Nephritis In Lupus-prone Mice Research Articles

Molecular mechanisms governing the progression of nephritis in lupus prone mice and human lupus patients.

Pathologic inflammation is a major driver of kidney damage in lupus nephritis (LN), but the immune mechanisms of disease progression and risk factors for end organ damage are poorly understood. To characterize molecular profiles through the development of LN, we carried out gene expression analysis of microdissected kidneys from lupus-prone NZM2328 mice. We examined male mice and the congenic NZM2328.R27 strain as a means to define mechanisms associated with resistance to chronic nephritis. Gene expression profiles in lupus mice were compared with those in human LN. NZM2328 mice exhibited progress from acute to transitional and then to chronic glomerulonephritis (GN). Each stage manifested a unique molecular profile. Neither male mice nor R27 mice progressed past the acute GN stage, with the former exhibiting minimal immune infiltration and the latter enrichment of immunoregulatory gene signatures in conjunction with robust kidney tubule cell profiles indicative of resistance to cellular damage. The gene expression profiles of human LN were similar to those noted in the NZM2328 mouse suggesting comparable stages of LN progression. Overall, this work provides a comprehensive examination of the immune processes involved in progression of murine LN and thus contributes to our understanding of the risk factors for end-stage renal disease. In addition, this work presents a foundation for improved classification of LN and illustrates the applicability of murine models to identify the stages of human disease.

The small heat shock protein HSPB5 attenuates the severity of lupus nephritis in lupus-prone mice

Lupus nephritis (LN) is a common and serious complication of systemic lupus erythematosus. The current treatments for LN are accompanied with severe immunotoxicity and have limits of effectiveness. Since our in vitro experiments demonstrated that a small heat shock protein (HSP), alpha-B crystallin (HSPB5; CRYAB), selectively modulates myeloid cells towards anti-inflammatory and tolerogenic phenotypes, the aim of this study was to investigate whether HSPB5 can attenuate the severity of LN. MRL/lpr mice were treated intravenously with HSPB5 at 2.5 or 10 μg/dose twice per week after disease onset, from 11 to 21 weeks of age. Disease progression was monitored by weekly measurements of proteinuria, and sera, spleens, and kidneys were collected for assessment at the terminal time point. Treatment with 10 μg HSPB5 substantially reduced endocapillary proliferation and tubular atrophy, which significantly reduced proteinuria and blood urea nitrogen (BUN). Compared to vehicle, 10 μg HSPB5 treatment substantially decreased activation/proliferation of splenocytes, increased IL-10+ macrophages, T and B regulatory cells (Treg, Breg), increased serum IL-10, and lowered expression of IL-6 in kidneys, which correlated with improved kidney function and pathology. This study demonstrated the utility of exogenous human HSPB5 to attenuate severe nephropathy in MRL/lpr mice and provides evidence in favour of a novel therapeutic approach for lupus nephritis.

The role of neuraminidase 1 (NEU1) in cytokine release by primary mouse mesangial cells and disease outcomes in murine lupus nephritis

The importance of altered glycosphingolipid (GSL) metabolism is increasingly gaining attention as a characteristic of multiple chronic kidney diseases. Previously, we reported elevated levels of GSLs and neuraminidase (NEU) enzyme activity/expression in the urine or kidney of lupus patients and lupus-prone mice, and demonstrated NEU activity mediates the production of cytokines by lupus-prone mouse primary mesangial cells. This mediation occurs in part through TLR4 and p38/ERK MAPK signalling in response to lipopolysaccharide (LPS) and lupus serum (LS). However, the precise role of NEU1, the most abundant NEU in the kidney, is incompletely known. In this study, we investigated the effect of genetically reduced Neu1 levels in vitro and in vivo. Mesangial cells from non-autoimmune prone Neu1+/− C57BL/6 mice had significantly reduced NEU activity, cytokine expression and cytokine secretion in response to LS and LPS, thereby suggesting reducing Neu1 expression may reduce the inflammatory response in lupus nephritis. Disease was assessed in female B6.SLE1/2/3 lupus-prone mice with genetically reduced levels (Neu1+/−) or wild-type levels (Neu1+/+) of Neu1 from 28 to 44 weeks of age along with aged-matched C57BL/6 controls. Renal disease was unexpectedly mild in all B6.SLE1/2/3 mice despite evidence of systemic disease. B6.SLE1/2/3 Neu1+/− mice exhibited significantly reduced levels of renal NEU1 expression and changes in renal α-2,6 linked sialylated N-glycans compared to the Neu1+/+ or healthy C57BL/6 mice, but measures of renal and systemic disease were similar between the B6.SLE1/2/3 Neu1+/+ and Neu1+/− mice. We conclude that NEU1 is the NEU largely responsible for mediating cytokine release by mesangial cells, at least in vitro, but may not be involved in modulating renal GSL levels in vivo or impact onset of nephritis in lupus-prone mice. However, the effect of reduced NEU1 levels on disease may not be appreciated in the mild disease expression in our colony of B6.SLE1/2/3 mice. The impact of the altered renal sialylated N-glycan levels and potential role of NEU1 with respect to established nephritis (late disease) in lupus-prone mice bears further investigation.

Immunization with Pentraxin3 prevents transition from subclinical to clinical lupus nephritis in lupus-prone mice: Insights from renal ultrastructural findings

BackgroundPentraxin3 (PTX3) is an emerging player in lupus nephritis (LN). Anti-PTX3 antibodies showed to delay LN occurrence in vivo. AimTo evaluate renal changes following immunization with PTX3 in a murine model of LN. Materials and methodsTwenty-two lupus-prone New Zealand Black/White (NZB/W)F1 mice were divided into two groups (n = 11) and subcutaneously injected with human recombinant (hr)PTX3 100 μg or phosphate buffer saline (PBS) 200 μl, three times 3 weeks apart, starting before development of proteinuria. Five mice from each group were scheduled for sacrifice at week 22 and 6 from each group at week 29. Renal lesions included electron-dense deposits (EDD), glomerular deposition of IgG, complement and PTX3 as markers of renal inflammation. They were evaluated by immunofluorescence (IF), confocal and immunoelectron microscopy (IEM). Validated semiquantitative scores were used when available to score renal lesions. Chi-squared test with Fisher exact test was used for comparison. ResultsNineteen out of 22 mice were sacrificed as scheduled. Only hrPTX3-immunized mice developed anti-PTX3 antibodies. Compared to PBS-injected mice, they displayed a dramatic decrease in glomerular deposits of IgG, C1q and PTX3, as well as in the amount of EDD (p = 0.006) and podocyte effacement (p = 0.043). Importantly, PTX3 was pinpointed inside the EDD and co-localized with nuclear material. ConclusionsImmunization with PTX3 prevented progression from the preclinical to the clinical stage of LN, inciting anti-PTX3 antibodies and preventing renal PTX3 deposition. PTX3 is a novel component of EDD, submitting it as one initiating autoantigen in LN and as potential target for early treatment.

Atializumab, a humanized anti-aminoacyl-tRNA synthetase-interacting multifunctional protein-1 (AIMP1) antibody significantly improves nephritis in (NZB/NZW) F1 mice

Aminoacyl-tRNA synthetase (ARS)-interacting multifunctional protein 1 (AIMP1) enhances the expression of proinflammatory cytokines. In our previous study, we have shown that serum AIMP1 in patients with SLE was significantly higher than that of healthy controls. To address whether neutralization of AIMP1 could ameliorate nephritis in lupus-prone mice, we generated atializumab, a humanized antibody against AIMP1 and investigated its therapeutic efficacy. ELISA showed that serum AIMP1 at 23 weeks old was significantly higher than that at 13 weeks old in lupus-prone mice. Therefore, lupus-prone mice were randomly assigned to 5 groups (vehicle, methylprednisolone and 0.5, 2, and 5 mg/kg atializumab). After treatment, disease severity was assessed using a variety of phenotypes, including proteinuria, histological damages, renal deposition of immune-complex. In addition, serum cytokines, anti-dsDNA and IgG subclasses were determined. T cell subsets were analyzed using a fluorescence-activated cell sorter. Atializumab significantly diminished proteinuria, improved glomerular and tubular damages and reduced the renal deposition of immune-complexes. Moreover, atializumab significantly decreased serum interferon (IFN)-γ, interleukin (IL)-17A, and IL-6, whereas it increased serum IL-10. Similarly, atializumab reduced the numbers of TH1, TH2 and TH17 cells in a dose-dependent manner, while atializumab enhanced the number of regulatory T (Treg) cells. Furthermore, atializumab decreased not only splenic plasma cells and serum anti-dsDNA but also pathogenic IgG subclasses for nephritis. It suppressed NF-κB activation by inhibiting IκBα degradation in a dose-dependent manner in vitro. Atializumab alleviated nephritis by inhibiting autoreactive T, B, and plasma cells and decreasing NF-κB-related proinflammatory cytokines in lupus-prone mice. These results suggest that treatment targeting AIMP1 could be a novel and highly immune-modulating therapeutic strategy in lupus nephritis.

Inhibition of G Protein βγ Subunit Signaling Abrogates Nephritis in Lupus-Prone Mice.

Despite considerable advances in the understanding of systemic lupus erythematosus (SLE), there is still an urgent need for new and more targeted treatment approaches. We previously demonstrated that small-molecule blockade of G protein βγ subunit (Gβγ) signaling inhibits acute inflammation through inhibition of chemokine receptor signal transduction. We undertook this study to determine whether inhibition of Gβγ signaling ameliorates disease in a mouse model of SLE. Lupus-prone (NZB × NZW)F1 female mice were prophylactically or therapeutically treated with the small-molecule Gβγ inhibitor gallein. Tissue samples were analyzed by flow cytometry and immunohistochemistry. The development and extent of nephritis were assessed by monitoring proteinuria and by immunohistochemical analysis. Serum immunoglobulin levels were measured by enzyme-linked immunosorbent assay, and total IgG and anti-double-stranded DNA (anti-dsDNA) antibody-secreting cells were measured by enzyme-linked immunospot assay. Gallein inhibited accumulation of T cells and germinal center (GC) B cells in the spleen. Both prophylactic and therapeutic treatment reduced GC size, decreased antibody-secreting cell production in the spleen, and markedly decreased accumulation of autoreactive anti-dsDNA antibody-secreting cells in kidneys. Gallein also reduced immune complex deposition in kidneys. Finally, gallein treatment dramatically inhibited kidney inflammation, prevented glomerular damage, and decreased proteinuria. Mechanistically, gallein inhibited immune cell migration and signaling in response to chemokines in vitro, which suggests that its mechanisms of action in vivo are inhibition of migration of immune cells to sites of inflammation and inhibition of immune cell maturation. Overall, these data demonstrate the potential use of gallein or novel inhibitors of Gβγ signaling in SLE treatment.

Frequency of CD4+Foxp3+ Treg Cells Increase But is Unable to Control Nephritis in Lupus Prone Mice

Frequency of CD4+Foxp3+ Treg Cells Increase But is Unable to Control Nephritis in Lupus Prone Mice

Soluble Receptor for Advanced Glycation End Products Alleviates Nephritis in (NZB/NZW)F1 Mice

To investigate the efficacy of different doses of the soluble form of the receptor for advanced glycation end products (sRAGE) (conjugated to the Fc portion of immunoglobulin) in the treatment of nephritis in lupus-prone mice, in comparison with the efficacy of combination therapy with mycophenolate mofetil plus prednisolone. Twenty-eight female (NZB/NZW)F1 mice were divided into 5 groups (untreated, sRAGE [dose groups of 0.5, 1, or 2 μg], or mycophenolate mofetil plus prednisolone). Proteinuria and histologic damage were evaluated. Immune complex deposition and the nuclear translocation of NF-κB in the kidney tissue were assessed by immunofluorescence staining. Serum concentrations of anti-double-stranded DNA (anti-dsDNA) and IgG subclasses were also measured. The population of T cells was evaluated using a fluorescence-activated cell sorter, and expression of intracellular adhesion molecule 1 and vascular cell adhesion molecule 1 in the kidney tissue was assessed by immunohistochemical staining. In comparison with untreated mice, mice treated with 1 or 2 μg sRAGE showed significantly reduced proteinuria and attenuated histologic renal damage, with efficacy comparable to that of combination therapy. Treatment with 2 μg sRAGE significantly reduced immune complex deposition and decreased the serum concentrations of anti-dsDNA, IgG2a, IgG2b, and IgG3. In addition, sRAGE interrupted the nuclear translocation of NF-κB in the kidney, resulting in reduction in the expression of downstream genes of NF-κB in vivo and in vitro. Furthermore, sRAGE effectively modified T cell populations. Treatment with sRAGE significantly improved nephritis in lupus-prone mice, with efficacy comparable to that of standard induction treatment for lupus nephritis. These data suggest that sRAGE has antiinflammatory effects on the pathophysiology of lupus nephritis and could serve as a potent new therapy for this disease.

AB0213 Alleviation of nephritis in lupus-prone NZB/WF1 mice by a combination treatment of thalidomide plus prednisolone

BackgroundProliferative lupus nephritis (Class III and IV) is the most severe form of lupus nephritis. The use of intravenous or oral prednisolone (PL) plus either intravenous cyclophosphamide or oral mycophenolate...

Treatment with Anti-Interleukin 23 Antibody Ameliorates Disease in Lupus-Prone Mice

Interleukin 23 receptor expressing IL-17 producing T cells have been shown to be important in the development of murine lupus. The usefulness of IL-23 inhibition in ameliorating lupus nephritis is unknown. We hypothesized that inhibition of IL-23 will ameliorate nephritis in lupus-prone mice. To this end, we treated MRL/lpr lupus-prone mice for 6 weeks with a rat anti-IL-23p19 antibody, which resulted in delaying the onset of nephritis without affecting the production of anti-dsDNA antibodies. The effect of the treatment was hampered by the production of murine anti-rat IgG antibodies. The amelioration of murine lupus by IL-23 inhibition strengthens the rationale for targeting IL-23 in patients with systemic lupus erythematosus.

Kidney-infiltrating CD4+ T-cell clones promote nephritis in lupus-prone mice

In systemic lupus erythematosus, CD4+ T cells play key roles in the initiation and promotion of autoantigen-specific humoral immunity, and indirect evidence suggests that T cells are pathogenic effectors in lupus nephritis. The contribution of kidney-infiltrating T cells to nephritis, however, has not been verified because of the difficulty in directly analyzing organ-infiltrating T cells. Here, we examined the pathogenic roles of autoreactive cytokine-expressing CD4+ T cells from the kidneys of early nephritic MRL/lpr mice. Interferon (IFN)-γ-secreting cells were enriched among CD5(high)CD4+ T cells found in the inflamed kidneys. Using single-cell analysis of the T-cell receptor (TCR)(high)CD5(high)CD4+ T cells from the kidneys of early nephritic MRL/lpr mice, two IFN-γ-expressing CD4+ T cell clones, MLK2 and MLK3, were identified. CD4+ T cells transduced with the T-cell receptor genes from each clone responded to splenic dendritic cells in an MHC class II-dependent manner, but not to B cells or macrophages. MLK3-transduced CD4+ T cells proliferated in the spleens of prenephritic mice, promoted nephritis progression upon adoptive transfer, and enhanced the deposition of C3 without promoting anti-double-stranded DNA antibody production. Thus, CD4+ T cells in the inflamed kidneys of MRL/lpr mice contribute to nephritis progression.

Attenuation of nephritis in lupus-prone mice by thalidomide

Thalidomide has various effects, such as immune modulation, anti-angiogenicity, anti-inflammation and anti-proliferation. Moreover, thalidomide modulates the activity of NF-κB, which can up-regulate the expression of downstream genes involved in the pathophysiology of LN. Here we investigated the efficacy of thalidomide monotherapy or thalidomide plus prednisolone (PL) on nephritis in NZB/WF1 mice at different doses and compared both with a combination therapy of MMF plus PL. Forty-three female NZB/WF1 mice were divided into eight groups (untreated; 1.7, 5 or 10 mg/kg of thalidomide alone; 1.7, 5 or 10 mg/kg of thalidomide plus 1.5 mg/kg of PL and 33.3 mg/kg of MMF plus PL). Proteinuria and histological damage were evaluated. Immune complex deposition and nuclear translocation of NF-κB in kidney tissues were assessed by immunofluorescence staining. Serum concentrations of anti-dsDNA and IgG subclasses were also measured. In comparison with untreated mice, mice treated with 10 mg/kg of thalidomide monotherapy showed a significant decrease in proteinuria and significantly lower glomerular and tubular damage scores, comparable to 5 or 10 mg/kg of thalidomide plus PL or MMF plus PL. Also, treatment with 10 mg/kg of thalidomide significantly decreased immune complex accumulation, reduced the serum concentration of anti-dsDNA, IgG2a and IgG2b and inhibited nuclear translocation of NF-κB in kidney tissues, comparable to standard therapy for LN. These data suggest that thalidomide might play an anti-inflammatory role in the pathophysiology of LN, and it could serve as a complementary therapy to standard induction regimens for refractory LN.

Inhibition of Calcium/calmodulin-dependent protein kinase IV suppresses the autoimmunity in lupus-prone mice. (56.4)

Abstract OBJECTIVE: Systemic lupus erythematosus (SLE) is a chronic inflammatory disease associated with abnormal immune cell function.SLE T cells express high levels of calcium/calmodulin-dependent protein kinase IV (CaMKIV). We have shown previously that pharmacologic (Arthritis Rheum. 2011) or genetic silencing of Camkiv (J Immunol. 2011) suppresses lupus nephritis in lupus-prone mice. The purpose of this study was to determine whether pharmacologic inhibition of CaMKIV would improve immune function abnormalities. METHODS: We treated MRL/lpr mice with KN-93, a CaMKIV inhibitor, starting at week 8 of age through week 16 and evaluated the presence of CD4+, CD8+, CD3+CD4-CD8- (double negative, DN) and CD62Llow T cells and proinflammatory cytokine production. We also determined the effect of inhibition of CaMKIV on proinflammatory cytokine production by human T cells and macrophages. RESULTS: CaMKIV inhibition in MRL/lpr mice resulted in significant suppression of DN and CD62Llow of T cells population and IFN-γ production by T cells. In human activated T cells and macrophages, pharmacologic inhibition of CaMKIV resulted in suppression of IFN-γ production and CD69 expression by T cells and IL-1β, IL-6 and TNF-α by macrophages. CONCLUSION: We conclude that pharmacologic inhibition of CaMKIV suppresses cell activation and cytokine production in lupus-prone mice. Our data justify the development of small-molecule CaMKIV inhibitors for the treatment of patients with SLE.

The Role of IL-23/IL-17 Axis in Lupus Nephritis

T cells that express IL-17 infiltrate the kidneys of patients with systemic lupus erythematosus. A significant proportion of these cells are CD3(+)CD4(-)CD8(-) double-negative T cells. In this study, we show that double-negative T cells from MRL/lpr mice express high amounts of IL-17 and that as disease progressively worsens, the expression of IL-17 and of IL-23 receptor in lymphocytes from these mice increases. Lymph node cells from lupus-prone mice, but not control mice, treated in vitro with IL-23 induce nephritis when transferred to non-autoimmune, lymphocyte-deficient Rag-1(-/-) mice. Kidney specimens from these recipient mice show significant Ig and complement deposition. The data indicate that an aberrantly active IL-23/IL-17 axis contributes to the development of nephritis in lupus-prone mice.

Major peptide autoepitopes for nucleosome-specific T cells of human lupus.

We tested 154 peptides spanning the entire length of core histones of nucleosomes for the ability to stimulate an anti-DNA autoantibody-inducing T helper (Th) clone, as well as CD4(+) T-cell lines and T cells, in fresh PBMCs from 23 patients with lupus erythematosus. In contrast to normal T cells, lupus T cells responded strongly to certain histone peptides, irrespective of the patient's disease status. Nucleosomal peptides in histone regions H2B(10-33), H4(16-39) (and overlapping H4(14-28)), H4(71-94), and H3(91-105) (and overlapping H3(100-114)) were recurrently recognized by CD4 T cells from the patients with lupus. Remarkably, these same peptides overlap with major epitopes for the Th cells that induce anti-DNA autoantibodies and nephritis in lupus-prone mice. We localized 2 other recurrent epitopes for human lupus T cells in H2A(34-48) and H4(49-63). All the T-cell autoepitopes have multiple HLA-DR binding motifs, and the epitopes are located in histone regions recognized by lupus autoantibodies, suggesting a basis for their immunodominance. Native nucleosomes and their peptides H4(16-39), H4(71-94), and H3(91-105) induced a stronger IFN-gamma response, whereas others, particularly, H2A(34-48), favored an IL-10- and/or IL-4-positive T-cell response. The major autoepitopes may reveal the mechanism of autoimmune T-cell expansion and lead to antigen-specific therapy of human lupus.

Lupus nephritis

Both immune and nonimmune mechanisms are operant in lupus nephritis. Recent findings have begun to elucidate fundamental questions in the pathogenesis of the disease. Genetic linkage studies have identified susceptibility loci contributing to nephritis in lupus-prone mice. Polymorphisms of the Fc gamma Rlla gene have been found to correlate with the development of renal disease in black Americans and white Europeans. Genetic factors are important in determining both predisposition to nephritis and outcome (and likely response to therapy). In lupus nephritis, prevention of tissue injury involves effective immunosuppressive therapy and aggressive management of hypertension and hyperlipidemia. Although with intensive immunosuppressive therapy most lupus patients achieve remission, a substantial number of these patients either do not respond, respond partially, or relapse after discontinuation of therapy. Moreover, the toxicity of available immunosuppressive drugs is substantial, suggesting that alternative therapeutic regimens are needed. In the future, other inhibitors of inflammatory, immune, vasoactive, proteolytic, and growth-promoting mediators are likely to play a role in the management of lupus nephritis.

Pathogenesis of early nephritis in lupus prone mice with a genetic accelerating (lpr) factor.

We investigated the relative roles of B cell activity, circulating immune complexes, complement concentration and kinetics of disappearance and uptake of immune complexes from the circulation in the pathogenesis of early nephritis of MRL/lpr mice. In comparison to data in control (C57BL/6J) mice, B cell activity was enhanced and the concentration of autoantibodies and endogenous immune complexes in plasma were increased, whereas complement (C3) concentration was not significantly different in MRL/lpr mice. The kinetics of disappearance of radiolabeled immune complexes from the circulation were similar in MRL/lpr and control mice, whereas uptake of radiolabeled immune complexes by the liver was decreased in MRL/lpr mice. Features of polyclonal B cell activation and impaired mononuclear phagocyte function are early events that may set the stage for progressive systemic involvement in MRL/lpr mice.

Differential effect of the autoimmune Yaa and lpr genes on the acceleration of lupus-like syndrome in MRL/MpJ mice.

The Yaa gene (Y chromosome-linked autoimmune acceleration), linked to the BXSB/MpJ Y chromosome, and the autosomal recessive lpr (lymphoproliferation) gene have been shown to accelerate the progression of the lupus-like autoimmune syndrome in the BXSB and MRL strains, respectively. To compare more directly the role of the Yaa and lpr genes in the development of the autoimmune syndrome, the Y chromosome of BXSB mice was transferred to MRL mice by backcross procedures, and the effect of the Yaa gene on the autoantibody formation and the development of lupus-like nephritis in MRL mice was investigated in comparison with those bearing the lpr mutation. The Yaa gene as well as the lpr gene were able to shorten the life span of MRL mice as a result of the accelerated development of lethal lupus-like nephritis. However, the acceleration promoted by the Yaa gene (50% mortality rate: 12 months) was less severe than that induced by the lpr gene (50% mortality rate: 7 months). This may be related to the finding that the lpr gene enhanced the production of a large spectrum of autoantibodies, including anti-DNA, rheumatoid factors and anti-gp70, and of cryoglobulins, whereas only anti-gp70 production among the autoantibodies studies was markedly enhanced by the Yaa gene. The selective autoimmune accelerating effect of the Yaa gene was similarly observed in (NZW X MRL)F1 hybrid mice. Our results suggest that the Yaa gene, unlike the lpr gene, exhibits selective autoimmune accelerating activity, but as a result of increased formation of certain nephritogenic autoantibodies such as anti-gp70 antibodies, the Yaa gene is able to accelerate the progression of lupus-like nephritis in lupus-prone mice.