Double-filtration plasmapheresis reduces type I interferon bioavailability and inducing activity in systemic lupus erythematosus.

Type I interferons (IFN-Is) play a significant role in systemic lupus erythematosus (SLE) pathogenesis. Double-filtration plasmapheresis (DFPP) is a treatment option for SLE; however, its effect on IFN-Is remains unclear. Therefore, we investigated the effects of DFPP on IFN-Is.

Effects of the induction of humoral and cellular immunity by third vaccination for SARS-CoV-2.

Introduction: To control the spread of severe disease caused by mutant strains of Severe Acute Respiratory Syndrome Coronavirus 2 (SARS-CoV-2), it is necessary to determine whether continued vaccination enhances humoral and cellular immunity.

Aim: In this study, we examined the changes in humoral and cellular immunity to SARS-CoV-2 after administration of the third vaccination in Japanese adults who had received the second dose of messenger ribonucleic acid (mRNA)-1273 vaccine and the third vaccination (BNT162b2 or mRNA-1273).

Methods: We measured anti-spike antibodies in immunoglobulin G (IgG) and anti-nucleocapsid IgG titers in the serum of the vaccinated subjects.

Early CD4 T cell responses induced by the BNT162b2 SARS-CoV-2 mRNA vaccine predict immunological memory.

Longitudinal studies have revealed large interindividual differences in antibody responses induced by SARS-CoV-2 mRNA vaccines. Thus, we performed a comprehensive analysis of adaptive immune responses induced by three doses of the BNT162b2 SARS-CoV-2 mRNA vaccines. The responses of spike-specific CD4 T cells, CD8 T cells and serum IgG, and the serum neutralization capacities induced by the two vaccines declined 6 months later.

Sex, Age, and Ethnic Background Shape Adaptive Immune Responses Induced by the SARS-CoV-2 mRNA Vaccine.

Severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) mRNA vaccine-induced adaptive responses have been well investigated. However, the effects of sex, age, and ethnic background on the immune responses elicited by the mRNA vaccine remain unclear. Here, we performed comprehensive analyses of adaptive immune responses elicited by the SARS-CoV-2 mRNA vaccine.

Different Spatial and Temporal Roles of Monocytes and Monocyte-Derived Cells in the Pathogenesis of an Imiquimod Induced Lupus Model.

Mounting evidence indicates the importance of aberrant Toll-like receptor 7 (TLR7) signaling in the pathogenesis of systemic lupus erythematosus (SLE). However, the mechanism of disease progression remains unclear. An imiquimod (IMQ)-induced lupus model was used to analyze the lupus mechanism related to the aberrant TLR7 signals.

Characteristics of mucosal-associated invariant T cells and their roles in immune diseases.

Mucosal-associated invariant T (MAIT) cells are a subset of innate-like T cells that express a semi-invariant T-cell receptor and are restricted by the major histocompatibility complex class I-related molecule 1 (MR1). MAIT cells recognize biosynthetic derivatives of the riboflavin synthesis pathway present in microbes. MAIT cells have attracted increased interest related to various immune responses because of their unique features including their abundance in humans, non-peptidic antigens and ability to respond to antigenic and non-antigenic stimuli.

Activated Mucosal-associated Invariant T Cells Have a Pathogenic Role in a Murine Model of Inflammatory Bowel Disease.

Background & Aims: Mucosal-associated invariant T (MAIT) cells are innate-like T cells restricted by major histocompatibility complex-related molecule 1 (MR1) and express a semi-invariant T cell receptor. Previously, we reported the activation status of circulating MAIT cells in patients with ulcerative colitis (UC) was associated with disease activity and that these cells had infiltrated the inflamed colonic mucosa. These findings suggest MAIT cells are involved in the pathogenesis of inflammatory bowel disease.

Resolution of One-Year Persisting COVID-19 Pneumonia and Development of Immune Thrombocytopenia in a Follicular Lymphoma Patient With Preceding Rituximab Maintenance Therapy: A follow-up Report and Literature Review of Cases With Prolonged Infections.

Background: We previously reported elsewhere of a follicular lymphoma patient suffering from persistent COVID-19 pneumonia that was still ongoing at 2 months after onset.

Materials And Methods: We provide a follow-up report of the case along with a literature review of immunocompromised lymphoma patients experiencing prolonged COVID-19 infections.

Results: Although requiring a full 1 year, the presented case eventually achieved spontaneous resolution of COVID-19 pneumonia.

Combination therapy with plasma exchange and glucocorticoid may be effective for severe COVID-19 infection: A retrospective observational study.

We retrospectively analyzed the characteristics and outcomes of five patients with COVID-19 who were received glucocorticoid (with or without pulse therapy) and therapeutic plasma exchange. The efficacy of the treatment was determined by whether the patient was able to be transferred from the COVID-19 exclusive ICU to the general ward. In comparing patients who received prednisolone pulse therapy (three cases) with those who did not (two cases), 2/3 (66%) and 0/2 (0%) patients could be discharged from the COVID-19 dedicated ICU, respectively.

Inhibition of mTOR suppresses IFNα production and the STING pathway in monocytes from systemic lupus erythematosus patients.

Objective: Increased IFNα is important in the pathogenesis of SLE. Plasmacytoid dendritic cells are considered the main producer of IFNα upon Toll-like receptor pathway activation. However, which cells produce IFNα following stimulation with cyclic GMP-AMP synthase (cGAS) and stimulator of IFN genes (STING) in SLE remains unknown.

Association of mucosal-associated invariant T cells with different disease phases of polymyalgia rheumatica.

Objectives: Although T cells are thought to be involved in the pathogenesis of PMR, whether innate-like T cells are involved in the process remains unknown.

Methods: The serum levels of 27 cytokines/chemokines in patients with PMR were measured by a multiplex immunoassay (Bio-Plex Assay). The cytokine-producing capacity of T and innate-like T cells was assessed by intracellular cytokine staining and flow cytometry.

Unique primed status of microglia under the systemic autoimmune condition of lupus-prone mice.

Background: Systemic lupus erythematosus (SLE) is an autoimmune disease characterized by the production of various autoantibodies. This disease causes disabling neuropsychiatric symptoms even in the absence of apparent inflammation in the central nervous system (CNS), but the mechanisms involved remain unknown. Innate immune-mediated inflammation has attracted attention as a pathogenic mechanism in neuropsychiatric diseases.

A Critical Role for Mucosal-Associated Invariant T Cells as Regulators and Therapeutic Targets in Systemic Lupus Erythematosus.

Mucosal-associated invariant T (MAIT) cells are a subset of innate-like lymphocytes that are restricted by major histocompatibility complex-related molecule 1 (MR1). In this study, we investigated the role of MAIT cells in the pathogenesis of lupus in FcγRIIb mice, a spontaneous animal model of lupus. Using two approaches of MAIT cell deficiency, MR1 knockout animals and a newly synthesized inhibitory MR1 ligand, we demonstrate that MAIT cells augment the disease course of lupus by enhancing autoantibody production and tissue inflammation.

Activation of mucosal-associated invariant T cells in the lungs of sarcoidosis patients.

Although the pathogenesis of sarcoidosis is not fully understood, immunological characterization has elucidated highly polarized expression of the type 1 T helper cell response. Mucosal-associated invariant T (MAIT) cells are innate T cells that recognize bacterial riboflavin and rapidly produce cytokines such as interferon γ and tumor necrosis factor α. We prospectively evaluated the proportion of MAIT cells and the expression levels of cell surface markers in peripheral blood from 40 sarcoidosis patients and 28 healthy controls.

Expanded circulating peripheral helper T cells in systemic lupus erythematosus: association with disease activity and B cell differentiation.

Objective: Peripheral helper T (TPH) cells are a recently identified Th cell subset that promotes B cell differentiation and antibody production in inflamed tissues. This study investigated circulating TPH cells to determine their involvement in systemic lupus erythematosus (SLE).

Methods: Peripheral blood mononuclear cells collected from SLE patients and healthy individuals were analysed.

Mucosal-Associated Invariant T Cells in Autoimmune Diseases.

Mucosal-associated invariant T (MAIT) cells are innate T cells restricted by MHC-related molecule 1 (MR1). MAIT cells express semi-invariant T-cell receptors TRAV1-2-TRAJ33/12/20 in humans and TRAV1-TRAJ33 in mice. MAIT cells recognize vitamin B2 biosynthesis derivatives presented by MR1.

Enhanced IFN-α production is associated with increased TLR7 retention in the lysosomes of palasmacytoid dendritic cells in systemic lupus erythematosus.

Background: Interferon-α (IFN-α) is increased and plays an important role in the pathogenesis of systemic lupus erythematosus (SLE). Plasmacytoid dendritic cells (pDCs) are the main producer of IFN-α, but their IFN-α producing capacity has been shown to be unchanged or reduced when stimulated with a Toll-like receptor 9 (TLR9) agonist in patients with SLE compared to in healthy individuals. In this study, we investigated the IFN-α-producing capacity of lupus pDCs under different stimulation.

Activation status of mucosal-associated invariant T cells reflects disease activity and pathology of systemic lupus erythematosus.

Background: Mucosal-associated invariant T (MAIT) cells are innate-like lymphocytes constituting a large proportion of peripheral blood T cells expressing αβ T-cell receptor in humans. In this study, we aimed to investigate their involvement in systemic lupus erythematosus (SLE).

Methods: Peripheral blood MAIT cells from patients with SLE were assessed for their frequency, activation markers, and cell death by flow cytometry.