Abstract
Early after HIV infection there is substantial depletion of CD4+ T cells in the gastrointestinal (GI) tract lamina propria (LP), with associated epithelial barrier damage, leading to microbial translocation and systemic inflammation and immune activation. In this study, we analyzed these early events in the GI tract in a cohort of Thai acute HIV-infected patients and determined the effect of early combination antiretroviral treatment (cART). HIV-uninfected and chronically and acutely HIV-infected patients at different Fiebig stages (I–V) underwent colonic biopsies and then received cART. Immunohistochemistry and quantitative image analysis were performed on cross-sectional and longitudinal colon biopsy specimens (day 0 to week 96) to measure GI tract damage (infiltration of polymorphonuclear cells), inflammation (Mx1, TNF-α), immune activation (Ki-67), and the CD4+ T cell population in the LP. The magnitude of GI tract damage, immune activation, and inflammation was significantly increased, with significantly depleted CD4+ T cells in the LP in all acutely infected groups prior to cART compared with HIV-uninfected control participants. While most patients treated during acute infection resolved GI tract inflammation and immune activation back to baseline levels after 24 weeks of cART, most acutely infected participants did not restore their CD4+ T cells after 96 weeks of cART.
Authors
Claire Deleage, Alexandra Schuetz, W. Gregory Alvord, Leslie Johnston, Xing-Pei Hao, David R. Morcock, Rungsun Rerknimitr, James L.K. Fletcher, Suwanna Puttamaswin, Nittaya Phanuphak, Robin Dewar, Joseph M. McCune, Irini Sereti, Merlin Robb, Jerome H. Kim, Timothy W. Schacker, Peter Hunt, Jeffrey D. Lifson, Jintanat Ananworanich, Jacob D. Estes, on behalf of the RV254/SEARCH 010 and RV304/SEARCH 013 Study Groups
Abstract
Since 2011, over 300 human cases of infection, especially in exposed children, with the influenza A H3N2 variant (H3N2v) virus that circulates in swine in the US have been reported. The structural and genetic basis for the lack of protection against H3N2v induced by vaccines containing seasonal H3N2 antigens is poorly understood. We isolated 17 human monoclonal antibodies (mAbs) that neutralized H3N2v virus from subjects experimentally immunized with an H3N2v candidate vaccine. Six mAbs exhibited very potent neutralizing activity (IC50 < 200 ng/ml) against the H3N2v virus but not against current human H3N2 circulating strains. Fine epitope mapping and structural characterization of antigen-antibody complexes revealed that H3N2v specificity was attributable to amino acid polymorphisms in the 150-loop and the 190-helix antigenic sites on the hemagglutinin protein. H3N2v-specific antibodies also neutralized human H3N2 influenza strains naturally circulating between 1995 and 2005. These results reveal a high level of antigenic relatedness between the swine H3N2v virus and previously circulating human strains, consistent with the fact that early human H3 seasonal strains entered the porcine population in the 1990s and reentered the human population, where they had not been circulating, as H3N2v about a decade later. The data also explain the increased susceptibility to H3N2v viruses in young children, who lack prior exposure to human seasonal strains from the 1990s.
Authors
Sandhya Bangaru, Travis Nieusma, Nurgun Kose, Natalie J. Thornburg, Jessica A. Finn, Bryan S. Kaplan, Hannah G. King, Vidisha Singh, Rebecca M. Lampley, Gopal Sapparapu, Alberto Cisneros III, Kathryn M. Edwards, James C. Slaughter, Srilatha Edupuganti, Lilin Lai, Juergen A. Richt, Richard J. Webby, Andrew B. Ward, James E. Crowe Jr.
Abstract
Atopic dermatitis (AD) is characterized by reduced barrier function, reduced innate immune activation, and susceptibility to
Authors
Ian A. Myles, Kelli W. Williams, Jensen D. Reckhow, Momodou L. Jammeh, Nathan B. Pincus, Inka Sastalla, Danial Saleem, Kelly D. Stone, Sandip K. Datta
Abstract
High-affinity self-reactive thymocytes are purged in the thymus, and residual self-reactive T cells, which are detectable in healthy subjects, are controlled by peripheral tolerance mechanisms. Breakdown in these mechanisms results in autoimmune disease, but antigen-specific therapy to augment natural mechanisms can prevent this. We aimed to determine when antigen-specific therapy is most effective. Islet autoantigens, proinsulin (PI), and islet-specific glucose-6-phosphatase catalytic subunit-related protein (IGRP) were expressed in the antigen-presenting cells (APCs) of autoimmune diabetes-prone nonobese diabetic (NOD) mice in a temporally controlled manner. PI expression from gestation until weaning was sufficient to completely protect NOD mice from diabetes, insulitis, and development of insulin autoantibodies. Insulin-specific T cells were significantly diminished, were naive, and did not express IFN-γ when challenged. This long-lasting effect from a brief period of treatment suggests that autoreactive T cells are not produced subsequently. We tracked IGRP206–214-specific CD8+ T cells in NOD mice expressing IGRP in APCs. When IGRP was expressed only until weaning, IGRP206–214-specific CD8+ T cells were not detected later in life. Thus, anti-islet autoimmunity is determined during early life, and autoreactive T cells are not generated in later life. Bolstering tolerance to islet antigens in the perinatal period is sufficient to impart lasting protection from diabetes.
Authors
Gaurang Jhala, Jonathan Chee, Prerak M. Trivedi, Claudia Selck, Esteban N. Gurzov, Kate L. Graham, Helen E. Thomas, Thomas W.H. Kay, Balasubramanian Krishnamurthy
Abstract
Tissue-resident memory T cells (TRM) are a recently defined, noncirculating subset with the potential for rapid in situ protective responses, although their generation and role in vaccine-mediated immune responses is unclear. Here, we assessed TRM generation and lung-localized protection following administration of currently licensed influenza vaccines, including injectable inactivated influenza virus (IIV, Fluzone) and i.n. administered live-attenuated influenza virus (LAIV, FluMist) vaccines. We found that, while IIV preferentially induced strain-specific neutralizing antibodies, LAIV generated lung-localized, virus-specific T cell responses. Moreover, LAIV but not IIV generated lung CD4+ TRM and virus-specific CD8+ TRM, similar in phenotype to those generated by influenza virus infection. Importantly, these vaccine-generated TRM mediated cross-strain protection, independent of circulating T cells and neutralizing antibodies, which persisted long-term after vaccination. Interestingly, intranasal administration of IIV or injection of LAIV failed to elicit T cell responses or provide protection against viral infection, demonstrating dual requirements for respiratory targeting and a live-attenuated strain to establish TRM. The ability of LAIV to generate lung TRM capable of providing long-term protection against nonvaccine viral strains, as demonstrated here, has important implications for protecting the population against emergent influenza pandemics by direct fortification of lung-specific immunity.
Authors
Kyra D. Zens, Jun Kui Chen, Donna L. Farber
Abstract
The mechanisms by which exercise mediates its multiple cardiac benefits are only partly understood. Prior comprehensive analyses of the cardiac transcriptional components and microRNAs dynamically regulated by exercise suggest that the CBP/p300-interacting protein CITED4 is a downstream effector in both networks. While CITED4 has documented functional consequences in neonatal cardiomyocytes in vitro, nothing is known about its effects in the adult heart. To investigate the impact of cardiac CITED4 expression in adult animals, we generated transgenic mice with regulated, cardiomyocyte-specific CITED4 expression. Cardiac CITED4 expression in adult mice was sufficient to induce an increase in heart weight and cardiomyocyte size with normal systolic function, similar to the effects of endurance exercise training. After ischemia-reperfusion, CITED4 expression did not change initial infarct size but mediated substantial functional recovery while reducing ventricular dilation and fibrosis. Forced cardiac expression of CITED4 also induced robust activation of the mTORC1 pathway after ischemic injury. Moreover, pharmacological inhibition of mTORC1 abrogated CITED4’s effects in vitro and in vivo. Together, these data establish CITED4 as a regulator of mTOR signaling that is sufficient to induce physiologic hypertrophy at baseline and mitigate adverse ventricular remodeling after ischemic injury.
Authors
Vassilios J. Bezzerides, Colin Platt, Carolin Lerchenmüller, Kaavya Paruchuri, Nul Loren Oh, Chunyang Xiao, Yunshan Cao, Nina Mann, Bruce M. Spiegelman, Anthony Rosenzweig
Abstract
Vertebrate life critically depends on renal filtration and excretion of low molecular weight waste products. This process is controlled by a specialized cell-cell contact between podocyte foot processes: the slit diaphragm (SD). Using a comprehensive set of targeted KO mice of key SD molecules, we provided genetic, functional, and high-resolution ultrastructural data highlighting a concept of a flexible, dynamic, and multilayered architecture of the SD. Our data indicate that the mammalian SD is composed of NEPHRIN and NEPH1 molecules, while NEPH2 and NEPH3 do not participate in podocyte intercellular junction formation. Unexpectedly, homo- and heteromeric NEPHRIN/NEPH1 complexes are rarely observed. Instead, single NEPH1 molecules appear to form the lower part of the junction close to the glomerular basement membrane with a width of 23 nm, while single NEPHRIN molecules form an adjacent junction more apically with a width of 45 nm. In both cases, the molecules are quasiperiodically spaced 7 nm apart. These structural findings, in combination with the flexibility inherent to the repetitive Ig folds of NEPHRIN and NEPH1, indicate that the SD likely represents a highly dynamic cell-cell contact that forms an adjustable, nonclogging barrier within the renal filtration apparatus.
Authors
Florian Grahammer, Christoph Wigge, Christoph Schell, Oliver Kretz, Jaakko Patrakka, Simon Schneider, Martin Klose, Sebastian J. Arnold, Anja Habermann, Ricarda Bräuniger, Markus M. Rinschen, Linus Völker, Andreas Bregenzer, Dennis Rubbenstroth, Melanie Boerries, Dontscho Kerjaschki, Jeffrey H. Miner, Gerd Walz, Thomas Benzing, Alessia Fornoni, Achilleas S. Frangakis, Tobias B. Huber
Abstract
Tregs imprint an early immunotolerant tumor environment that prevents effective antitumor immune responses. Using transcriptomics of tumor tissues, we identified early upregulation of VEGF and TGF-β pathways compatible with tolerance imprinting. Silencing of VEGF or TGF-β in tumor cells induced early and pleiotropic modulation of immune-related transcriptome signatures in tumor tissues. These were surprisingly similar for both silenced tumors and related to common downstream effects on Tregs. Silencing of VEGF or TGF-β resulted in dramatically delayed tumor growth, associated with decreased Tregs and myeloid-derived suppressor cells and increased effector T cell activation in tumor infiltrates. Strikingly, co-silencing of TGF-β and VEGF led to a substantial spontaneous tumor eradication rate and the combination of their respective inhibitory drugs was synergistic. VEGF and/or TGF-β silencing also restored tumor sensitivity to tumor-specific cell therapies and markedly improved the efficacy of anti–PD-1/anti–CTLA-4 treatment. Thus, TGF-β and VEGF cooperatively control the tolerant environment of tumors and are targets for improved cancer immunotherapies.
Authors
Tristan Courau, Djamel Nehar-Belaid, Laura Florez, Béatrice Levacher, Thomas Vazquez, Faustine Brimaud, Bertrand Bellier, David Klatzmann
Abstract
Despite identification of causal genes for various lipodystrophy syndromes, the molecular basis of some peculiar lipodystrophies remains obscure. In an African-American pedigree with a novel autosomal dominant, atypical familial partial lipodystrophy (FPLD), we performed linkage analysis for candidate regions and whole-exome sequencing to identify the disease-causing mutation. Affected adults reported marked loss of fat from the extremities, with excess fat in the face and neck at age 13–15 years, and developed metabolic complications later. A heterozygous g.112837956C>T mutation on chromosome 10 (c.202C>T, p.Leu68Phe) affecting a highly conserved residue in adrenoceptor α 2A (
Authors
Abhimanyu Garg, Shireesha Sankella, Chao Xing, Anil K. Agarwal
Abstract
Mosaicism is increasingly recognized as a cause of developmental disorders with the advent of next-generation sequencing (NGS). Mosaic mutations of
Authors
Ghayda Mirzaa, Andrew E. Timms, Valerio Conti, Evan August Boyle, Katta M. Girisha, Beth Martin, Martin Kircher, Carissa Olds, Jane Juusola, Sarah Collins, Kaylee Park, Melissa Carter, Ian Glass, Inge Krägeloh-Mann, David Chitayat, Aditi Shah Parikh, Rachael Bradshaw, Erin Torti, Steve Braddock, Leah Burke, Sondhya Ghedia, Mark Stephan, Fiona Stewart, Chitra Prasad, Melanie Napier, Sulagna Saitta, Rachel Straussberg, Michael Gabbett, Bridget C. O’Connor, Catherine E. Keegan, Lim Jiin Yin, Angeline Hwei Meeng Lai, Nicole Martin, Margaret McKinnon, Marie-Claude Addor, Luigi Boccuto, Charles E. Schwartz, Agustina Lanoel, Robert L. Conway, Koenraad Devriendt, Katrina Tatton-Brown, Mary Ella Pierpont, Michael Painter, Lisa Worgan, James Reggin, Raoul Hennekam, Karen Tsuchiya, Colin C. Pritchard, Mariana Aracena, Karen W. Gripp, Maria Cordisco, Hilde Van Esch, Livia Garavelli, Cynthia Curry, Anne Goriely, Hulya Kayserilli, Jay Shendure, John Graham Jr., Renzo Guerrini, William B. Dobyns
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