Autoimmunity
Abstract
T follicular helper (Tfh) cells represent an important subset of CD4+ T cells that is crucial to the maturation and differentiation of B cells and the production of high-affinity antibodies. Since BAFF, a vital B cell survival factor, is also crucial to B cell maturation and differentiation, we assessed the effects of BAFF on Tfh cell development and function. We demonstrate that deficiency of BAFF, but not of APRIL, markedly inhibits Tfh cell development, germinal center (GC) formation, and antigen-specific antibody production. The promoting effect of BAFF on Tfh cell development is dependent on expression of BR3 on T cells, and its promoting effect on GC formation is dependent on expression of BR3 on both T cells and B cells. BAFF directly promotes expression of the Tfh cell-characteristic genes via NF-κB signaling. This effect does need BR3 expression. Thus, BAFF not only has direct effects on B cells, but it also has direct effects on Tfh cell differentiation via engagement of BR3 which collectively promote GC formation and production of high-affinity antibodies. This dual effect of BAFF on B cells and Tfh cells may help explain the clinical utility of BAFF antagonists in the management of certain autoimmune diseases.
Authors
Ye Chen, Maogen Chen, Yu Liu, Qiang Li, Youqiu Xue, Liu Liu, Rongzhen Liang, Yiding Xiong, Jun Zhao, Jingrong Chen, Weidong Lin, Julie Wang, YunFeng Pan, William Stohl, Song Guo Zheng
Abstract
The pathogenesis of the murine model of autoimmune pancreatitis associated with IgG4-related disease (AIP/IgG4-RD) induced by administration of polyinosinic-polycytidylic acid, is incompletely understood. While it is known that murine and human AIP/IgG4-RD is driven by plasmacytoid dendritic cells (pDCs) producing IFN-α, the origin of these cells and their relation to effector T cells is not known. Here we show that murine AIP was initiated by TLR3-bearing conventional DCs in the uninflamed pancreas whose activation by TLR3 ligand (polyinosinic-polycytidylic acid) caused IFN-α, CXCL9, and CXCL10 secretion. This, in turn, induced pancreatic recruitment of CXCR3+ T cells and these T cells, via their secretion of CCL25, facilitated migration of pDCs bearing CCR9 into the pancreas. This established a feedback loop anchored by the now dominant pDC production of IFN-α and the continued CXCR3+ T cell facilitation of pDC migration. Remarkably, the interaction between CXCR3+ T cells and pDCs also existed at the functional levels since this interaction enhanced the production of CCL25 and IFN-α by CXCR3+ T cells and pDCs, respectively. Evidence presented here that a similar disease mechanism was present in human AIP/IgG4-RD creates new avenues of disease treatment.
Authors
Akane Hara, Tomohiro Watanabe, Kosuke Minaga, Tomoe Yoshikawa, Masayuki Kurimoto, Ikue Sekai, Yasuhiro Masuta, Ryutaro Takada, Yasuo Otsuka, Ken Kamata, Shiki Takamura, Masatoshi Kudo, Warren Strober
Abstract
Despite growing recognition, neuropsychiatric diseases associated with infections are a major unsolved problem worldwide. Group A streptococcal (GAS) infections can cause autoimmune sequelae characterized by movement disorders, such as Sydenham chorea (SC), and neuropsychiatric disorders. The molecular mechanisms underlying these diseases are not fully understood. Our previous work demonstrates that autoantibodies (AAbs) can target dopaminergic neurons and increase dopamine receptor D2 (D2R) signaling. However, AAb influence on dopamine receptor D1 (D1R) activity is underexplored. We found evidence that suggests GAS-induced cross-reactive AAbs promote autoimmune encephalitis of the basal ganglia (BGE), a region of high dopamine receptor density. Here, we report a new mechanism whereby neuropsychiatric syndromes are distinguished from movement disorders by differences in D1R and D2R AAb titers, signaling, receiver operating characteristic (ROC) curves, and immunoreactivity with D1R and D2R autoreactive epitopes. D1R AAb signaling was observed through patient serum AAbs and novel patient-derived mAbs, which induced both D1R G protein- and -arrestin transduced signals. Furthermore, patient AAbs and mAbs enhanced D1R signaling mechanisms mediated by the neurotransmitter dopamine. Our findings suggest that AAb-mediated D1R signaling may contribute to the pathogenesis of neuropsychiatric sequelae and inform new options for diagnosis and treatment of GAS sequelae and related disorders.
Authors
Chandra M. Menendez, Jonathan Zuccolo, Susan E. Swedo, Sean Reim, Brian Richmand, Hilla Ben-Pazi, Abraham Kovoor, Madeleine W. Cunningham
Abstract
Multiple sclerosis (MS) is a complex disease with significant heterogeneity in disease course and progression. Genetic studies have identified numerous loci associated with MS risk, but the genetic basis of disease progression remains elusive. To address this, we leveraged the Collaborative Cross (CC), a genetically diverse mouse strain panel, and experimental autoimmune encephalomyelitis (EAE). The thirty-two CC strains studied captured a wide spectrum of EAE severity, trajectory, and presentation, including severe-progressive, monophasic, relapsing remitting, and axial rotary (AR)-EAE, accompanied by distinct immunopathology. Sex differences in EAE severity were observed in six strains. Quantitative trait locus analysis revealed distinct genetic linkage patterns for different EAE phenotypes, including EAE severity and incidence of AR-EAE. Machine learning-based approaches prioritized candidate genes for loci underlying EAE severity (Abcc4 and Gpc6) and AR-EAE (Yap1 and Dync2h1). This work expands the EAE phenotypic repertoire and identifies novel loci controlling unique EAE phenotypes, supporting the hypothesis that heterogeneity in MS disease course is driven by genetic variation.
Authors
Emily A. Nelson, Anna L. Tyler, Taylor Lakusta-Wong, Karolyn G. Lahue, Katherine C. Hankes, Cory Teuscher, Rachel M. Lynch, Martin T. Ferris, J. Matthew Mahoney, Dimitry N. Krementsov
Abstract
This study aimed at defining the role of the B-cell adaptor protein BANK1 in the appearance of age-associated B cells (ABCs) in two SLE mouse models (TLR7.tg6 and Imiquimod-induced mice), crossed with Bank1-/- mice. The absence of Bank1 led to a significant reduction in ABC levels, also affecting other B cell populations. To gain deeper insights into their differentiation pathway and the impact of Bank1 on B cell populations, a single-cell transcriptome assay was performed. In the TLR7.tg6 model, we identified 10 clusters within B cells, including an ABC-specific cluster which was decreased in Bank1-deficient mice. In its absence, ABCs exhibited an anti-inflammatory gene expression profile, while being pro-inflammatory in Bank1-sufficient lupus mice. Trajectory analyses revealed that ABCs originated from marginal zone and memory-like B cells, ultimately acquiring transcriptional characteristics associated with atypical memory cells and long-lived plasma cells. Also, Bank1 deficiency normalized the presence of naïve B cells, which were nearly absent in lupus mice. Interestingly, Bank1 deficiency significantly reduced a distinct cluster containing IFN-responsive genes. These findings underscore the critical role of Bank1 in ABC development, impacting early B cell stages towards ABC differentiation, and the presence of IFN-stimulated gene-containing B cells, both populations determinant for autoimmunity.
Authors
Gonzalo Gómez Hernández, Daniel Toro-Domínguez, Georgina Galicia, María Morell, Marta E. Alarcón-Riquelme
Abstract
Palatine tonsils are the only air-contacted lymphoid organs that constantly engage in crosstalk with commensal microorganisms and serve as the first handling sites against microbial antigens. While tonsil inflammations have been implicated in various autoimmune diseases, including rheumatoid arthritis (RA), the precise role of tonsillar microbiota in autoimmune pathogenesis remains inadequately characterized. In this study, we conducted a profiling of the tonsillar microbiota and identified a notable dysbiosis in RA patients, particularly within the Streptococcus genus. Specifically, RA patients exhibited an enrichment of pathogenic Streptococcus species, including S. pyogenes, S. dysgalactiae, and S. agalactiae. Colonization with these bacteria significantly exacerbated arthritis severity and increased autoimmune responses in collagen-induced arthritis (CIA). Furthermore, immunization with peptides derived from these pathogenic Streptococcus species directly induced experimental arthritis. Conversely, RA patients demonstrated a marked deficiency in commensal Streptococcus members, notably S. salivarius. Treatment of CIA mice with S. salivarius attenuated the progression of arthritis and downregulated autoimmune responses. These findings highlight a functional link between tonsillar microbiota and RA, shedding light on their contribution to autoimmunity.
Authors
Jing Li, Shenghui Li, Jiayang Jin, Ruochun Guo, Yuebo Jin, Lulu Cao, Xuanlin Cai, Peishi Rao, Yan Zhong, Xiaohong Xiang, Xiaolin Sun, Jianping Guo, Fanlei Hu, Hua Ye, Yuan Jia, Wenjing Xiao, Yuan An, Xuan Zhang, BinBin Xia, Rentao Yang, Yuanjie Zhou, Lijun Wu, Junjie Qin, Jing He, Jun Wang, Zhanguo Li
Abstract
The interleukin-17 (IL-17) family of cytokines has emerged as a critical player in autoimmune disease, including systemic lupus erythematosus (SLE). However, the role of IL-17B, a poorly understood cytokine, in the pathogenesis of SLE is still not clear. In this study, we investigated the role of IL-17B in the activation and differentiation of B cells, and the pathogenesis of SLE. Intriguingly, IL-17B deficiency aggravated disease in lupus-prone mice and promoted the activation of B cells and the differentiation of germinal center (GC) B cells and plasma cells, while recombinant mouse IL-17B (rmIL-17B) significantly alleviated disease in lupus-prone mice. Mechanistically, rmIL-17B inhibited the activation of the Toll-like receptor (TLR) and interferon (IFN) pathways in B cells by downregulating the FASN-mediated lipid metabolism. Loss of FASN significantly alleviated the disease in lupus-prone mice and inhibited the activation and differentiation of B cells. In addition, B cells had greater FASN expression and lower IL-17RB levels in patients with SLE than in healthy controls. Our study described the role of IL-17B in regulating B-cell activation and differentiation, and alleviating the onset of SLE. These findings will lay a theoretical foundation for further understanding of the pathogenesis of SLE.
Authors
Yucai Xiao, Yuxin Hu, Yangzhe Gao, Lin Wang, Lili Zhang, Qun Ma, Zhaochen Ning, Lu Yu, Haochen Li, Jiakun Liu, Junyu Wang, Yonghong Yang, Huabao Xiong, Guanjun Dong
Abstract
Loss of NADPH oxidase (NOX2) exacerbates systemic lupus erythematosus (SLE) in mice and humans, but the mechanisms underlying this effect remain unclear. To identify the cell lineages in which NOX2 deficiency drives SLE, we employed conditional knockout (KO) and chimera approaches to delete Cybb in several hematopoietic cell lineages of MRL.Faslpr lupus-prone mice. Deletion of Cybb in macrophages/monocytes exacerbated lupus nephritis, though not to the degree observed in the Cybb global KOs. Unexpectedly, the absence of Cybb in B cells resulted in profound glomerulonephritis and interstitial nephritis, rivaling that seen with global deletion. Further, we identified that NOX2 is a key regulator of TLR7, a driver of SLE pathology, both globally and specifically in B cells. This is mediated in part through suppression of TLR7-mediated NF-kB signaling in B cells. Thus, NOX2's immunomodulatory effect in SLE is orchestrated not only by its function in the myeloid compartment, but through a pivotal role in B cells by selectively inhibiting TLR7 signaling.
Authors
Rachael A. Gordon, Haylee A. Cosgrove, Anthony Marinov, Sebastien Gingras, Jeremy S. Tilstra, Allison M. Campbell, Sheldon I. Bastacky, Michael Kashgarian, Andras Perl, Kevin M. Nickerson, Mark J. Shlomchik
Abstract
Gain-of-function mutations in the dsDNA sensing adaptor STING lead to a severe autoinflammatory syndrome known as STING-associated vasculopathy with onset in Infancy (SAVI). SAVI patients develop interstitial lung disease (ILD) and produce autoantibodies that are commonly associated with systemic autoimmune diseases. Mice expressing the most common SAVI mutation STING V154M (VM) similarly develop ILD, but exhibit severe T and B cell lymphopenia, low serum Ig titers, and lack autoantibodies. Importantly, lethally irradiated VM hosts reconstituted with wildtype (WT) stem cells (WT→VM) still develop ILD. In this study, we find that WT→VM chimeras had restored B cell function, produced autoantibodies, and thereby recapitulated the loss of tolerance seen in SAVI patients. Lymphocytes derived from both WT and BCR or TCR transgenic (Tg) donors accumulated in the extravascular lung tissue of WT+Tg→VM mixed chimeras, but lymphocyte activation and germinal center formation required WT cells with a diverse repertoire. Furthermore, when T cells isolated from the WTVM chimeras were adoptively transferred to naïve Rag1-deficient 2º hosts, they trafficked to the lung and recruited neutrophils. Overall, these findings indicated that VM expression by radioresistant cells promoted the activation of autoreactive B cells and T cells that then differentiated into potentially pathogenic effector subsets.
Authors
Kevin MingJie Gao, Kristy Chiang, Sharon Subramanian, Xihui Yin, Paul J. Utz, Kerstin Nündel, Kate A. Fitzgerald, Ann Marshak-Rothstein
Abstract
HLA-B*27 was one of the first HLA alleles associated with an autoimmune disease, i.e., axial spondyloarthritis (axSpA) and acute anterior uveitis (B27AAU), which cause joint and eye inflammation, respectively. Gastrointestinal inflammation has been suggested as a trigger of axSpA. We recently identified a bacterial peptide (YeiH) that can be presented by HLA-B*27 to expanded public T cell receptors (TCRs) in the joint in axSpA and the eye in B27AAU. While YeiH is present in enteric microbiota and pathogens, additional evidence that pathogenic T cells in HLA-B*27-associated autoimmunity may have had a prior antigenic encounter within the gastrointestinal tract remains lacking. Here, we analyze ocular, synovial, and blood T cells in B27AAU and axSpA, showing that YeiH-specific CD8 T cells express a mucosal gene set and surface proteins consistent with intestinal differentiation, including CD161, integrin α4β7, and CCR6. In addition, we find an expansion of YeiH-specific CD8 T cells in the blood of axSpA and B27AAU over healthy controls, whereas influenza-specific CD8 T cells were equivalent across groups. Lastly, we demonstrate the dispensability of TRBV9 for antigen recognition. Collectively, our data suggest that, in HLA-B27-associated autoimmunity, early antigen exposure and differentiation of pathogenic CD8 T cells may occur in enteric organs.
Authors
Michael A. Paley, Xinbo Yang, Lynn M. Hassman, Frank Penkava, Lee I. Garner, Grace L. Paley, Nicole Linskey, Ryan Agnew, Paulo Henrique Arantes de Faria, Annie Feng, Sophia Y. Li, Davide Simone, Elisha D.O. Roberson, Philip A. Ruzycki, Ekaterina Esaulova, Jennifer Laurent, Lacey Feigl-Lenzen, Luke E. Springer, Chang Liu, Geraldine M. Gillespie, Paul Bowness, K. Christopher Garcia, Wayne M. Yokoyama
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