Imbalance of Th1/Th2 transcription factors in patients with lupus nephritis

Association of TBX21 gene haplotypes in a Chinese population with systemic lupus erythematosus

OBJECTIVE

T-cell-specific T-box transcription factor (T-bet) is a member of the T-box family of transcription factors regulating type 1 T-helper (Th1) cell development and is thought to be linked with several autoimmune diseases including systemic lupus erythematosus (SLE). The aim of this study was to evaluate whether T-bet gene (TBX21) polymorphisms or its haplotypes are associated with SLE in a Chinese population.

METHODS

The study included 248 cases with SLE and 261 gender- and age-matched healthy controls. The polymorphisms T-1993C (rs4794067) and T-1514C (rs17250932) in the TBX21 promoter were identified by a polymerase chain reaction-restriction fragment length polymorphism (PCR-RFLP) assay.

RESULTS

The frequency of both the -1993T and the -1514T allele were significantly higher in SLE patients than in controls. By haplotype analysis, there was significantly decreased frequency of the haplotype at positions -1993C/-1514C in the case group compared with the control group (p = 0.0002). Multifactorial logistic regression analysis showed that individuals with CC/CC haplotype homozygotes had a decreased susceptibility to SLE [p = 0.0004, odds ratio (OR) 0.316, 95% confidence interval (CI) 0.167-0.599].

CONCLUSION

Our results suggest that the -1993C/-1514C haplotype may be a protective factor for genetic susceptibility to SLE in the Chinese population.

Regulation and dysregulation of immunoglobulin E: a molecular and clinical perspective

BACKGROUND

Altered levels of Immunoglobulin E (IgE) represent a dysregulation of IgE synthesis and may be seen in a variety of immunological disorders. The object of this review is to summarize the historical and molecular aspects of IgE synthesis and the disorders associated with dysregulation of IgE production.

METHODS

Articles published in Medline/PubMed were searched with the keyword Immunoglobulin E and specific terms such as class switch recombination, deficiency and/or specific disease conditions (atopy, neoplasia, renal disease, myeloma, etc.). The selected papers included reviews, case reports, retrospective reviews and molecular mechanisms. Studies involving both sexes and all ages were included in the analysis.

RESULTS

Both very low and elevated levels of IgE may be seen in clinical practice. Major advancements have been made in our understanding of the molecular basis of IgE class switching including roles for T cells, cytokines and T regulatory (or Treg) cells in this process. Dysregulation of this process may result in either elevated IgE levels or IgE deficiency.

CONCLUSION

Evaluation of a patient with elevated IgE must involve a detailed differential diagnosis and consideration of various immunological and non-immunological disorders. The use of appropriate tests will allow the correct diagnosis to be made. This can often assist in the development of tailored treatments.

The gene expression of type 17 T-helper cell-related cytokines in the urinary sediment of patients with systemic lupus erythematosus

OBJECTIVE

We studied the role of type 17 Th cells (TH17) in the pathogenesis of SLE.

METHODS

We quantified the mRNA expression of IL-17, -23, -27 and retinoic-acid-related orphan receptor (ROR)-gamma, the regulator for the development and function of TH17, in the urinary sediment of 23 subjects with active lupus nephritis, 25 subjects with a history of lupus nephritis in remission, 30 SLE patients with no history of renal involvement and 8 healthy subjects.

RESULTS

All three groups of lupus patients had a higher urinary expression of TH17-related cytokines than the controls. However, urinary expression of IL-17 and -27 was found to be inversely correlated with the SLEDAI score (r = -0.252 and -0.258, respectively; P < 0.05 for both). For patients with active lupus nephritis, the histological activity index of kidney biopsy was also found to be inversely correlated with the urinary expression of ROR-gamma (r = -0.447; P = 0.032), IL-17 (r = -0.454; P = 0.029) and IL-23 (r = -0.455; P = 0.029). Urinary expression of IL-17, -23, -27 and ROR was also found to be inversely correlated with the urinary expression of IFN-gamma and T-bet, the key transcription factor of type 1 Th cells. After 6 months of treatment, urinary IL-27 expression rose significantly in patients with complete response (from 2.07 +/- 1.62 to 3.70 +/- 1.69; P = 0.028) but remained unchanged in those with partial or no response (from 2.60 +/- 1.87 to 2.52 +/- 1.94; P = 0.9).

CONCLUSIONS

The urinary expression of TH17-related genes is increased in SLE patients. The degree of up-regulation, however, is inversely related to systemic and renal lupus activity, as well as urinary expression of TH1-related genes. Urinary expression of TH17-related genes increased again after successful immunosuppressive treatment of active disease. Our findings suggest a regulatory role of TH17-related cytokines in pathogenesis of lupus nephritis.

Si-Ni-San, a traditional Chinese prescription, and its active ingredient glycyrrhizin ameliorate experimental colitis through regulating cytokine balance

Si-Ni-San, a traditional Chinese medicinal formula, exerts an important function in the treatment of inflammatory bowel diseases based upon thousands of years of clinical practice, but the underlying mechanism is still unclear. In this study, we investigated the therapeutic potential of Si-Ni-San and its ingredient glycyrrhizin in trinitrobenzene sulfonic acid (TNBS)-induced experimental colitis in mice, a well-characterized murine model for Crohn's disease. Si-Ni-San and glycyrrhizin significantly ameliorated TNBS-induced colitis with reduced mortality and recovery of body weights. In addition, Si-Ni-San and glycyrrhizin dose-dependently decreased macroscopic inflammation scores, microscopic histological scores, and myeloperoxidase activity. Furthermore, Si-Ni-San and glycyrrhizin caused a decrease in pro-inflammatory cytokines including IFN-gamma, IL-12, TNF-alpha and IL-17 and an increase in regulatory cytokine IL-10 in colon of the mice. It should be noticed the therapeutic effect of Si-Ni-San at 450 mg/kg was much better than that of its contained content of glycyrrhizin at 10 mg/kg. In conclusion, Si-Ni-San and glycyrrhizin significantly ameliorated TNBS-induced colitis in mice through regulating pro- and anti-inflammatory cytokine production.

Deconvolution of blood microarray data identifies cellular activation patterns in systemic lupus erythematosus

Systemic Lupus Erythematosus (SLE) is a systemic autoimmune disease with a complex spectrum of cellular and molecular characteristics including several dramatic changes in the populations of peripheral leukocytes. These changes include general leukopenia, activation of B and T cells, and maturation of granulocytes. The manifestation of SLE in peripheral blood is central to the disease but is incompletely understood. A technique for rigorously characterizing changes in mixed populations of cells, microarray expression deconvolution, has been applied to several areas of biology but not to SLE or to blood. Here we demonstrate that microarray expression deconvolution accurately quantifies the constituents of real blood samples and mixtures of immune-derived cell lines. We characterize a broad spectrum of peripheral leukocyte cell types and states in SLE to uncover novel patterns including: specific activation of NK and T helper lymphocytes, relationships of these patterns to each other, and correlations to clinical variables and measures. The expansion and activation of monocytes, NK cells, and T helper cells in SLE at least partly underlie this disease's prominent interferon signature. These and other patterns of leukocyte dynamics uncovered here correlate with disease severity and treatment, suggest potential new treatments, and extend our understanding of lupus pathology as a complex autoimmune disease involving many arms of the immune system.

No evidence for activation of T(H)1 or T(H)17 pathways in unstimulated peripheral blood mononuclear cells from children with β-cell autoimmunity or T1D

Introduction

The balance between T_H1, T_H2, T_H17, and regulatory T cells has been suggested to be disturbed in type 1 diabetes (T1D). We investigated this balance in peripheral blood mononuclear cells (PBMC) from children at risk of developing T1D and children with T1D.

Methods

We studied PBMC expression levels of markers related to T_H1 (T-bet, IL-12Rβ₁, IL-12Rβ₂), T_H2 (GATA-3, IL-4Rα), T_H17 (IL-17A), and regulatory T cells (Foxp3, ICOS, and CTLA-4) with real-time polymerase chain reaction from 17 children with T1D, 13 children with β-cell autoimmunity, 15 children with T1D risk-associated human leukocyte antigen (HLA) haplotypes, and 24 healthy, control children.

Results

We observed decreased expression levels of GATA-3 by PBMC of healthy children with autoantibodies compared to healthy, control children (p = 0.014) or children with HLA risk alleles (p = 0.032). Children with T1D demonstrated lower expression levels of T-bet, IL-12Rβ₁, and IL-4Rα both at diagnosis and 12 months later.

Conclusion

We found no indication of aberrant activation of T_H1, T_H17, or Treg in peripheral blood from children with or without risk of T1D. The observed immunological differences between children at risk of and with T1D should be considered when immunopathogenesis of β-cell destruction is studied.

Urinary exosomal transcription factors, a new class of biomarkers for renal disease

Urinary exosomes are excreted from all nephron segments and constitute a rich source of intracellular kidney injury biomarkers. To study whether they contain transcription factors, we collected urine from two acute kidney injury models (cisplatin or ischemia-reperfusion), two podocyte injury models (puromycin-treated rats or podocin-Vpr transgenic mice) and from patients with focal segmental glomerulosclerosis, acute kidney injury and matched controls. Exosomes were isolated by differential centrifugation and found to contain activating transcription factor 3 (ATF3) and Wilms Tumor 1 (WT-1) proteins detected by Western blot. These factors were found in the concentrated exosomal fraction, but not in whole urine. ATF3 was continuously present in urine exosomes of the rat models following acute injury at times earlier than the increase in serum creatinine. ATF3 was found in exosomes isolated from patients with acute kidney injury but not from patients with chronic kidney disease or controls. Urinary WT-1 was present in animal models before significant glomerular sclerosis and in 9/10 patients with focal segmental glomerulosclerosis but not in 8 controls. Our findings suggest that transcription factor ATF3 may provide a novel renal tubular cell biomarker for acute kidney injury while WT-1 may detect early podocyte injury. Measurement of urinary exosomal transcription factors may offer insight into cellular regulatory pathways.

Expression of mRNA for functional molecules in urinary sediment in glomerulonephritis

Recent studies have suggested that gene expression studies using urinary sediment might be a non-invasive approach to assessing activity and pathogenesis in glomerulonephritis. However, little information is available regarding the mRNA expression patterns of functional molecules, such as T-bet, GATA-3, FOXP3, and retinoic acid-inducible gene-I (RIG-I), in urinary sediment, from patients with immunocomplex-mediated glomerulonephritis. Fourteen lupus nephritis (LN) patients, 13 IgA nephropathy (IgAN) patients, and 12 healthy controls were enrolled in the study. The mRNA expressions of T-bet, GATA-3, FOXP3 and RIG-I in urinary sediment were measured using real time quantitative polymerase chain reaction. We also studied the expression of RIG-I in kidney tissue specimens obtained from LN and IgAN patients. Significant differences in the expression patterns of GATA-3, FOXP3 and RIG-I, and marginal differences in T-bet expression, were observed between the three study groups. Immunofluorescent staining for RIG-I was observed in the tissue specimens from the LN patients, but not in those from the IgAN patients. The mRNA expression patterns of T-bet, GATA-3, FOXP3 and RIG-I in urinary sediment differ according to diagnostic category. These results suggest that the measurement of these target gene expressions might be a useful, non-invasive method for clinical monitoring and studying of pathogenesis in glomerulonephritis.

T-bet deficiency attenuates renal injury in experimental crescentic glomerulonephritis

T-bet is a transcription factor that is essential for T helper (Th)1 lineage commitment and optimal IFN-gamma production by CD4(+) T cells. We examined the role of T-bet in the development of experimental crescentic glomerulonephritis, which is induced by Th1-predominant, delayed-type hypersensitivity-like responses directed against a nephritogenic antigen. Anti-glomerular basement membrane (GBM) glomerulonephritis was induced in T-bet(-/-) and wild-type C57BL/6 mice. Compared with wild-type controls, renal injury was attenuated in T-bet(-/-) mice with glomerulonephritis, evidenced by less proteinuria, glomerular crescents, and tubulointerstitial inflammation. Accumulation of glomerular CD4(+) T cells and macrophages was decreased, and was associated with reduced intrarenal expression of the potent Th1 chemoattractants CCL5/RANTES and CXCL9/Mig. Supporting the pro-inflammatory nature of T-bet signaling, assessment of systemic immunity confirmed that T-bet(-/-) mice had a reduction in Th1 immunity. The kinetic profile of T-bet mRNA in wild-type mice supported the hypothesis that T-bet deficiency attenuates renal injury in part by shifting the Th1/Th2 balance away from a Th1 phenotype. Expression of renal and splenic IL-17A, characteristically expressed by the Th17 subset of effector T cells, which have been implicated in the pathogenesis of autoimmune disease, was increased in T-bet(-/-) mice. We conclude that T-bet directs Th1 responses that induce renal injury in experimental crescentic glomerulonephritis.

Skin disease is prevented but nephritis is accelerated by multiple pregnancies in autoimmune MRL/LPR mice

The role of pregnancy in the progression of systemic lupus erythematosus (SLE) is still poorly understood. We analysed the effect of repeated pregnancies in MRL/lpr mice, a murine model of SLE. Seven-week old female mice were used: multiparous mice underwent three consecutive pregnancies (M); age-matched virgin mice served as controls (V). Animals were harvested at 20 weeks of age. Skin lesions were characterized by hair loss and scabs in the dorsum of the neck. Virgin skins showed thickened dermis, fibrosis and mononuclear cell infiltrates, which were practically absent in M. This was accompanied by higher IFN-gamma and lower IL-10 mRNA expression levels in V compared to M skin. Plasma IFN-gamma protein levels were also upregulated in V versus M. However, survival and kidney function were dramatically reduced and accompanied by hypertension after multiple pregnancies. Kidney histology also showed markedly increased renal lesions in M. In contrast to plasma and skin levels, both IL-10 and IFN-gamma mRNA were lower in the kidneys of V versus M mice. Concluding our findings, the pathomechanisms of lupus kidney and skin disease may be regulated differently at the organ level during pregnancy. Both IFN-gamma and IL-10 may be important regulatory cytokines at the local level.

Quantification of gene expression in urinary sediment for the study of renal diseases

Urinalysis has been used extensively in clinical practice to aid in the diagnosis of various renal diseases. With the advances in technology of molecular biology, gene expression and proteomic studies are now possible for urinary sediment. In this review article, we focus on the quantification of messenger RNA expression in urinary sediment by reverse-transcription and real-time quantitative polymerase chain reaction. Recently, this technique has been explored for three potential applications: (i) distinguishing the different causes of kidney disease; (ii) assessment of kidney disease activity, progression and response to therapy; and (iii) as a tool to study the pathogenesis. Although the method is simple and non-invasive, it requires further research to define the role in routine clinical practice. At this moment, the technique should only be considered experimental albeit promising.

Intrarenal cytokine gene expression in lupus nephritis

BACKGROUND

Lupus nephritis is characterised by intrarenal inflammation and lymphocyte activation.

AIM

To examine the profile of cytokine gene expression in glomerulus and tubulointerstitium in patients with lupus nephritis.

METHODS

36 consecutive patients with systemic lupus erythematosus having active renal disease were recruited, and they were required to undergo kidney biopsy. Glomerular and tubulointestitial cytokine expression of interleukin (IL)2, 4, 10, 12, 18, interferon gamma (IFN)gamma, T-bet (the Th1 transcription factor), GATA-3 (the Th2 transcription factor), transforming growth factor beta and monocyte chemoattractant protein (MCP)1 were studied by laser microdissection of the renal biopsy specimen, followed by real-time quantitative PCR.

RESULTS

There were 13 patients with World Health Organization class III nephritis, 14 patients with class IV nephritis and 9 patients with class V nephritis. There was a significant correlation between serum C3, C4 and anti-double strand DNA antibody level with glomerular expression of T-bet, IFNgamma and IL2. There was a significant correlation between histological activity index and glomerular expression of IL12, IL18, IL10 and MCP1. In addition, the degree of glomerular leucocyte infiltration significantly correlated with glomerular expression of IFNgamma, IL10, IL12 and IL18. By contrast, histological chronicity index correlated with the tubulointerstitial expression of IL2, MCP1 and GATA-3.

CONCLUSIONS

Intraglomerular expression of certain target genes correlate with the severity of systemic as well as histological activity, whereas the tubulointerstitial expression of other target genes correlate with the degree of chronic kidney scarring. This result may shed light on the immunopathogenesis of lupus nephritis.

Human Clinical Trials in Lupus Nephritis

Improved patient survival after treatment of lupus nephritis with corticosteroids, immunosuppressants, and renal replacement therapy allows greater emphasis on long-term management issues. In particular, the recent focus has been on therapies to treat nephritis with fewer adverse effects compared with cyclophosphamide and immunosuppressive regimens. Issues complicating clinical trial design in lupus nephritis have severely limited comparisons across trials. These issues, including recognition and stratification of high-risk populations, comparable remission and response criteria, and appropriate use and interpretation of activity and damage indices have been the subject of much discussion and emerging consensus. Mycophenolate mofetil (MMF) has been used in the field of transplantation for more than 10 years. After initial anecdotal reports describing the benefits of MMF in the treatment of lupus nephritis, randomized controlled trials have established a role for MMF in the treatment of lupus nephritis. A host of newer agents including rituximab, abatacept, and monoclonal antibodies blocking costimulatory targets are in current clinical trials for lupus nephritis. As long-term outcomes in lupus nephritis improve, the toxicity of therapy and risk of relapse become increasingly important determinants of the choice of therapeutic agents.