Endogenous retroelement activation is implicated in IFN-α production and anti-CCP autoantibody generation in early Rheumatoid Arthritis.

Objectives: Endogenous retroelements (EREs) stimulate type 1 interferon (IFN-I) production but have not been explored as potential interferonogenic triggers in Rheumatoid Arthritis (RA). We investigated ERE expression in early RA (eRA), a period where IFN-I is increased.

Methods: ERE expression (LTR5, LINE1, SINE) in disease modifying treatment naïve eRA whole blood and bulk synovial tissue was examined by RT-PCR and Nanostring alongside IFN-α activity.

Distinct lung cell signatures define the temporal evolution of diffuse alveolar damage in fatal COVID-19.

Background: Lung damage in severe COVID-19 is highly heterogeneous however studies with dedicated spatial distinction of discrete temporal phases of diffuse alveolar damage (DAD) and alternate lung injury patterns are lacking. Existing studies have also not accounted for progressive airspace obliteration in cellularity estimates. We used an imaging mass cytometry (IMC) analysis with an airspace correction step to more accurately identify the cellular immune response that underpins the heterogeneity of severe COVID-19 lung disease.

Challenges in tolerogenic dendritic cell therapy for autoimmune diseases: the route of administration.

Tolerogenic dendritic cells (tolDCs) are a promising strategy to treat autoimmune diseases since they have the potential to re-educate and modulate pathological immune responses in an antigen-specific manner and, therefore, have minimal adverse effects on the immune system compared to conventional immunosuppressive treatments. TolDC therapy has demonstrated safety and efficacy in different experimental models of autoimmune disease, such as multiple sclerosis (MS), type 1 diabetes (T1D), and rheumatoid arthritis (RA). Moreover, data from phase I clinical trials have shown that therapy with tolDCs is safe and well tolerated by MS, T1D, and RA patients.

Tolerogenic dendritic cell reporting: Has a minimum information model made a difference?

Minimum information models are reporting frameworks that describe the essential information that needs to be provided in a publication, so that the work can be repeated or compared to other work. In 2016, Minimum Information about Tolerogenic Antigen-Presenting cells (MITAP) was created to standardize the reporting on tolerogenic antigen-presenting cells, including tolerogenic dendritic cells (tolDCs). tolDCs is a generic term for dendritic cells that have the ability to (re-)establish immune tolerance; they have been developed as a cell therapy for autoimmune diseases or for the prevention of transplant rejection.

In Vitro Generation of Human Tolerogenic Monocyte-Derived Dendritic Cells.

Human monocyte-derived dendritic cells (moDC) are commonly used as a research tool to investigate interactions between antigen-presenting cells and T cells. Generation of these cells involves the isolation of CD14 positive monocytes from peripheral blood and their in vitro differentiation into immature moDC by the cytokines GM-CSF and IL-4. Their functional characteristics can then be manipulated by maturing these cells with a cocktail of agents, which can be tailored to induce either immune activating or tolerogenic properties.

Effective Endotoxin Removal from Chitosan That Preserves Chemical Structure and Improves Compatibility with Immune Cells.

Chitosan is one of the most researched biopolymers for healthcare applications, however, being a naturally derived polymer, it is susceptible to endotoxin contamination, which elicits pro-inflammatory responses, skewing chitosan's performance and leading to inaccurate conclusions. It is therefore critical that endotoxins are quantified and removed for in vivo use. Here, heat and mild NaOH treatment are investigated as facile endotoxin removal methods from chitosan.

Interplay between biomaterials and the immune system: Challenges and opportunities in regenerative medicine.

The use of biomaterials for tissue engineering and regenerative medicine applications has increased dramatically over recent years. However, the clinical uptake of a wide variety of biomaterials remains limited due to adverse effects commonly exhibited by patients, which are caused by the host immune response. Despite this, current in vitro evaluation standards (ISO-10993) for assessing the host response to biomaterials have limitations in predicting the likelihood of in vivo biomaterial acceptance.

Fluorine labelling of therapeutic human tolerogenic dendritic cells for F-magnetic resonance imaging.

Tolerogenic dendritic cell (tolDC) therapies aim to restore self-tolerance in patients suffering from autoimmune diseases. Phase 1 clinical trials with tolDC have shown the feasibility and safety of this approach, but have also highlighted a lack of understanding of their distribution . Fluorine-19 magnetic resonance imaging (F-MRI) promises an attractive cell tracking method because it allows for detection of F-labelled cells in a non-invasive and longitudinal manner.

Preclinical models of arthritis for studying immunotherapy and immune tolerance.

Increasingly earlier identification of individuals at high risk of rheumatoid arthritis (RA) (eg, with autoantibodies and mild symptoms) improves the feasibility of preventing or curing disease. The use of antigen-specific immunotherapies to reinstate immunological self-tolerance represent a highly attractive strategy due to their potential to induce disease resolution, in contrast to existing approaches that require long-term treatment of underlying symptoms.Preclinical animal models have been used to understand disease mechanisms and to evaluate novel immunotherapeutic approaches.

BIOlogical Factors that Limit sustAined Remission in rhEumatoid arthritis (the BIO-FLARE study): protocol for a non-randomised longitudinal cohort study.

Background: Our knowledge of immune-mediated inflammatory disease (IMID) aetiology and pathogenesis has improved greatly over recent years, however, very little is known of the factors that trigger disease relapses (flares), converting diseases from inactive to active states. Focussing on rheumatoid arthritis (RA), the challenge that we will address is why IMIDs remit and relapse. Extrapolating from pathogenetic factors involved in disease initiation, new episodes of inflammation could be triggered by recurrent systemic immune dysregulation or locally by factors within the joint, either of which could be endorsed by overarching epigenetic factors or changes in systemic or localised metabolism.

Synovial Macrophages in Osteoarthritis: The Key to Understanding Pathogenesis?

Effective treatment of osteoarthritis (OA) remains a huge clinical challenge despite major research efforts. Different tissues and cell-types within the joint contribute to disease pathogenesis, and there is great heterogeneity between patients in terms of clinical features, genetic characteristics and responses to treatment. Inflammation and the most abundant immune cell type within the joint, macrophages, have now been recognised as possible players in disease development and progression.

Dendritic cell integrin expression patterns regulate inflammation in the rheumatoid arthritis joint.

Objectives: Immune dysregulation contributes to the development of RA. Altered surface expression patterns of integrin adhesion receptors by immune cells is one mechanism by which this may occur. We investigated the role of β2 integrin subunits CD11a and CD11b in dendritic cell (DC) subsets of RA patients.

Targeting of tolerogenic dendritic cells to heat-shock proteins in inflammatory arthritis.

Background: Autologous tolerogenic dendritic cells (tolDC) are a promising therapeutic strategy for inflammatory arthritis (IA) as they can regulate autoantigen-specific T cell responses. Here, we investigated two outstanding priorities for clinical development: (i) the suitability of using heat-shock proteins (HSP), abundant in inflamed synovia, as surrogate autoantigens to be presented by tolDC and (ii) identification of functional biomarkers that confirm tolDC regulatory activity.

Methods: Cell proliferation dye-labelled human peripheral blood mononuclear cells of IA (rheumatoid arthritis (RA) and psoriatic arthritis (PsA)) patients or healthy donors were cultured with HSP40-, HSP60- and HSP70-derived peptides or recall antigens (e.

Matured Tolerogenic Dendritic Cells Effectively Inhibit Autoantigen Specific CD4 T Cells in a Murine Arthritis Model.

Tolerogenic dendritic cells (tolDCs) are a promising treatment modality for diseases caused by a breach in immune tolerance, such as rheumatoid arthritis. Current medication for these diseases is directed toward symptom suppression but no real cure is available yet. TolDC-based therapy aims to restore immune tolerance in an antigen-specific manner.

Ways Forward for Tolerance-Inducing Cellular Therapies- an AFACTT Perspective.

Clinical studies with cellular therapies using tolerance-inducing cells, such as tolerogenic antigen-presenting cells (tolAPC) and regulatory T cells (Treg) for the prevention of transplant rejection and the treatment of autoimmune diseases have been expanding the last decade. In this perspective, we will summarize the current perspectives of the clinical application of both tolAPC and Treg, and will address future directions and the importance of immunomonitoring in clinical studies that will result in progress in the field.

Macrophage proliferation distinguishes 2 subgroups of knee osteoarthritis patients.

Osteoarthritis (OA) is a leading cause of disability, globally. Despite an emerging role for synovial inflammation in OA pathogenesis, attempts to target inflammation therapeutically have had limited success. A better understanding of the cellular and molecular processes occurring in the OA synovium is needed to develop novel therapeutics.

Phenotypic and Transcriptomic Analysis of Peripheral Blood Plasmacytoid and Conventional Dendritic Cells in Early Drug Naïve Rheumatoid Arthritis.

Objective: Dendritic cells (DCs) are key orchestrators of immune function. To date, rheumatoid arthritis (RA) researchers have predominantly focused on a potential pathogenic role for CD1c+ DCs. In contrast, CD141+ DCs and plasmacytoid DCs (pDCs) have not been systematically examined, at least in early RA.

β Integrins As Regulators of Dendritic Cell, Monocyte, and Macrophage Function.

Emerging evidence suggests that the β integrin family of adhesion molecules have an important role in suppressing immune activation and inflammation. β integrins are important adhesion and signaling molecules that are exclusively expressed on leukocytes. The four β integrins (CD11a, CD11b, CD11c, and CD11d paired with the β chain CD18) play important roles in regulating three key aspects of immune cell function: recruitment to sites of inflammation; cell-cell contact formation; and downstream effects on cellular signaling.

A document-centric approach for developing the tolAPC ontology.

Background: There are many challenges associated with ontology building, as the process often touches on many different subject areas; it needs knowledge of the problem domain, an understanding of the ontology formalism, software in use and, sometimes, an understanding of the philosophical background. In practice, it is very rare that an ontology can be completed by a single person, as they are unlikely to combine all of these skills. So people with these skills must collaborate.

Targeting of tolerogenic dendritic cells towards heat-shock proteins: a novel therapeutic strategy for autoimmune diseases?

Tolerogenic dendritic cells (tolDCs) are a promising therapeutic tool to restore immune tolerance in autoimmune diseases. The rationale of using tolDCs is that they can specifically target the pathogenic T-cell response while leaving other, protective, T-cell responses intact. Several ways of generating therapeutic tolDCs have been described, but whether these tolDCs should be loaded with autoantigen(s), and if so, with which autoantigen(s), remains unclear.

T-regulatory cells exhibit a biphasic response to prolonged endurance exercise in humans.

Purpose: T-regulatory cells (Tregs) are a sub-population of lymphocytes that act to suppress aberrant immune responses. We investigated changes in the numbers of naïve and terminally differentiated Tregs in the peripheral blood to establish their role in the immuno-suppressive response to prolonged exercise.

Methods: Blood was drawn from seventeen experienced runners (age 40 ± 12 years; height 1.