Invariant NKT Cells and Rheumatic Disease: Focus on Primary Sjogren Syndrome

Primary Sjogren syndrome (pSS) is a complex autoimmune disease mainly affecting salivary and lacrimal glands. Several factors contribute to pSS pathogenesis; in particular, innate immunity seems to play a key role in disease etiology. Invariant natural killer (NK) T cells (iNKT) are a T-cell subset able to recognize glycolipid antigens. Their function remains unclear, but studies have pointed out their ability to modulate the immune system through the promotion of specific cytokine milieu. In this review, we discussed the possible role of iNKT in pSS development, as well as their implications as future markers of disease activity

JAK/STAT inhibition modifies the ILC1 immune response in patients with rheumatoid arthritis

Objectives: Recent evidence suggests that innate lymphoid cells (ILCs) might be involved in rheumatoid arthritis (RA) pathogenesis and individuals at risk of RA exhibited an increased frequency of ILC1. JAK3 participates in ILC1 and ILC3 differentiation. Tofacitinib and the Janus Kinase (JAK) 3 inhibitor, PF-06651600, impair the ability of human intraepithelial ILC1 (iILC1) to produce IFN-γ and the proliferation of ILC1 and ILC3. Our study aims to evaluate the ex vivo effects of tofacitinib in RA patients and to investigate if ILC1s and ILC3s are specific targets of tofacitinib in RA. Methods: Twenty RA patients starting tofacitinib and 10 RA patients starting anti-TNFα were enrolled. Peripheral blood mononuclear cells (PBMCs) from RA patients, collected before and three months after therapy, were cultured to evaluate ILC1 and ILC3 frequencies and the respective production of IFN-γ and IL-17 by flow cytometry analysis. PBMCs of RA patients were in vitro cultured with tofacitinib to evaluate the dose effects on ILC frequencies. Results: RA patients showed a significant expansion of ILC1 but not ILC3. Unlike anti-TNFα treated patients, in whom no reduction in ILCs was reported, after three months of tofacitinib therapy the overall ILC frequency was reduced, as well as the ILC1 ability to release IFN-γ. In vitro treatment of PBMCs with tofacitinib demonstrated a dose-dependent reduction in the frequency of ILCs compared to untreated cells. Conclusions: Our preliminary results demonstrate that tofacitinib modulates the innate immune response by reducing the frequency of ILC1 cells and their production of IFN-γ

Integrated Analysis of Single-Cell and Bulk RNA Sequencing Data Reveals Memory-like NK Cell Subset Associated with <i>Mycobacterium tuberculosis</i> Latency

Natural killer (NK) cells are innate-like lymphocytes that belong to the family of type-1 innate lymphoid cells and rapidly respond to virus-infected and tumor cells. In this study, we have combined scRNA-seq data and bulk RNA-seq data to define the phenotypic and molecular characteristics of peripheral blood NK cells. While the role of NK cells in immune surveillance against virus infections and tumors has been well established, their contribution to protective responses to other intracellular microorganisms, such as Mycobacterium tuberculosis (Mtb), is still poorly understood. In this study, we have combined scRNA-seq data and bulk RNA-seq data to illuminate the molecular characteristics of circulating NK cells in patients with active tuberculosis (TB) disease and subjects with latent Mtb infection (LTBI) and compared these characteristics with those of healthy donors (HDs) and patients with non-TB other pulmonary infectious diseases (ODs). We show here that the NK cell cluster was significantly increased in LTBI subjects, as compared to patients with active TB or other non-TB pulmonary diseases and HD, and this was mostly attributable to the expansion of an NK cell population expressing KLRC2, CD52, CCL5 and HLA-DRB1, which most likely corresponds to memory-like NK2.1 cells. These data were validated by flow cytometry analysis in a small cohort of samples, showing that LTBI subjects have a significant expansion of NK cells characterized by the prevalence of memory-like CD52+ NKG2C+ NK cells. Altogether, our results provide some new information on the role of NK cells in protective immune responses to Mtb

Interleukin (IL)-9/IL-9R axis drives γδ T cells activation in psoriatic arthritis patients

Cytokines such as tumour necrosis factor (TNF)-α, interleukin (IL)-12, interferon (IFN)-γ, IL-23 and, more recently, IL-9, have been implicated in the initiation/maintenance of inflammation in psoriasis and psoriatic arthritis (PsA). In the present study we aimed to characterize the role of γδ T cells in peripheral blood and synovial fluid of PsA patients and to investigate their response to in-vitro stimulation with antigen or cytokines (IL-9 and IL-23). γδ T cells isolated from peripheral blood mononuclear cells and synovial fluid were analysed by flow cytometry to evaluate the phenotype and cytokine production. IL-23R and IL-9R gene expression were also evaluated by reverse transcription-polymerase chain reaction (RT-PCR). Peripheral blood mononuclear cells (PBMC), sorted γδ T cells and γδ cell lines were also stimulated in vitro with isopentenyl pyrophosphate (IPP), recombinant IL-9 or recombinant IL-23. Our results show an expansion of γδ T cells with a predominant effector memory phenotype in peripheral blood and synovium of untreated PsA patients, which reverses significantly after treatment with anti-TNF-α or anti-IL-12/IL-23R monoclonal antibodies (mAbs). Moreover, in PsA patients γδ T cells activation is driven prevalently by IL-9/IL-9R interaction, and not only by IL-23/IL-23R. Together these findings indicate γδ T cells and IL-9 as new players in the pathogenesis of PsA

Interleukin 9 neutralisation reduces collagen-induced arthritis severity in mouse models

Interleukin 9 (IL-9) is a mediator of tissue damage in several inflammatory diseases. In this study we aimed to evaluate the effects of in vivo IL-9 neutralisation in mice developing collagen induced arthritis (CIA)

Wheat Consumption Leads to Immune Activation and Symptom Worsening in Patients with Familial Mediterranean Fever: A Pilot Randomized Trial

Abstract: We have identified a clinical association between self-reported non-celiac wheat sensitivity (NCWS) and Familial Mediterranean Fever (FMF). Objectives: A) To determine whether a 2-week double-blind placebo-controlled (DBPC) cross-over wheat vs. rice challenge exacerbates the clinical manifestations of FMF; B) to evaluate innate immune responses in NCWS/FMF patients challenged withwheatvs. rice. ThestudywasconductedattheDepartmentofInternalMedicineoftheUniversity Hospital of Palermo and the Hospital of Sciacca, Italy. Six female volunteers with FMF/NCWS (mean age36±6years)wereenrolled,12age-matchednon-FMF,NCWSfemales,and8sex-andage-matched healthy subjects served as controls. We evaluated: 1. clinical symptoms by the FMF-specific AIDAI (Auto-Inflammatory Diseases Activity Index) score; 2. serum soluble CD14 (sCD14), C-reactive protein (CRP), and serum amyloid A (SSA); 3. circulating CD14+ monocytes expressing interleukin (IL)-1β and tumor necrosis factor (TNF)-α. The AIDAI score significantly increased in FMF patients during DBPC with wheat, but not with rice (19 ± 6.3 vs. 7 ± 1.6; p = 0.028). sCD14 values did not differ in FMF patients before and after the challenge, but were higher in FMF patients than in healthy controls (median values 11357 vs. 8710 pg/ml; p = 0.002). The percentage of circulating CD14+/IL-1β+ and of CD14+/TNF-α+ monocytes increased significantly after DBPC with wheat vs. baseline or rice challenge. Self-reported NCWS can hide an FMF diagnosis. Wheat ingestion exacerbated clinical and immunological features of FMF. Future studies performed on consecutive FMF patients recruited in centers for auto-inflammatory diseases will determine the real frequency and relevance of this association

TNF-α, IL-17 AND IL-22 PRODUCTION IN THE RECTAL MUCOSA OF NON-CELIAC WHEAT SENSITIVITY PATIENTS: ROLE OF ADAPTIVE IMMUNITY

In recent years, a new gluten- or wheat-related disease has emerged, a condition labelled "non-celiac gluten sensitivity" (NCGS) or "non-celiac wheat sensitivity" (NCWS). NCWS pathogenesis is still uncertain and attributed to very different mechanisms. We aimed to study the different T lymphocyte subsets in the rectal mucosa of NCWS patients, to demonstrate the possible contribution of adaptative immune response. Twelve patients (11 females, 1 male, age range 23-61 years, median 32) with a definitive diagnosis of NCWS were recruited at random for the present study. They underwent rectal endoscopy with multiple mucosal biopsies at the end of a double-blind placebo-controlled (DBPC) wheat challenge when they reported the reappearance of the symptoms. As controls we included 11 "healthy patients", sex- and age-matched with the patients, who underwent colonoscopy evaluation for rectal bleeding due to hemorrhoids. Cells freshly obtained from rectal tissue were stained to detect anti-CD45, anti-CD3, anti-CD4, and anti-CD8. Furthermore, intracellular staining was performed with anti-Tumor Necrosis Factor (TNF)-α, anti-interleukin (IL)-17, and anti-IL-22. Production of TNF-α by CD45+, CD3+, CD4+ and CD8+ cells, as well as of IL-17 by CD4+ cells, was higher in the rectal tissue of NCWS patients than in controls. On the contrary, IL-22 production by CD8+ cells was lower in NCWS patients than in the controls. In NCWS patients diagnosed by DBPC wheat challenge, there is a complex immunological activation, with a significant role for the adaptive response

T helper 1 response is correlated with widespread pain, fatigue, sleeping disorders and the quality of life in patients with fibromyalgia and is modulated by hyperbaric oxygen therapy

Hyperbaric oxygen therapy (HBOT) has been used as treatment for different clinical conditions, including fibromyalgia (FM). HBOT modulates brain activity, ameliorates chronic pain and modifies the ratio of immune cells. Clinical studies have provided evidence that FM is associated with immune system dysregulation. In the present study we aimed to evaluate the effect of HBOT on immune system and on the quality of life-style of FM patients