Amino-bisphosphonates, γδT cells, and their roles in Rheumatoid Arthritis

Immunoproteasome inhibition attenuates experimental psoriasis

Introduction

Psoriasis is an autoimmune skin disease associated with multiple comorbidities. The immunoproteasome is a special form of the proteasome expressed in cells of hematopoietic origin.

Methods

The therapeutic use of ONX 0914, a selective inhibitor of the immunoproteasome, was investigated in Card14ΔE138+/- mice, which spontaneously develop psoriasis-like symptoms, and in the imiquimod murine model.

Results

In both models, treatment with ONX 0914 significantly reduced skin thickness, inflammation scores, and pathological lesions in the analyzed skin tissue. Furthermore, immunoproteasome inhibition normalized the expression of several pro-inflammatory genes in the ear and significantly reduced the inflammatory infiltrate, accompanied by a significant alteration in the αβ+ and γδ+ T cell subsets.

Discussion

ONX 0914 ameliorated psoriasis-like symptoms in two different murine psoriasis models, which supports the use of immunoproteasome inhibitors as a therapeutic treatment in psoriasis.

Gamma Delta T Cells and Their Pathogenic Role in Psoriasis

γδT cells are an unconventional population of T lymphocytes that play an indispensable role in host defense, immune surveillance, and homeostasis of the immune system. They display unique developmental, distributional, and functional patterns and rapidly respond to various insults and contribute to diverse diseases. Although γδT cells make up only a small portion of the total T cell pool, emerging evidence suggest that aberrantly activated γδT cells may play a role in the pathogenesis of psoriasis. Dermal γδT cells are the major IL-17-producing cells in the skin that respond to IL-23 stimulation. Furthermore, γδT cells exhibit memory-cell-like characteristics that mediate repeated episodes of psoriatic inflammation. This review discusses the differentiation, development, distribution, and biological function of γδT cells and the mechanisms by which they contribute to psoriasis. Potential therapeutic approaches targeting these cells in psoriasis have also been detailed.

Autoimmune diseases in China

Autoimmune diseases, such as rheumatoid arthritis, systematic lupus erythematosus and Sjögren's syndrome, are a group of diseases characterized by the activation of immune cells and excessive production of autoantibodies. Although the pathogenesis of these diseases is still not completely understood, studies have shown that multiple factors including genetics, environment and immune responses play important roles in the development and progression of the diseases. In China, there are great achievements in the mechanisms of autoimmune diseases during the last decades. These studies provide new insight to understand the diseases and also shed light on the development of novel therapy.

[Expression of gamma-delta T cells in immune microenvironment in children with Henoch-Schönlein purpura]

OBJECTIVE

To study the role of gamma-delta T (γδ T) cells and its subsets in the immunopathogenesis of Henoch-Schönlein purpura (HSP) in children, and to provide new ideas for the treatment of HSP in children from the aspect of γδ T cell regulation.

METHODS

A total of 33 children with HSP were enrolled as the HSP group, and 21 healthy children were enrolled as the healthy control group. The percentages of γδ T cells and its subsets Vδ1⁺ T and Vδ2⁺ T cells among peripheral blood mononuclear cells (PBMCs) were measured, as well as the apoptosis rate of γδ T cell and plasma level of interleukin-17 (IL-17).

RESULTS

Compared with the healthy control group, the HSP group had significantly lower percentages of lymphocytes in PBMCs and Vδ2⁺ T cells in γδ T cells (P<0.05). The HSP group had significantly higher percentage of Vδ1⁺ T cells in γδ T cells and plasma level of IL-17 than the healthy control group. The HSP group had a significantly higher overall apoptosis rate of γδ T cells than the healthy control group (P<0.05), especially early apoptosis. The percentage of Vδ2⁺ T cells was positively correlated with overall apoptosis rate (r_s=0.615, P<0.05) and was negatively correlated with IL-17 level (r_s=-0.398, P<0.05).

CONCLUSIONS

Vδ1⁺/Vδ2⁺ T cell immune imbalance mediated by γδ T cells and over-activation of IL-17 may be involved in the development of HSP, among which the disturbance of immune tolerance induced by Vδ2⁺ T cells plays an important role in the pathophysiology of the disease.