Interleukin-35 in immune-related diseases: protection or destruction

Increased Interleukin-35 suppresses peripheral CD14+ monocytes function in patients with Kawasaki disease

Background

Interleukin-35 (IL-35) is a newly identified IL-12 cytokine family member, which regulates the activity of immune cells in infectious diseases and autoimmune disorders. However, the regulatory function of IL-35 in Kawasaki disease is not well elucidated.

Methods

Thirty-three patients with Kawasaki disease and seventeen healthy controls were studied. Peripheral IL-35 concentration was measured by enzyme linked immunosorbent assay. CD14⁺ monocytes were purified, and mRNA expression of IL-35 receptor (IL-12Rβ2 and gp130) was semi-quantified by real-time polymerase chain reaction. CD14⁺ monocytes were stimulated with recombinant IL-35. The modulatory role of IL-35 treated CD14⁺ monocytes to naïve CD4⁺ T cell activation was investigated by flow cytometry. The influence of IL-35 to cytotoxicity of CD14⁺ monocytes was assessed by measuring target cell death, cytokine and granzyme secretion.

Results

Plasma IL-35 concentration was elevated in patients with Kawasaki disease. There was no significant differences of either IL-12Rβ2 or gp130 mRNA expression in CD14⁺ monocytes between Kawasaki disease patients and controls. IL-35 suppressed CD14⁺ monocytes induced naïve CD4⁺ T cell activation in Kawasaki disease, and this process required direct cell-to-cell contact. IL-35 also inhibited tumor necrosis factor-α and granzyme B secretion by CD14⁺ monocytes from patients with Kawasaki disease, however, only granzyme B was responsible for the cytotoxicity of CD14⁺ monocytes.

Conclusions

IL-35 played an important immunosuppressive role to CD14⁺ monocytes function in Kawasaki disease.

Correlation between miR-223 and IL-35 and their regulatory effect in children with allergic rhinitis

The relationship between microRNA (miR) and immune activity in allergic rhinitis (AR) remains unclear. 37 children with AR and 30 healthy children were enrolled to study the correlation of miR-223 and IL-35. There was a significant inverse correlation between plasma levels of IL-35 and serum eosinophil cationic protein (ECP) levels and eosinophils counts, while there was a positive correlation between serum miR-223 level and ECP levels and eosinophils counts. Besides, the serum levels of IL-35 or miR-223 were found to be negatively or positively correlated with TNSS respectively. The serum level of miR-223 was increased, while IL-35 level was decreased. Moreover, the expression of miRNA-223 was inversely correlated with expression of IL-35. Finally, the levels of miR-223 and IL-35 were related to Th1/Th2 cytokines, eosinophils count as well as the clinical severity. Our study suggests the potential of miR-223 and IL-35 as a molecular target for the treatment of AR.

Future prospects for CD8+ regulatory T cells in immune tolerance

CD8⁺ Tregs have been long described and significant progresses have been made about their phenotype, their functional mechanisms, and their suppressive ability compared to conventional CD4⁺ Tregs. They are now at the dawn of their clinical use. In this review, we will summarize their phenotypic characteristics, their mechanisms of action, the similarities, differences and synergies between CD8⁺ and CD4⁺ Tregs, and we will discuss the biology, development and induction of CD8⁺ Tregs, their manufacturing for clinical use, considering open questions/uncertainties and future technically accessible improvements notably through genetic modifications.