut Microbiome Contribute to Tumor Immunity by Eliciting Cross-Reactive T Cells.

A growing body of evidence supports the notion that the gut microbiome plays an important role in cancer immunity. However, the underpinning mechanisms remain to be fully elucidated. One attractive hypothesis envisages that among the T cells elicited by the plethora of microbiome proteins a few exist that incidentally recognize neo-epitopes arising from cancer mutations ("molecular mimicry (MM)" hypothesis).

Rheumatic immune-and nonimmune-related adverse events in phase 3 clinical trials assessing PD-(L)1 checkpoint inhibitors for lung cancer: A systematic review and meta-analysis.

Objectives: We aimed to analyze rheumatic immune-related (ir) and nonimmune-related adverse events (AEs) due to immune-checkpoint inhibitors (ICIs) targeting programmed cell death-1 or its ligand PD-(L)1 in lung cancer patients from the available literature.

Methods: We performed a systematic review and meta-analysis of phase III randomized clinical trials (RCTs) assessing PD-(L)1-ICIs in lung cancer patients, from inception until January 12th, 2021. We extracted data of each trial to estimate odds ratio (OR) for rheumatic ir or non-irAE as classified in RCTs safety data.

Commensal Strains Enhance the Efficacy of Neo-Epitope Based Cancer Vaccines.

A large body of data both in animals and humans demonstrates that the gut microbiome plays a fundamental role in cancer immunity and in determining the efficacy of cancer immunotherapy. In this work, we have investigated whether and to what extent the gut microbiome can influence the antitumor activity of neo-epitope-based cancer vaccines in a BALB/c-CT26 cancer mouse model. Similarly to that observed in the C57BL/6-B16 model, administration per se has a beneficial effect on CT26 tumor inhibition.

Multi-Antigen Outer Membrane Vesicle Engineering to Develop Polyvalent Vaccines: The Case.

Modification of surface antigens and differential expression of virulence factors are frequent strategies pathogens adopt to escape the host immune system. These escape mechanisms make pathogens a "moving target" for our immune system and represent a challenge for the development of vaccines, which require more than one antigen to be efficacious. Therefore, the availability of strategies, which simplify vaccine design, is highly desirable.

Circulating autoreactive proteinase 3+ B cells and tolerance checkpoints in ANCA-associated vasculitis.

BACKGROUNDLittle is known about the autoreactive B cells in antineutrophil cytoplasmic antibody-associated (ANCA-associated) vasculitis (AAV). We aimed to investigate tolerance checkpoints of circulating antigen-specific proteinase 3-reactive (PR3+) B cells.METHODSMulticolor flow cytometry in combination with bioinformatics and functional in vitro studies were performed on baseline samples of PBMCs from 154 well-characterized participants of the RAVE trial (NCT00104299) with severely active PR3-AAV and myeloperoxidase-AAV (MPO-AAV) and 27 healthy controls (HCs).

Meta-analysis of immune-related adverse events in phase 3 clinical trials assessing immune checkpoint inhibitors for lung cancer.

Introduction: The introduction in clinical practice of the immune checkpoint inhibitors (ICIs) radically changed the treatment algorithm of lung cancers. To characterize the toxicity of ICIs (atezolizumab, durvalumab, nivolumab, pembrolizumab) is important for personalizing treatment.

Patients And Methods: We performed a systematic review and meta-analysis of phase III randomized controlled trials assessing ICIs, from inception until April 23, 2020.

Proteome-minimized outer membrane vesicles from as a generalized vaccine platform.

Because of their potent adjuvanticity, ease of manipulation and simplicity of production Gram-negative Outer Membrane Vesicles OMVs have the potential to become a highly effective vaccine platform. However, some optimization is required, including the reduction of the number of endogenous proteins, the increase of the loading capacity with respect to heterologous antigens, the enhancement of productivity in terms of number of vesicles per culture volume. In this work we describe the use of Synthetic Biology to create BL21(DE3)Δ60, a strain releasing OMVs (OMVs) deprived of 59 endogenous proteins.

Structure, dynamics and immunogenicity of a catalytically inactive CC chemokine-degrading protease SpyCEP from .

Over 18 million disease cases and half a million deaths worldwide are estimated to be caused annually by Group A Streptococcus. A vaccine to prevent GAS disease is urgently needed. SpyCEP (Streptococcus Cell-Envelope Proteinase) is a surface-exposed serine protease that inactivates chemokines, impairing neutrophil recruitment and bacterial clearance, and has shown promising immunogenicity in preclinical models.

Bacterial outer membrane vesicles engineered with lipidated antigens as a platform for vaccine.

Bacterial outer membrane vesicles (OMVs) represent an interesting vaccine platform for their built-in adjuvanticity and simplicity of production process. Moreover, OMVs can be decorated with foreign antigens using different synthetic biology approaches. However, the optimal OMV engineering strategy, which should guarantee the OMV compartmentalization of most heterologous antigens in quantities high enough to elicit protective immune responses, remains to be validated.

Whole-genome epidemiology, characterisation, and phylogenetic reconstruction of Staphylococcus aureus strains in a paediatric hospital.

Background: Staphylococcus aureus is an opportunistic pathogen and a leading cause of nosocomial infections. It can acquire resistance to all the antibiotics that entered the clinics to date, and the World Health Organization defined it as a high-priority pathogen for research and development of new antibiotics. A deeper understanding of the genetic variability of S.

Vaccination With a FAT1-Derived B Cell Epitope Combined With Tumor-Specific B and T Cell Epitopes Elicits Additive Protection in Cancer Mouse Models.

Human FAT1 is overexpressed on the surface of most colorectal cancers (CRCs) and in particular a 25 amino acid sequence (D8) present in one of the 34 cadherin extracellular repeats carries the epitope recognized by mAb198.3, a monoclonal antibody which partially protects mice from the challenge with human CRC cell lines in xenograft mouse models. Here we present data in immune competent mice demonstrating the potential of the D8-FAT1 epitope as CRC cancer vaccine.

Protective effect of Group B Streptococcus type-III polysaccharide conjugates against maternal colonization, ascending infection and neonatal transmission in rodent models.

Group B Streptococcus (GBS) is a normal inhabitant of recto-vaginal mucosae in up to 30% of healthy women. Colonization is a major risk factor for perinatal infection which can lead to severe complications such as stillbirth and neonatal invasive disease. Intra-partum antibiotic prophylaxis in colonized women is a safe and cost-effective preventive measure against early-onset disease in the first days of life, but has no effect on late-onset manifestations or on early maternal infection.

Functional activity of maternal and cord antibodies elicited by an investigational group B Streptococcus trivalent glycoconjugate vaccine in pregnant women.

Objectives: The main aim of this exploratory study was to evaluate functional activity of antibodies elicited by a maternal Group B Streptococcus (GBS) investigational vaccine composed of capsular polysaccharides Ia, Ib, and III conjugated to genetically detoxified Diphtheria toxin CRM. The second objective was to investigate the relationship between serotype-specific IgG concentrations and functional activity in maternal and cord sera.

Methods: Maternal and cord sera collected at baseline and at delivery from vaccine and placebo recipients during a double-blind placebo-controlled Phase II study (www.

Multiple Stepwise Gene Knockout Using CRISPR/Cas9 in .

With the recent implementation of the CRISPR/Cas9 technology as a standard tool for genome editing, laboratories all over the world are undergoing one of the biggest advancements in molecular biology since PCR. The key advantage of this method is its simplicity and universal applicability for species of any phylum. Of particular interest is the extensively studied Gram-negative bacterium , as it is considered as the workhorse for both research and industrial purposes.

TCTN2: a novel tumor marker with oncogenic properties.

Tectonic family member 2 () encodes a transmembrane protein that belongs to the tectonic family, which is involved in ciliary functions. Previous studies have demonstrated the role of tectonics in regulating a variety of signaling pathways at the transition zone of cilia. However, the role of tectonics in cancer is still unclear.

Synergistic Protective Activity of Tumor-Specific Epitopes Engineered in Bacterial Outer Membrane Vesicles.

Introduction: Bacterial outer membrane vesicles (OMVs) are naturally produced by all Gram-negative bacteria and, thanks to their plasticity and unique adjuvanticity, are emerging as an attractive vaccine platform. To test the applicability of OMVs in cancer immunotherapy, we decorated them with either one or two protective epitopes present in the B16F10EGFRvIII cell line and tested the protective activity of OMV immunization in C57BL/6 mice challenged with B16F10EGFRvIII.

Materials And Methods: The 14 amino acid B cell epitope of human epidermal growth factor receptor variant III (EGFRvIII) and the mutation-derived CD4+ T cell neo-epitope of gene (B16-M30) were used to decorate OMVs either alone or in combination.

Some Gram-negative Lipoproteins Keep Their Surface Topology When Transplanted from One Species to Another and Deliver Foreign Polypeptides to the Bacterial Surface.

In Gram-negative bacteria, outer membrane-associated lipoproteins can either face the periplasm or protrude out of the bacterial surface. The mechanisms involved in lipoprotein transport through the outer membrane are not fully elucidated. Some lipoproteins reach the surface by using species-specific transport machinery.

Large scale validation of an efficient CRISPR/Cas-based multi gene editing protocol in Escherichia coli.

Background: The exploitation of the CRISPR/Cas9 machinery coupled to lambda (λ) recombinase-mediated homologous recombination (recombineering) is becoming the method of choice for genome editing in E. coli. First proposed by Jiang and co-workers, the strategy has been subsequently fine-tuned by several authors who demonstrated, by using few selected loci, that the efficiency of mutagenesis (number of mutant colonies over total number of colonies analyzed) can be extremely high (up to 100%).