Although the immune response within draining lymph nodes (DLNs) has been studied for decades, how their stromal compartment contributes to this process remains to be fully explored. Here, we show that donor mast cells were prominent activators of collagen I deposition by fibroblastic reticular cells (FRCs) in DLNs shortly following transplantation. Serial analysis of the DLN indicated that the LN stroma did not return to its baseline microarchitecture following organ rejection and that the DLN contained significant fibrosis following repetitive organ transplants. Using several FRC conditional-knockout mice, we show that induction of senescence in the FRCs of the DLN resulted in massive production of collagen I and a proinflammatory milieu within the DLN. Stimulation of herpes virus entry mediator (HVEM) on FRCs by its ligand LIGHT contributed chiefly to the induction of senescence in FRCs and overproduction of collagen I. Systemic administration of ex vivo–expanded FRCs to mice decreased DLN fibrosis and strengthened the effect of anti-CD40L in prolonging heart allograft survival. These data demonstrate that the transformation of FRCs into proinflammatory myofibroblasts is critically important for the maintenance of a proinflammatory milieu within a fibrotic DLN.
Xiaofei Li, Jing Zhao, Vivek Kasinath, Mayuko Uehara, Liwei Jiang, Naima Banouni, Martina M. McGrath, Takaharu Ichimura, Paolo Fiorina, Dario R. Lemos, Su Ryon Shin, Carl F. Ware, Jonathan S. Bromberg, Reza Abdi
Despite effective antiretroviral therapy, HIV-1-nfected cells continue to produce viral antigens and induce chronic immune exhaustion. We propose to identify HIV-1-suppressing agents which can inhibit HIV-1 reactivation and reduce HIV-1-induced immune activation. Using a novel dual reporter system and a high-throughput drug screen, we identified FDA-approved drugs which can suppress HIV-1 reactivation in both cell line models and CD4+ T cells from virally suppressed, HIV-1-infected individuals. We identified 11 cellular pathways required for HIV-1 reactivation as druggable targets. Using differential expression analysis, gene set enrichment analysis and exon-intron landscape analysis, we examined the impact of drug treatment on the cellular environment at a genome-wide level. We identified a new function of a JAK inhibitor filgotinib which suppresses HIV-1 splicing. First, filgotinib preferentially suppresses spliced HIV-1 RNA transcription. Second, filgotinib suppresses HIV-1-driven aberrant cancer-related gene expression at the integration site. Third, we found that filgotinib suppresses HIV-1 transcription by inhibiting T cell activation and by modulating RNA splicing. Finally, we found that filgotinib treatment reduces the proliferation of HIV-1-infected cells. Overall, the combination of a drug screen and transcriptome analysis provides systemic understanding of cellular targets required for HIV-1 reactivation and drug candidates that may reduce HIV-1-related immune activation.
Yang-Hui Jimmy Yeh, Katharine M. Jenike, Rachela M. Calvi, Jennifer Chiarella, Rebecca Hoh, Steven G. Deeks, Ya-Chi Ho
Cachexia, a devastating wasting syndrome characterized by severe weight loss with specific losses of muscle and adipose tissue, is driven by reduced food intake, increased energy expenditure, excess catabolism, and inflammation. Cachexia is associated with poor prognosis and high mortality, and frequently occurs in patients with cancer, chronic kidney disease, infection, and many other illnesses. There is no effective treatment for this condition. Hypothalamic melanocortins have a potent and long-lasting inhibitory effect on feeding and anabolism, and pathophysiological processes increase melanocortin signaling tone leading to anorexia, metabolic changes, and eventual cachexia. We utilized three rat models of anorexia and cachexia (LPS, methylcholanthrene sarcoma, and 5/6 subtotal nephrectomy) to evaluate efficacy of TCMCB07, a synthetic antagonist of the melanocortin-4 receptor. Our data show that peripheral treatment of TCMCB07 with intraperitoneal, subcutaneous, and oral administration increased food intake and body weight, and preserved fat mass and lean mass during cachexia and LPS-induced anorexia. Furthermore, administration of TCMCB07 diminished hypothalamic inflammatory gene expression in cancer cachexia. These results suggest that peripheral TCMCB07 treatment effectively inhibits central melanocortin signaling and therefore stimulates appetite and enhances anabolism, indicating that TCMCB07 is a promising drug candidate to treat cachexia.
Xinxia Zhu, Michael F. Callahan, Kenneth A. Gruber, Marek Szumowski, Daniel L. Marks
There are more than 7000 described rare diseases, most lacking specific treatment. Autosomal-dominant hyper-IgE syndrome (AD-HIES, Job’s syndrome) is caused by mutations in signal transducer and activator of transcription 3 (STAT3). These patients present with immunodeficiency accompanied by severe non-immunological features including skeletal, connective tissue and vascular abnormalities, poor post-infection lung healing, and subsequent pulmonary failure. No specific therapies are available for these abnormalities. Here we investigated underlying mechanisms in order to identify therapeutic targets. Histological analysis of skin wounds demonstrated delayed granulation tissue formation and vascularization during skin wound healing in AD-HIES patients. Global gene expression analysis in AD-HIES patient skin fibroblasts identified deficiencies in a STAT3 controlled transcriptional network regulating extracellular matrix (ECM) remodeling and angiogenesis, with hypoxia inducible factor 1α (HIF1α) being a major contributor. Consistent with this, histological analysis of skin wounds and coronary arteries from AD-HIES patients showed decreased HIF1α expression, and revealed abnormal organization of the ECM and altered formation of the coronary vasa vasorum. Disease modeling utilizing cell culture and mouse models of angiogenesis and wound healing confirmed these predicted deficiencies and demonstrated therapeutic benefit of HIF1α stabilizing drugs. The study provides mechanistic insights into AD-HIES pathophysiology and finds new treatment option for this rare disease.
Natalia I. Dmitrieva, Avram D. Walts, Dai P. Nguyen, Alex Grubb, Xue Zhang, Xujing Wang, Xianfeng Ping, Hui Jin, Zhen Yu, Zu-Xi Yu, Dan Yang, Robin Schwartzbeck, Clifton L. Dalgard, Beth A. Kozel, Mark D. Levin, Russell H. Knutsen, Delong Liu, Joshua D. Milner, Diego B. López, Michael P. O'Connell, Chyi-Chia R. Lee, Ian A. Myles, Amy P. Hsu, Alexandra F. Freeman, Steven M. Holland, Guibin Chen, Manfred Boehm
Nadine Haase, Donald J. Foster, Mark W. Cunningham, Julia Bercher, Tuyen Nguyen, Svetlana Shulga-Morskaya, Stuart Milstein, Sarfraz Shaikh, Jeff Rollins, Michaela Golic, Florian Herse, Kristin Kräker, Ivo Bendix, Meray Serdar, Hanna Napieczynska, Arnd Heuser, Alexandra Gellhaus, Kristin Thiele, Gerd Wallukat, Dominik N. Müller, Babbette LaMarca, Ralf Dechend
Tumor-associated peptide–human leukocyte antigen complexes (pHLAs) represent the largest pool of cell surface–expressed cancer-specific epitopes, making them attractive targets for cancer therapies. Soluble bispecific molecules that incorporate an anti-CD3 effector function are being developed to redirect T cells against these targets using 2 different approaches. The first achieves pHLA recognition via affinity-enhanced versions of natural TCRs (e.g., immune-mobilizing monoclonal T cell receptors against cancer [ImmTAC] molecules), whereas the second harnesses an antibody-based format (TCR-mimic antibodies). For both classes of reagent, target specificity is vital, considering the vast universe of potential pHLA molecules that can be presented on healthy cells. Here, we made use of structural, biochemical, and computational approaches to investigate the molecular rules underpinning the reactivity patterns of pHLA-targeting bispecifics. We demonstrate that affinity-enhanced TCRs engage pHLA using a comparatively broad and balanced energetic footprint, with interactions distributed over several HLA and peptide side chains. As ImmTAC molecules, these TCRs also retained a greater degree of pHLA selectivity, with less off-target activity in cellular assays. Conversely, TCR-mimic antibodies tended to exhibit binding modes focused more toward hot spots on the HLA surface and exhibited a greater degree of crossreactivity. Our findings extend our understanding of the basic principles that underpin pHLA selectivity and exemplify a number of molecular approaches that can be used to probe the specificity of pHLA-targeting molecules, aiding the development of future reagents.
Christopher J. Holland, Rory M. Crean, Johanne M. Pentier, Ben de Wet, Angharad Lloyd, Velupillai Srikannathasan, Nikolai Lissin, Katy A. Lloyd, Thomas H. Blicher, Paul J. Conroy, Miriam Hock, Robert J. Pengelly, Thomas E. Spinner, Brian Cameron, Elizabeth A. Potter, Anitha Jeyanthan, Peter E. Molloy, Malkit Sami, Milos Aleksic, Nathaniel Liddy, Ross A. Robinson, Stephen Harper, Marco Lepore, Chris R. Pudney, Marc W. van der Kamp, Pierre J. Rizkallah, Bent K. Jakobsen, Annelise Vuidepot, David K. Cole
Seizures often herald the clinical appearance of gliomas or appear at later stages. Dissecting their precise evolution and cellular pathogenesis in brain malignancies could inform the development of staged therapies for these highly pharmaco-resistant epilepsies. Studies in immunodeficient xenograft models have identified local interneuron loss and excess glial glutamate release as chief contributors to network disinhibition, but how hyperexcitability in the peritumoral microenvironment evolves in an immunocompetent brain is unclear. We generated gliomas in WT mice via in utero deletion of key tumor suppressor genes and serially monitored cortical epileptogenesis during tumor infiltration with in vivo electrophysiology and GCAMP7 calcium imaging, revealing a reproducible progression from hyperexcitability to convulsive seizures. Long before seizures, coincident with loss of inhibitory cells and their protective scaffolding, gain of glial glutamate antiporter xCT expression, and reactive astrocytosis, we detected local Iba1+ microglial inflammation that intensified and later extended far beyond tumor boundaries. Hitherto unrecognized episodes of cortical spreading depolarization that arose frequently from the peritumoral region may provide a mechanism for transient neurological deficits. Early blockade of glial xCT activity inhibited later seizures, and genomic reduction of host brain excitability by deleting MapT suppressed molecular markers of epileptogenesis and seizures. Our studies confirmed xenograft tumor–driven pathobiology and revealed early and late components of tumor-related epileptogenesis in a genetically tractable, immunocompetent mouse model of glioma, allowing the complex dissection of tumor versus host pathogenic seizure mechanisms.
Asante Hatcher, Kwanha Yu, Jochen Meyer, Isamu Aiba, Benjamin Deneen, Jeffrey L. Noebels
Inherited retinal degenerations (IRDs) are characterized by the progressive loss of photoreceptors and represent one of the most prevalent causes of blindness among working-age populations. Cyclic nucleotide dysregulation is a common pathological feature linked to numerous forms of IRD, yet the precise mechanisms through which this contributes to photoreceptor death remain elusive. Here we demonstrate that cAMP induced upregulation of the dependence receptor neogenin in the retina. Neogenin levels were also elevated in both human and murine degenerating photoreceptors. We found that overexpressing neogenin in mouse photoreceptors was sufficient to induce cell death, whereas silencing neogenin in degenerating murine photoreceptors promoted survival, thus identifying a pro-death signal in IRDs. A possible treatment strategy is modeled whereby peptide neutralization of neogenin in Rd1, Rd10, and Rho P23H–knockin mice promotes rod and cone survival and rescues visual function as measured by light-evoked retinal ganglion cell recordings, scotopic/photopic electroretinogram recordings, and visual acuity tests. These results expose neogenin as a critical link between cAMP and photoreceptor death, and identify a druggable target for the treatment of retinal degeneration.
Jason Charish, Alireza P. Shabanzadeh, Danian Chen, Patrick Mehlen, Santhosh Sethuramanujam, Hidekiyo Harada, Vera L. Bonilha, Gautam Awatramani, Rod Bremner, Philippe P. Monnier
Spondyloarthritis (SpA) represents a family of inflammatory diseases of the spine and peripheral joints. Ankylosing spondylitis (AS) is the prototypic form of SpA in which progressive disease can lead to fusion of the spine. Therapeutically, knowledge of type 3 immunity has translated into the development of IL-23– and IL-17A–blocking antibodies for the treatment of SpA. Despite being able to provide symptomatic control, the current biologics do not prevent the fusion of joints in AS patients. Thus, there is an unmet need for disease-modifying drugs. Genetic studies have linked the Janus kinase TYK2 to AS. TYK2 is a mediator of type 3 immunity through intracellular signaling of IL-23. Here, we describe and characterize a potentially novel small-molecule inhibitor of TYK2 that blocked IL-23 signaling in vitro and inhibited disease progression in animal models of SpA. The effect of the inhibitor appears to be TYK2 specific, using TYK2-inactive mice, which further revealed a duality in the induction of IL-17A and IL-22 by IL-23. Specifically, IL-22 production was TYK2/JAK2/STAT3 dependent, while IL-17A was mostly JAK2 dependent. Finally, we examined the effects of AS-associated TYK2 SNPs on TYK2 expression and function and correlated them with AS disease progression. This work provides evidence that TYK2 inhibitors have great potential as an orally delivered therapeutic for SpA.
Eric Gracey, Dominika Hromadová, Melissa Lim, Zoya Qaiyum, Michael Zeng, Yuchen Yao, Archita Srinath, Yuriy Baglaenko, Natalia Yeremenko, William Westlin, Craig Masse, Mathias Müller, Birgit Strobl, Wenyan Miao, Robert D. Inman
Peptide MHC class II–based (pMHCII-based) nanomedicines trigger the formation of multicellular regulatory networks by reprogramming autoantigen-experienced CD4+ T cells into autoimmune disease–suppressing T regulatory type 1 (TR1) cells. We have shown that pMHCII-based nanomedicines displaying liver autoimmune disease–relevant yet ubiquitously expressed antigens can blunt various liver autoimmune disorders in a non–disease-specific manner without suppressing local or systemic immunity against infectious agents or cancer. Here, we show that such ubiquitous autoantigen-specific T cells are also awakened by extrahepatic tissue damage and that the corresponding TR1 progeny can suppress experimental autoimmune encephalomyelitis (EAE) and pancreatic β cell autoreactivity. In mice having EAE, nanomedicines displaying either ubiquitous or CNS-specific epitopes triggered the formation and expansion of cognate TR1 cells and their recruitment to the CNS-draining lymph nodes, sparing their liver-draining counterparts. Surprisingly, in mice having both liver autoimmunity and EAE, liver inflammation sequestered these ubiquitous or even CNS-specific TR1 cells away from the CNS, abrogating their antiencephalitogenic activity. In these mice, only the ubiquitous antigen-specific TR1 cells suppressed liver autoimmunity. Thus, the scope of antigen spreading in autoimmune disorders is larger than previously anticipated, involving specificities expected to be silenced by mechanisms of tolerance; the regulatory activity, but not the retention of autoreactive TR1 cells, requires local autoantigen expression.
Channakeshava Sokke Umeshappa, Jacques Mbongue, Santiswarup Singha, Saswat Mohapatra, Jun Yamanouchi, Justin A. Lee, Roopa Hebbandi Nanjundappa, Kun Shao, Urs Christen, Yang Yang, Kristofor K. Ellestad, Pere Santamaria
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