TNFalpha inhibition in MRL/lpr mice ameliorates pulmonary but not renal disease

Therapeutic Potential of Anti-Interferon α Vaccination on SjS-Related Features in the MRL/lpr Autoimmune Mouse Model

Sjögren’s syndrome (SjS) is a frequent systemic autoimmune disease responsible for a major decrease in patients’ quality of life, potentially leading to life-threatening conditions while facing an unmet therapeutic need. Hence, we assessed the immunogenicity, efficacy, and tolerance of IFN-Kinoid (IFN-K), an anti-IFNα vaccination strategy, in a well-known mouse model of systemic autoimmunity with SjS-like features: MRL/MpJ-Faslpr/lpr (MRL/lpr) mice. Two cohorts (with ISA51 or SWE01 as adjuvants) of 26 female MRL/lpr were divided in parallel groups, “controls” (not treated, PBS and Keyhole Limpet Hemocyanin [KLH] groups) or “IFN-K” and followed up for 122 days. Eight-week-old mice received intra-muscular injections (days 0, 7, 28, 56 and 84) of PBS, KLH or IFN-K, emulsified in the appropriate adjuvant, and blood samples were serially collected. At sacrifice, surviving mice were euthanized and their organs were harvested for histopathological analysis (focus score in salivary/lacrimal glands) and IFN signature evaluation. SjS-like features were monitored. IFN-K induced a disease-modifying polyclonal anti-IFNα antibody response in all treated mice with high IFNα neutralization capacities, type 1 IFN signature’s reduction and disease features’ (ocular and oral sicca syndrome, neuropathy, focus score, glandular production of BAFF) improvement, as reflected by the decrease in Murine Sjögren’s Syndrome Disease Activity Index (MuSSDAI) modelled on EULAR Sjögren’s Syndrome Disease Activity Index (ESSDAI). No adverse effects were observed. We herein report on the strong efficacy of an innovative anti-IFNα vaccination strategy in a mouse model of SjS, paving the way for further clinical development (a phase IIb trial has just been completed in systemic lupus erythematosus with promising results).

From Systemic Inflammation to Neuroinflammation: The Case of Neurolupus

It took decades to arrive at the general consensus dismissing the notion that the immune system is independent of the central nervous system. In the case of uncontrolled systemic inflammation, the relationship between the two systems is thrown off balance and results in cognitive and emotional impairment. It is specifically true for autoimmune pathologies where the central nervous system is affected as a result of systemic inflammation. Along with boosting circulating cytokine levels, systemic inflammation can lead to aberrant brain-resident immune cell activation, leakage of the blood⁻brain barrier, and the production of circulating antibodies that cross-react with brain antigens. One of the most disabling autoimmune pathologies known to have an effect on the central nervous system secondary to the systemic disease is systemic lupus erythematosus. Its neuropsychiatric expression has been extensively studied in lupus-like disease murine models that develop an autoimmunity-associated behavioral syndrome. These models are very useful for studying how the peripheral immune system and systemic inflammation can influence brain functions. In this review, we summarize the experimental data reported on murine models developing autoimmune diseases and systemic inflammation, and we explore the underlying mechanisms explaining how systemic inflammation can result in behavioral deficits, with a special focus on in vivo neuroimaging techniques.

Suppression of lupus nephritis and skin lesions in MRL/lpr mice by administration of the topoisomerase I inhibitor irinotecan

BACKGROUND

Since the precise mechanism for the pathogenesis of systemic lupus erythematosus (SLE) is unknown, no targeted therapies in addition to immunosuppression are available so far. We recently demonstrated that administration of the topoisomerase I (topo I) inhibitor irinotecan at extremely low concentrations reversed established lupus nephritis in NZB/NZW mice. While profound immunosuppression was absent, we proposed changes in DNA relaxation and anti-double-stranded (ds)DNA antibody binding as the underlying mechanism. To exclude that these effects were restricted to NZB/NZW mice, irinotecan was used in a genetically different strain of lupus-prone mice.

METHODS

MRL/lpr mice were treated with high- and low-dose irinotecan beginning at 8 weeks of age. Treatment was repeated every fourth week. In vitro, DNA was relaxed by recombinant topo I, and altered anti-dsDNA antibody binding was measured by enzyme-linked immunosorbent assay.

RESULTS

Administration of both high- and low-dose irinotecan prevented proteinuria and prolonged survival in MRL/lpr mice. Moreover, both concentrations of irinotecan significantly improved histopathology of the skin at 18 weeks of age. While only high-dose irinotecan diminished the numbers of plasmablasts and double-negative T cells, no changes in IgG-secreting cells or anti-dsDNA IgG were observed. In vitro, relaxation of DNA by topo I increased the binding of anti-dsDNA IgG but not the binding of anti-dsDNA IgM derived from the plasma of MRL/lpr mice.

CONCLUSION

The beneficial effects of topo I inhibition in a second, genetically different strain of lupus-prone mice strongly implicate irinotecan as a new therapeutic option for human SLE.

Effects of tetra-arsenic tetra-sulfide on BXSB lupus-prone mice: a pilot study

Systemic lupus erythematosus (SLE) is an autoimmune disease of uncertain etiology that affects multiple tissues and organs. Arsenic trioxide (ATO) has been used in lupus-prone mice with a regulatory effect on immune abnormality. Tetra-arsenic tetra-sulfide (As4S4), a traditional Chinese medicine, is effective on acute promyelocytic leukemia with mild side effects than ATO. In this study, a pilot study was performed to investigate the effects and the mechanism of As4S4 on the lupus-prone BXSB mice. Improvement of monocytosis (p<0.05) in spleen and decreased serum interleukin-6 (IL-6) (p=0.0277) were observed with As4S4 treatment. As4S4-treated mice exhibited amelioration of skin, liver and renal disease with mild side effects. Histological analysis revealed that As4S4 suppressed immune complex deposition, mesangial proliferation and inflammatory cell infiltration in kidney and liver. Our study support that As4S4 selectively suppresses cutaneous lupus and nephritis in BXSB mice and might be a potential treatment for SLE.

The effect of targeted delivery of anti-TNF-α oligonucleotide into CD169+ macrophages on disease progression in lupus-prone MRL/lpr mice

Systemic blockade of TNF-α via monoclonal antibodies and soluble receptors has shown considerable effects against several typical autoimmune disorders, but remains unconvincing for the treatment of lupus. Based on our previous study, a CD169(+) macrophage-specific therapy using TNF-α antisense oligonucleotides (ASO) was tested for its efficacy in MRL/lpr lupus-prone mice. ASO-containing cationic agarose hydrogel were injected into mice subcutaneously. Tissue distribution and cellular localization of ASO were determined. The therapeutic effects and possible mechanism were further studied in MRL/lpr lupus-prone mice. The results showed that specifically accumulation of the anti-TNF-α ASO in CD169(+) macrophages could significantly reduce TNF-α expression in CD169(+) macrophages and inhibit lymphocytes over-proliferation, finally resulted in the relief of the lupus-like symptoms of the animals. The nucleic acid drug based on CD169(+) macrophage-specific TNF-α regulation represents a potential therapeutic approach that may be valuable for lupus therapy.

Effect on tumor necrosis factor-α production and antioxidant ability of black alder, as factors related to its anti-inflammatory properties

Alders exhibit several uses in different areas and also offer some nutritional and medicinal values. The bark and leaves from black alder [Alnus glutinosa (L.) Gaertn] are used in folk medicine for the treatment of inflammatory processes and other health disorders. This study assessed if an extract of A. glutinosa stem bark exhibits some biological properties linked to improving the inflammatory state, which could partly justify its ethnopharmacological use. Therefore, various aspects of antioxidant activity as well as the effect on tumor necrosis factor-α (TNF-α) production were evaluated. The phytochemical study revealed the presence of terpenes, saponins, tannins, flavonoids, and anthraquinones (by high-performance thin-layer chromatography). The betulinic acid content in the extract, determined by reversed-phase high-performance liquid chromatography (validated method), was 0.72±0.027%. In addition, high amounts for total phenols as well as flavonoids were determined. The extract exhibited a 2,2'-diphenylpicrylhydrazyl radical scavenging capacity similar to that of ascorbic acid and had a significant effect on superoxide anion scavenging, superior to that of ascorbic acid. It was also able to protect HeLa cells from induced oxidative stress. In the TNF-α assay, levels of this citokine were depressed by the extract in HL-60 cells. To test the effect of the extract on cell proliferation, a 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide assay was performed. According to the results, the antioxidant properties displayed by the extract of A. glutinosa stem bark, together with the effect on TNF-α levels, suggest that these activities, linked to a successful reduction in inflammatory processes, may support, in part, its ethnopharmacological use.

Recombinant chaperonin 10 suppresses cutaneous lupus and lupus nephritis in MRL-(Fas)lpr mice

BACKGROUND

Systemic lupus erythematosus (SLE) is still treated with global immunosuppressants with serious toxicities. We hypothesized that endogenous immunosuppressive molecules might be able to control SLE manifestations more specifically. Heat shock protein 10, or chaperonin 10 (Cpn10), is a secretory molecule that can suppress innate and adaptive immunity.

METHODS

Recombinant human Cpn10 (100 μg per mouse) was given intraperitoneally to healthy-appearing female MRL-(Fas)lpr mice from 12 to 22 weeks of age. At the age of 22 weeks, mice were analysed for treatment outcome by harvesting organs, plasma and urine.

RESULTS

Cpn10 entirely prevented cutaneous lupus lesions as compared to vehicle-treated mice. Cpn10 also suppressed lupus nephritis as evident from serum creatinine levels, albuminuria and the scores of disease activity and chronicity. Autoimmune lung disease was unaffected by Cpn10 treatment while overall survival of mice was prolonged. Cpn10 did not have any major effects on either dendritic cell or B-cell counts except T cells in spleen, plasma interferon-gamma, tumour necrosis factor-alpha, interleukin-10, anti-nuclear autoantibody levels or markers of lymphoproliferation.

CONCLUSIONS

In summary, recombinant Cpn10 selectively prevents cutaneous lupus and suppresses nephritis in MRL-(Fas)lpr mice without affecting the underlying systemic autoimmune process. Hence, Cpn10 might be useful for the treatment of skin and kidney manifestations of SLE.

Lack of the long pentraxin PTX3 promotes autoimmune lung disease but not glomerulonephritis in murine systemic lupus erythematosus

The long pentraxin PTX3 has multiple roles in innate immunity. For example, PTX3 regulates C1q binding to pathogens and dead cells and regulates their uptake by phagocytes. It also inhibits P-selectin-mediated recruitment of leukocytes. Both of these mechanisms are known to be involved in autoimmunity and autoimmune tissue injury, e.g. in systemic lupus erythematosus, but a contribution of PTX3 is hypothetical. To evaluate a potential immunoregulatory role of PTX3 in autoimmunity we crossed Ptx3-deficient mice with Fas-deficient (lpr) C57BL/6 (B6) mice with mild lupus-like autoimmunity. PTX3 was found to be increasingly expressed in kidneys and lungs of B6lpr along disease progression. Lack of PTX3 impaired the phagocytic uptake of apoptotic T cells into peritoneal macrophages and selectively expanded CD4/CD8 double negative T cells while other immune cell subsets and lupus autoantibody production remained unaffected. Lack of PTX3 also aggravated autoimmune lung disease, i.e. peribronchial and perivascular CD3+ T cell and macrophage infiltrates of B6lpr mice. In contrast, histomorphological and functional parameters of lupus nephritis remained unaffected by the Ptx3 genotype. Together, PTX3 specifically suppresses autoimmune lung disease that is associated with systemic lupus erythematosus. Vice versa, loss-of-function mutations in the Ptx3 gene might represent a genetic risk factor for pulmonary (but not renal) manifestations of systemic lupus or other autoimmune diseases.

The MRL/lpr mouse strain as a model for neuropsychiatric systemic lupus erythematosus

To date, CNS disease and neuropsychiatric symptoms of systemic lupus erythematosus (NP-SLE) have been understudied compared to end-organ failure and peripheral pathology. In this review, we focus on a specific mouse model of lupus and the ways in which this model reflects some of the most common manifestations and potential mechanisms of human NP-SLE. The mouse MRL lymphoproliferation strain (a.k.a. MRL/lpr) spontaneously develops the hallmark serological markers and peripheral pathologies typifying lupus in addition to displaying the cognitive and affective dysfunction characteristic of NP-SLE, which may be among the earliest symptoms of lupus. We suggest that although NP-SLE may share common mechanisms with peripheral organ pathology in lupus, especially in the latter stages of the disease, the immunologically privileged nature of the CNS indicates that early manifestations of particularly mood disorders maybe derived from some unique mechanisms. These include altered cytokine profiles that can activate astrocytes, microglia, and alter neuronal function before dysregulation of the blood-brain barrier and development of clinical autoantibody titres.

The TNFalpha locus is altered in monocytes from patients with systemic lupus erythematosus

In systemic lupus erythematosus, TNFalpha is elevated in the serum and correlates with disease activity and triglyceride levels. The stimuli that drive TNFalpha in this setting are incompletely understood. This study was designed to evaluate monocyte chromatin at the TNFalpha locus to identify semi-permanent changes that might play a role in altered expression of TNFalpha. SLE patients with relatively quiescent disease (mean Physician Global Assessment=0.6) and healthy controls were recruited for this study. TNFalpha expression was measured by intracellular cytokine staining of different monocyte subsets in patients (n=24) and controls (n=12). Histone acetylation at the TNFalpha locus was measured by chromatin immunoprecipitation using a normalized quantitative PCR in patients (n=46) and controls (n=24). There were no differences in the overall fractions of cells expressing CD14 in SLE patients compared to controls; however, the fraction of DR+/CD16+ cells expressing CD14 was slightly higher as was true in the monocyte subset defined by DR+/CD11b+. Within the monocyte population defined by physical characteristics and DR+/CD14+, TNFalpha expressing cells were more frequent in SLE patients compared to controls. Both the fraction of positive cells and the mean fluorescence intensity were higher in patients than controls. Consistent with this was the finding that monocytes from patients had increased TNFalpha transcripts and more highly acetylated histones at the TNFalpha locus compared to controls. Furthermore, patients with the highest levels of TNFalpha histone acetylation were more likely to have had consistently elevated erythrocyte sedimentation rates, and to have required cytotoxic use. Histone acetylation, associated with increased transcriptional competence of TNFalpha, may play a role in certain inflammatory aspects of the disease.

Anti-type V collagen lymphocytes that express IL-17 and IL-23 induce rejection pathology in fresh and well-healed lung transplants

Immunity to collagen V [col(V)] contributes to lung 'rejection.' We hypothesized that ischemia reperfusion injury (IRI) associated with lung transplantation unmasks antigenic col(V) such that fresh and well-healed lung grafts have differential susceptibility to anti-col(V)-mediated injury; and expression of the autoimmune cytokines, IL-17 and IL-23, are associated with this process. Adoptive transfer of col(V)-reactive lymphocytes to WKY rats induced grade 2 rejection in fresh isografts, but induced worse pathology (grade 3) when transferred to isograft recipients 30 days post-transplantation. Immunhistochemistry detected col(V) in fresh and well-healed isografts but not native lungs. Hen egg lysozyme-reactive lymphocytes (HEL, control) did not induce lung disease in any group. Col(V), but not HEL, immunization induced transcripts for IL-17 and IL-23 (p19) in the cells utilized for adoptive transfer. Transcripts for IL-17 were upregulated in fresh, but not well-healed isografts after transfer of col(V)-reactive cells. These data show that IRI predisposes to anti-col(V)-mediated pathology; col(V)-reactive lymphocytes express IL-17 and IL-23; and anti-col(V)-mediated lung disease is associated with local expression of IL-17. Finally, because of similar histologic patterns, the pathology of clinical rejection may reflect the activity of autoimmunity to col(V) and/or alloimmunity.