Toll-like receptors TLR7 and TLR9 are both implicated in the activation of autoreactive B cells and other cell types associated with systemic lupus erythematosus (SLE) pathogenesis. However, Tlr9–/– autoimmune-prone strains paradoxically develop more severe disease. We have now leveraged the negative regulatory role of TLR9 to develop an inducible rapid-onset murine model of systemic autoimmunity that depends on T cell detection of a membrane-bound OVA fusion protein expressed by MHC class II+ cells, expression of TLR7, expression of the type I IFN receptor, and loss of expression of TLR9. These mice are distinguished by a high frequency of OVA-specific Tbet+, IFN-γ+, and FasL-expressing Th1 cells as well as autoantibody-producing B cells. Unexpectedly, contrary to what occurs in most models of SLE, they also developed skin lesions that are very similar to those of human cutaneous lupus erythematosus (CLE) as far as clinical appearance, histological changes, and gene expression. FasL was a key effector mechanism in the skin, as the transfer of FasL-deficient DO11gld T cells completely failed to elicit overt skin lesions. FasL was also upregulated in human CLE biopsies. Overall, our model provides a relevant system for exploring the pathophysiology of CLE as well as the negative regulatory role of TLR9.
Purvi Mande, Bahar Zirak, Wei-Che Ko, Keyon Taravati, Karen L. Bride, Tia Y. Brodeur, April Deng, Karen Dresser, Zhaozhao Jiang, Rachel Ettinger, Katherine A. Fitzgerald, Michael D. Rosenblum, John E. Harris, Ann Marshak-Rothstein
Ikaros/IKZF1 is an essential transcription factor expressed throughout hematopoiesis. IKZF1 is implicated in lymphocyte and myeloid differentiation and negative regulation of cell proliferation. In humans, somatic mutations in IKZF1 have been linked to the development of B cell acute lymphoblastic leukemia (ALL) in children and adults. Recently, heterozygous germline IKZF1 mutations have been identified in patients with a B cell immune deficiency mimicking common variable immunodeficiency. These mutations demonstrated incomplete penetrance and led to haploinsufficiency. Herein, we report 7 unrelated patients with a novel early-onset combined immunodeficiency associated with de novo germline IKZF1 heterozygous mutations affecting amino acid N159 located in the DNA-binding domain of IKZF1. Different bacterial and viral infections were diagnosed, but Pneumocystis jirovecii pneumonia was reported in all patients. One patient developed a T cell ALL. This immunodeficiency was characterized by innate and adaptive immune defects, including low numbers of B cells, neutrophils, eosinophils, and myeloid dendritic cells, as well as T cell and monocyte dysfunctions. Notably, most T cells exhibited a naive phenotype and were unable to evolve into effector memory cells. Functional studies indicated these mutations act as dominant negative. This defect expands the clinical spectrum of human IKZF1-associated diseases from somatic to germline, from haploinsufficient to dominant negative.
David Boutboul, Hye Sun Kuehn, Zoé Van de Wyngaert, Julie E. Niemela, Isabelle Callebaut, Jennifer Stoddard, Christelle Lenoir, Vincent Barlogis, Catherine Farnarier, Frédéric Vely, Nao Yoshida, Seiji Kojima, Hirokazu Kanegane, Akihiro Hoshino, Fabian Hauck, Ludovic Lhermitte, Vahid Asnafi, Philip Roehrs, Shaoying Chen, James W. Verbsky, Katherine R. Calvo, Ammar Husami, Kejian Zhang, Joseph Roberts, David Amrol, John Sleaseman, Amy P. Hsu, Steven M. Holland, Rebecca Marsh, Alain Fischer, Thomas A. Fleisher, Capucine Picard, Sylvain Latour, Sergio D. Rosenzweig
Very few B cells in germinal centers (GCs) and extrafollicular (EF) regions of lymph nodes express CD30. Their specific features and relationship to CD30-expressing Hodgkin and Reed/Sternberg (HRS) cells of Hodgkin lymphoma are unclear but highly relevant, because numerous patients with lymphoma are currently treated with an anti-CD30 immunotoxin. We performed a comprehensive analysis of human CD30+ B cells. Phenotypic and IgV gene analyses indicated that CD30+ GC B lymphocytes represent typical GC B cells, and that CD30+ EF B cells are mostly post-GC B cells. The transcriptomes of CD30+ GC and EF B cells largely overlapped, sharing a strong MYC signature, but were strikingly different from conventional GC B cells and memory B and plasma cells, respectively. CD30+ GC B cells represent MYC+ centrocytes redifferentiating into centroblasts; CD30+ EF B cells represent active, proliferating memory B cells. HRS cells shared typical transcriptome patterns with CD30+ B cells, suggesting that they originate from these lymphocytes or acquire their characteristic features during lymphomagenesis. By comparing HRS to normal CD30+ B cells we redefined aberrant and disease-specific features of HRS cells. A remarkable downregulation of genes regulating genomic stability and cytokinesis in HRS cells may explain their genomic instability and multinuclearity.
Marc A. Weniger, Enrico Tiacci, Stefanie Schneider, Judith Arnolds, Sabrina Rüschenbaum, Janine Duppach, Marc Seifert, Claudia Döring, Martin-Leo Hansmann, Ralf Küppers
Medial vascular calcification, associated with enhanced mortality in chronic kidney disease (CKD), is fostered by osteo-/chondrogenic transdifferentiation of vascular smooth muscle cells (VSMCs). Here, we describe that serum- and glucocorticoid-inducible kinase 1 (SGK1) was upregulated in VSMCs under calcifying conditions. In primary human aortic VSMCs, overexpression of constitutively active SGK1S422D, but not inactive SGK1K127N, upregulated osteo-/chondrogenic marker expression and activity, effects pointing to increased osteo-/chondrogenic transdifferentiation. SGK1S422D induced nuclear translocation and increased transcriptional activity of NF-κB. Silencing or pharmacological inhibition of IKK abrogated the osteoinductive effects of SGK1S422D. Genetic deficiency, silencing, and pharmacological inhibition of SGK1 dissipated phosphate-induced calcification and osteo-/chondrogenic transdifferentiation of VSMCs. Aortic calcification, stiffness, and osteo-/chondrogenic transdifferentiation in mice following cholecalciferol overload were strongly reduced by genetic knockout or pharmacological inhibition of Sgk1 by EMD638683. Similarly, Sgk1 deficiency blunted vascular calcification in apolipoprotein E–deficient mice after subtotal nephrectomy. Treatment of human aortic smooth muscle cells with serum from uremic patients induced osteo-/chondrogenic transdifferentiation, effects ameliorated by EMD638683. These observations identified SGK1 as a key regulator of vascular calcification. SGK1 promoted vascular calcification, at least partly, via NF-κB activation. Inhibition of SGK1 may, thus, reduce the burden of vascular calcification in CKD.
Jakob Voelkl, Trang T.D. Luong, Rashad Tuffaha, Katharina Musculus, Tilman Auer, Xiaoming Lian, Christoph Daniel, Daniel Zickler, Beate Boehme, Michael Sacherer, Bernhard Metzler, Dietmar Kuhl, Maik Gollasch, Kerstin Amann, Dominik N. Müller, Burkert Pieske, Florian Lang, Ioana Alesutan
Radiographic contrast agents cause acute kidney injury (AKI), yet the underlying pathogenesis is poorly understood. Nod-like receptor pyrin containing 3–deficient (Nlrp3-deficient) mice displayed reduced epithelial cell injury and inflammation in the kidney in a model of contrast-induced AKI (CI-AKI). Unexpectedly, contrast agents directly induced tubular epithelial cell death in vitro that was not dependent on Nlrp3. Rather, contrast agents activated the canonical Nlrp3 inflammasome in macrophages. Intravital microscopy revealed diatrizoate (DTA) uptake within minutes in perivascular CX3CR1+ resident phagocytes in the kidney. Following rapid filtration into the tubular luminal space, DTA was reabsorbed and concentrated in tubular epithelial cells via the brush border enzyme dipeptidase-1 in volume-depleted but not euvolemic mice. LysM-GFP+ macrophages recruited to the kidney interstitial space ingested contrast material transported from the urine via direct interactions with tubules. CI-AKI was dependent on resident renal phagocytes, IL-1, leukocyte recruitment, and dipeptidase-1. Levels of the inflammasome-related urinary biomarkers IL-18 and caspase-1 were increased immediately following contrast administration in patients undergoing coronary angiography, consistent with the acute renal effects observed in mice. Taken together, these data show that CI-AKI is a multistep process that involves immune surveillance by resident and infiltrating renal phagocytes, Nlrp3-dependent inflammation, and the tubular reabsorption of contrast via dipeptidase-1.
Arthur Lau, Hyunjae Chung, Takanori Komada, Jaye M. Platnich, Christina F. Sandall, Saurav Roy Choudhury, Justin Chun, Victor Naumenko, Bas G.J. Surewaard, Michelle C. Nelson, Annegret Ulke-Lemée, Paul L. Beck, Hallgrimur Benediktsson, Anthony M. Jevnikar, Sarah L. Snelgrove, Michael J. Hickey, Donna L. Senger, Matthew T. James, Justin A. Macdonald, Paul Kubes, Craig N. Jenne, Daniel A. Muruve
Epigenetic modifications control cancer development and clonal evolution in various cancer types. Here, we show that loss of the male-specific histone demethylase lysine-specific demethylase 5D (KDM5D) encoded on the Y chromosome epigenetically modifies histone methylation marks and alters gene expression, resulting in aggressive prostate cancer. Fluorescent in situ hybridization demonstrated that segmental or total deletion of the Y chromosome in prostate cancer cells is one of the causes of decreased KDM5D mRNA expression. The result of ChIP-sequencing analysis revealed that KDM5D preferably binds to promoter regions with coenrichment of the motifs of crucial transcription factors that regulate the cell cycle. Loss of KDM5D expression with dysregulated H3K4me3 transcriptional marks was associated with acceleration of the cell cycle and mitotic entry, leading to increased DNA-replication stress. Analysis of multiple clinical data sets reproducibly showed that loss of expression of KDM5D confers a poorer prognosis. Notably, we also found stress-induced DNA damage on the serine/threonine protein kinase ATR with loss of KDM5D. In KDM5D-deficient cells, blocking ATR activity with an ATR inhibitor enhanced DNA damage, which led to subsequent apoptosis. These data start to elucidate the biological characteristics resulting from loss of KDM5D and also provide clues for a potential novel therapeutic approach for this subset of aggressive prostate cancer.
Kazumasa Komura, Yuki Yoshikawa, Teppei Shimamura, Goutam Chakraborty, Travis A. Gerke, Kunihiko Hinohara, Kalyani Chadalavada, Seong Ho Jeong, Joshua Armenia, Shin-Yi Du, Ying Z. Mazzu, Kohei Taniguchi, Naokazu Ibuki, Clifford A. Meyer, Gouri J. Nanjangud, Teruo Inamoto, Gwo-Shu Mary Lee, Lorelei A. Mucci, Haruhito Azuma, Christopher J. Sweeney, Philip W. Kantoff
Drug resistance remains the key problem in cancer treatment. It is now accepted that each myeloma patient harbors multiple subclones and subclone dominance may change over time. The coexistence of multiple subclones with high or low chromosomal instability (CIN) signature causes heterogeneity and drug resistance with consequent disease relapse. In this study, using a tandem affinity purification–mass spectrometry (TAP-MS) technique, we found that NEK2, a CIN gene, was bound to the deubiquitinase USP7. Binding to USP7 prevented NEK2 ubiquitination resulting in NEK2 stabilization. Increased NEK2 kinase levels activated the canonical NF-κB signaling pathway through the PP1α/AKT axis. Newly diagnosed myeloma patients with activated NF-κB signaling through increased NEK2 activity had poorer event-free and overall survivals based on multiple independent clinical cohorts. We also found that NEK2 activated heparanase, a secreted enzyme, responsible for bone destruction in an NF-κB–dependent manner. Intriguingly, both NEK2 and USP7 inhibitors showed great efficacy in inhibiting myeloma cell growth and overcoming NEK2-induced and -acquired drug resistance in xenograft myeloma mouse models.
Reinaldo Franqui-Machin, Mu Hao, Hua Bai, Zhimin Gu, Xin Zhan, Hasem Habelhah, Yogesh Jethava, Lugui Qiu, Ivana Frech, Guido Tricot, Fenghuang Zhan
The human brain is an important site of HIV replication and persistence during antiretroviral therapy (ART). Direct evaluation of HIV infection in the brains of otherwise healthy individuals is not feasible; therefore, we performed a large-scale study of bone marrow/liver/thymus (BLT) humanized mice as an in vivo model to study HIV infection in the brain. Human immune cells, including CD4+ T cells and macrophages, were present throughout the BLT mouse brain. HIV DNA, HIV RNA, and/or p24+ cells were observed in the brains of HIV-infected animals, regardless of the HIV isolate used. HIV infection resulted in decreased numbers of CD4+ T cells, increased numbers of CD8+ T cells, and a decreased CD4+/CD8+ T cell ratio in the brain. Using humanized T cell–only mice (ToM), we demonstrated that T cells establish and maintain HIV infection of the brain in the complete absence of human myeloid cells. HIV infection of ToM resulted in CD4+ T cell depletion and a reduced CD4+/CD8+ T cell ratio. ART significantly reduced HIV levels in the BLT mouse brain, and the immune cell populations present were indistinguishable from those of uninfected controls, which demonstrated the effectiveness of ART in controlling HIV replication in the CNS and returning cellular homeostasis to a pre-HIV state.
Jenna B. Honeycutt, Baolin Liao, Christopher C. Nixon, Rachel A. Cleary, William O. Thayer, Shayla L. Birath, Michael D. Swanson, Patricia Sheridan, Oksana Zakharova, Francesca Prince, JoAnn Kuruc, Cynthia L. Gay, Chris Evans, Joseph J. Eron, Angela Wahl, J. Victor Garcia
Although nonmalignant stromal cells facilitate tumor growth and can occupy up to 90% of a solid tumor mass, better strategies to exploit these cells for improved cancer therapy are needed. Here, we describe a potent MMAE-linked antibody-drug conjugate (ADC) targeting tumor endothelial marker 8 (TEM8, also known as ANTXR1), a highly conserved transmembrane receptor broadly overexpressed on cancer-associated fibroblasts, endothelium, and pericytes. Anti-TEM8 ADC elicited potent anticancer activity through an unexpected killing mechanism we term DAaRTS (drug activation and release through stroma), whereby the tumor microenvironment localizes active drug at the tumor site. Following capture of ADC prodrug from the circulation, tumor-associated stromal cells release active MMAE free drug, killing nearby proliferating tumor cells in a target-independent manner. In preclinical studies, ADC treatment was well tolerated and induced regression and often eradication of multiple solid tumor types, blocked metastatic growth, and prolonged overall survival. By exploiting TEM8+ tumor stroma for targeted drug activation, these studies reveal a drug delivery strategy with potential to augment therapies against multiple cancer types.
Christopher Szot, Saurabh Saha, Xiaoyan M. Zhang, Zhongyu Zhu, Mary Beth Hilton, Karen Morris, Steven Seaman, James M. Dunleavey, Kuo-Sheng Hsu, Guo-Jun Yu, Holly Morris, Deborah A. Swing, Diana C. Haines, Yanping Wang, Jennifer Hwang, Yang Feng, Dean Welsch, Gary DeCrescenzo, Amit Chaudhary, Enrique Zudaire, Dimiter S. Dimitrov, Brad St. Croix
Ischemia-reperfusion injury, a form of sterile inflammation, is the leading risk factor for both short-term mortality following pulmonary transplantation and chronic lung allograft dysfunction. While it is well recognized that neutrophils are critical mediators of acute lung injury, processes that guide their entry into pulmonary tissue are not well understood. Here, we found that CCR2+ classical monocytes are necessary and sufficient for mediating extravasation of neutrophils into pulmonary tissue during ischemia-reperfusion injury following hilar clamping or lung transplantation. The classical monocytes were mobilized from the host spleen, and splenectomy attenuated the recruitment of classical monocytes as well as the entry of neutrophils into injured lung tissue, which was associated with improved graft function. Neutrophil extravasation was mediated by MyD88-dependent IL-1β production by graft-infiltrating classical monocytes, which downregulated the expression of the tight junction–associated protein ZO-2 in pulmonary vascular endothelial cells. Thus, we have uncovered a crucial role for classical monocytes, mobilized from the spleen, in mediating neutrophil extravasation, with potential implications for targeting of recipient classical monocytes to ameliorate pulmonary ischemia-reperfusion injury in the clinic.
Hsi-Min Hsiao, Ramiro Fernandez, Satona Tanaka, Wenjun Li, Jessica H. Spahn, Stephen Chiu, Mahzad Akbarpour, Daniel Ruiz-Perez, Qiang Wu, Cem Turam, Davide Scozzi, Tsuyoshi Takahashi, Hannah P. Luehmann, Varun Puri, G.R. Scott Budinger, Alexander S. Krupnick, Alexander V. Misharin, Kory J. Lavine, Yongjian Liu, Andrew E. Gelman, Ankit Bharat, Daniel Kreisel