Impaired production of IL-12 in systemic lupus erythematosus. III: deficient IL-12 p40 gene expression and cross-regulation of IL-12, IL-10 and IFN-gamma gene expression

Altered expression of miR-125a and dysregulated cytokines in systemic lupus erythematosus: Unveiling diagnostic and prognostic markers

BACKGROUND

Systemic lupus erythematosus (SLE) is a chronic autoimmune disorder impacting multiple organs, influenced by genetic factors, especially those related to the immune system. However, there is a need for new biomarkers in SLE. MicroRNA-125a (miR-125a) levels are decreased in T cells, B cells, and dendritic cells of SLE patients. MiR-125a plays a regulatory role in controlling the levels of tumor necrosis factor-alpha (TNF-α) and interleukin 12 (IL-12), which are crucial pro-inflammatory cytokines in SLE pathogenesis.

AIM

To assess the levels of miR-125a, IL-12, and TNF-α in SLE patients' plasma, evaluating their diagnostic and prognostic value.

METHODS

The study included 100 healthy individuals, 50 newly diagnosed (ND), and 50 SLE patients undergoing treatment. The patients were monitored for a duration of 24 wk to observe and record instances of relapses. MiR-125a expression was measured using real-time reverse transcription polymerase chain reaction, while ELISA kits were used to assess IL-12 and TNF-α production.

RESULTS

The results showed significantly reduced miR-125a expression in SLE patients compared to healthy individuals, with the lowest levels in ND patients. TNF-α and IL-12 expression levels were significantly elevated in SLE patients, especially in the early stages of the disease. Receiver operating characteristic curve analyses, and Cox-Mantel Log-rank tests indicated miR-125a, TNF-α, and IL-12 as proper diagnostic biomarkers for SLE. A negative correlation was found between plasma miR-125a expression and IL-12/TNF-α levels in SLE patients.

CONCLUSION

Decreased miR-125a levels may be involved in the development of SLE, while elevated levels of IL-12 and TNF-α contribute to immune dysregulation. These findings offer new diagnostic and prognostic markers for SLE. Moreover, the negative correlation observed suggests an interaction between miR-125a, TNF-α, and IL-12. Further research is necessary to uncover the underlying mechanisms that govern these relationships.

Medicinal Plant Extracts and Natural Compounds for the Treatment of Cutaneous Lupus Erythematosus: A Systematic Review

Cutaneous lupus erythematosus (CLE) is a group of autoimmune connective tissue disorders that significantly impact quality of life. Current treatment approaches typically use antimalarial medications, though patients may become recalcitrant. Other treatment options include general immunosuppressants, highlighting the need for more and more targeted treatment options. The purpose of this systematic review was to identify potential compounds that could be repurposed for CLE from natural products since many rheumatologic drugs are derived from natural products, including antimalarials. This study was registered with PROSPERO, the international prospective register of systematic reviews (registration number CRD42021251048). We comprehensively searched Ovid Medline, Cochrane Library, and Scopus databases from inception to April 27th, 2021. These terms included cutaneous lupus erythematosus; general plant, fungus, bacteria terminology; selected plants and plant-derived products; selected antimalarials; and JAK inhibitors. Our search yielded 13,970 studies, of which 1,362 were duplicates. We screened 12,608 abstracts, found 12,043 to be irrelevant, and assessed 565 full-text studies for eligibility. Of these, 506 were excluded, and 59 studies were included in the data extraction. The ROBINS-I risk of bias assessment tool was used to assess studies that met our inclusion criteria. According to our findings, several natural compounds do reduce inflammation in lupus and other autoimmune skin diseases in studies using in vitro methods, mouse models, and clinical observational studies, along with a few randomized clinical trials. Our study has cataloged evidence in support of potential natural compounds and plant extracts that could serve as novel sources of active ingredients for the treatment of CLE. It is imperative that further studies in mice and humans are conducted to validate these findings.

Systematic Review Registration:https://www.crd.york.ac.uk/prospero/display_record.php?RecordID=251048.

SCIMP is a spatiotemporal transmembrane scaffold for Erk1/2 to direct pro-inflammatory signaling in TLR-activated macrophages

Immune cells are armed with Toll-like receptors (TLRs) for sensing and responding to pathogens and other danger cues. The role of extracellular-signal-regulated kinases 1/2 (Erk1/2) in TLR signaling remains enigmatic, with both pro- and anti-inflammatory functions described. We reveal here that the immune-specific transmembrane adaptor SCIMP is a direct scaffold for Erk1/2 in TLR pathways, with high-resolution, live-cell imaging revealing that SCIMP guides the spatial and temporal recruitment of Erk2 to membrane ruffles and macropinosomes for pro-inflammatory TLR4 signaling. SCIMP-deficient mice display defects in Erk1/2 recruitment to TLR4, c-Fos activation, and pro-inflammatory cytokine production, with these effects being phenocopied by Erk1/2 signaling inhibition. Our findings thus delineate a selective role for SCIMP as a key scaffold for the membrane recruitment of Erk1/2 kinase to initiate TLR-mediated pro-inflammatory responses in macrophages.

Innate lymphoid cell disturbance with increase in ILC1 in systemic lupus erythematosus

The innate lymphoid cell (ILC) is a group of effector cells with diverse important cellular functions in both health and disease states. In comparison with healthy controls, there were increases in circulating ILC in SLE patients. The proportion of ILC1 significantly increased with significant decreases of ILC2 in SLE patients and ILC3 in SLE patients with moderate to severe activity. IL-12, IL-18, IL-25, IL-33, IL-23, IL-1β and IFN-γ were significantly increased in SLE patients. Moreover, IL-12, IL-18 and IL-1β but not IFN-γ correlated significantly with SLEDAI. Successful treatments rapidly reduced them and with certain normalization of the ILC subsets. In addition to increases in ILC1 numbers, ~ 80% of the ILC1 in SLE patients were positive for synthesis of IFN-γ. Plasma from SLE patients were shown to be potent in inducing ILC1. Thus, increased circulating ILC1 might contribute to the pathogenesis of SLE through mounting type 1 immune response.

Cytokines in systemic lupus erythematosus

Systemic lupus erythematosus (SLE) is a chronic autoimmune disease characterized by the production of autoantibodies that can form immune complexes and deposit in tissues, causing inflammation and organ damage. There is evidence that interferons and some interleukins can have an active role in the pathogenesis of SLE and can contribute significantly to the immune imbalance in the disease, whereas the role of some cytokines (such as TNF) is still debated. This review discusses the activity of several cytokines in SLE, their effects on the immune cells in relation to the disease pathogenesis, and the promise and limitations of cytokine-based therapies in clinical trials for lupus patients.

Overexpression of interleukin-12 and T helper 1 predominance in lupus nephritis

Imbalance of cytokine homeostasis is a prominent feature of both experimental and human systemic lupus erythematosus (SLE). Because interleukin (IL)-12 promotes interferon (IFN)-gamma production leading to polarization of peripheral cells toward a T helper (Th) 1 phenotype, we investigated its role in lupus nephritis (LN). Soluble Th1 and Th2 cytokines were measured by enzyme-linked immunosorbent assay (ELISA) in sera and urines of SLE patients and controls. Th1/Th2 peripheral lymphocyte polarization was determined by flow cytometry. Glomerular accumulation of IL-12 was evaluated by immunohistochemistry, whereas urinary IL-12 was evaluated by ELISA. Higher serum IL-12 levels in SLE were associated with LN, whereas IL-4 was unrelated to the renal damage. Peripheral cells from LN patients showed a Th1 phenotype with a high IFN-gamma expression that paralleled the severity of renal damage. IL-12 was present within glomerular mononuclear cells in classes IV and V LN, and its accumulation was correlated strongly with urinary levels. IL-12 overexpression in SLE may contribute to the development of LN. Both serum and urinary IL-12 elevation reflect its glomerular production and parallel Th1 polarization of peripheral T cells and high IFN-gamma production. In SLE patients, IL-12 measurement may thus be predictive of the development of LN.

Cytokine induction by circulating immune complexes and signs of in-vivo complement activation in systemic lupus erythematosus are associated with the occurrence of anti-Sjögren's syndrome A antibodies

Circulating immune complexes (IC) and levels of IC-induced cytokines have been correlated with complement activation and autoantibody profiles in systemic lupus erythematosus (SLE). SLE sera were analysed concerning levels of immune complexes (IC), classical complement function and different antinuclear and anti-C-reactive protein (CRP) autoantibodies. Blood mononuclear cells from healthy donors were stimulated with isolated IC and production of interleukin (IL)-10, IL-6 and IL-12p40 was measured. Functional experiments revealed that increased levels of IC-induced cytokines were associated with both increased classical complement activation and the occurrence of anti-Sjögren's syndrome A (SSA) and anti-SSB but not other autoantibodies. Biochemical measurement of circulating IC showed that the degree of complement activation and the occurrence of anti-SSA were synergistically associated with levels of circulating IC in SLE sera, as complement activation was a prerequisite for the enhancing effect of anti-SSA. Anti-CRP was associated with complement activation, but not with other autoantibodies. Our results indicate that anti-SSA and possibly anti-SSB antibodies influence IC formation and subsequent IC-induced cytokine induction, and that they thereby participate in the inflammatory process in active SLE.

Microarray profiling of lymphocytes in internal diseases with an altered immune response: potential and methodology

Recently it has become possible to investigate expression of all human genes with microarray technique. The authors provide arguments to consider peripheral white blood cells and in particular lymphocytes as a model for the investigation of pathophysiology of asthma, RA, and SLE diseases in which inflammation is a major component. Lymphocytes are an alternative to tissue biopsies that are most often difficult to collect systematically. Lymphocytes express more than 75% of the human genome, and, being an important part of the immune system, they play a central role in the pathogenesis of asthma, RA, and SLE. Here we review alterations of gene expression in lymphocytes and methodological aspects of the microarray technique in these diseases. Lymphocytic genes may become activated because of a general nonspecific versus disease-specific mechanism. The authors suppose that in these diseases microarray profiles of gene expression in lymphocytes can be disease specific, rather than inflammation specific. Some potentials and pitfalls of the array technologies are discussed. Optimal clinical designs aimed to identify disease-specific genes are proposed. Lymphocytes can be explored for research, diagnostic, and possible treatment purposes in these diseases, but their precise value should be clarified in future investigation.

Lupus patients with pulmonary involvement have a pro-inflammatory cytokines profile

OBJECTIVES

The literature on cytokine response in systemic lupus erythematosus (SLE) is confusing. It is possible that different disease phenotypes have different cytokine profiles. Our aim was to examine the levels of selected pro-inflammatory and anti-inflammatory cytokines in SLE patients with and without pulmonary involvement.

METHODS AND SUBJECTS

Patients with SLE were interviewed and were subjected to the pulmonary function test and high-resolution computed tomography studies. Serum levels of interleukin (IL)-6, IL-8, IL-10, Il-12, interferon (IFN) gamma, and tumor necrosis factor (TNF) alpha were estimated by enzyme-linked immunosorbent assay.

RESULTS

Forty-nine of the 61 SLE patients had pulmonary involvement. Median levels of IL-8, IFNgamma, and TNFalpha were significantly higher in the pulmonary group as compared to the non-pulmonary group (p = 0.027, 0.027 and 0.002, respectively). Ratios of pro-inflammatory cytokines to anti-inflammatory cytokines were higher in the pulmonary group as compared to the non-pulmonary group as well as in the pulmonary restrictive subgroup compared to the obstructive subgroup.

CONCLUSION

Lupus patients with pulmonary involvement have a stronger pro-inflammatory cytokine bias than those without pulmonary involvement.

Monoclonal ribosomal P autoantibody inhibits the expression and release of IL-12, TNF-α and iNOS in activated RAW macrophage cell line

Monoclonal ribosomal P protein antibody (anti-P mAb) may bind to the cell surface, penetrate into cells, and induce apoptosis of Jurkat T cells. Recently, modulation of cytokines has been considered to be important in the pathogenesis of systemic lupus erythematous (SLE). In this study, effects of anti-P mAbs (9B6) on gene expression of cytokines, apoptosis, and reactive oxygen species in murine macrophage RAW 264.7 were analyzed by RT-PCR and ELISA and those on IL-12 promoter activity was determined in an IL-12p40 promoter-reporter gene transfected cell line RAW (IL-12p40-SEAP). After treating LPS-activated RAW 264.7 with 9B6 for 6 or 24 h, the levels of mRNA and protein expression of IL-12, TNF-alpha, and iNOS were significantly inhibited by 25%, 16%, and 13%, respectively. The IL-12 promoter activity of RAW (IL-12p40-SEAP) was also inhibited by 13-22%. However, inhibitory effects were not observed in cells pre-treated with IgG1 for 1 h. The productions of IL-10 in LPS-activated RAW 264.7 and human macrophages were potentiated by 9B6 up to 65% and 51%, respectively. Since anti-P Abs inhibit productions of IL-12 and TNF-alpha and enhance IL-10 production in macrophages, these autoantibodies may augment Th2 responses and amplify lupus manifestations by causing immunological polarity and lymphocyte dysfunction.

Th1/Th2 cytokines in patients with systemic lupus erythematosus: is tumor necrosis factor alpha protective?

OBJECTIVES

To determine the circulating levels of Th1 and Th2 cytokines in patients with systemic lupus erythematosus (SLE) and to elucidate their association with disease activity and autoimmune response.

METHODS

We included 52 patients and 25 healthy controls. Serum levels of tumor necrosis factor (TNF) alpha, interferon (IFN) gamma, interleukin (IL)-12p70, IL-10, and IL-4, as well as anti-DNA, -Ro, -La, -RNP, and -Sm antibodies were determined by enzyme-linked immunosorbent assay. Disease activity was recorded according to the Systemic Lupus Erythematosus Disease Activity Index (SLEDAI) and classified as very active (SLEDAI > or = 13), moderately active (SLEDAI: 3-12), or inactive (SLEDAI < or = 2).

RESULTS

The mean age of the patients was 34.2 +/- 12.6 years, and the mean duration of disease was 4.9 +/- 7.6 years. Twelve patients (23%), 20 patients (34.5%), and 20 patients (34.5%) had highly, moderately, and inactive SLE, respectively. Levels of IFN-gamma, TNF-alpha, and IL-12 were significantly higher in patients than in healthy controls (P <.03), as well as the IL-12/IL-10, IL-12/IL-4, IFN/IL-10, IFN/IL-4, TNF/IL-10, and TNF/IL-4 ratios (P <.01), suggesting a major participation of Th1 over Th2 cytokines. Nevertheless, a direct correlation between Th1 (IFN-gamma and TNF-alpha) and Th2 (IL-4 and IL-10) cytokines was observed in patients (r >.5, P <.01), indicating a mutual Th1-Th2 participation. TNF-alpha levels and the TNF/IL-10 ratio were higher in patients with inactive disease compared with patients with very active disease and controls (P <.04). IL-12 levels and IL-12/IL-4, as well as IL-12/IL-10, ratios were higher in patients with very active disease than in those with inactive SLE and controls (P <.01). IL-10 levels were associated with anti-DNA, anti-Ro, and anti-La response (P <.01).

CONCLUSION

Our results suggest that TNF-alpha could be a protective factor in SLE patients, whereas IL-12p70 participates in disease activity and IL-10 influences the autoimmune response (autoantibody production).

Serum IL-12 in systemic lupus erythematosus: absence of p70 heterodimers but presence of p40 monomers correlating with disease activity

Biologically active IL-12 is a 70 kDa heterodimeric cytokine (IL-12 p70) mainly produced by antigen-presenting cells (APC) and made of disulfide-linked alpha (p35) and beta (p40) chains. Since the production of the p40 subunit is independently regulated from that of IL-12 p70, we compared levels of p40 and IL-12 p70 in the sera of patients with systemic lupus erythematosus (SLE). Sera obtained from rheumatoid arthritis (RA) patients and healthy subjects were used as controls. Serum p40 titers were significantly higher in SLE patients (mean +/- s.e.m.: 348 +/- 40 pg/ml) compared with patients with rheumatoid arthiritis (mean +/- s.e.m.: 116 +/- 18 pg/ml, P < 0.0001) or controls (mean +/- s.e.m.: 0 +/- pg/ml, P < 0.0001). By contrast, IL-12 p70 was not detected in any serum. In SLE patients, serum p40 levels were positively correlated with the SLEDAI (r = + 0.56, P = 0.02) and negatively with serum C3 levels (r = - 0.42, P = 0.03). Follow-up measurements indicated that serum p40 dropped significantly after immunosuppressive therapy. Finally, size exclusion chromatography with p40 immunoprecipitates obtained from SLE sera demonstrated that p40 was present as a monomer, and not as a homodimer, nor as a p19/p40 (IL-23) heterodimer. In conclusion, serum p40 monomers (but not IL-12 p70 titers) are elevated in the sera of SLE patients commensurate with disease activity. While the relevance of these observations needs to be further investigated, our results are consistent with the APC dysfunction described in SLE.

Promotion of lupus in NZB x NZWF1 mice by plasmids encoding interferon (IFN)-gamma but not by those encoding interleukin (IL)-4

The present study extended our previous observation that interferon (IFN)-gamma may be responsible for the active disease that develops in NZB x NZWF1 mice and serves as a model for human systemic lupus erythematosus. Treatments with cytokine-encoding plasmids were delivered intraperitoneally every 4 weeks, starting at 3 months of age (i.e. before the onset of lupus). In comparison with the control plasmid and the IL-4-encoding plasmid, the IFN-gamma-encoding plasmid promoted increased blood urea nitrogen values and reduced the survival rate, and these changes were accompanied by the development of anti-nuclear antibody. There were no differences, however, between treatment with control plasmids and treatment with IL-4-encoding plasmids in terms of the development of lupus. The findings clearly indicated that IFN-gamma but not IL-4 contributed to the development of lupus in the NZB x NZWF1 mice.

Postmenopausal changes in production of type 1 and type 2 cytokines and the effects of hormone replacement therapy

OBJECTIVE

An appropriate defense against infective agents or malignant cells is attributed to the exquisitely balanced T helper 1 type (cellular) and T helper 2 type (humoral) immune reactions. We investigated the effect of hormone replacement therapy (HRT) on postmenopausal changes in the production of interferon (IFN)-gamma and interleukin (IL)-10, a type 1 and a type 2 cytokine, respectively.

DESIGN

Both cytokines were measured by ELISA in the supernatant of lipopolysaccharide-stimulated whole blood cells from 72 untreated and 44 HRT-treated women. Thirteen women were examined before and during HRT.

RESULTS

The production of IFN-gamma in women in their 40s and in postmenopausal women was significantly higher compared with that of younger women. However, IFN-gamma fell to the lowest level in the late postmenopausal stage, whereas the production of IL-10 increased gradually with age and in parallel with the postmenopausal period. Thus, in women in the mid-and late postmenopausal period, excessive production of type 2 cytokine (IL-10) compared with type 1 cytokine (IFN-gamma) occurred. The IFN-gamma levels of women on HRT were significantly lower than those of untreated women in the early and mid-postmenopausal stages, and IL-10 levels of women on HRT were significantly lower than those of untreated women in the mid-and late postmenopausal stages. HRT induced a significant decrease in the production of IL-10 and tended to lower the level of IFN-gamma.

CONCLUSIONS

Production of IL-10 is augmented in postmenopausal women. HRT probably prevents postmenopausal women from an aberration of the immune system by improving the balance of type 1 and type 2 immune reactions.

Elevation of proinflammatory cytokine (IL-18, IL-17, IL-12) and Th2 cytokine (IL-4) concentrations in patients with systemic lupus erythematosus

Previous studies have indicated that the autoimmune phenomenon might be caused by an imbalance of T helper cell (Th) cytokines. We measured the plasma concentrations of three novel proinflammatory cytokines interleukin (IL)-17, IL-18, IL-12 and a key Th2 cytokine IL-4 in patients with systemic lupus erythematosus (SLE) and correlated the ratio of proinflammatory/Th2 cytokines with SLE disease activity index (SLEDAI). Plasma IL-12, IL-17, IL-18 and IL-4 concentrations of 36 SLE patients and 18 sex- and age-matched control subjects were measured by enzyme linked immunosorbent assay. All were significantly higher in SLE patients than control subjects (IL-12, mean+/-s.d. of 166.7+/-84.5 vs 93.5+/-39.2 pg/ml, P<0.001; IL-17, 76.5+/-45.7 vs 37.6+/-35.3 pg/ml, P=0.002; IL-18, 368.7+/-199. 5 vs 141.1+/-47.1 pg/ml, P<0.001; and IL-4, 27.1+/-15.3 vs 17.3+/-7. 2 pg/ml, P<0.05), and IL-18/IL-4 ratio correlated positively and significantly with SLEDAI score (r=0.435, P=0.006). We propose that SLE is characterized by an elevation of both Th1 and Th2 cytokines: the elevation of proinflammatory cytokine IL-12, IL-17 and IL-18 may trigger the inflammatory process in SLE and the elevation of IL-18/IL-4 ratio suggests an imbalance of cytokine profile to mediate the inflammatory response.