Abstract
CD4+ T cells predominate in salivary gland (SG) inflammatory lesions in Sjögren’s syndrome (SS). However, their antigen specificity, degree of clonal expansion, and relationship to clinical disease features remain unknown. We used multiplex reverse-transcriptase PCR to amplify paired T cell receptor α (TCRα) and β transcripts of single CD4+CD45RA– T cells from SG and peripheral blood (PB) of 10 individuals with primary SS, 9 of whom shared the HLA DR3/DQ2 risk haplotype. TCRα and β sequences were obtained from a median of 91 SG and 107 PB cells per subject. The degree of clonal expansion and frequency of cells expressing two productively rearranged α genes were increased in SG versus PB. Expanded clones from SG exhibited complementary-determining region 3 (CDR3) sequence similarity both within and among subjects, suggesting antigenic selection and shared antigen recognition. CDR3 similarities were shared among expanded clones from individuals discordant for canonical Ro and La autoantibodies, suggesting recognition of alternative SG antigen(s). The extent of SG clonal expansion correlated with reduced saliva production and increased SG fibrosis, linking expanded SG T cells with glandular dysfunction. Knowledge of paired TCRα and β sequences enables further work toward identification of target antigens and development of novel therapies.
Authors
Michelle L. Joachims, Kerry M. Leehan, Christina Lawrence, Richard C. Pelikan, Jacen S. Moore, Zijian Pan, Astrid Rasmussen, Lida Radfar, David M. Lewis, Kiely M. Grundahl, Jennifer A. Kelly, Graham B. Wiley, Mikhail Shugay, Dmitriy M. Chudakov, Christopher J. Lessard, Donald U. Stone, R. Hal Scofield, Courtney G. Montgomery, Kathy L. Sivils, Linda F. Thompson, A. Darise Farris
Abstract
Infections are an important cause of morbidity and mortality in patients with decompensated cirrhosis and ascites. Hypothesizing that innate immune dysfunction contributes to susceptibility to infection, we assessed ascitic fluid macrophage phenotype and function. The expression of complement receptor of the immunoglobulin superfamily (CRIg) and CCR2 defined two phenotypically and functionally distinct peritoneal macrophage subpopulations. The proportion of CRIghi macrophages differed between patients and in the same patient over time, and a high proportion of CRIghi macrophages was associated with reduced disease severity (model for end-stage liver disease) score. As compared with CRIglo macrophages, CRIghi macrophages were highly phagocytic and displayed enhanced antimicrobial effector activity. Transcriptional profiling by RNA sequencing and comparison with human macrophage and murine peritoneal macrophage expression signatures highlighted similarities among CRIghi cells, human macrophages, and mouse F4/80hi resident peritoneal macrophages and among CRIglo macrophages, human monocytes, and mouse F4/80lo monocyte-derived peritoneal macrophages. These data suggest that CRIghi and CRIglo macrophages may represent a tissue-resident population and a monocyte-derived population, respectively. In conclusion, ascites fluid macrophage subset distribution and phagocytic capacity is highly variable among patients with chronic liver disease. Regulating the numbers and/or functions of these macrophage populations could provide therapeutic opportunities in cirrhotic patients.
Authors
Katharine M. Irvine, Xuan Banh, Victoria L. Gadd, Kyle K. Wojcik, Juliana K. Ariffin, Sara Jose, Samuel Lukowski, Gregory J. Baillie, Matthew J. Sweet, Elizabeth E. Powell
Abstract
Eosinophilic inflammation and Th2 cytokine production are central to the pathogenesis of asthma. Agents that target either eosinophils or single Th2 cytokines have shown benefits in subsets of biomarker-positive patients. More broadly effective treatment or disease-modifying effects may be achieved by eliminating more than one inflammatory stimulator. Here we present a strategy to concomitantly deplete Th2 T cells, eosinophils, basophils, and type-2 innate lymphoid cells (ILC2s) by generating monoclonal antibodies with enhanced effector function (19A2) that target CRTh2 present on all 4 cell types. Using human CRTh2 (hCRTh2) transgenic mice that mimic the expression pattern of hCRTh2 on innate immune cells but not Th2 cells, we demonstrate that anti-hCRTh2 antibodies specifically eliminate hCRTh2+ basophils, eosinophils, and ILC2s from lung and lymphoid organs in models of asthma and
Authors
Tao Huang, Meredith Hazen, Yonglei Shang, Meijuan Zhou, Xiumin Wu, Donghong Yan, Zhonghua Lin, Margaret Solon, Elizabeth Luis, Hai Ngu, Yongchang Shi, Arna Katewa, David F. Choy, Nandhini Ramamoorthi, Erick R. Castellanos, Mercedesz Balazs, Min Xu, Wyne P. Lee, Marissa L. Matsumoto, Jian Payandeh, Joseph R. Arron, Jo-Anne Hongo, Jianyong Wang, Isidro Hötzel, Cary D. Austin, Karin Reif
Abstract
Secreted by activated cells or passively released by damaged cells, extracellular HMGB1 is a prototypical damage-associated molecular pattern (DAMP) inflammatory mediator. During the course of developing extracorporeal approaches to treating injury and infection, we inadvertently discovered that haptoglobin, the acute phase protein that binds extracellular hemoglobin and targets cellular uptake through CD163, also binds HMGB1. Haptoglobin-HMGB1 complexes elicit the production of antiinflammatory enzymes (heme oxygenase-1) and cytokines (e.g., IL-10) in WT but not in CD163-deficient macrophages. Genetic disruption of haptoglobin or CD163 expression significantly enhances mortality rates in standardized models of intra-abdominal sepsis in mice. Administration of haptoglobin to WT and to haptoglobin gene-deficient animals confers significant protection. These findings reveal a mechanism for haptoglobin modulation of the inflammatory action of HMGB1, with significant implications for developing experimental strategies targeting HMGB1-dependent inflammatory diseases.
Authors
Huan Yang, Haichao Wang, Yaakov A. Levine, Manoj K. Gunasekaran, Yongjun Wang, Meghan Addorisio, Shu Zhu, Wei Li, Jianhua Li, Dominique P.V. de Kleijn, Peder S. Olofsson, H. Shaw Warren, Mingzhu He, Yousef Al-Abed, Jesse Roth, Daniel J. Antoine, Sangeeta S. Chavan, Ulf Andersson, Kevin J. Tracey
Abstract
Obesity is an increasing health problem worldwide, and nonsurgical strategies to treat obesity have remained rather inefficient. We here show that acute loss of TGF-β–activated kinase 1 (TAK1) in adipocytes results in an increased rate of apoptotic adipocyte death and increased numbers of M2 macrophages in white adipose tissue. Mice with adipocyte-specific TAK1 deficiency have reduced adipocyte numbers and are resistant to obesity induced by a high-fat diet or leptin deficiency. In addition, adipocyte-specific TAK1-deficient mice under a high-fat diet showed increased energy expenditure, which was accompanied by enhanced expression of the uncoupling protein UCP1. Interestingly, acute induction of adipocyte-specific TAK1 deficiency in mice already under a high-fat diet was able to stop further weight gain and improved glucose tolerance. Thus, loss of TAK1 in adipocytes reduces the total number of adipocytes, increases browning of white adipose tissue, and may be an attractive strategy to treat obesity, obesity-dependent diabetes, and other associated complications.
Authors
Antonia Sassmann-Schweda, Pratibha Singh, Cong Tang, Astrid Wietelmann, Nina Wettschureck, Stefan Offermanns
Abstract
The
Authors
Keisuke Maeshima, Stephanie M. Stanford, Deepa Hammaker, Cristiano Sacchetti, Li-fan Zeng, Rizi Ai, Vida Zhang, David L. Boyle, German R. Aleman Muench, Gen-Sheng Feng, John W. Whitaker, Zhong-Yin Zhang, Wei Wang, Nunzio Bottini, Gary S. Firestein
Abstract
Despite major advances in early detection and prognosis, chemotherapy resistance is a major hurdle in the battle against breast cancer. Identifying predictive markers and understanding the mechanisms are key steps to overcoming chemoresistance. Methylation-controlled J protein (MCJ, also known as DNAJC15) is a negative regulator of mitochondrial respiration and has been associated with chemotherapeutic drug sensitivity in cancer cell lines. Here we show, in a retrospective study of a large cohort of breast cancer patients, that low MCJ expression in breast tumors predicts high risk of relapse in patients treated with chemotherapy; however, MCJ expression does not correlate with response to endocrine therapy. In a prospective study in breast cancer patients undergoing neoadjuvant therapy, low MCJ expression also correlates with poor clinical response to chemotherapy and decreased disease-free survival. Using MCJ-deficient mice, we demonstrate that lack of MCJ is sufficient to induce mammary tumor chemoresistance in vivo. Thus, loss of expression of this endogenous mitochondrial modulator in breast cancer promotes the development of chemoresistance.
Authors
Maria J. Fernández-Cabezudo, Issam Faour, Kenneth Jones, Devin P. Champagne, Mohammed A. Jaloudi, Yassir A. Mohamed, Ghada Bashir, Saeeda Almarzooqi, Alia Albawardi, M. Jawad Hashim, Thomas S. Roberts, Haytham El-Salhat, Hakam El-Taji, Adnan Kassis, Dylan E. O’Sullivan, Brock C. Christensen, James DeGregori, Basel K. al-Ramadi, Mercedes Rincon
Abstract
Reperfusion injury can exacerbate tissue damage in ischemic stroke, but little is known about the mechanisms linking ROS to stroke severity. Here, we tested the hypothesis that protein methionine oxidation potentiates NF-κB activation and contributes to cerebral ischemia/reperfusion injury. We found that overexpression of methionine sulfoxide reductase A (MsrA), an antioxidant enzyme that reverses protein methionine oxidation, attenuated ROS-augmented NF-κB activation in endothelial cells, in part, by protecting against the oxidation of methionine residues in the regulatory domain of calcium/calmodulin-dependent protein kinase II (CaMKII). In a murine model, MsrA deficiency resulted in increased NF-κB activation and neutrophil infiltration, larger infarct volumes, and more severe neurological impairment after transient cerebral ischemia/reperfusion injury. This phenotype was prevented by inhibition of NF-κB or CaMKII. MsrA-deficient mice also exhibited enhanced leukocyte rolling and upregulation of E-selectin, an endothelial NF-κB–dependent adhesion molecule known to contribute to neurovascular inflammation in ischemic stroke. Finally, bone marrow transplantation experiments demonstrated that the neuroprotective effect was mediated by MsrA expressed in nonhematopoietic cells. These findings suggest that protein methionine oxidation in nonmyeloid cells is a key mechanism of postischemic oxidative injury mediated by NF-κB activation, leading to neutrophil recruitment and neurovascular inflammation in acute ischemic stroke.
Authors
Sean X. Gu, Ilya O. Blokhin, Katina M. Wilson, Nirav Dhanesha, Prakash Doddapattar, Isabella M. Grumbach, Anil K. Chauhan, Steven R. Lentz
Abstract
Central clonal deletion has been considered the critical factor responsible for the robust state of tolerance achieved by chimerism-based experimental protocols, but split-tolerance models and the clinical experience are calling this assumption into question. Although clone-size reduction through deletion has been shown to be universally required for achieving allotolerance, it remains undetermined whether it is sufficient by itself. Therapeutic Treg treatment induces chimerism and tolerance in a stringent murine BM transplantation model devoid of myelosuppressive recipient treatment. In contrast to irradiation chimeras, chronic rejection (CR) of skin and heart allografts in Treg chimeras was permanently prevented, even in the absence of complete clonal deletion of donor MHC-reactive T cells. We show that minor histocompatibility antigen mismatches account for CR in irradiation chimeras without global T cell depletion. Furthermore, we show that Treg therapy–induced tolerance prevents CR in a linked suppression–like fashion, which is maintained by active regulatory mechanisms involving recruitment of thymus-derived Tregs to the graft. These data suggest that highly efficient intrathymic and peripheral deletion of donor-reactive T cells for specificities expressed on hematopoietic cells preclude the expansion of donor-specific Tregs and, hence, do not allow for spreading of tolerance to minor specificities that are not expressed by donor BM.
Authors
Nina Pilat, Benedikt Mahr, Lukas Unger, Karin Hock, Christoph Schwarz, Andreas M. Farkas, Ulrike Baranyi, Fritz Wrba, Thomas Wekerle
Abstract
Limited transendothelial permeability across tumor microvessels represents a significant bottleneck in the development of tumor-specific diagnostic agents and theranostic drugs. Here, we show an approach to increase transendothelial permeability of macromolecular and nanoparticle-based contrast agents via inhibition of the type I TGF-β receptor, activin-like kinase 5 (Alk5), in tumors. Alk5 inhibition significantly increased tumor contrast agent delivery and enhancement on imaging studies, while healthy organs remained relatively unaffected. Imaging data correlated with significantly decreased tumor interstitial fluid pressure, while tumor vascular density remained unchanged. This immediately clinically translatable concept involving Alk5 inhibitor pretreatment prior to an imaging study could be leveraged for improved tumor delivery of macromolecular and nanoparticle-based imaging probes and, thereby, facilitate development of more sensitive imaging tests for cancer diagnosis, enhanced tumor characterization, and personalized, image-guided therapies.
Authors
Heike E. Daldrup-Link, Suchismita Mohanty, Celina Ansari, Olga Lenkov, Aubie Shaw, Ken Ito, Su Hyun Hong, Matthias Hoffmann, Laura Pisani, Nancy Boudreau, Sanjiv Sam Gambhir, Lisa M. Coussens
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