Dendritic cell inhibitory receptor (DCIR) is a C-type lectin receptor selectively expressed on myeloid cells, including monocytes, macrophage, dendritic cells, and neutrophils. Its role in immune regulation has been implicated in murine models and human genome-wide association studies (GWAS), suggesting defective DCIR function associates with increased susceptibility to autoimmune diseases such as rheumatoid arthritis, lupus and Sjogren’s syndrome. However, little is known about the mechanisms underlying DCIR activation to dampen inflammation. Here, we developed anti-DCIR agonistic antibodies that promote phosphorylation on DCIR’s immune receptor tyrosine-based inhibitory motifs (ITIM) and recruitment of SH2 containing protein tyrosine phosphatase-2 (SHP2) for reducing inflammation. We also explored the inflammation resolution by depleting DCIR+ cells with antibodies. Utilizing a human DCIR knock-in mouse model, we validated the anti-inflammatory properties of the agonistic anti-DCIR antibody in experimental peritonitis and colitis. These findings provide critical evidence for targeting DCIR to develop transformative therapies for inflammatory diseases.
Liang Chen, Suresh Patil, Jeffrey Barbon, James Waire, F. Stephen Laroux, Donna McCarthy, Mishra Pratibha, Suju Zhong, Feng Dong, Karin Orsi, Gunarso Nguyen, Yingli Yang, Nancy Crosbie, Eric Dominguez, Arun Deora, Geertruida Veldman, Susan V. Westmoreland, Liang Jin, Timothy Radstake, Kevin White, Hsi-Ju Wei
The mechanisms responsible for the distribution and severity of joint involvement in rheumatoid arthritis (RA) are not known. To explore whether site-specific FLS biology might be associated with location-specific synovitis and explain the predilection for hand (wrist/metacarpal phalangeal joints) involvement in RA, we generated transcriptomic and chromatin accessibility data from FLS to identify the transcription factors (TFs) and pathways. Networks were constructed by integration of chromatin accessibility and gene expression data. Analysis revealed joint-specific patterns of FLS phenotype, with proliferative, migratory, proinflammatory, and matrix-degrading characteristics observed in resting FLS derived from the hand joints compared with hip or knee. TNF-stimulation amplified these differences, with greater enrichment of proinflammatory and proliferative genes in hand FLS compared with hip and knee FLS. Hand FLS also had the greatest expression of markers associated with an ‘activated’ state relative to the ‘resting’ state, with the greatest cytokine and MMP expression in TNF-stimulated hand FLS. Predicted differences in proliferation and migration were biologically validated with hand FLS exhibiting greater migration and cell growth than hip or knee FLS. Distinctive joint-specific FLS biology associated with a more aggressive inflammatory response might contribute to the distribution and severity of joint involvement in RA.
Eunice Choi, Camilla R. L. Machado, Takaichi Okano, David L. Boyle, Wei Wang, Gary S. Firestein
Juvenile Dermatomyositis (JDM) is one of several childhood-onset autoimmune disorders characterized by a type I interferon response and autoantibodies. Treatment options are limited due to incomplete understanding of how the disease emerges from dysregulated cell states across the immune system. We therefore investigated the blood of JDM patients at different stages of disease activity using single-cell transcriptomics paired with surface protein expression. By immunophenotyping peripheral blood mononuclear cells, we observed skewing of the B cell compartment towards an immature naive state as a hallmark of JDM at diagnosis. Furthermore, we find that these changes in B cells are paralleled by T cell signatures suggestive of Th2-mediated inflammation that persist despite disease quiescence. We applied network analysis to reveal that hyperactivation of the type I interferon response in all immune populations is coordinated with previously masked cell states including dysfunctional protein processing in CD4+ T cells and regulation of cell death programming in NK, CD8+ T cells and gdT cells. Together, these findings unveil the coordinated immune dysregulation underpinning JDM and provide insight into strategies for restoring balance in immune function.
Gabrielle Rabadam, Camilla Wibrand, Emily Flynn, George C. Hartoularos, Yang Sun, Chioma Madubata, Gabriela K. Fragiadakis, Jimmie Ye, Susan Kim, Zev J. Gartner, Marina Sirota, Jessica Neely
Applying advanced molecular profiling together with highly specific targeted therapies offers the possibility to better dissect the mechanisms underlying immune mediated inflammatory diseases such as systemic lupus erythematosus (SLE) in humans. Here we apply a combination of single cell RNA sequencing and T/B cell repertoire analysis to perform an in-depth characterization of molecular changes in the immune-signature upon CD19 CAR T cell-mediated depletion of B cells in SLE patients. The resulting datasets do not only confirm a selective CAR T cell-mediated reset of the B cell response, but simultaneously reveal consequent changes in the transcriptional signature of monocyte and T cell subsets that respond with a profound reduction in type 1 interferon signaling. Our current data thus provide evidence for a causal relationship between the B cell response and the increased interferon signature observed in SLE and additionally demonstrate the usefulness of combining targeted therapies and novel analytic approaches to decipher molecular mechanisms of immune-mediated inflammatory diseases in humans.
Artur Wilhelm, David Chambers, Fabian Müller, Aline Bozec, Ricardo Grieshaber-Bouyer, Thomas Winkler, Dimitrios Mougiakakos, Andreas Mackensen, Georg Schett, Gerhard Krönke
IgA nephropathy (IgAN) represents the main cause of renal failure, while the precise pathogenetic mechanisms have not been fully determined. Herein, we conducted a cross-species single-cell survey on human IgAN and mouse and rat IgAN models to explore the pathogenic programs. Cross-species single-cell RNA sequencing (scRNA-Seq) revealed that the IgAN mesangial cells (MCs) expressed high levels of inflammatory signatures CXCL12, CCL2, CSF1, and IL-34 and specifically interacted with IgAN macrophages via the CXCL12/CXCR4, CSF1/IL-34/CSF1 receptor, and integrin subunit alpha X/integrin subunit alpha M/complement C3 (C3) axes. IgAN macrophages expressed high levels of CXCR4, PDGFB, triggering receptor expressed on myeloid cells 2, TNF, and C3, and the trajectory analysis suggested that these cells derived from the differentiation of infiltrating blood monocytes. Additionally, protein profiling of 21 progression and 28 nonprogression IgAN samples revealed that proteins CXCL12, C3, mannose receptor C-type 1, and CD163 were negatively correlated with estimated glomerular filtration rate (eGFR) value and poor prognosis (30% eGFR as composite end point). Last, a functional experiment revealed that specific blockade of the Cxcl12/Cxcr4 pathway substantially attenuated the glomerulus and tubule inflammatory injury, fibrosis, and renal function decline in the mouse IgAN model. This study provides insights into IgAN progression and may aid in the refinement of IgAN diagnosis and the optimization of treatment strategies.
Xizhao Chen, Tiantian Wang, Lei Chen, Yinghua Zhao, Yiyao Deng, Wanjun Shen, Lin Li, Zhong Yin, Chaoran Zhang, Guangyan Cai, Min Zhang, Xiangmei Chen
The homeostasis of immunoglobulin G (IgG) is maintained by the neonatal Fc receptor, FcRn. Consequently, antagonism of FcRn to reduce endogenous IgG levels is an emerging strategy for treating antibody-mediated autoimmune disorders using either FcRn-specific antibodies or an engineered Fc fragment. For certain FcRn-specific antibodies, this approach has resulted in reductions in the levels of serum albumin, the other major ligand transported by FcRn. Cellular and molecular analyses of a panel of FcRn antagonists have been carried out to elucidate the mechanisms leading to their differential effects on albumin homeostasis. These analyses have identified two processes underlying decreases in albumin levels during FcRn blockade: increased degradation of FcRn and competition between antagonist and albumin for FcRn binding. These findings have potential implications for the design of drugs to modulate FcRn function.
Guanglong Ma, Andrew R. Crowley, Liesbeth Heyndrickx, Ilse Rogiers, Eef Parthoens, Jolien Van Santbergen, Raimund J. Ober, Vladimir Bobkov, Hans de Haard, Peter Ulrichts, Erik Hofman, Els Louagie, Bianca Balbino, E. Sally Ward
Mesenchymal stem cells (MSCs) have demonstrated potent immunomodulatory properties that have shown promise in the treatment of autoimmune diseases, including rheumatoid arthritis (RA). However, the inherent heterogeneity of MSCs triggered conflicting therapeutic outcomes, raising safety concerns and limiting their clinical application. This study aimed to investigate the potential of extracellular vesicles derived from human gingival mesenchymal stem cells (GMSC-EVs) as a therapeutic strategy for RA. Through in vivo experiments using an experimental RA model, our results demonstrated that GMSC-EVs selectively homed to inflamed joints and recovered Treg and Th17 cells balance, resulting in the reduction of arthritis progression. Our investigations also uncovered miR-148a-3p as a critical contributor to the Treg/Th17 balance modulation via IKKB/NF-κB signaling orchestrated by GMSC-EVs, which was subsequently validated in a model of human xenograft versus host disease (xGvHD). Furthermore, we successfully developed a humanized animal model by utilizing synovial fibroblasts obtained from patients with RA (RASFs). We found that GMSC-EVs impeded the invasiveness of RASFs and minimized cartilage destruction, indicating their potential therapeutic efficacy in the context of RA patients. Overall, the unique characteristics, including reduced immunogenicity, simplified administration, and inherent ability to target inflamed tissues, position GMSC-EVs as a viable alternative for RA and other autoimmune diseases.
Jingrong Chen, Xiaoyi Shi, Yanan Deng, Junlong Dang, Yan Liu, Jun Zhao, Liang Rongzhen, Donglan Zeng, Wenbin Wu, Yiding Xiong, Jia Yuan, Ye Chen, Julie Wang, Weidong Lin, Xiangfang Chen, Weishan Huang, Nancy Olsen, Yunfeng Pan, Qing-Ling Fu, Song Guo Zheng
Tregs have the potential to establish long-term immune tolerance in patients recently diagnosed with type 1 diabetes (T1D) by preserving β cell function. Adoptive transfer of autologous thymic Tregs, although safe, exhibited limited efficacy in previous T1D clinical trials, likely reflecting a lack of tissue specificity, limited IL-2 signaling support, and in vivo plasticity of Tregs. Here, we report a cell engineering strategy using bulk CD4+ T cells to generate a Treg cell therapy (GNTI-122) that stably expresses FOXP3, targets the pancreas and draining lymph nodes, and incorporates a chemically inducible signaling complex (CISC). GNTI-122 cells maintained an expression profile consistent with Treg phenotype and function. Activation of CISC using rapamycin mediated concentration-dependent STAT5 phosphorylation and, in concert with T cell receptor engagement, promoted cell proliferation. In response to the cognate antigen, GNTI-122 exhibited direct and bystander suppression of polyclonal, islet-specific effector T cells from patients with T1D. In an adoptive transfer mouse model of T1D, a mouse engineered-Treg analog of GNTI-122 trafficked to the pancreas, decreased the severity of insulitis, and prevented progression to diabetes. Taken together, these findings demonstrate in vitro and in vivo activity and support further development of GNTI-122 as a potential treatment for T1D.
Gene I. Uenishi, Marko Repic, Jennifer Y. Yam, Ashley Landuyt, Priya Saikumar-Lakshmi, Tingxi Guo, Payam Zarin, Martina Sassone-Corsi, Adam Chicoine, Hunter Kellogg, Martina Hunt, Travis Drow, Ritika Tewari, Peter J. Cook, Soo Jung Yang, Karen Cerosaletti, Darius Schweinoch, Benjamin Guiastrennec, Eddie James, Chandra Patel, Tiffany F. Chen, Jane H. Buckner, David J. Rawlings, Thomas J. Wickham, Karen T. Mueller
Understanding the immune responses to SARS-CoV-2 vaccination is critical to optimizing vaccination strategies for individuals with autoimmune diseases, such as systemic lupus erythematosus (SLE). Here, we comprehensively analyzed innate and adaptive immune responses in 19 patients with SLE receiving a complete 2-dose Pfizer-BioNTech mRNA vaccine (BNT162b2) regimen compared with a control cohort of 56 healthy control (HC) volunteers. Patients with SLE exhibited impaired neutralizing antibody production and antigen-specific CD4+ and CD8+ T cell responses relative to HC. Interestingly, antibody responses were only altered in patients with SLE treated with immunosuppressive therapies, whereas impairment of antigen-specific CD4+ and CD8+ T cell numbers was independent of medication. Patients with SLE also displayed reduced levels of circulating CXC motif chemokine ligands, CXCL9, CXCL10, CXCL11, and IFN-γ after secondary vaccination as well as downregulation of gene expression pathways indicative of compromised innate immune responses. Single-cell RNA-Seq analysis reveals that patients with SLE showed reduced levels of a vaccine-inducible monocyte population characterized by overexpression of IFN-response transcription factors. Thus, although 2 doses of BNT162b2 induced relatively robust immune responses in patients with SLE, our data demonstrate impairment of both innate and adaptive immune responses relative to HC, highlighting a need for population-specific vaccination studies.
Kavita Y. Sarin, Hong Zheng, Yashaar Chaichian, Prabhu S. Arunachalam, Gayathri Swaminathan, Alec Eschholz, Fei Gao, Oliver F. Wirz, Brandon Lam, Emily Yang, Lori W. Lee, Allan Feng, Matthew A. Lewis, Janice Lin, Holden T. Maecker, Scott D. Boyd, Mark M. Davis, Kari C. Nadeau, Bali Pulendran, Purvesh Khatri, Paul J. Utz, Lisa C. Zaba
In autoimmunity, FOXP3+ regulatory T cells (Tregs) skew towards a pro-inflammatory, non-suppressive phenotype and are therefore unable to control the exaggerated autoimmune response. This largely impacts the success of autologous Treg therapy which is currently under investigation for autoimmune diseases, including multiple sclerosis (MS). There is a need to ensure in vivo Treg stability before successful application of Treg therapy. Using genetic fate-mapping mice, we demonstrate that inflammatory, cytokine-expressing exFOXP3 T cells accumulate in the central nervous system during experimental autoimmune encephalomyelitis. In a human in vitro model, we discovered that interaction with inflamed blood-brain barrier endothelial cells (BBB-ECs) induces loss-of-function by Tregs. Transcriptome and cytokine analysis revealed that in vitro migrated Tregs have disrupted regenerative potential, a pro-inflammatory Th1/17 signature and upregulate the mTORC1 signaling pathway. In vitro treatment of migrated human Tregs with the clinically-approved mTORC1 inhibitor rapamycin restored suppression. Finally, flow cytometric analysis indicated an enrichment of inflammatory, less suppressive CD49d+ Tregs in the cerebrospinal fluid of people with MS. In sum, interaction with BBB-ECs is sufficient to affect Treg function, and transmigration triggers an additive pro-inflammatory phenotype switch. These insights help improve the efficacy of autologous Treg therapy of MS.
Paulien Baeten, Ibrahim Hamad, Cindy Hoeks, Michael Hiltensperger, Bart Van Wijmeersch, Veronica Popescu, Lilian Aly, Veerle Somers, Thomas Korn, Markus Kleinewietfeld, Niels Hellings, Bieke Broux
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