Interleukin 1, interleukin 6, interleukin 10, and tumor necrosis factor α in active and quiescent systemic lupus erythematosus

Cytokines in Systemic Lupus Erythematosus-Focus on TNF-α and IL-17

Systemic lupus erythematosus (SLE) is an autoimmune disorder known for its complex pathogenesis, in which cytokines play an essential role. It seems that the modulation of these cytokines may impact disease progression, being considered potential biomarkers. Thus, TNF (tumor necrosis factor)-α and IL (interleukin)-17 are molecules of great interest in SLE. TNF-α plays a dual role in SLE, with both immunosuppressive and proinflammatory functions. The role of IL-17 is clearly described in the pathogenesis of SLE, having a close association with IL-23 in stimulating the inflammatory response and consecutive tissue destruction. It appears that patients with elevated levels of these cytokines are associated with high disease activity expressed by the SLE disease activity index (SLEDAI) score, although some studies do not confirm this association. However, TNF-α and IL-17 are found in increased titers in lupus patients compared to the general population. Whether inhibition of these cytokines would lead to effective treatment is under discussion. In the case of anti-TNF-α therapies in SLE, the possibility of ATIL (anti-TNF-induced lupus) is a serious concern that limits their use. The use of anti-IL-17 therapies in SLE is a promising option, but not yet approved. Future studies of these cytokines in large cohorts will provide valuable information for the management of SLE.

The P2X7 Receptor in Autoimmunity

The P2X7 receptor (P2X7R) is an ATP-gated nonselective cationic channel that, upon intense stimulation, can progress to the opening of a pore permeable to molecules up to 900 Da. Apart from its broad expression in cells of the innate and adaptive immune systems, it is expressed in multiple cell types in different tissues. The dual gating property of P2X7R is instrumental in determining cellular responses, which depend on the expression level of the receptor, timing of stimulation, and microenvironmental cues, thus often complicating the interpretation of experimental data in comprehensive settings. Here we review the existing literature on P2X7R activity in autoimmunity, pinpointing the different functions in cells involved in the immunopathological processes that can make it difficult to model as a druggable target.

Immunoprofiling of cytokines, chemokines, and growth factors in female patients with systemic lupus erythematosus- a pilot study

Systemic Lupus Erythematosus (SLE) is a chronic autoimmune disease affecting different organ systems. This study aimed to determine the concentrations of 30 different human cytokines, chemokines, and growth factors in human plasma to understand the role of these markers in the pathogenicity of SLE using Luminex Multiple Analyte Profiling (xMAP) technology. Plasma samples were obtained from patients with SLE (n = 28), osteoarthritis (OA) (n = 9), and healthy individuals (n = 12) were obtained. High levels of TNF, IL-6, IFN-γ, INF-α, IL-4, IL-5, IL-13, IL-8, IP-10, MIG, MCP-1, MIP-1β, GM-CSF, G-CSF, EGF, VEGF, IL-12, IL-1RA, and IL-10 was detected in SLE patients compared with the OA and healthy control groups. xMAP analysis has been used to address the differential regulation of clinical heterogeneity and immunological phenotypes in SLE patients. In addition, complete disease phenotyping information along with cytokine immune profiles would be useful for developing personalized treatments for patients with SLE.

Increased Serum Interleukin 10 Levels Are Associated with Increased Disease Activity and Increased Risk of Anti-SS-A/Ro Antibody Positivity in Patients with Systemic Lupus Erythematosus

Interleukin 10 (IL-10) plays a role in inflammation and cell-type responses. The anti-SS-A/Ro antibody contributes to leucopenia, and cutaneous and neonatal lupus.

OBJECTIVES

To evaluate the association between serum IL-10 levels and autoantibodies, disease activity and organ involvement in systemic lupus erythematosus (SLE) patients.

PATIENTS AND METHODS

We studied 200 SLE patients and 50 controls. We analyzed organ involvement, disease activity, serum IL-10 and interleukin-6 (IL-6) levels, and antinuclear and antiphospholipid antibody profiles.

RESULTS

Serum IL-10 and IL-6 levels were higher in SLE patients than in controls (all p < 0.00001). Serum IL-10 levels were positively correlated with IL-6 (p < 0.00001), CRP (p < 0.00001), fibrinogen (p = 0.003), and ESR (p < 0.00001), and negatively correlated with hemoglobin (p = 0.0004) and lymphocytes (p = 0.01). Serum IL-6 levels were positively correlated with CRP (p < 0.00001), fibrinogen (p = 0.001), and ESR (p < 0.00001); and negatively correlated with hemoglobin (p = 0.008) and lymphocytes (p = 0.03). Elevated serum IL-10 levels were associated with an increased risk of anti-SS-A/Ro antibody positivity (p = 0.03). Elevated serum IL-6 levels were associated with an increased risk of heart (p = 0.007) and lung (p = 0.04) involvement.

CONCLUSIONS

In SLE patients, increased serum IL-10 levels were associated with increased disease activity and risk of anti-SS-A/Ro antibody positivity.

Altered PTPN22 and IL10 mRNA Expression Is Associated with Disease Activity and Renal Involvement in Systemic Lupus Erythematosus

Systemic lupus erythematosus (SLE) is a complex autoimmune disease with very heterogeneous clinical behavior between affected individuals. Therefore, the search for biomarkers clinically useful for the diagnosis, prognosis, and monitoring of the disease is necessary. Here, we determined the association between PTPN22, IL10, OAS2, and CD70 mRNA expression with the clinical characteristics and with the serum levels of IL-10, IFN-γ, and IL-17 in SLE patients. Forty patients with SLE and 34 control subjects (CS) were included, mRNA expression was determined by real-time qPCR and cytokine levels were quantified by a multiplex bead-based immunoassay. Compared to CS, SLE patients showed increased IL10 mRNA and high IL-10 and IL-17 serum levels; in contrast, PTPN22 mRNA and IFN-γ were decreased. PTPN22 and IL10 gene expression was negatively correlated with Mex-SLEDAI score and were notably downregulated in SLE patients with lupus nephritis. Interestingly, SLE patients with renal damage were the ones with the lowest levels of PTPN22 and IL10 mRNA and the highest SLEDAI scores. No associations were observed for OAS2 and CD70 mRNA and IL-10, IL-17, and IFN-γ. In conclusion, we suggest that the assessment of IL10 and PTPN22 mRNA could be useful for monitoring disease activity in SLE patients showing renal involvement.

Cytokines as Biomarkers in Systemic Lupus Erythematosus: Value for Diagnosis and Drug Therapy

Systemic Lupus Erythematosus (SLE) is a chronic autoimmune disease. The disease is characterized by activation and dysregulation of both the innate and the adaptive immune systems. The autoimmune response targets self-molecules including cell nuclei, double stranded DNA and other intra and extracellular structures. Multiple susceptibility genes within the immune system have been identified, as well as disturbances in different immune pathways. SLE may affect different organs and organ systems, and organ involvement is diverse among individuals. A universal understanding of pathophysiological mechanism of the disease, as well as directed therapies, are still missing. Cytokines are immunomodulating molecules produced by cells of the immune system. Interferons (IFNs) are a broad group of cytokines, primarily produced by the innate immune system. The IFN system has been observed to be dysregulated in SLE, and therefore IFNs have been extensively studied with a hope to understand the disease mechanisms and identify novel targeted therapies. In several autoimmune diseases identification and subsequent blockade of specific cytokines has led to successful therapies, for example tumor necrosis factor-alpha (TNF-α) inhibition in rheumatoid arthritis. Authors of this review have sought corresponding developments in SLE. In the current review, we cover the actual knowledge on IFNs and other studied cytokines as biomarkers and treatment targets in SLE.

Systemic lupus erythematosus is associated with impaired autophagic degradation via interleukin-6 in macrophages

Systemic lupus erythematosus (SLE) is an autoimmune disease associated with dysregulated interleukin (IL)-6 and autophagy. Although such disturbances are increasingly recognized in patients with SLE and animal models of the disease, little is known about the specific role of IL-6 and autophagy in SLE macrophages. Here, we investigated alterations in the IL-6 axis and autophagy in macrophages derived from patients with SLE and determined whether IL-6 modulates autophagy using human macrophage models. Serum IL-6 detected by ELISA was higher in SLE patients (n = 19) than in normal controls (n = 19, p < 0.001). Levels of the IL-6 receptor (IL-6R) and autophagic markers LC3B and p62 in SLE and normal macrophages were assessed by real-time PCR, western blotting, and immunofluorescence. Compared with normal macrophages, SLE macrophages not only overexpressed IL-6Rs but also exhibited impaired autophagic degradation as evidenced by elevated levels of LC3B and p62. In vitro analyses using macrophage models revealed that prolonged exposure to exogenous recombinant human IL-6 induced a marked impairment of autophagic degradation indicated by elevated levels of LC3B and p62 in both primary macrophages and transformed macrophages. Pretreatment with tocilizumab, a humanized anti-IL-6R monoclonal antibody, restored autophagic degradation and reversed p62 accumulation in a paracrine manner in macrophages. These findings demonstrate that SLE involves IL-6-induced impairment of autophagic degradation through augmentation of IL-6R in human macrophages.

Systemic Lupus Erythematosus Activity Affects the Sinusoidal Uptake Transporter OATP1B1 Evaluated by the Pharmacokinetics of Atorvastatin

The present study assessed the effect of systemic lupus erythematosus (SLE) activity, a chronic and inflammatory autoimmune disease, on the sinusoidal uptake transporter OATP1B1 using atorvastatin (ATV) as a probe drug. Fifteen healthy subjects, 13 patients with controlled SLE (SLEDAI 0-4), and 12 patients with uncontrolled SLE (SLEDAI from 6 to 15), all women, were investigated. Apparent total clearance of midazolam (MDZ), a marker of CYP3A4 activity, did not vary among the three investigated groups. The controlled and uncontrolled SLE groups showed higher plasma concentrations of MCP-1 and TNF-α, while the uncontrolled SLE group also showed higher plasma concentrations of IL-10. The uncontrolled SLE group showed higher area under the curve (AUC) for ATV (60.47 (43.76-83.56) vs. 30.56 (22.69-41.15) ng⋅hour/mL) and its inactive metabolite ATV-lactone (98.74 (74.31-131.20) vs. 49.21 (34.89-69.42) ng⋅hour/mL), and lower apparent total clearance (330.7 (239.30-457.00) vs. 654.5 (486.00-881.4) L/hour) and apparent volume of distribution (2,609 (1,607-4,234) vs. 7,159 (4,904-10,450) L), when compared to the healthy subjects group (geometric mean and 95% confidence interval). The pharmacokinetics of ATV and its metabolites did not differ between the healthy subject group and the patients with controlled SLE group. In conclusion, uncontrolled SLE increased the systemic exposure to both ATV and ATV-lactone, inferring inhibition of OATP1B1 activity, once in vivo CYP3A4 activity assessed by oral clearance of MDZ was unaltered. The inflammatory state, not the disease itself, was responsible for the changes described in the uncontrolled SLE group as a consequence of inhibition of OATP1B1, because systemic exposure to ATV and its metabolites were not altered in patients with controlled SLE.

Anti-atopic dermatitis effects of hydrolyzed celery extract in mice

This study investigated the ameliorative effects of acid hydrolyzed celery extract (HCE) and celery extract (CE) in an atopic dermatitis (AD) mice model. The results of the study showed that HCE, more than CE improved AD-like skin lesions caused by fluoro-2,4-dinitrobenzene and house dust mite antigen administration. Further analysis also showed the dominance of HCE than CE in preventing mast cell infiltration in the dermis; inhibiting the IL-31 expression in mice skin and reducing the immunoglobulin-E, IL-4, IL-5, TNF-α, IFN-γ, IL-31, and TSLP in serum of mice. Using in vitro studies in a murine macrophage cell line, we showed that apigetrin, luteolin, and apigenin present in both extracts could be accountable for the observed effects as these three compounds and not apiin prevented the nitric oxide production in the murine macrophage. Based on this study, we suggest that hydrolyzing celery extracts can improve the therapeutic efficacy of celery extracts for management of AD. PRACTICAL APPLICATIONS: Apigenin, apigetrin, and luteolin are known biologically active compounds present in celery. Acid hydrolysis could increase the biologically active compounds in natural products. The research investigated the effects of acid HCE in a mice model of atopic dermatitis. The data obtained from this study sheds light on the use of hydrolysis methods to improve the biological activities of plant extracts used in nutraceutical industries.

IL-1 Transcriptional Responses to Lipopolysaccharides Are Regulated by a Complex of RNA Binding Proteins

The IL1A and IL1B genes lie in close proximity on chromosome 2 near the gene for their natural inhibitor, IL1RN Despite diverse functions, they are all three inducible through TLR4 signaling but with distinct kinetics. This study analyzed transcriptional induction kinetics, chromosome looping, and enhancer RNA production to understand the distinct regulation of these three genes in human cells. IL1A, IL1B, and IL1RN were rapidly induced after stimulation with LPS; however, IL1B mRNA production was less inhibitable by iBET151, suggesting it does not use pause-release regulation. Surprisingly, chromatin looping contacts between IL1A and IL1B were highly intermingled, although those of IL1RN were distinct, and we focused on comparing IL1A and IL1B transcriptional pathways. Our studies demonstrated that enhancer RNAs were produced from a subset of the regulatory regions, that they were critical for production of the mRNAs, and that they bound a diverse array of RNA binding proteins, including p300 but not CBP. We, furthermore, demonstrated that recruitment of p300 was dependent on MAPKs. Integrator is another RNA binding protein recruited to the promoters and enhancers, and its recruitment was more dependent on NF-κB than MAPKs. We found that integrator and NELF, an RNA polymerase II pausing protein, were associated with RNA in a manner that facilitated interaction. We conclude that IL1A and IL1B share many regulatory contacts, signaling pathways, and interactions with enhancer RNAs. A complex of protein interactions with enhancer RNAs emphasize the role of enhancer RNAs and the overall structural aspects of transcriptional regulation.

P2X7 Receptor Expression in Patients With Serositis Related to Systemic Lupus Erythematosus

Introduction: P2X7R is an extracellular ATP-gated receptor involved in inflammatory and autoimmune processes mainly acting through NLPR3-inflammasome activation and IL-1β release, also implicated in lymphocyte proliferation and cellular apoptosis. Several observations from animal models and patients’ studies highlight a possible link between P2X7R-NLRP3 axis and Systemic Lupus Erythematosus (SLE) pathogenesis. The P2X7R-inflammasome axis in addition to the direct production of IL-1β and IL-18, indirectly mediates the release of other cytokines implicated in the pathogenesis of SLE, such as IL-6. The aim of this study was to investigate the role of P2X7R and NLRP3-inflammasome in SLE.

Methods: Forty-eight SLE patients, 16 with (SLE-S) and 32 without (SLE-NS) history of serositis, and 20 healthy control (HC) subjects were enrolled. Demographic, clinical, and therapeutic data were collected. IL-1β and IL-6 plasma levels were evaluated by ELISA. Peripheral blood mononuclear cells (PBMCs) were isolated from venous blood by Ficoll gradient sedimentation and employed as follows: (1) evaluation of P2X7R and NLRP3 expression by RT-PCR; (2) determination of P2X7R activity as Benzoyl ATP (BzATP)-induced [Ca²⁺]_i increments using Fura-2-AM fluorescent probe; (3) isolation of monocytes/macrophages and assessment of in vitro IL-1β and IL-6 release following stimulation with lipopolysaccharide (LPS) and BzATP, either separately or in combination.

Results: Plasma IL-1β levels were unmodified in SLE respect to HC whereas IL-6 levels were higher in SLE than in HC, resulting significantly increased in SLE-S. Macrophages isolated from SLE patients released lower quantities of IL-1β after stimulation with BzATP, whereas IL-6 release was significantly augmented in SLE-NS respect to both HC and SLE-S after all types of stimulation. The [Ca²⁺]i increase following BzATP stimulation was significantly lower in PBMCs from SLE patients than in PBMCs from HC. RT-PCR showed significantly reduced P2X7R and significantly augmented NLRP3 expression in PBMCs from SLE patients.

Conclusion: Our data indicate reduced P2X7R expression and function in SLE patients compared with HC and, conversely, increased IL-6 signaling. The possible consequences of reduced P2X7R, mainly on cytokines network deregulation and lymphocyte proliferation, will be further investigated as well as the role of IL-6 as a possible therapeutic target especially in lupus serositis.

ATP signaling and NTPDase in Systemic Lupus Erythematosus (SLE)

Systemic lupus erythematosus (SLE) is an autoimmune and inflammatory disease with periods of exacerbation and remission. SLE is characterized by the irreversible breakdown of immunological self-tolerance, where there is deregulation of multiple aspects of the immune system. SLE immune dysfunction is characterized by activation of autoreactive T lymphocytes, and hyperactivity of B lymphocytes with consequent production of several autoantibodies. ATP is a purinergic mediator released into the extracellular space in response to cell and tissue damage which operates as a danger signal to modulate immune and inflammatory responses. ATP binds to P2 receptors and its levels are regulated by NTPDase (CD39). SLE patients exhibit increased levels of ATP which binds to P2X receptors resulting in activation of the inflammasome and consequent release of IL-1β and IL-18, cytokines associated with disease pathogenesis. CD39 is upregulated in SLE representing an important immunoregulatory mechanism by controlling inflammation and favoring the production of adenosine. The aim of this review is to clarify the effects of ATP on the modulation of the inflammatory process and immune responses via P2 receptors as well as the role of NTPDase in the immunopathogenesis of SLE.

Principal component analysis reveals disconnect between regulatory cytokines and disease activity in Systemic Lupus Erythematosus

OBJECTIVE

Cytokine dysregulation contributes to inflammation and organ damage in Systemic Lupus Erythematosus (SLE). Principle Component Analysis (PCA) can determine which groups of cytokines have the most influence across disease activity states.

MATERIAL AND METHOD

A cross-sectional study of age- and gender-matched SLE patients (n = 100) and controls (n = 31). SLE patients had a median Systemic Lupus Erythematosus Disease Activity Index - 2000 (SLEDAI-2K) score of 6 (IQR 2, 11). IFN-γ, interleukin (IL)-1β, IL-4, IL-6, IL-10, IL-12, IL-17, BAFF, TNF-α, TGF-β1, MIP-1α, MIP-1β and MCP-1 levels were quantified by sandwich ELISA, and compared non-parametrically between groups. PCA was used to determine the principal components across controls, SLE patients in states of remission (SLEDAI-2K = 0), low disease activity (LDA = SLEDAI-2K from 1 ≤ x ≤ 4) or high disease activity (HDA = SLEDAI-2K > 4).

RESULTS

TGF-β1 (Rs -0.266, p = 0.005) and IL-1β (Rs -0.199, p = 0.004) inversely correlated, whereas BAFF correlated with increasing disease activity (Rs 0.465, p < 0.001). IL-1β, IL-4, IL-10, IL-12, IL-17, IFN-γ, MCP-1, and TNF-α were featured consistently in the PC1 of all study groups. PC1 changes from controls to SLE-HDA patients, included: the increased impact of IL-1β (from 0.58 to >0.95); increased impact of IL-6 in HDA (0.76); increased influence of MIP-1α (0.60) and MIP-1β (0.85); and the uncoupling of TGF-β1 (0.14). PC2 changes from healthy controls to the HDA state, included: the increased influence of BAFF (from -0.18 to 0.88); the oppositional effect of TGF-β1 (-0.36); and, the inclusion of MCP-1 (0.65). Levels of cytokine profiles were equivalent between controls and SLE patients (p > 0.18). BAFF was not associated with the cytokine profiles. TGF-β1 associated with Th1 (Rs 0.36), Th1 + Th17 (Rs 0.22), and inversely with Th17/Th2 (Rs -0.23) profiles. IL-1β associated with the proinflammatory (Rs 0.47), Th1 (Rs 0.55), Th2 (Rs 0.55), Th17 (Rs 0.51), Th1 + Th17 (Rs 0.56), Th2 + Treg (Rs 0.45), and inversely with the (Th1 + Th17 / Th2 + Treg) (Rs -0.22) and Th17/Th2 (Rs -0.27) profiles (all, p < 0.05).

CONCLUSION

Principal component analysis helped to describe the influence of complex cytokine interactions in SLE in a manner congruent with the wider literature. The typical univariate changes in BAFF and TGF-β1 levels with increasing levels of disease activity, were not the dominant factors (in PC1) in the PCA. The PCA demonstrated that IL-1β did not seem to change its regulatory function in SLE.

BAFF-R and TACI expression on CD3+ T cells: Interplay among BAFF, APRIL and T helper cytokines profile in systemic lupus erythematosus

BACKGROUND

Systemic lupus erythematosus (SLE) is the prototype of systemic autoimmune disease, characterized by loss of immune tolerance against self-antigens where autoantibody production is the hallmark of disease. B-cell-activating factor (BAFF) and A proliferation-inducing ligand (APRIL) are cytokines that promote autoreactive cell survival, immunoglobulin-class switching and autoantibody responses in human and mouse SLE models. BAFF and APRIL exert their functions through interactions with their receptors BAFF-R and TACI that are differentially expressed in B lymphocyte subsets, monocytes, dendritic cells and T lymphocytes. BAFF stimulation favors T lymphocyte activation and cytokine production through BAFF-R, which could contribute to the Th1, Th17 and/or Th2 response dysregulation observed in SLE patients.

OBJECTIVE

To evaluate the expression of the cytokines BAFF and APRIL and their association with the receptors BAFF-R and TACI on CD3+ T cells and to evaluate Th1/Th2/Th17 cytokine profile in patients with SLE.

METHODS

Fifteen healthy controls (HC) and 36 SLE patients were included, and their demographic and clinical data were assessed. The disease activity index (Mex-SLEDAI) and damage index (SLICC) were applied to the SLE patients. BAFF-R and TACI expression on CD3+ T cells were evaluated by flow cytometry. Serum BAFF and APRIL concentrations were measured by enzyme-linked immunosorbent assays (ELISA). Cytokine levels of Th1 (IL-12, IL-2, IFN-γ, TNF-α), Th2 (IL-4, IL-6, IL-10, IL-13) and Th17 (IL-1β e IL-17) were quantified with a multiplex assay (MAGPIX). Statistical analysis was performed using PASW Statistics v.20 and GraphPad Prism v.6 software.

RESULTS

No differences in BAFF-R or TACI expression on the CD3+ T cells of SLE and HC were observed. BAFF-R expression correlates inversely with disease activity (r = -0.538, p < 0.01), while TACI correlates with disease activity (r = 0.530, p < 0.05). Serum BAFF and APRIL levels were high in SLE patients and correlated with the disease activity index Mex-SLEDAI (r = 0.621, p < 0.01 and r = 0.416, p < 0.05). SLE patients were found to have significantly higher levels of IL-12, IFN-γ, TNF-α, IL-6, IL-10, IL-13, IL-1β and IL-17 compared to HC (p < 0.05). Cytokines IL-17 (r = 0.526) and TNF-α (r = 0.410) correlate with disease activity (p < 0.05), while APRIL (r = 0.477), IL-10 (r = 0.426) and IFN-γ (r = 0.440) levels were associated with organ damage (p < 0.01). Serum BAFF expression levels correlate with IL-4 (r = 0.424; p < 0.05), IL-6 (r = 0.420; p < 0.05) and IL-10 (r = 0.459; p < 0.01), whereas APRIL levels correlate with IL-2 (r = 0.666; p < 0.01), IL-12 (r = 0.611; p < 0.01) and TNF-α (r = 0.471; p < 0.05) cytokines. A subgroup of SLE patients with high serum BAFF levels (>2 ng/mL) also showed increased APRIL, IL-2, IL-6 and IL-10 levels (p < 0.05). Finally, BAFF, IL-4 and TNF-α serum levels were associated with high titers of antinuclear antibodies.

CONCLUSIONS

The study demonstrates an imbalance in the Th1/Th2 cytokine profile, with increased proinflammatory cytokines, as well as BAFF and APRIL serum levels. Associations of BAFF with Th2 profile cytokines and disease activity, as well as APRIL with Th1 profile cytokines and organ damage, suggest that BAFF and APRIL generated in the autoimmunity context could through still unknown mechanisms, modulate the microenvironment, and perpetuate the inflammatory response, autoantibody production and organ damage observed in SLE patients.

Palisaded neutrophilic and granulomatous dermatitis associated with systemic lupus erythematosus: possible involvement of CD163+ M2 macrophages in two cases, and a review of published works

BACKGROUND

Palisaded neutrophilic and granulomatous dermatitis (PNGD) is a commonly occurring condition related to systemic autoimmune disease. It is characterized histopathologically by a distinct pattern of granulomatous inflammation in the presence or absence of leukocytoclastic vasculitis. The properties of granulomatous cells in PNGD are still uncertain.

OBJECTIVE

We sought further investigation on the phenotype of the infiltrated cells in PNGD from two patients with systemic lupus erythematosus (SLE) and reviewed the previous published reports in order to provide a comprehensive summary on the clinical features of PNGD in SLE.

METHODS

The immunohistochemical features of granulomatous cells in PNGD associated with SLE were analyzed. Immunohistochemical studies were performed on sections from our two cases using antibodies against CD68, CD163, CD15, Factor XIIIa, myeloperoxidase and neutrophil elastase. The clinical characteristics of the SLE patients who developed PNGD were also evaluated. We included all cases retrieved through a PubMed search with the key words PNGD and SLE.

RESULTS

Cutaneous lesions consisted of erythematous plaques distributed on the face and upper limbs in both cases. The infiltrated cells were mainly positive for CD68 and CD163, a phenotype suggestive of M2 macrophages. Some mature neutrophils and lymphocytes were also present. A review of the literature of PNGD associated with SLE revealed a predominance in females, high prevalence of lupus nephritis and a good response to systemic steroids, with frequent skin lesions relapses during tapering of the treatment.

LIMITATIONS

This study examined only two cases; the pathogenesis of the disease remains to be clarified.

CONCLUSION

PNGD lesions were abundantly infiltrated by M2 macrophages, suggesting that they may have a role in this condition. SLE accompanied by PNGD might be associated with lupus nephritis and frequent relapses of skin lesions.

Association of the Interleukin-6 rs1800795 Polymorphism with Type 2 Diabetes Mellitus in the Population of the Island of Crete, Greece

BACKGROUND

Interleukin 6 (IL-6), a proinflammatory cytokine, is elevated in patients with type 2 diabetes (T2D), and is considered an independent predictor of T2D. IL-6 single-nucleotide polymorphisms (SNPs) have been associated with higher levels of IL-6. This study investigated the role of an IL-6 gene polymorphism and its possible association to T2D in the genetically homogeneous Greek population of the island of Crete.

MATERIALS AND METHODS

A total of 144 patients with T2D and 180 controls, all Cretans, selected from the Diabetes Clinic and the Department of Internal Medicine at the University Hospital of Heraklion, Crete, Greece, were genotyped for the IL-6 -174G>C (rs1800795) SNP by the restriction fragment length polymorphism method.

RESULTS

The G/C genotype and the minor allele C of the IL-6 rs1800795 SNP were more common in individuals with T2D than controls (p = 0.004, odds ratio [OR] = 1.98, 95% confidence interval [CI]: 1.24-3.18 and p = 0.011, OR = 1.59, 95% CI: 1.11-2.26, respectively).

CONCLUSION

An association of the rs1800795 SNP of the IL-6 gene with T2D has been detected for the first time in Cretans. The present results, in combination with those presented previously from different ethnic/racial populations, highlight the necessity of comparative studies among different ethnic/racial populations to detect genetic characteristics and associations with T2D.

Analysis of Serum Interleukin (IL)-1β and IL-18 in Systemic Lupus Erythematosus

Systemic lupus erythematosus (SLE) is a chronic multisystem autoimmune disease characterized by biological and clinical heterogeneity. The interleukin (IL)-1 superfamily is a group of innate cytokines that contribute to pathogenesis in many autoimmune diseases. IL-1β and IL-18 are two members that have been shown to play a role in murine lupus-like models, but their role in human SLE remains poorly understood. Here, IL-1β and IL-18 were quantified by enzyme-linked immunosorbent assay in the serum of healthy controls (HCs) and SLE patients from a prospectively followed cohort. Disease activity and organ damage were assessed using SLE disease activity index 2000 (SLEDAI-2K) and SLE damage index scores (SDI), respectively. 184 SLE patients (mean age 44.9 years, 91% female, 56% double-stranded deoxyribonucleic acid positive) were compared to 52 HC. SLE patients had median [IQR] SLEDAI-2K of 4 [2,6], and SDI of 1 [0–2]. Serum IL-18 levels were statistically significantly higher in SLE patients compared to HCs. Univariable linear regression analyses showed that patients with active renal disease or irreversible organ damage had statistically significantly elevated serum IL-18 levels. The association between serum IL-18 and active renal disease was confirmed in multivariable analysis after adjusting for ethnicity and organ damage. High baseline serum IL-18 levels were associated with organ damage at the subsequent visit. Serum IL-1β levels were not significantly elevated in SLE patients when compared to HCs and had no association with overall or organ-specific disease activity or organ damage in cross-sectional and longitudinal analyses. Our data suggest that serum IL-18 and IL-1β have different clinical implications in SLE, with IL-18 being potentially associated with active renal disease.

TNF-α and plasma albumin as biomarkers of disease activity in systemic lupus erythematosus

OBJECTIVES

Composite criteria/indices are presently used to diagnose and monitor patients with systemic lupus erythematosus (SLE). Biomarkers for these purposes would be helpful in clinical practice. We therefore evaluated a large panel of cytokines and basic laboratory tests and investigated their performance as discriminators versus controls and as biomarkers of disease activity (DA).

METHODS

We examined 437 patients with SLE, fulfilling American College of Rheumatology-82 criteria, and 322 matched controls. DA was assessed according to both SLE DA Index 2000 (SLEDAI-2K) and SLE Activity Measure (SLAM). British Isles Lupus Activity Group (BILAG) was used to assess renal DA. Additionally, 132 patients self-assessed their Global Disease Activity (PtGDA). Mesoscale Discovery 30-plex cytokine assay and routine blood chemistry was performed on fasting EDTA-plasma.

RESULTS

Of 26 tested biomarkers, we identified TNF-α as the superior discriminator between patients with SLE and controls (median=4.5 pg/mL, IQR=3.1-6.2 vs median=2.3 pg/mL, IQR=2.0-2.8). The strongest correlations to SLEDAI-2K and SLAM were obtained with TNF-α (Spearman rho (ρ)=0.32 and ρ=0.34, respectively), partly driven by the nephritis subgroup, and with p-albumin (ρ=-0.33 and ρ=-0.31, respectively). P-albumin was decreased and TNF-α was increased in patients with kidney involvement (renal BILAG A/B vs C/D/E, p=4×10-16 and p=6×10-9 respectively). IP-10 was increased in patients with joint involvement (SLAM item 24≥2 vs ≤1, p=0.0005) but did not differ when comparing patients with active/inactive kidney involvement. The most powerful correlations to PtGDA was observed with p-albumin (ρ=-0.42), IL-6 (ρ=0.30) and TNF-α (ρ=0.29).

CONCLUSION

TNF-α and p-albumin both performed well as discriminators between patients with SLE and controls and as proxies for DA according to both rheumatologists' and patients' assessments. In particular, renal DA was well reflected by TNF-α. We propose that the TNF-α and p-albumin merit further investigations as clinically useful biomarkers in SLE. We also observed that the pattern of activated cytokines varies with organ involvement.

Long non-coding RNA TUG1 protects renal tubular epithelial cells against injury induced by lipopolysaccharide via regulating microRNA-223

BACKGROUND

Lupus nephritis (LN) is a serious complication of systemic lupus erythematosus (SLE). Long non-coding RNA taurine upregulated gene 1 (lncRNA TUG1) exerted critical regulatory effects on inhibiting cell injury and inflammation. However, its role in LN is still unclear.

METHODS

HK-2 cells were treated with lipopolysaccharide (LPS) to simulate cell inflammatory injury. Cell viability and apoptosis, as well as pro-inflammatory factors expression were measured, respectively. Then, HK-2 cells were transfected with pEX-TUG1 or sh-TUG1 to explore the effects of TUG1 on LPS-induced cell injury. Potential binding effects between TUG1 and microRNA-223 (miR-223), as well as between miR-223 and Sirtuin 1 (Sirt1) were verified. miR-223 mimic or miR-223 inhibitor was transfected to assess the effects of miR-223 on cell injury. Finally, the roles of Sirt1 in LPS-induced HK-2 cell injury and activation of phosphatidylinositol 3-kinase/protein kinase 3 (PI3K/AKT) and nuclear factor kappa B (NF-κB) pathways were explored.

RESULTS

LPS administration inhibited HK-2 cell viability and proliferation, increased expression of pro-inflammatory factors, and promoted cell apoptosis. TUG1 overexpression protected HK-2 cells against LPS-induced injury via negatively regulating miR-223 expression. TUG1 suppression had opposite effects. Sirt1 was a direct target gene of miR-223 in HK-2 cells, which participated in the effects of miR-223 on HK-2 cells and was related with the activation of PI3K/AKT and NF-κB pathways.

CONCLUSION

TUG1 protected HK-2 cells against LPS-induced inflammatory injury by regulating miR-223 and Sirt1 expression, and then activating PI3K/AKT and inactivating NF-κB pathways. TUG1 might be a potential therapeutic target for LN treatment.

Cytokine and autoantibody clusters interaction in systemic lupus erythematosus

Background

Evidence supports the existence of different subphenotypes in systemic lupus erythematosus (SLE) and the pivotal role of cytokines and autoantibodies, which interact in a highly complex network. Thus, understanding how these complex nonlinear processes are connected and observed in real-life settings is a major challenge. Cluster approaches may assist in the identification of these subphenotypes, which represent such a phenomenon, and may contribute to the development of personalized medicine. Therefore, the relationship between autoantibody and cytokine clusters in SLE was analyzed.

Methods

This was an exploratory study in which 67 consecutive women with established SLE were assessed. Clinical characteristics including disease activity, a 14-autoantibody profile, and a panel of 15 serum cytokines were measured simultaneously. Mixed-cluster methodology and bivariate analyses were used to define autoantibody and cytokine clusters and to identify associations between them and related variables.

Results

First, three clusters of autoantibodies were defined: (1) neutral, (2) antiphospholipid antibodies (APLA)-dominant, and (3) anti-dsDNA/ENA-dominant. Second, eight cytokines showed levels above the threshold thus making possible to find 4 clusters: (1) neutral, (2) chemotactic, (3) G-CSF dominant, and (4) IFNα/Pro-inflammatory. Furthermore, the disease activity was associated with cytokine clusters, which, in turn, were associated with autoantibody clusters. Finally, when all biomarkers were included, three clusters were found: (1) neutral, (2) chemotactic/APLA, and (3) IFN/dsDNA, which were also associated with disease activity.

Conclusion

These results support the existence of three SLE cytokine-autoantibody driven subphenotypes. They encourage the practice of personalized medicine, and support proof-of-concept studies.

Electronic supplementary material

The online version of this article (10.1186/s12967-017-1345-y) contains supplementary material, which is available to authorized users.

Systemic lupus erythematosus biomarkers: the challenging quest

SLE, a multisystem heterogeneous disease, is characterized by production of antibodies to cellular components, with activation of both the innate and the adaptive immune system. Decades of investigation of blood biomarkers has resulted in incremental improvements in the understanding of SLE. Owing to the heterogeneity of immune dysregulation, no single biomarker has emerged as a surrogate for disease activity or prediction of disease. Beyond identification of surrogate biomarkers, a multitude of clinical trials have sought to inhibit elevated SLE biomarkers for therapeutic benefit. Armed with new -omics technologies, the necessary yet daunting quest to identify better surrogate biomarkers and successful therapeutics for SLE continues with tenacity.

Purinergic signalling in autoimmunity: A role for the P2X7R in systemic lupus erythematosus?

Purinergic signalling plays a crucial role in immunity and autoimmunity. Among purinergic receptors, the P2X7 receptor (P2X7R) has an undisputed role as it is expressed to high level by immune cells, triggers cytokine release and modulates immune cell differentiation. In this review, we focus on evidence supporting a possible role of the P2X7R in the pathogenesis of systemic lupus erythematosus (SLE).

C/EBP β mRNA expression is upregulated and positively correlated with the expression of TNIP1/TNFAIP3 in peripheral blood mononuclear cells from patients with systemic lupus erythematosus

CCAAT/enhancer-binding protein β (C/EBP β) has important roles in numerous signaling pathways. The expression of the majority of regulators and target gene products of C/EBP β, including tumor necrosis factor α-induced protein 3 (TNFAIP3) and TNFAIP3-interacting protein 1 (TNIP1), are upregulated in patients with systemic lupus erythematosus (SLE). The aim of the present study was to investigate whether C/EBP β expression is associated with SLE pathogenesis and correlates with TNIP1 and TNFAIP3 expression. Quantitative reverse transcription-polymerase chain reaction analysis was used to assess the expression of C/EBP β, TNIP1, and TNFAIP3 mRNA in peripheral blood mononuclear cells (PBMC) from 20 patients with SLE and 20 healthy controls. Spearman's rank test was used to determine the correlation between C/EBP β expression and SLE disease activity, and that between C/EBP β expression and TNIP1/TNFAIP3 expression in PBMCs from patients with SLE. C/EBP β mRNA expression was markedly increased in patients with SLE compared with healthy controls. The expression of C/EBP β was positively correlated with the SLE disease activity index and negatively correlated with the serum level of complement components C3 and C4. In addition, C/EBP β mRNA expression was increased in PBMCs from SLE patients that were positive for antinuclear, anti-Smith and anti-nRNP antibodies, compared with the antibody negative SLE patients. Furthermore, the mRNA expression levels of C/EBP β in patients with SLE was positively correlated with TNIP1 and TNFAIP3 expression. The results of the current study suggest that the increased expression of C/EBP β in PBMCs and the interaction between C/EBP β and TNIP1/TNFAIP3 may be involved in the pathogenesis of SLE.

Upregulation of the C/EBP β LAP isoform could be due to decreased TNFAIP3/TNIP1 expression in the peripheral blood mononuclear cells of patients with systemic lupus erythematosus

OBJECTIVES

We aimed to examine CCAAT/enhancer-binding protein β (C/EBP β), TNF-alpha-induced protein 3 (TNFAIP3), and TNFAIP3-interacting protein 1 (TNIP1) expression in peripheral blood mononuclear cells (PBMCs) of systemic lupus erythematosus (SLE) patients to assess their relationship in SLE pathogenesis.

METHODS

C/EBP β, TNIP1, and TNFAIP3 expression was assessed in PBMCs from 20 SLE patients and 20 controls by western blotting. The correlation between C/EBP β/TNFAIP3/TNIP1 expression and SLE disease activity was determined by Spearman's rank. C/EBP β, TNIP1, and TNFAIP3 levels in THP-1 cells, THP-1 cells transfected with plasmids encoding TNFAIP3 shRNA, and THP-1 cells infected with lentiviral vectors encoding TNIP1 shRNA were assessed by western blotting.

RESULTS

C/EBP β LAP isoform expression was increased and LIP/TNFAIP3/TNIP1 expression was decreased in SLE patients. LAP expression was positively correlated with SLE disease activity; TNFAIP3 and TNIP1 expression was negatively correlated with SLE disease activity. LAP expression was increased in SLE patients with proteinuria and elevated anti-dsDNA antibody, as well as in THP-1 cells transfected with plasmids encoding TNFAIP3 shRNA and THP-1 cells infected with lentiviral vectors encoding TNIP1 shRNA.

CONCLUSIONS

C/EBP β/TNFAIP3/TNIP1 is associated with SLE activity. The upregulated expression of C/EBP β LAP could be caused by reduced TNFAIP3/TNIP1 expression.

The effects of hydroxychloroquine on endothelial dysfunction

Hydroxychloroquine is an anti-malarial drug which, due to its anti-inflammatory and immunomodulatory effects, is widely used for the treatment of autoimmune diseases. In a model of systemic lupus erythematosus hydroxychloroquine has been shown to exert protective endothelial effects. In this study, we aimed to investigate whether hydroxychloroquine was endothelial protective in an in vitro model of TNF-α and preeclamptic serum induced dysfunction. We showed that hydroxychloroquine significantly reduced the production of TNF-α and preeclamptic serum induced endothelin-1 (ET-1). Hydroxychloroquine also significantly mitigated TNF-α induced impairment of angiogenesis. These findings support the further assessment of hydroxychloroquine as an adjuvant therapy in preeclampsia.

Are micromegakaryocytes specific for refractory cytopenia of childhood (RCC)? A study of 38 pediatric patients with thrombocytopenia unrelated to RCC

BACKGROUND

Micromegakaryocytes (microMKs) are considered the most reliable dysplastic feature for myelodysplastic syndrome (MDS), particularly refractory cytopenia of childhood (RCC); there is no minimal threshold for the diagnosis of RCC. Since most RCC patients present with thrombocytopenia, the presence of microMKs should raise concern for MDS/RCC. This study attempted to investigate the prevalence of microMKs and associated marrow fibrosis in patients with thrombocytopenia unrelated to MDS/RCC and the need for establishing a threshold for microMKs for the diagnosis of MDS/RCC.

DESIGN

Bone marrow biopsies of pediatric patients with thrombocytopenia unrelated to RCC were examined for microMKs and fibrosis by CD61 immunohistochemical and reticulin stains respectively.

RESULT

Thirty eight patients (1-18 years old) were included: 33 immune thrombocytopenia (ITP), 3 chronic thrombocytopenia, and 2 inherited macrothrombocytopenia. Fourteen cases (37%) had microMKs; four cases showed increased marrow fibrosis associated with microMKs (two had ITP and two had macrothrombocytopenia). All patients are alive and none developed MDS (follow up: 3months to 4 years).

CONCLUSION

MicroMKs can be seen in pediatric patients with thrombocytopenia unrelated to RCC. Hence the mere presence of microMKs is insufficient for the diagnosis of RCC in the pediatric population, and a quantitative threshold needs to be established.

CD163+ M2c-like macrophages predominate in renal biopsies from patients with lupus nephritis

Background

The role of macrophages in the pathogenesis of lupus nephritis, in particular their differentiation to a certain subtype (e.g., M1- or M2-like) modulating the inflammatory reaction, is unknown. Here we investigated whether the differentiation in M1- or M2-like macrophages depends on the stage of lupus nephritis and whether this correlates with clinical parameters.

Method

Using immunohistochemical analysis we analyzed renal biopsies from 68 patients with lupus nephritis (ISN/RPS classes II–V) for infiltration with M1-like (iNOS+/CD68+), M2a-like (CD206+/CD68+), M2c-like macrophages (CD163+/CD68+), and FoxP3+ regulatory T-cells. In addition, clinical parameters at the time of renal biopsy, i.e., blood pressure, proteinuria and serum urea were correlated with the macrophage infiltration using the Spearman test.

Results

The mean number of CD68+ macrophages was related to the diagnosed ISN/RPS class, showing the highest macrophage infiltration in biopsies with diffuse class IV and the lowest number in ISN/RPS class V. In all ISN/RPS classes we detected more M2c-like CD163+/CD68+ than M2a-like CD206+/CD68+ cells, while M1-macrophages played only a minor role. Cluster analysis using macrophage subtype numbers in different renal compartments revealed three main clusters showing cluster 1 dominated by class V. Clusters 2 and 3 were dominated by lupus class IV indicating that this class can be further differentiated by its macrophage population. The number of tubulointerstitial FoxP3+ cells correlated with all investigated macrophage subtypes showing the strongest association to numbers of M2a-like macrophages. Kidney function, as assessed by serum creatinine and serum urea, correlated positively with the number of total CD68+, M2a-like and M2c-like macrophages in the tubulointerstitium. In addition, total CD68+ and M2c-like macrophage numbers highly correlated with Austin activity score. Interestingly, in hypertensive lupus patients only the number of M2a-like macrophages was significantly increased compared to biopsies from normotensive lupus patients.

Conclusion

M2-like macrophages are the dominant subpopulation in human lupus nephritis and particularly, M2a subpopulations were associated with disease progression, but their role in disease progression remains unclear.

The murine Pbx1-d lupus susceptibility allele accelerates mesenchymal stem cell differentiation and impairs their immunosuppressive function

Pre–B cell leukemia homeobox 1 (Pbx1)-d is a dominant-negative splice isoform of the gene Pbx1 that corresponds to the NZM2410 lupus susceptibility locus Sle1a1. Pbx1 is required to maintain stem cell self-renewal, including that of mesenchymal stem cells (MSCs). MSCs have immunosuppressive functions that require stem cell maintenance. We tested the hypothesis that the expression of Pbx1-d favors MSC differentiation and impairs their immunosuppressive functions. We demonstrate that Sle1a1 MSCs express high levels of Pbx1-d as compared with congenic C57BL/6J (B6) MSCs. Sle1a1 MSCs grew faster and differentiated significantly more rapidly into osteoblasts than did B6 MSCs. This corresponded to a significant decrease in the expression of genes associated with stemness and an increase in the expression of genes associated with differentiation. Additionally, Sle1a1 MSCs express a gene expression profile associated with an enhanced innate immunity and inflammation. Suppression of Ig production from TLR-activated B6 B cells and IL-2 secretion from activated B6 CD4+ T cells was significantly impaired in Sle1a1 MSCs as compared with B6 MSCs. B6.Sle1a1 MSCs showed intermediate activity in suppressing lupus immunophenotypes in three different mouse models. Taken together, these data suggest that the expression of the lupus susceptibility allele Pbx1-d isoform impairs MSC functions, which may contribute to lupus pathogenesis both through a defective immunosuppression and the promotion of a proinflammatory environment.

The association of interleukin-31 polymorphisms with interleukin-31 serum levels and risk of systemic lupus erythematosus

Interleukin-31 (IL-31) is the most recently discovered member of the gp130/IL-6 cytokine family which is produced mainly by activated Th2 cells. IL-31 was proved to play a crucial role in autoimmune and inflammatory diseases such as atopic dermatitis, asthma, cutaneous T cell lymphomas, Kawasaki disease and allergic rhinitis. Previous studies have identified that IL-31 could significantly induce the release of proinflammatory cytokines IL-6. Moreover, a large number of studies have shown that IL-6 plays an important role in the pathogenesis of systemic lupus erythematosus (SLE). However, up to date, no study to data was reported on the relationship between IL-31 and SLE. Therefore, in the present study, we investigated the association between IL-31 polymorphisms and its serum levels with the risk of SLE in a Chinese population. We analyzed two single nucleotide polymorphisms of IL-31 gene rs7977932 C/G and rs4758680 G/T in 190 patients with SLE and 250 age- and sex-matched controls, using polymerase chain reaction-single base extension and DNA sequencing methods. Soluble IL-31 (sIL-31) levels were measured by ELISA. From this study, we found that there were significant differences in the genotype and allele frequencies of IL-31 gene rs7977932 C/G polymorphism between the group of patients with SLE and the control group (P < 0.05). sIL-31 levels were increased in patients with SLE compared with controls (P < 0.01). Moreover, genotypes carrying the IL-31 rs7977932 G variant allele were associated with increased IL-31 levels compared to the homozygous wild-type genotype in patients with SLE. The rs7977932 C/G polymorphism of IL-31 gene and its sIL-31 levels were associated with SLE in the Chinese population. Our data suggest that IL-31 gene may play a role in the development of SLE.

Genetic polymorphisms of interleukin 6 and interleukin 10 in Egyptian patients with systemic lupus eythematosus

Systemic lupus erythematosus (SLE) is a complex autoimmune disease. Cytokine gene polymorphisms play an important role in SLE. Thus, this study aimed to investigate the associations between interleukin 6 (IL-6) and interleukin 10 (IL-10) promoter single-nucleotide polymorphisms (SNPs) and their susceptibility to SLE and the implications for plasma levels. We genotyped IL-6-174G/C (rs1800795) using mutagenically separated polymerase chain reaction (MS-PCR) and IL-10-1082G/A (rs1800896) and -819C/T (rs1800871) using sequence specific primer polymerase chain reaction (SSP-PCR) in 100 Egyptian patients and 119 controls. The plasma levels of IL-6 and IL-10 were measured by enzyme-linked immunosorbent assay (ELISA). There was significant increase in the frequency of IL-6 (-174) GG genotype ( P < 0.05) and G allele ( P < 0.01) compared to controls. A significant increase in the distribution of IL-10 (-1082G/A) GG ( P < 0.05) and AA ( P < 0.05) genotypes and a significant reduction in the frequency of GA genotype ( P < 0.05) was found in SLE patients. The mean serum concentration of IL-6 ( P < 0.001) and IL-10 ( P < 0.001) was significantly elevated in SLE patients compared to healthy controls. There was no  significant association of the most common clinical findings and IL-6 and IL-10 gene polymorphisms in SLE patients. In conclusion, our preliminary study indicated that both GG genotype and G allele of IL-6 (-174G/C) could be considered as risk factors for SLE. In addition, the polymorphisms at IL-10 (-1082 G/G and AA) may play a role in SLE susceptibility in Egyptian patients. Larger prospective studies are needed to confirm our findings.

Epidermal injury promotes nephritis flare in lupus-prone mice

Systemic lupus erythematosus is clinically characterized by episodes of flare and remission. In patients, cutaneous exposure to ultraviolet light has been proposed as a flare trigger. However, induction of flare secondary to cutaneous exposure has been difficult to emulate in many murine lupus models. Here, we describe a system in which epidermal injury is able to trigger the development of a lupus nephritis flare in New Zealand Mixed (NZM) 2328 mice. 20-week old NZM2328 female mice underwent removal of the stratum corneum via duct tape, which resulted in rapid onset of proteinuria and death when compared to sham-stripped littermate control NZM2328 mice. This was coupled with a drop in serum C3 concentrations and dsDNA antibody levels and enhanced immune complex deposition in the glomeruli. Recruitment of CD11b(+)CD11c(+)F4/80(high) macrophages and CD11b(+)CD11c(+)F4/80(low) dendritic cells was noted prior to the onset of proteinuria in injured mice. Transcriptional changes within the kidney suggest a burst of type I IFN-mediated and inflammatory signaling which is followed by upregulation of CXCL13 following epidermal injury. Thus, we propose that tape stripping of lupus-prone NZM2328 mice is a novel model of lupus flare induction that will allow for the study of the role of cutaneous inflammation in lupus development and how crosstalk between dermal and systemic immune systems can lead to lupus flare.

Association of TNF-α gene promoter region polymorphisms in bovine leukemia virus (BLV)-infected cattle with different proviral loads

Tumor necrosis factor alpha (TNF-α) is a pleiotropic cytokine involved in the immune response against viral and other infections. Its expression levels are affected by a polymorphism in the promoter region of the gene. Bovine leukemia virus is a retrovirus that infects cattle and develops two different infection profiles in the host. One profile is characterized by a high number of proviral copies integrated into the host genome and a strong immune response against the virus, while the most relevant property of the other profile is that the number of copies integrated into the host genome is almost undetectable and the immune response is very weak. We selected a population of cattle sufficiently large for statistical analysis and classified them according to whether they had a high or low proviral load (HPL or LPL). Polymorphisms in the promoter region were identified by PCR-RFLP. The results indicated that, in the HPL group, the three possible genotypes were normally distributed and that, in the LPL group, there was a significant association between the proviral load and a low frequency of the G/G genotype at position -824.