Immunology
Abstract
Neutrophils amplify inflammation in lupus through release of neutrophil extracellular traps (NETs). The endoplasmic reticulum stress sensor inositol-requiring enzyme 1 alpha (IRE1α) has been implicated as a perpetuator of inflammation in various chronic diseases; however, IRE1α has been little studied in relation to neutrophil function or lupus pathogenesis. Here, we found that neutrophils activated by lupus-derived immune complexes demonstrate markedly increased IRE1α ribonuclease activity. Importantly, heightened IRE1α activity was also detected in neutrophils isolated from lupus patients, where it correlated with global disease activity. Immune complex-stimulated neutrophils produced both mitochondrial reactive oxygen species (mitoROS) and the activated form of caspase-2 in IRE1α-dependent fashion, while inhibition of IRE1α mitigated immune complex-mediated NETosis (both in human neutrophils and in a mouse model of lupus). Administration of an IRE1α inhibitor to lupus-prone MRL/lpr mice over eight weeks reduced mitochondrial ROS levels in peripheral blood neutrophils, while also restraining plasma-cell expansion and autoantibody formation. In summary, these data are the first to identify a role for IRE1α in the hyperactivity of lupus neutrophils, with this pathway apparently upstream of mitochondrial dysfunction, mitochondrial ROS formation, and NETosis. Inhibition of the IRE1α pathway appears to be a novel strategy for neutralizing NETosis in lupus, and potentially other inflammatory conditions.
Authors
Gautam Sule, Basel H. Abuaita, Paul A. Steffes, Andrew T. Fernandes, Shanea K. Estes, Craig J. Dobry, Deepika Pandian, Johann E. Gudjonsson, J. Michelle Kahlenberg, Mary X. O'Riordan, Jason S. Knight
Abstract
BACKGROUND. Immunization with replication-competent recombinant vectors provides exposure to transgene-encoded antigens in the context of inflammation that may drive more potent and durable immunity compared to non-replicating vaccines. To understand the features of a replicating vaccine that drive such responses we tested a replication-competent adenovirus type 4 encoding influenza virus H5 hemagglutinin (Ad4-H5-Vtn) administered by an oral capsule or via a tonsillar swab or nasal spray. METHODS. Viral shedding from the nose, mouth, and rectum was measured by PCR and culture. H5-specific IgG and IgA antibodies were measured by bead array binding assays. Serum antibodies were measured by a pseudovirus entry inhibition assay (PVEI), microneutralization (MN), and hemagglutinin inhibition (HAI). RESULTS. Ad4-H5-Vtn DNA was shed from most upper respiratory tract (URT)-immunized volunteers for 2-4 weeks, but cultured from only 60% of participants with a median duration of one day. Ad4-H5-Vtn vaccination induced increases in H5-specific CD4+ and CD8+ T cells in the peripheral blood and IgG and IgA in nasal, cervical and rectal secretions. URT immunizations induced high levels of serum neutralizing antibodies (NAb) to H5 which remained stable at week 26. The duration of viral shedding correlated with the magnitude of the NAb response at week 26. Adverse events (AE) were mild, and peak NAb titer was associated with overall AE frequency or duration. Serum neutralizing antibody titers could be boosted to very high levels 2-5 years after Ad4-H5-Vtn vaccination with recombinant H5 or inactivated split H5N1 vaccine. CONCLUSION. Replicating Ad4 delivered to the URT causes prolonged exposure to antigen, drives durable systemic and mucosal immunity, and is a promising platform for the induction of immunity against viral surface glycoprotein targets. TRIAL REGISTRATION. ClinicalTrials.gov NCT01443936, NCT01806909. FUNDING. Intramural and Extramural Research Programs of the NIAID, NIH; and the Centers of Influenza Virus Research and SurveillanceFunding. Intramural and Extramural Research Programs of the NIAID, NIH; and the Centers of Influenza Virus Research and Surveillance.
Authors
Kenta Matsuda, Stephen A. Migueles, Jinghe Huang, Lyuba Bolkhovitinov, Sarah Stuccio, Trevor Griesman, Alyssa A. Pullano, Byong H. Kang, Elise Ishida, Matthew Zimmerman, Neena Kashyap, Kelly M. Martins, Daniel Stadlbauer, Jessica Pederson, Andy Patamawenu, Nathaniel E. Wright, Tulley Shofner, Sean Evans, C. Jason Liang, Julián Candia, Angelique Biancotto, Giovanna Fantoni, April Poole, Jonathan Smith, Jeff Alexander, Marc Gurwith, Florian Krammer, Mark Connors
Abstract
T regulatory cells (Treg) restrain both the innate and adaptive immune systems to maintain homeostasis. Allergic airway inflammation, characterized by a type 2 (Th2) response that results from a breakdown of tolerance to innocuous environmental antigens, is negatively regulated by Treg. We previously reported that prostaglandin I2 (PGI2) promoted immune tolerance in models of allergic inflammation; however, the effect of PGI2 on Treg function was not investigated. Treg from mice deficient in the PGI2 receptor IP (IP KO) had impaired suppressive capabilities during allergic airway inflammatory responses compared to mice with PGI2 signaling was intact. IP KO Treg had significantly enhanced expression of immunoglobulin-like transcript 3 (ILT3) compared to wild-type Treg, which may contribute to the impairment of the IP KO Treg’s ability to suppress Th2 responses. Using fate-mapping mice, we reported that PGI2 signaling prevents Treg reprogramming toward a pathogenic phenotype. PGI2 analogs promoted the differentiation of naïve T cells to Treg in both mice and humans via repression of β-catenin signaling. Finally, a missense variant in IP in humans was strongly associated with chronic obstructive asthma. Together, these data support that PGI2 signaling licenses Treg suppressive function and that PGI2 is a therapeutic target to enhance Treg function.
Authors
Allison E. Norlander, Melissa H. Bloodworth, Shinji Toki, Jian Zhang, Weisong Zhou, Kelli L. Boyd, Vasiliy V. Polosukhin, Jacqueline-Yvonne Cephus, Zachary J. Ceneviva, Vivek D. Gandhi, Nowrin U. Chowdhury, Louis-Marie Charbonnier, Lisa M. Rogers, Janey Wang, David M. Aronoff, Lisa Bastarache, Dawn C. Newcomb, Talal A. Chatila, R. Stokes Peebles, Jr.
Abstract
The coat protein I (COPI) complex mediates retrograde trafficking from the Golgi to the endoplasmic reticulum (ER). Five siblings with persistent bacterial and viral infections and defective humoral and cellular immunity had a homozygous p.K652E mutation in the γ1 subunit of COPI (γ1-COP). The mutation disrupts COPI binding to the KDEL receptor and impairs the retrieval of KDEL-bearing chaperones from the Golgi to the ER. Homozygous Copg1K652E mice had increased ER stress in activated T and B cells, poor antibody responses, and normal numbers of T cells that proliferated normally, but underwent increased apoptosis upon activation. Exposure of the mutants to pet store mice caused weight loss, lymphopenia, and defective T cell proliferation that recapitulated the findings in the patients. The ER stress-relieving agent tauroursodeoxycholic acid corrected the immune defects of the mutants and reversed the phenotype they acquired following exposure to pet store mice. This study establishes the role of γ1-COP in the ER retrieval of KDEL-bearing chaperones and thereby the importance of ER homeostasis in adaptive immunity.
Authors
Wayne Bainter, Craig D. Platt, Seung-Yeol Park, Kelsey Stafstrom, Jacqueline G. Wallace, Zachary T. Peters, Michel J. Massaad, Michel Becuwe, Sandra Andrea Salinas, Jennifer Jones, Sarah Beaussant-Cohen, Faris Jaber, Jia-Shu Yang, Tobias C. Walther, Jordan S. Orange, Chitong Rao, Seth Rakoff-Nahoum, Maria Tsokos, Shafiq Ur Rehman Naseem, Salem Al-Tamemi, Janet Chou, Victor W. Hsu, Raif S. Geha
Abstract
Multisystem inflammatory syndrome associated with the SARS-CoV-2 pandemic has recently been described in children (MIS-C), partially overlapping with Kawasaki disease (KD). We hypothesized that: 1) MIS-C and pre-pandemic KD cytokine profiles may be unique and justify the clinical differences observed; 2) SARS-CoV-2-specific immune complexes (IC) may explain the immunopathology of MIS-C. Seventy-four children were included: 14 MIS-C; 9 patients with positive SARS-CoV-2-PCR without MIS-C (COVID); 14 pre-pandemic KD and 37 healthy controls (HC). Thirty-four circulating cytokines were quantified in pre-treatment serum or plasma samples and the presence of circulating SARS-CoV-2 IC was evaluated in MIS-C patients. Compared to HC, MIS-C and KD groups showed most cytokines to be significantly elevated, with IFN-γ-induced response markers (including IFN-γ, IL-18, IP-10) and inflammatory monocytes activation markers (including MCP-1, IL-1α, IL-1RA) being the main triggers of inflammation. With linear discriminant analysis, MIS-C and KD profiles overlapped; however, a subgroup of MIS-C patients (MIS-Cplus) differentiated from the remaining MIS-C patients in IFN-γ, IL-18, GM-CSF, RANTES, IP-10, IL-1α and SDF-1 and incipient signs of macrophagic activation syndrome. Circulating SARS-CoV-2-IC were not detected in MIS-C patients. Our findings suggest a major role of IFN-γ in the pathogenesis of MIS-C, which may be relevant for therapeutic management.
Authors
Ana Esteve-Sole, Jordi Anton, Rosa Maria Pino-Ramírez, Judith Sanchez-Manubens, Victoria Fumadó, Clàudia Fortuny, María Rios-Barnes, Joan Sanchez-de-Toledo, Mónica Girona-Alarcón, Juan M. Mosquera, Silvia Ricart, Cristian Launes, Mariona Fernández de Sevilla, Cristina Jou, Carmen Muñoz-Almagro, Eva González-Roca, Andrea Vergara, Jorge Carrillo, Manel Juan, Daniel Cuadras, Antoni Noguera-Julian, Iolanda Jordan, Laia Alsina
Abstract
The immunopathology of COVID-19 remains enigmatic, exhibiting immunodysregulation and T cell lymphopenia. Monocytic myeloid-derived suppressor cells (M-MDSC) are T cell suppressors that expand in inflammatory conditions, but their role in acute respiratory infections remains unclear. We studied blood and airways of COVID-19 patients across disease severity at multiple timepoints. M-MDSC frequencies were elevated in blood but not in nasopharyngeal or endotracheal aspirates of COVID-19 patients compared to controls. M-MDSCs isolated from COVID-19 patients suppressed T cell proliferation and IFNg production partly via an arginase-1 (Arg-1) dependent mechanism. Furthermore, patients showed increased Arg-1 and IL-6 plasma levels. COVID-19 patients had fewer T cells, and displayed downregulated expression of the CD3ζ chain. Ordinal regression showed that early M-MDSC frequency predicted subsequent disease severity. In conclusion, M-MDSCs expand in blood of COVID-19 patients, suppress T cells and strongly associate with disease severity, suggesting a role for M-MDSCs in the dysregulated COVID-19 immune response.
Authors
Sara Falck-Jones, Sindhu Vangeti, Meng Yu, Ryan Falck-Jones, Alberto Cagigi, Isabella Badolati, Björn Österberg, Maximilian Julius Lautenbach, Eric Ahlberg, Ang Lin, Rico Lepzien, Inga Szurgot, Klara Lenart, Fredrika Hellgren, Holden T. Maecker, Jörgen Sälde, Jan Albert, Niclas Johansson, Max Bell, Karin Lore, Anna Färnert, Anna Smed-Sörensen
Abstract
Neoantigens generated by somatic non-synonymous mutations are key targets of tumor-specific T cells, but only a small number of mutations predicted to be immunogenic are presented by MHC molecules on cancer cells. Vaccination studies in mice and patients have shown that the majority of neoepitopes that elicit T cell responses fail to induce significant anti-tumor activity, for incompletely understood reasons. We report that radiotherapy upregulates the expression of genes containing immunogenic mutations in a poorly immunogenic mouse model of triple negative breast cancer. Vaccination with neoepitopes encoded in these genes elicited CD8+ and CD4+ T cells that, whereas ineffective in preventing tumor growth, improved the therapeutic efficacy of radiotherapy. Mechanistically, neoantigen-specific CD8+ T cells preferentially killed irradiated tumor cells. Neoantigen-specific CD4+ T cells were required for the therapeutic efficacy of vaccination and acted by producing Th1 cytokines, killing irradiated tumor cells and promoting epitope spread. Such a cytotoxic activity relied on the ability of radiation to upregulate class II MHC molecules as well as the death receptors FAS/CD95 and DR5 on the surface of tumor cells. These results provide proof-of-principle evidence that radiotherapy works in concert with neoantigen vaccination to improve tumor control.
Authors
Claire Lhuillier, Nils-Petter Rudqvist, Takahiro Yamazaki, Tuo Zhang, Maud Charpentier, Lorenzo Galluzzi, Noah Dephoure, Cristina C. Clement, Laura Santambrogio, Xi K. Zhou, Silvia C. Formenti, Sandra Demaria
Abstract
BACKGROUND There has been a striking generational increase in the prevalence of food allergies. We have proposed that this increase can be explained, in part, by alterations in the commensal microbiome.METHODS To identify bacterial signatures and metabolic pathways that may influence the expression of this disease, we collected fecal samples from a unique, well-controlled cohort of twins concordant or discordant for food allergy. Samples were analyzed by integrating 16S rRNA gene amplicon sequencing and liquid chromatography–tandem mass spectrometry metabolite profiling.RESULTS A bacterial signature of 64 operational taxonomic units (OTUs) distinguished healthy from allergic twins; the OTUs enriched in the healthy twins were largely taxa from the Clostridia class. We detected significant enrichment in distinct metabolite pathways in each group. The enrichment of diacylglycerol in healthy twins is of particular interest for its potential as a readily measurable fecal biomarker of health. In addition, an integrated microbial-metabolomic analysis identified a significant association between healthy twins and Phascolarctobacterium faecium and Ruminococcus bromii, suggesting new possibilities for the development of live microbiome-modulating biotherapeutics.CONCLUSION Twin pairs exhibited significant differences in their fecal microbiomes and metabolomes through adulthood, suggesting that the gut microbiota may play a protective role in patients with food allergies beyond the infant stage.TRIAL REGISTRATION Participants in this study were recruited as part of an observational study (ClinicalTrials.gov NCT01613885) at multiple sites from 2014 to 2018.FUNDING This work was supported by the Sunshine Charitable Foundation; the Moss Family Foundation; the National Institute of Allergy and Infectious Diseases (NIAID) (R56AI134923 and R01AI 140134); the Sean N. Parker Center for Allergy and Asthma Research; the National Heart, Lung, and Blood Institute (R01 HL 118612); the Orsak family; the Kepner family; and the Stanford Institute for Immunity, Transplant and Infection.
Authors
Riyue Bao, Lauren A. Hesser, Ziyuan He, Xiaoying Zhou, Kari C. Nadeau, Cathryn R. Nagler
Abstract
T cell–mediated responses are dependent on their secretion of key effector molecules. However, the critical molecular determinants of the secretion of these proteins are largely undefined. Here, we demonstrate that T cell activation increases trafficking via the ER-to-Golgi pathway. To study the functional role of this pathway, we generated mice with a T cell–specific deletion in SEC23B, a core subunit of coat protein complex II (COPII). We found that SEC23B critically regulated the T cell secretome following activation. SEC23B-deficient T cells exhibited a proliferative defect and reduced effector functions in vitro, as well as in experimental models of allogeneic and xenogeneic hematopoietic cell transplantation in vivo. However, T cells derived from 3 patients with congenital dyserythropoietic anemia II (CDAII), which results from Sec23b mutation, did not exhibit a similar phenotype. Mechanistic studies demonstrated that unlike murine KO T cells, T cells from patients with CDAII harbor increased levels of the closely related paralog, SEC23A. In vivo rescue of murine KO by expression of Sec23a from the Sec23b genomic locus restored T cell functions. Together, our data demonstrate a critical role for the COPII pathway, with evidence for functional overlap in vivo between SEC23 paralogs in the regulation of T cell immunity in both mice and humans.
Authors
Stephanie Kim, Rami Khoriaty, Lu Li, Madison McClune, Theodosia A. Kalfa, Julia Wu, Daniel Peltier, Hideaki Fujiwara, Yaping Sun, Katherine Oravecz-Wilson, Richard A. King, David Ginsburg, Pavan Reddy
Abstract
Early appearance of neutralizing antibodies during acute hepatitis C virus (HCV) infection is associated with spontaneous viral clearance. However, the longitudinal changes in antigen-specific memory B cell (MBCs) associated with divergent HCV infection outcomes remain undefined. We characterized longitudinal changes in E2 glycoprotein-specific MBCs from subjects who either spontaneously resolved acute HCV infection or progressed to chronic infection, using single-cell RNA-seq and functional assays. HCV-specific antibodies in plasma from chronically infected subjects recognized multiple E2 genotypes, while those from spontaneous resolvers exhibited variable cross-reactivity to heterotypic E2. E2-specific MBCs from spontaneous resolvers peaked early after infection (4–6 months), following expansion of activated circulating T follicular helper cells (cTfh) expressing interleukin 21. In contrast, E2-specific MBCs from chronically infected subjects, enriched in VH1-69, expanded during persistent infection (> 1 year), in the absence of significantly activated cTfh expansion. Early E2-specific MBCs from spontaneous resolvers produced monoclonal antibodies (mAbs) with fewer somatic hypermutations and lower E2 binding but similar neutralization as mAbs from late E2-specific MBCs of chronically infected subjects. These findings indicate that early cTfh activity accelerates expansion of E2-specific MBCs during acute infection, which might contribute to spontaneous clearance of HCV.
Authors
Eduardo Salinas, Maude Boisvert, Amit A. Upadhyay, Nathalie Bédard, Sydney A. Nelson, Julie Bruneau, Cynthia A. Derdeyn, Joseph Marcotrigiano, Matthew J. Evans, Steven E. Bosinger, Naglaa H. Shoukry, Arash Grakoui
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ISSN: 0021-9738 (print), 1558-8238 (online)