Intrarenal macrophage infiltration induced by T cells is associated with podocyte injury in lupus nephritis patients

Lupus ◽  
2016 ◽  
Vol 25 (14) ◽  
pp. 1577-1586 ◽  
Author(s):  
R Ma ◽  
W Jiang ◽  
Z Li ◽  
Y Sun ◽  
Z Wei

Proteinuria is the hallmark of clinical manifestation of disease activity in lupus nephritis (LN) patients, which arises from direct or indirect podocyte injury. This study is to explore the relationship between intrarenal T cell infiltration and podocyte injury in lupus nephritis (LN), and to understand the potential mechanisms of podocyte injury induced by intrarenal T cells. Sixty renal biopsies from patients diagnosed with LN were included in the present study. Histological changes in LN patients were detected by light and electron microscopy. Podocyte-specific nephrin expression in renal tissues was detected by immunofluorescence. Infiltration of T cells (CD3+ cells), infiltration of macrophages (CD68+ cells) and the expression of osteopontin (OPN) in renal tissues were examined by immunohistochemical staining. Pearson or Spearman’s tests were used to perform correlation analysis. Morphologic lesions of podocytes were more severe in LN patients than in normal control subjects. Compared with normal control subjects, nephrin expression was significantly decreased in LN patients. The expression level of nephrin was significantly lower in active LN patients than in the inactive group of patients ( P < 0.05). Compared with normal control subjects, the number of infiltrated intrarenal T cells and macrophages was significantly increased in LN patients. T cells were mainly distributed in renal interstitium, with very few being in glomeruli, while macrophages were mainly located in glomeruli. The number of intrarenal infiltrated T cells and macrophages in active LN patients was more than that in the inactive group ( P < 0.05). Compared with normal control subjects, OPN expression in LN patients was increased significantly. The expression level of OPN in active LN patients was significantly higher than that in the inactive group ( P < 0.05). Podocyte-specific nephrin was negatively correlated with 24-hour proteinuria, intrarenal T cells infiltration and intrarenal OPN expression in LN patients ( P < 0.001). Intrarenal macrophages had significantly positive correlation with intrarenal OPN expression ( P < 0.001). The present study provides possible links between intrarenal T cells, OPN, macrophages with reduced podocyte-nephrin and podocytopathy in systemic lupus erythematosus. In addition, infiltration of macrophages in glomeruli induced by OPN that is induced by T cells may be a crucial mechanism for podocyte injury.

Lupus ◽  
2019 ◽  
Vol 28 (12) ◽  
pp. 1468-1472 ◽  
Author(s):  
N Yoshida ◽  
F He ◽  
V C Kyttaris

Signal transducer and activator of transcription (STAT) 3 is a regulator of T-cell responses to external stimuli, such as pro-inflammatory cytokines and chemokines. We have previously shown that STAT3 is activated (phosphorylated) at high levels in systemic lupus erythematosus (SLE) T cells and mediates chemokine-induced migration and T:B cell interactions. Stattic, a small molecular STAT3 inhibitor, can partially ameliorate lupus nephritis in mice. To understand the role of STAT3 better in T-cell pathophysiology in lupus nephritis and its potential as a treatment target, we silenced its expression in T cells using a cd4-driven CRE-Flox model. We found that lupus-prone mice that do not express STAT3 in T cells did not develop lymphadenopathy, splenomegaly, or glomerulonephritis. Moreover, the production of anti-dsDNA antibodies was decreased in these mice compared to controls. To dissect the mechanism, we also used a nephrotoxic serum model of nephritis. In this model, T cell–specific silencing of STAT3 resulted in amelioration of nephrotoxic serum-induced kidney damage. Taken together, our results suggest that in mouse models of autoimmune nephritis, T cell–specific silencing of STAT3 can hamper their ability to help B cells to produce autoantibodies and induce cell tissue infiltration. We propose that STAT3 inhibition in T cells represents a novel approach in the treatment of SLE and lupus nephritis in particular.


2020 ◽  
Vol 35 (Supplement_3) ◽  
Author(s):  
Kenneth Kalunian ◽  
Richard Furie ◽  
Jai Radhakrishnan ◽  
Vandana Mathur ◽  
Joel Rothman ◽  
...  

Abstract Background and Aims Lupus nephritis (LN) is a leading cause of morbidity and mortality in systemic lupus erythematosus (SLE) patients. T cells are believed to play a central role in the pathogenesis of both SLE and LN. CD6 is a co-stimulatory receptor, predominantly expressed on T cells, that binds to activated leukocyte cell adhesion molecule (ALCAM), a ligand expressed on antigen presenting cells and various epithelial and endothelial tissues. The CD6-ALCAM pathway plays an integral role in modulating T cell activation, proliferation, differentiation and trafficking, and is central to immune mediated inflammation. Itolizumab (EQ001) is a humanized IgG1 monoclonal antibody that binds CD6, blocks the interaction between CD6 and ALCAM, and inhibits both the activation and trafficking of T cells. Inhibiting the CD6-ALCAM pathway with itolizumab potentially represents a promising therapeutic approach for the treatment of LN. The aim of this study is to assess the safety and tolerability, pharmacokinetics, pharmacodynamics, and clinical activity of subcutaneously administered itolizumab in patients with SLE with and without active proliferative lupus nephritis (apLN). Method This cohort-based dose escalation study includes two types of patients: The Type A cohort will enroll ∼24 patients with SLE without apLN (all treated with itolizumab) and the Type B cohort will randomize in a blinded manner ∼36 patients (3:1, itolizumab:placebo) with biopsy-proven ISN/RPS class III or IV (+ V) apLN who have had inadequate response to induction and/or post-induction maintenance treatment, exhibiting urine protein to creatinine ratio [UPCR] ≥1 g/g and active serology. Within both the Type A and Type B cohorts, up to 4 dose groups will be tested (Figure). Background treatments for SLE or LN are allowed. Following 4 weeks of treatment in a new higher dose Type A cohort and recommendation by an independent safety data review committee (DRC), the dose studied in the Type A cohort may then be studied in a Type B Cohort for a 12-week treatment duration (Figure). The primary endpoint is the safety and tolerability of itolizumab. Efficacy endpoints (in the Type B cohorts) include UPCR, estimated glomerular filtration rate, prednisone dose requirements, renal response, Systemic Lupus Erythematosus Disease Activity Index 2000 (SLEDAI-2K), FACIT Fatigue Scale, serologic markers, and other patient reported outcomes. In Type A cohort patients, clinical responses and pharmacologic activity will be assessed based on changes in serologic markers, SLEDAI-2K, FACIT Fatigue Scale. Pharmacodynamic markers, including markers that may allow future risk stratification, urinary ALCAM and CD6, will be examined in both cohort types. Results The study is ongoing. Six patients have been enrolled in Type A Cohort 1 (0.4 mg/kg dose) and completed both treatment and 4 weeks of post-treatment follow-up. The mean age was 59.5 (12.9) years, 100% were female; 67% were Hispanic/Latino; and 50% were White, and 50% were Black. Duration of SLE ranged from 3 years to 31 years. Concomitant medications for lupus included prednisone (83%, dose range 2.5 mg – 10 mg), methotrexate (33%), and anti-malarials (33%). Baseline SLEDAI-2K (mean 7.5 [2.2]) was based on findings of alopecia (83%); arthritis (67%); mucosal ulcers and rash (50% each); fever, increased dsDNA, and low complement (17% each). There were no adverse events. Additional data from this ongoing study will be presented. Conclusion Itolizumab, a monoclonal antibody blocking the CD6-ALCAM pathway, is a novel experimental treatment for LN. This is the first trial of itolizumab in patients with SLE and apLN. Data from the first cohort of patients suggest that the drug is safe and well-tolerated at a dose of 0.4 mg/kg over a 4-week treatment period. Additional cohorts of patients with SLE and apLN are currently being enrolled.


2019 ◽  
Vol 8 (9) ◽  
pp. 1340 ◽  
Author(s):  
Hamza Sakhi ◽  
Anissa Moktefi ◽  
Khedidja Bouachi ◽  
Vincent Audard ◽  
Carole Hénique ◽  
...  

Systemic lupus erythematosus (SLE) is characterized by a broad spectrum of renal lesions. In lupus glomerulonephritis, histological classifications are based on immune-complex (IC) deposits and hypercellularity lesions (mesangial and/or endocapillary) in the glomeruli. However, there is compelling evidence to suggest that glomerular epithelial cells, and podocytes in particular, are also involved in glomerular injury in patients with SLE. Podocytes now appear to be not only subject to collateral damage due to glomerular capillary lesions secondary to IC and inflammatory processes, but they are also a potential direct target in lupus nephritis. Improvements in our understanding of podocyte injury could improve the classification of lupus glomerulonephritis. Indeed, podocyte injury may be prominent in two major presentations: lupus podocytopathy and glomerular crescent formation, in which glomerular parietal epithelial cells play also a key role. We review here the contribution of podocyte impairment to different presentations of lupus nephritis, focusing on the podocyte signaling pathways involved in these lesions.


1987 ◽  
Vol 165 (5) ◽  
pp. 1252-1268 ◽  
Author(s):  
S K Datta ◽  
H Patel ◽  
D Berry

We investigated the underlying mechanisms of systemic autoimmune disease in MRL-+/+, (NZB X NZW)F1, and (NZB X SWR)F1 mice, since these strains develop glomerulonephritis without the superimposition of any secondary lupus-accelerating genes. All three strains manifested a common immunoregulatory defect specific for the production of pathogenic anti-DNA autoantibodies that are of IgG class and cationic in charge. At or just before the age they began to develop lupus nephritis, spleen cells of the mice contained a subpopulation of Th cells that selectively induced their B cells in vitro to produce highly cationic IgG autoantibodies to both single-stranded DNA (ssDNA) and double-stranded DNA (dsDNA). By contrast, T cells from younger preautoimmune mice were incapable of providing this help. Moreover, only B cells of the older lupus mice could be induced to secrete cationic anti-DNA antibodies of IgG class. B cells of young lupus mice could not produce the cationic autoantibodies even with the help of T cells from the older mice, nor upon stimulation with mitogens. In the older lupus mice we found two sets of Th cells that spontaneously induced the cationic shift in autoantibodies; one set belonged to the classical Th category with L3T4+,Lyt-2- phenotype, whereas the other surprisingly belonged to a double-negative (L3T4-,Lyt-2-), Lyt-1+ subpopulation. The latter set of unusual Th cells were unexpected in these lupus mice since they lacked the lpr (lympho-proliferation) gene. Thus three apparently different murine models of systemic lupus erythematosus possess a common underlying mechanism specific for the spontaneous production of pathogenic anti-DNA autoantibodies.


1992 ◽  
Vol 76 (2) ◽  
pp. 251-260 ◽  
Author(s):  
Daniel W. McVicar ◽  
Donna F. Davis ◽  
Randall E. Merchant

✓ Patients harboring a malignant brain tumor have been described as being highly immunosuppressed, as evidenced by reduced numbers of T cells and the decreased ability of their lymphocytes to produce interleukin-2 (IL-2). In order to determine whether an intrinsic abnormality exists in the T lymphocytes of glioma patients and to evaluate what role corticosteroids may play in glioma-associated immunosuppression, in vitro T cell proliferative function in the presence of recombinant IL-2 (rIL-2) was examined in age-matched groups of normal control subjects, steroid-free patients with glial tumors, steroid-dependent patients with glial tumors, and steroid-dependent patients with nonglial cerebral tumors. The results demonstrated that, when enriched T cell populations of all brain-tumor patients were stimulated with rIL-2 and phytohemagglutinin (PHA), there were no statistically significant differences between any groups. In contrast, when T cell populations were stimulated with mitogenic combinations of phorbol ester, calcium ionophore, and rIL-2, those from steroid-dependent patients with glial tumors had a significantly lower response than those from normal control subjects, suggesting that a population of T cells capable of responding to phorbol ester/ionomycin and not PHA stimulation is inhibited by corticosteroid therapy in glioma patients. In addition, T cells of four brain-tumor patient/age-matched control subject pairs were stimulated with either phorbol ester/ionomycin or PHA for 24 hours; three of the four patients expressed low-affinity IL-2 receptor levels as high or higher than their respective control subjects, suggesting that IL-2 receptor expression in these patients may be quantitatively normal once the T cell number is corrected. Taken together, these results show that the decreased PHA responsiveness that has been previously reported in lymphocytes of glioma patients is not due to a cellular abnormality within the potentially responsive cells, but rather reflects the reduced proportion of T cells within their peripheral blood which, as a consequence, reduces the level of IL-2 production attained upon activation.


Author(s):  
Alice Graham ◽  
Crystal Fong ◽  
Asghar Naqvi ◽  
Jian-Qiang Lu

Toxoplasmosis is an opportunistic infection caused by Toxoplasma gondii (TG), commonly involving the brain. Symptomatic clinical disease of TG infection is much more commonly associated with immunodeficiency; clinicopathological manifestations of brain toxoplasmosis are linked to individual immune responses including brain infiltration of T-cells that are thought to fight against toxoplasmosis. In patients with autoimmune diseases, immune status is typically characterized by T-cell infiltration and complicated mainly by immunosuppressant and/or immunomodulatory treatment. In this study, we demonstrate clinical and radiological features correlated with pathological features of brain toxoplasmosis at different disease stages in a patient with coexisting autoimmune diseases, including systemic lupus erythematosus and autoimmune hepatitis. The infiltration of CD8+ T-cells in toxoplasma immunostaining-positive acute lesions was greater than that in toxoplasma immunostaining-negative chronic lesions. We also review previously reported cases of brain toxoplasmosis with comorbid autoimmune diseases. Our present case and literature review suggest that brain toxoplasmosis in patients with autoimmune diseases may be asymptomatic unless disease complications occur; it may present as an incidental finding at postmortem examination of rapidly developed lesions. T-cell infiltration in patients with autoimmune diseases and coexisting toxoplasmosis may be at least partially reduced; ultimately, the roles of T-cell infiltration in brain toxoplasmosis deserve further investigation.Learning ObjectivesDiscuss complicated immune response to toxoplasmosis in patients with autoimmune diseases.Describe clinical, radiological, and pathological features of brain toxoplasmosis in patients with autoimmune diseases.


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