Roles of interleukin-21 and its receptor in autoimmune diseases / 中国当代儿科杂志

Interleukin-21 (IL-21) is a new member of the interleukin-2 family. It is mainly synthesized and secreted by the activated of CD4(+) T cells and natural killer T cells. IL-21 receptor (IL-21R) is mainly expressed in T cells, B cells, and natural killer (NK) cells. After binding to its receptor, IL-21 can regulate the activation and proliferation of T cells, B cells, and NK cells through activating JAKs-STATs signaling pathways. As a new immunoregulatory factor, IL-21 and its receptor play important roles in the development and progression of various autoimmune diseases. Regulation of the expression levels of IL-21 and IL-21R and blocking of their signal transduction pathways with blockers may be new treatment options for autoimmune diseases.

Interleukin-21 Receptor Gene Polymorphisms in Kawasaki Disease

BACKGROUND AND OBJECTIVES: Interleukin-21 receptor (IL-21R) gene polymorphism is related with the development of systemic vasculitis. In this study, we investigated the polymorphisms of IL-21R gene in patients with Kawasaki disease (KD). SUBJECTS AND METHODS: We genotyped the promoter region of IL-21R gene (-2500 bp to +1 bp) in 100 patients with KD and 100 healthy controls. All study subjects were Korean. We designed five pairs of primers and performed polymerase chain reaction (PCR) and direct sequencing. We analyzed whole promoter sequences of 200 individuals with comparison to reference sequences of IL-21R gene (NG_012222.1/NC_000016.9). RESULTS: We found five single nucleotide polymorphisms (SNPs) of which minor allele frequency (MAF) >0.01 in the promoter region of IL-21R gene. Those are -1681 G>T (chromosome site 27411802), -379 G>A (27413104), -332 G>C (27413151, rs2214537), -237 A>T (27413246), and -53 G>A (27413430). There is no significant difference in MAF of each SNP between patients with KD and healthy controls except -237 A>T. Twenty five patients with KD had more than 1 SNP in contrast to only seven healthy controls had. The patients with KD have significantly more IL-21R gene polymorphisms than controls (odds ratio: 3.0, 95% confidence interval: 1.6-5.6, p=0.0005). There was no significant correlation between IL-21R gene polymorphisms and the serum level of IL-21. The serum level of total IgE was not significantly correlated with the presence of IL-21R gene polymorphisms. CONCLUSION: Our data suggest that the genetic susceptibility profile for KD may include IL-21R gene.

Effects of humanized interleukin 21 on anti-leukemic activity of cytokine induced killer cells and the mechanism / 中华血液学杂志

<p><b>OBJECTIVE</b>To explore the effects of humanized interleukin 21 (IL-21) on anti-leukemic activity of cytokine induced killer(CIK) cells derived from peripheral blood(PB) and the mechanism.</p><p><b>METHODS</b>Mononuclear cells were separated from peripheral blood and cultured with cytokines to induce CIK cells. Proliferation of CIK cells with or without IL-21 stimulation and their cytotoxic activity against K562 cells was measured by MTT method. IL-21 receptor (IL-21R) and immunophenotypes of CIK cells were measured by flow cytometry. The expression of interferon-γ (IFN-γ), tumor necrosis factor-α (TNF-α), tumor necrosis factor-β (TNF-β), perforin, granzyme A, granzyme B, FasL and NKG2D mRNA were measured by semi-quantitative RT-PCR. FasL on the surface of CIK cells and intra-cellular perforin and granzyme B of CIK cells were measured by flow cytometry. The concentration of IFN-γ and TNF-α in the cultured supernatant were measured by enzyme immunoassay. JAK-STAT signalling pathway of CIK cells were measured by Western-blot.</p><p><b>RESULTS</b>After IL-21 stimulation, the proportion of CIK cells increased from (17.5 ± 4.7)% to (26.5 ± 2.1)%. Cytotoxic activity against K562 cells by CIK cells increased from (22.8 ± 2.8)% to(44.6 ± 8.3)%. The expression of IL-21R increased about 2 folds. The mRNA expression of IFN-γ increased almost 2 folds from (0.3760 ± 0.2358) to (0.7786 ± 0.2493), TNF-α increased almost 2 folds from (0.6557 ± 0.1598) to (1.3145 ± 0.2136), perforin increased almost 1.5 folds from (0.6361 ± 0.1457) to (0.9831 ± 0.1265), granzyme B increased almost 2 folds from (0.4084 ± 0.1589) to (0.7319 ± 0.1639), FasL increased almost 2 folds from (0.4015 ± 0.2842) to (0.7381 ± 0.2568), the expression of granzyme A, TNF-β and NKG2D were similar with control. Flow cytometry analysis showed that the expression of FasL of CIK cells was higher than that of control (0.19% vs 0.04%), the expression of perforin increased from 35.28% to 53.16%, and the expression of granzyme B increased from 43.16% to 78.82%. The concentration of IFN-γ in the culture supernatant increased almost 2 folds from (25.8 ± 6.1) ng/L to (56.0 ± 2.3) ng/L, and TNF-α increased almost 3 folds from (5.64 ± 0.61) µg/L to (15.14 ± 0.93) µg/L. Western blot showed that the expression of STAT1 and STAT5a had no significant differences, but the expression of STAT3 and STAT5b were higher than that of control.</p><p><b>CONCLUSION</b>Humanized IL-21 could enhance the anti-leukemic activity of CIK cells via increasing IL-21R, perforin, granzyme B, FasL, IFN-γ and TNF-α, as well as activating JAK-STAT signaling pathway. These data indicate that IL-21 has a potential clinical value in the enhancement of anti-leukemic immunotherapy.</p>

Integrated Analysis of MicroRNA and mRNA Expression Profiles in Rheumatoid Arthritis Synovial Monocytes

OBJECTIVE: MicroRNAs (miRNAs) play important roles in many biological processes and recent studies have provided growing evidences that miRNA dysregulation might play important roles in the pathogenesis of rheumatoid arthritis (RA). The aim of this study was to investigate the contribution of miRNAs to altered gene expressions in RA. METHODS: To investigate whether the differential expression of miRNA in RA could account for the altered expression of certain genes, we compared the different expressions of miRNAs and mRNAs in rheumatoid synovial fluid monocytes with that of normal peripheral blood (PB) monocytes by using a gene expression oligonucleotide microarray and a microRNA microarray. RESULTS: Comparative analysis of the mRNA profiles showed significant different expressions of 430 genes in RA synovial monocytes, of which 303 (70%) were upregulated and 127 (30%) were downregulated, as compared with that of normal PB monocytes. Out of differentially expressed 13 miRNAs, 9 miRNAs were upregulated and 4 miRNAs were downregulated in the RA synovial monocytes. A total of 62 genes were predicted as target genes of the 13 differentially expressed miRNAs in the RA synovial monocytes. Among the 62 miRNA-targeted genes, a few genes such as GSTM1, VIPR1, PADI4, CDA, IL21R, CCL5, IL7R, STAT4, HTRA1 and IL18BP have been reported to be associated with RA. CONCLUSION: In the present study, we observed that several miRNAs are differentially expressed in RA synovial monocytes, and we suggest that these different expressions of miRNAs may regulate the expression of several genes associated with the pathogenesis of RA.

Expression of IL-21 in the peripheral blood of myasthenia gravis patients and its correlation with anti-AChR-Ab class switch / 中南大学学报(医学版)

OBJECTIVE@#To explore the role of IL-21 in the pathogenesis of myasthenia gravis (MG) and its influence on the the class switch of anti-AChR antibodies.@*METHODS@#Blood was taken from 26 patients and 18 healthy controls, and the expression of IL-21R mRNA in peripheral blood mononuclear cells (PBMCs) was detected by RT-PCR. The expression of IL-21R on B lymphocytes was measured by flow cytometry, while the concentrations of serum IL-21 and the levels of anti-AChR-IgG and its isotype IgG(1), IgG(2), and IgG(3) were tested by ELISA.@*RESULTS@#The serum concentration of IL-21 in the MG group was higher than that in the control group (31.686±8.499 pg/mL, 15.147±6.366 pg/mL) and the difference was significant (P0.05). Compared with the control group, the expression of IL-21R on B lymphocytes also increased in the MG group (P0.05). Expression of IL-21R mRNA in the PBMCs showed no correlation with the level of serum anti-AChR-IgG and its isotype IgG(1), IgG(2), and IgG(3), respectively(P>0.05); however the expression of IL-21R in B lymphocytes showed positive correlation with anti-AChR-IgG and it's isotype IgG(1) and IgG(3) (P0.05).@*CONCLUSION@#IL-21 might induce the class switch of anti-AChR antibodies to IgG(1) and IgG(3) isotype through IL-21R on B lymphocytes which promotes the pathogenesis of the MG.