Follicular T helper cells shape the HCV-specific CD4 T cell repertoire after viral elimination

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Abstract

Background: Chronic HCV-infection is characterized by a severe impairment of HCV-specific CD4 T cell help that is driven by chronic antigen stimulation. We aimed to study the fate of HCV-specific CD4 T cells after viral elimination. Methods:HCV-specific CD4 T cell responses were longitudinally analyzed using MHC class II tetramer-technology, multicolor flow cytometry and RNA sequencing in a cohort of chronically HCV-infected patients undergoing therapy with direct-acting antivirals. In addition, HCV-specific neutralizing antibodies and CXCL13 levels were analyzed. Results: We observed that the frequency of HCV-specific CD4 T cells increased within two weeks after initiation of DAA therapy. Multicolor flow cytometry revealed a downregulation of exhaustion and activation markers and an upregulation of memory-associated markers. While cells with a Th1 phenotype were the predominant subset at baseline, cells with phenotypic and transcriptional characteristics of follicular T helper cells increasingly shaped the circulating HCV-specific CD4 T cell repertoire, suggesting antigen-independent survival of this subset. These changes were accompanied by a decline of HCV-specific neutralizing antibodies and the germinal center activity. Conclusion: We identified a population of HCV-specific CD4 T cells with a follicular T helper cell signature that is maintained after therapy-induced elimination of persistent infection and may constitute an important target population for vaccination efforts to prevent re-infection and immunotherapeutic approaches for persistent viral infections.

Authors

Maike Smits, Katharina Zoldan, Naveed Ishaque, Zuguang Gu, Katharina Jechow, Dominik Wieland, Christian Conrad, Roland Eils, Catherine Fauvelle, Thomas F. Baumert, Florian Emmerich, Bertram Bengsch, Christoph Neumann-Haefelin, Maike Hofmann, Robert Thimme, Tobias Boettler

Immune exclusion by naturally-acquired secretory IgA to the pneumococcal pilus-1

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Abstract

Successful infection by mucosal pathogens requires overcoming the mucus barrier. To better understand this key step, we performed a survey of the interactions between human respiratory mucus and the human pathogen S. pneumoniae. Pneumococcal adherence to adult human nasal fluid was seen only by isolates expressing pilus-1. Robust binding was independent of pilus-1 adhesive properties but required Fab-dependent recognition of RrgB, the pilus shaft protein, by naturally-acquired secretory immunoglobulin A (sIgA). Pilus-1 binding by specific sIgA led to bacterial agglutination, but adherence required interaction of agglutinated pneumococci and entrapment in mucus particles. To test the effect of these interactions in vivo, pneumococci were preincubated with human sIgA prior to intranasal challenge in a mouse model of colonization. sIgA-treatment resulted in rapid immune exclusion of pilus-expressing pneumococci. Our findings predict that immune exclusion would select for non-piliated isolates in individuals who acquired RrgB-specific sIgA from prior episodes of colonization with piliated strains. Accordingly, genomic data comparing isolates carried by mothers and their children showed that mothers are less likely to be colonized with pilus-expressing strains. Our study provides a specific example of immune exclusion involving naturally-acquired antibody in the human host, a major factor driving pneumococcal adaptation.

Authors

Ulrike Binsker, John A. Lees, Alexandria J. Hammond, Jeffrey N. Weiser

Glucocorticoids paradoxically facilitate steroid resistance in T-cell acute lymphoblastic leukemias and thymocytes

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Abstract

Glucocorticoids (GCs) are a central component of therapy for patients with T-cell acute lymphoblastic leukemia (T-ALL) and while resistance to GCs is a strong negative prognostic indicator in T-ALL, mechanisms of GC resistance remain poorly understood. Using diagnostic samples from patients enrolled on the frontline Children’s Oncology Group (COG) T-ALL clinical trial AALL1231, we demonstrated that one-third of primary T-ALLs were resistant to GCs when cultured in the presence of interleukin-7 (IL7), a cytokine that is critical for normal T-cell function and that plays a well-established role in leukemogenesis. We demonstrated that in these T-ALLs and in distinct populations of normal developing thymocytes, GCs paradoxically induced their own resistance by promoting upregulation of IL7 receptor (IL7R) expression. In the presence of IL7, this augmented downstream signal transduction resulting in increased STAT5 transcriptional output and upregulation of the pro-survival protein BCL-2. Taken together, we demonstrated that IL7 mediates an intrinsic and physiologic mechanism of GC resistance in normal thymocyte development that is retained during leukemogenesis in a subset of T-ALLs and is reversible with targeted inhibition of the IL7R/JAK/STAT5/BCL-2 axis.

Authors

Lauren K. Meyer, Benjamin J. Huang, Cristina Delgado-Martin, Ritu P. Roy, Aaron Hechmer, Anica M. Wandler, Tiffaney L. Vincent, Paolo Fortina, Adam B. Olshen, Brent L. Wood, Terzah M. Horton, Kevin M. Shannon, David T. Teachey, Michelle L. Hermiston

Defective glycosylation and multisystem abnormalities characterize the primary immunodeficiency XMEN disease

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Abstract

X-linked immunodeficiency with magnesium defect, Epstein-Barr virus (EBV) infection, and neoplasia (XMEN) disease is caused by deficiency of the magnesium transporter 1 gene (MAGT1). We studied 23 XMEN patients, 8 of whom were EBV-naïve. We observed lymphadenopathy (LAD), cytopenias, liver disease, cavum septum pellucidum, and increased CD4-CD8-B220-TCRalpha/beta+ T (abDNT) cells, in addition to the previously described features of an inverted CD4:CD8 ratio, CD4+ T lymphocytopenia, increased B cells, dysgammaglobulinemia, and decreased expression of the “Natural-Killer Group 2, member D” (NKG2D) receptor. EBV-associated B cell malignancies occurred frequently in EBV-infected patients. We investigated XMEN patients and autoimmune lymphoproliferative syndrome (ALPS) patients by deep immunophenotyping (32 immune markers) using Time of Flight Mass Cytometry (CyTOF). Our analysis revealed that the abundance of two populations of naïve B cells (CD20+CD27-CD22+IgM+HLA-DR+CXCR5+CXCR4++CD10+CD38+ and CD20+CD27-CD22+IgM+HLA-DR+CXCR5+CXCR4+CD10-CD38-) could differentially classify XMEN, ALPS, and normal individuals. We also performed glycoproteomics analysis on T lymphocytes and show that XMEN disease is a congenital disorder of glycosylation that affects a restricted subset of glycoproteins. Transfection of MAGT1 mRNA enabled us to rescue proteins with defective glycosylation. Together, these data provide new clinical and pathophysiological foundations with important ramifications for the diagnosis and treatment of XMEN disease.

Authors

Juan C. Ravell, Mami Matsuda-Lennikov, Samuel D. Chauvin, Juan Zou, Matthew Biancalana, Sally J. Deeb, Susan Price, Helen C. Su, Giulia Notarangelo, Ping Jiang, Aaron Morawski, Chrysi Kanellopoulou, Kyle W. Binder, Ratnadeep Mukherjee, James T. Anibal, Brian Sellers, Lixin Zheng, Tingyan He, Alex B. George, Stefania Pittaluga, Astin Powers, David E. Kleiner, Devika Kapuria, Marc Ghany, Sally Hunsberger, Jeffrey I. Cohen, Gulbu Uzel, Jenna Bergerson, Lynne Wolfe, Camilo Toro, William Gahl, Les R. Folio, Helen Matthews, Pam Angelus, Ivan K. Chinn, Jordan S. Orange, Claudia M. Trujillo-Vargas, Jose Luis Franco, Julio Orrego-Arango, Sebastian Gutiérrez-Hincapié, Niraj Chandrakant Patel, Kimiyo Raymond, Turkan Patiroglu, Ekrem Unal, Musa Karakukcu, Alexandre G.R. Day, Pankaj Mehta, Evan Masutani, Suk S. De Ravin, Harry L. Malech, Grégoire Altan-Bonnet, V. Koneti Rao, Matthias Mann, Michael J. Lenardo

Off-the-shelf EBV-specific T cell immunotherapy for rituximab-refractory EBV-associated lymphoma following transplant

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Abstract

Background: Adoptive transfer of donor-derived EBV-specific T-cells (EBV-CTLs) can eradicate EBV associated lymphomas post hematopoietic cell (HCT) or solid organ (SOT) transplants but is not available for most patients. Methods: We developed a 3rd-party, allogeneic, off-the-shelf bank of 330 GMP grade EBV-CTL lines from specifically consented healthy HCT donors. We treated 46 recipients of HCT (N=33) or SOT (N=13) with established EBV associated lymphomas, who failed rituximab therapy, with 3rd-party EBV-CTLs. Treatment cycles consisted of 3 weekly infusions of EBV-CTLs and 3 weeks of observation. Results: The EBV-CTLs did not induce significant toxicities or graft injury. One patient developed grade I skin GVHD requiring topical therapy. Complete and sustained partial remissions were achieved in 68% of HCT recipients and 54% of SOT recipients. For patients who achieved CR/PR or stable disease after cycle 1, overall survival was 88.9% and 81.8% respectively at 1 year. Although only 1/11 patients (9.1%) with progression of disease (POD) after cycle 1 who received additional EBV-CTLs from the same donor survived, 3 of 5 with POD subsequently treated with EBV-CTLs from a different donor achieved CR or durable PR (60%) and survive > 1 year. Maximal responses were achieved after a median of 2 cycles. Conclusions: Third party EBV-CTLs of defined HLA restriction provide safe, immediately accessible treatment for EBV PTLD. Secondary treatment with EBV-CTLs restricted by a different HLA allele (switch therapy) can also induce remissions if initial EBV-CTLs are ineffective. These results suggest a promising potential therapy for patients with rituximab refractory EBV-associated lymphoma post transplant. Phase II protocols (NCT01498484 and NCT00002663) were approved by the Institutional Review Board at Memorial Sloan Kettering Cancer Center, Food and Drug Administration and National Marrow Donor Program. This work was supported through NIH grants CA23766, NIH R21CA162002, Aubrey Fund, The Claire Tow Foundation, Major Family Foundation, Max Cure Foundation, Richard “Rick” J. EIsemann Pediatric Research Fund, Banbury Foundation, Edith Robertson Foundation, Larry Smead Foundation. In June 2015 Atara Biotherapeutics licensed the EBV-CTL bank and is developing this as ATA-129.

Authors

Susan Prockop, Ekaterina Doubrovina, Stephanie Suser, Glenn Heller, Juliet Barker, Parastoo Dahi, Miguel A. Perales, Esperanza Papadopoulos, Craig Sauter, Hugo Castro-Malaspina, Farid Boulad, Kevin J. Curran, Sergio Giralt, Boglarka Gyurkocza, Katharine C. Hsu, Ann Jakubowski, Alan M. Hanash, Nancy A. Kernan, Rachel Kobos, Guenther Koehne, Heather Landau, Doris Ponce, Barbara Spitzer, James W. Young, Gerald Behr, Mark Dunphy, Sofia Haque, Julie Teruya-Feldstein, Maria Arcila, Christine Moung, Susan Hsu, Aisha Hasan, Richard J. O'Reilly

EphA4/Tie2 crosstalk regulates leptomeningeal collateral remodeling following ischemic stroke

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Abstract

Leptomeningeal anastomoses or pial collateral vessels play a critical role in cerebral blood flow (CBF) restoration following ischemic stroke. The magnitude of this adaptive response is postulated to be controlled by the endothelium, although the underlying molecular mechanisms remain under investigation. Here we demonstrated that endothelial genetic deletion, using EphA4f/f/Tie2-Cre and EphA4f/f/VeCahderin-CreERT2 mice and vessel painting strategies, implicated EphA4 receptor tyrosine kinase as a major suppressor of pial collateral remodeling, CBF and functional recovery following permanent middle cerebral artery occlusion. Pial collateral remodeling is limited by the cross talk between EphA4-Tie2 signaling in vascular endothelial cells, which is mediated through p-Akt regulation. Furthermore, peptide inhibition of EphA4 resulted in acceleration of the pial arteriogenic response. Our findings demonstrate EphA4 is a negative regulator of Tie2 receptor signaling which limits pial collateral arteriogenesis following cerebrovascular occlusion. Therapeutic targeting of EphA4 and/or Tie2 represents an attractive new strategy for improving collateral function, neural tissue health and functional recovery following ischemic stroke.

Authors

Benjamin Okyere, William A. Mills III, Xia Wang, Michael Chen, Jiang Chen, Amanda Hazy, Yun Qian, John B. Matson, Michelle H. Theus

Correcting Smad1/5/8, mTOR, and VEGFR2 treats pathology in hereditary hemorrhagic telangiectasia models

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Abstract

Hereditary hemorrhagic telangiectasia (HHT), a genetic bleeding disorder leading to systemic arteriovenous malformations (AVMs), is caused by loss-of-function mutations in the ALK1-ENG-Smad1/5/8 pathway. Evidence suggests that HHT pathogenesis strongly relies on overactivated PI3K-Akt-mTOR and VEGFR2 pathways in endothelial cells (ECs). In the BMP9/10-immunoblocked (BMP9/10ib) neonatal mouse model of HHT, we report here that the mTOR inhibitor, sirolimus, and the receptor tyrosine-kinase inhibitor, nintedanib, could synergistically fully block, but also reversed, retinal AVMs to avert retinal bleeding and anemia. Sirolimus plus nintedanib prevented vascular pathology in the oral mucosa, lungs, and liver of the BMP9/10ib mice, as well as significantly reduced gastrointestinal bleeding and anemia in inducible ALK1-deficient adult mice. Mechanistically, in vivo in BMP9/10ib mouse ECs, sirolimus and nintedanib blocked the overactivation of mTOR and VEGFR2, respectively. Furthermore, we found that sirolimus activated ALK2-mediated Smad1/5/8 signaling in primary ECs—including in HHT patient blood outgrowth ECs—and partially rescued Smad1/5/8 activity in vivo in BMP9/10ib mouse ECs. These data demonstrate that the combined correction of endothelial Smad1/5/8, mTOR, and VEGFR2 pathways opposes HHT pathogenesis. Repurposing of sirolimus plus nintedanib might provide therapeutic benefit in HHT patients.

Authors

Santiago Ruiz, Haitian Zhao, Pallavi Chandakkar, Julien Papoin, Hyunwoo Choi, Aya Nomura-Kitabayashi, Radhika Patel, Matthew Gillen, Li Diao, Prodyot K. Chatterjee, Mingzhu He, Yousef Al-Abed, Ping Wang, Christine N. Metz, S. Paul Oh, Lionel Blanc, Fabien Campagne, Philippe Marambaud

Notch inhibition overcomes resistance to Tyrosine Kinase Inhibitors in EGFR-driven lung adenocarcinoma

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Abstract

EGFR mutated lung adenocarcinoma patients treated with gefitinib and osimertinib show a therapeutic benefit limited by the appearance of secondary mutations, such as EGFRT790M and EGFRC797S. It is generally assumed that these secondary mutations render EGFR completely unresponsive to the inhibitors, but contrary to this, we uncovered here that gefitinib and osimertinib increased STAT3 phosphorylation (pSTAT3) in EGFRT790M and EGFRC797S tumoral cells. Interestingly, we also found that concomitant Notch inhibition with gefitinib or osimertinib treatment induced a pSTAT3-dependent strong reduction in the levels of the transcriptional repressor HES1. Importantly, we showed that tyrosine kinase inhibitor resistant tumors, with EGFRT790M and EGFRC797S mutations, were highly responsive to the combined treatment of Notch inhibitors with gefitinib and osimertinib respectively. Finally, in patients with EGFR mutations treated with tyrosine kinase inhibitors, HES1 protein levels increased during relapse and correlated with shorter progression-free survival. Therefore, our results offer a proof of concept for an alternative treatment to chemotherapy in lung adenocarcinoma osimertinib treated patients after disease progression.

Authors

Emilie Bousquet Mur, Sara Bernardo, Laura Papon, Maicol Mancini, Eric Fabbrizio, Marion Goussard, Irene Ferrer, Anais Giry, Xavier Quantin, Jean-Louis Pujol, Olivier Calvayrac, Herwig P. Moll, Yaël Glasson, Nelly Pirot, Andrei Turtoi, Marta Cañamero, Kwok-Kin Wong, Yosef Yarden, Emilio Casanova, Jean-Charles Soria, Jacques Colinge, Christian W. Siebel, Julien Mazieres, Gilles Favre, Luis Paz-Ares, Antonio Maraver

SDR9C7 catalyzes critical dehydrogenation of acylceramides for skin barrier formation

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Abstract

The corneocyte lipid envelope composed of covalently bound ceramides and fatty acids is important to the integrity of the permeability barrier in the stratum corneum, and its absence is a prime structural defect in various skin diseases associated with defective skin barrier function. SDR9C7 encodes a short chain dehydrogenase/reductase family 9C member 7 (SDR9C7) recently found mutated in ichthyosis. In a patient with SDR9C7 mutation and a mouse Sdr9c7 knockout model we show loss of covalent binding of epidermal ceramides to protein, a structural fault in the barrier. For reasons unresolved, protein binding requires lipoxygenase-catalyzed transformations of linoleic acid (18:2) esterified in ω-O-acylceramides. In Sdr9c7-/- epidermis, quantitative LC-MS assays revealed almost complete loss of a species of ω-O-acylceramide esterified with linoleate-9,10-trans-epoxy-11E-13-ketone; other acylceramides related to the lipoxygenase pathway were in higher abundance. Recombinant SDR9C7 catalyzed NAD+-dependent dehydrogenation of linoleate 9,10-trans-epoxy-11E-13-alcohol to the corresponding 13-ketone, while ichthyosis mutants were inactive. We propose, therefore, that the critical requirement for lipoxygenases and SDR9C7 is in producing acylceramide containing the 9,10-epoxy-11E-13-ketone, a reactive moiety known for its non-enzymatic coupling to protein. This suggests a mechanism for coupling of ceramide to protein and provides important insights into skin barrier formation and pathogenesis.

Authors

Takuya Takeichi, Tetsuya Hirabayashi, Yuki Miyasaka, Akane Kawamoto, Yusuke Okuno, Shijima Taguchi, Kana Tanahashi, Chiaki Murase, Hiroyuki Takama, Kosei Tanaka, William E. Boeglin, M. Wade Calcutt, Daisuke Watanabe, Michihiro Kono, Yoshinao Muro, Junko Ishikawa, Tamio Ohno, Alan R. Brash, Masashi Akiyama

KBTBD13 is an actin-binding protein that modulates muscle kinetics

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Abstract

The mechanisms that modulate the kinetics of muscle relaxation are critically important for muscle function. A prime example of the impact of impaired relaxation kinetics is nemaline myopathy caused by mutations in KBTBD13 (NEM6). In addition to weakness, NEM6 patients have slow muscle relaxation, compromising contractility and daily-life activities. The role of KBTBD13 in muscle is unknown, and the pathomechanism underlying NEM6 is undetermined. A combination of transcranial magnetic stimulation-induced muscle relaxation, muscle fiber- and sarcomere-contractility assays, low angle X-ray diffraction and super-resolution microscopy revealed that the impaired muscle relaxation kinetics in NEM6 patients are caused by structural changes in the thin filament, a sarcomeric microstructure. Using homology modeling, binding- and contractility assays with recombinant KBTBD13, novel Kbtbd13-knockout and Kbtbd13R408C-knockin mouse models and a GFP-labeled Kbtbd13- transgenic zebrafish model we discovered that KBTBD13 binds to actin – a major constituent of the thin filament - and that mutations in KBTBD13 cause structural changes impairing muscle relaxation kinetics. We propose that this actin-based impaired relaxation is central to NEM6 pathology.

Authors

Josine M. de Winter, Joery P. Molenaar, Michaela Yuen, Robbert van der Pijl, Shengyi Shen, Stefan Conijn, Martijn van de Locht, Menne Willigenburg, Sylvia J.P. Bogaards, Esmee S.B. van Kleef, Saskia Lassche, Malin Persson, Dilson E. Rassier, Tamar E. Sztal, Avnika A. Ruparelia, Viola Oorschot, Georg Ramm, Thomas E. Hall, Zherui Xiong, Christopher N. Johnson, Frank Li, Balazs Kiss, Noelia Lozano-Vidal, Reinier A. Boon, Manuela Marabita, Leonardo Nogara, Bert Blaauw, Richard J. Rodenburg, Benno Kϋsters, Jonne Doorduin, Alan H. Beggs, Henk Granzier, Ken Campbell, Weikang Ma, Thomas Irving, Edoardo Malfatti, Norma B. Romero, Robert J. Bryson-Richardson, Baziel G.M. van Engelen, Nicol C. Voermans, Coen A.C. Ottenheijm