BACKGROUND. The fungus Aspergillus fumigatus causes a variety of clinical phenotypes in patients with cystic fibrosis (pwCF). T-helper (Th) cells orchestrate immune responses against fungi, but the types of A. fumigatus-specific Th-cells in pwCF and their contribution to protective immunity or inflammation remain poorly characterized. METHODS. We used antigen-reactive T cell enrichment (ARTE) to investigate fungus-reactive Th cells in peripheral blood of pwCF and healthy controls. RESULTS. We show that clonally expanded, high-avidity A. fumigatus-specific effector Th-cells develop in pwCF, which are absent in healthy donors. Individual patients were characterized by distinct Th1, Th2, or Th17 dominated responses that remained stable over years. These different Th subsets target different A. fumigatus proteins, indicating that differential antigen uptake and presentation directs Th-cell subset development. Patients with allergic bronchopulmonary aspergillosis (ABPA) are characterized by high frequencies of Th2-cells that cross-recognize various filamentous fungi. CONCLUSION. Our data highlight the development of heterogenous Th responses targeting different protein fractions of a single fungal pathogen and identify the development of multispecies cross-reactive Th2-cells as a potential risk factor for ABPA. FUNDING. This research was supported by grants from the German Research Foundation (DFG) under Germany’s Excellence Strategy - EXC 2167-390884018 “Precision Medicine in Chronic Inflammation”, EXC 2051-390713860 “Balance of the Microverse”; the Oskar Helene Heim Stiftung; the Christiane Herzog Stiftung, Stuttgart, Germany; the Mukoviszidose Institut gGmbH, Bonn, the research and development arm of the German Cystic Fibrosis Association Mukoviszidose e.V; the German Federal Ministry of Education and Science (BMBF) InfectControl 2020 Projects AnDiPath, BMBF 03ZZ0838A+B.
Carsten Schwarz, Patience Eschenhagen, Henrijette Schmidt, Thordis Hohnstein, Christina Iwert, Claudia Grehn, Jobst Roehmel, Eva Steinke, Mirjam Stahl, Laura Lozza, Ekaterina Tikhonova, Elisa Rosati, Ulrik Stervbo, Nina Babel, Jochen G. Mainz, Hilmar Wisplinghoff, Frank Ebel, Lei-Jie Jia, Matthew G. Blango, Peter Hortschansky, Sascha Brunke, Bernhard Hube, Axel A. Brakhage, Olaf Kniemeyer, Alexander Scheffold, Petra Bacher
Tick bites have been shown to transmit a novel form of severe food allergy, the galactose-α-1,3-galactose (α-Gal) syndrome (AGS). Cellular responses to α-Gal in AGS patients have to date not been thoroughly scrutinized. Therefore, we investigated T and B cell proliferation, activation and cytokine profiles in response to tick protein extract (TE) and α-Gal-free TE in AGS patients and healthy controls. T and B cells from both patients and controls proliferated in response to TE, but significantly more in the patients. B cell proliferation, but not T cell proliferation, in AGS patients was reduced by removing α-Gal from the TE. In addition, TE induced a clear Th2 cytokine profile in AGS patients. Expression of CD23 by B cells correlated only to T cell proliferation. However, both B cell proliferation and CD23 expression were reduced when CD40L and IL-4 were blocked. A large proportion of the IgG1 and IgE antibodies binding TE in AGS patients were directed against the α-Gal epitope. We have for the first time investigated T and B cell responses to α-Gal carrying tick proteins in AGS patients, which will be essential for the understanding of the immune response against an allergenic carbohydrate transmitted by ticks.
Danijela Apostolovic, Jeanette Grundström, Mensiena B. Gea Kiewiet, Marija Perusko, Carl Hamsten, Maria H. Starkhammar, Staffan Paulie, Marianne van Hage
In IgE-mediated food allergies, exposure to the allergen activates systemic allergic responses. Oral immunotherapy (OIT) treats food allergies through incremental increases in oral allergen exposure. However, OIT only induces sustained clinical tolerance and decreased basophil sensitivity in a subset of individuals despite increases in circulating allergen-specific IgG in all treated individuals. Therefore, we examined the allergen-specific antibodies from 2 OIT cohorts of patients with sustained and transient responses. Here, we compared antibodies from individuals with sustained or transient responses and discovered specific tolerance-associated conformational epitopes of the immunodominant allergen Ara h 2 recognized by neutralizing antibodies. First, we identified what we believe to be previously unknown conformational, intrahelical epitopes using x-ray crystallography with recombinant antibodies. We then identified epitopes only recognized in sustained tolerance. Finally, antibodies recognizing tolerance-associated epitopes effectively neutralized allergen to suppress IgE-mediated effector cell activation. Our results demonstrate the molecular basis of antibody-mediated protection in IgE-mediated food allergy, by defining how these antibodies disrupt IgE-allergen interactions to prevent allergic reactions. Our approach to studying the structural and functional basis for neutralizing antibodies demonstrates the clinical relevance of specific antibody clones in antibody-mediated tolerance. We anticipate that our findings will form the foundation for treatments of peanut allergy using neutralizing antibodies and hypoallergens.
Nicole A. LaHood, Jungki Min, Tarun Keswani, Crystal M. Richardson, Kwasi Amoako, Jingjia Zhou, Orlee Marini-Rapoport, Hervé Bernard, Stéphane Hazebrouck, Wayne G. Shreffler, J. Christopher Love, Anna Pomes, Lars C. Pedersen, Geoffrey A. Mueller, Sarita U. Patil
Anil Dangi, Irma Husain, Collin Z. Jordan, Shuangjin Yu, Xunrong Luo
BACKGROUND. To date, only limited data is available on the mechanisms of protection against colonization with Bordetella pertussis in humans. METHODS. In this study, the cellular responses to Bordetella pertussis challenge were monitored longitudinally using high-dimensional EuroFlow-based flow cytometry, allowing quantitative detection of >250 different immune cell subsets in the blood of 15 healthy donors. RESULTS. Participants who were protected against colonization showed different early cellular responses compared to colonized participants. Especially prominent for colonization-protected participants were the early expansion of (CD36-) non classical monocytes at day 1 (d1), Natural Killer cells (d3), follicular T helper cells (d1-d3) and plasma cells (d3). Plasma cell expansion at d3 correlated negatively with the CFU load at d7 and d9 post-challenge. Increased plasma cell maturation at d11-14 was found in participants with seroconversion. CONCLUSION. These early cellular immune responses following experimental infection can now be further characterized and potentially linked to an efficient mucosal immune response, preventing colonization. Ultimately, their presence may be used to evaluate whether new Bordetella pertussis vaccine candidates are protective against Bordetella pertussis colonization, e.g., by bacterial challenge post-vaccination. TRIAL REGISTRATION. NCT03751514. FUNDING. This study is part of the PERISCOPE Project, which has received funding from the Innovative Medicines Initiative 2 Joint Undertaking under grant agreement No 115910. The flow cytometric studies were supported by the EuroFlow Consortium.
Annieck M. Diks, Hans de Graaf, Cristina Teodosio, Rick J. Groenland, Bas de Mooij, Muktar Ibrahim, Alison R. Hill, Robert C. Read, Jacques J.M. van Dongen, Magdalena A. Berkowska
The role of tumor-associated macrophages (TAMs) along with the regulatory mechanisms underlying distinct macrophage activation states remain poorly understood in prostate cancer (PCa). Herein, we reported that PCa growth in macrophage-specific Ubc9 deficient mice is substantially suppressed compared to their wild-type littermates, an effect partially ascribed to the augmented CD8+ T cell response. Biochemical and molecular analyses revealed that the signal transducer and activator of transcription 4 (STAT4) is a crucial UBC9-mediated SUMOylation target, with lysine residue 350 (K350) as the major modification site. Site-directed mutation of STAT4 (K350R) enhanced its nuclear translocation and stability, thereby facilitating the proinflammatory activation of macrophages. Importantly, administration of UBC9 inhibitor, 2-D08, promoted the antitumor effect of TAMs and increased the expression of PD-1 on CD8+ T cells, supporting a synergistic antitumor efficacy once it combined with the immune checkpoint blockade (ICB) therapy. Together, our results demonstrated that ablation of UBC9 could reverse the immunosuppressive phenotype of TAMs via promoting STAT4 mediated macrophage activation and macrophage-CD8+ T cell crosstalk, which provides valuable insights to halt the pathogenic process of tumorigenesis.
Jun Xiao, Fei Sun, Ya-Nan Wang, Bo Liu, Peng Zhou, Fa-Xi Wang, Hai-Feng Zhou, Yue Ge, Tian-Tian Yue, Jia-Hui Luo, Chun-Liang Yang, Shan-Jie Rong, Ze-Zhong Xiong, Sheng Ma, Qi Zhang, Yang Xun, Chun-Guang Yang, Yang Luan, Shao-Gang Wang, Cong-Yi Wang, Zhi-Hua Wang
Aberrant immune responses to resident microbes promote inflammatory bowel disease and other chronic inflammatory conditions. However, how microbiota-specific immunity is controlled in mucosal tissues remains poorly understood. Here, we find that mice lacking epithelial expression of microbiota-sensitive histone deacetylase 3 (HDAC3) exhibit increased accumulation of commensal-specific CD4+ T cells in the intestine, provoking the hypothesis that epithelial HDAC3 may instruct local microbiota-specific immunity. Consistent with this, microbiota-specific CD4+ T cells and epithelial HDAC3 expression were concurrently induced following early-life microbiota colonization. Further, epithelial-intrinsic ablation of HDAC3 decreased commensal-specific Tregs, increased commensal-specific Th17 cells, and promoted T cell-driven colitis. Mechanistically, HDAC3 was essential for NFκB-dependent regulation of epithelial MHC class II (MHCII). Epithelial-intrinsic MHCII dampened local accumulation of commensal-specific Th17 cells in adult mice, and protected against microbiota-triggered inflammation. Remarkably, HDAC3 enabled the microbiota to induce MHCII on epithelial cells and limit the number of commensal-specific T cells in the intestine. Collectively, these data reveal a central role for an epithelial histone deacetylase in directing the dynamic balance of tissue-intrinsic CD4+ T cell subsets that recognize commensal microbes and control inflammation.
Emily M. Eshleman, Tzu-Yu Shao, Vivienne Woo, Taylor Rice, Laura Engleman, Bailey J. Didriksen, Jordan Whitt, David B. Haslam, Sing Sing Way, Theresa Alenghat
Control of intracellular parasites responsible for malaria requires host IFN-γ+T-bet+CD4+ T cells (Th1 cells) with IL-10 produced by Th1 cells to mitigate the pathology induced by this inflammatory response. However, these IL-10–producing Th1 (induced type I regulatory [Tr1]) cells can also promote parasite persistence or impair immunity to reinfection or vaccination. Here, we identified molecular and phenotypic signatures that distinguished IL-10–Th1 cells from IL-10+Tr1 cells in Plasmodium falciparum–infected people who participated in controlled human malaria infection studies, as well as C57BL/6 mice with experimental malaria caused by P. berghei ANKA. We also identified a conserved Tr1 cell molecular signature shared between patients with malaria, dengue, and graft-versus-host disease. Genetic manipulation of primary human CD4+ T cells showed that the transcription factor cMAF played an important role in the induction of IL-10, while BLIMP-1 promoted the development of human CD4+ T cells expressing multiple coinhibitory receptors. We also describe heterogeneity of Tr1 cell coinhibitory receptor expression that has implications for targeting these molecules for clinical advantage during infection. Overall, this work provides insights into CD4+ T cell development during malaria that offer opportunities for creation of strategies to modulate CD4+ T cell functions and improve antiparasitic immunity.
Chelsea L. Edwards, Susanna S. Ng, Fabian de Labastida Rivera, Dillon Corvino, Jessica A. Engel, Marcela Montes de Oca, Luzia Bukali, Teija C.M. Frame, Patrick T. Bunn, Shashi Bhushan Chauhan, Siddharth Sankar Singh, Yulin Wang, Jinrui Na, Fiona H. Amante, Jessica R. Loughland, Megan S.F. Soon, Nicola Waddell, Pamela Mukhopadhay, Lambros T. Koufariotis, Rebecca L. Johnston, Jason S. Lee, Rachel Kuns, Ping Zhang, Michelle J. Boyle, Geoffrey R. Hill, James S. McCarthy, Rajiv Kumar, Christian R. Engwerda
Accumulation of activated immune cells results in nonspecific hepatocyte killing in chronic hepatitis B (CHB), leading to fibrosis and cirrhosis. This study aims to understand the underlying mechanisms in humans and to define whether these are driven by widespread activation or a subpopulation of immune cells. We enrolled CHB patients with active liver damage to receive antiviral therapy and performed longitudinal liver sampling using fine-needle aspiration to investigate mechanisms of CHB pathogenesis in the human liver. Single-cell sequencing of total liver cells revealed a distinct liver-resident, polyclonal CD8+ T cell population that was enriched at baseline and displayed a highly activated immune signature during liver damage. Cytokine combinations, identified by in silico prediction of ligand-receptor interaction, induced the activated phenotype in healthy liver CD8+ T cells, resulting in nonspecific Fas ligand–mediated killing of target cells. These results define a CD8+ T cell population in the human liver that can drive pathogenesis and a key pathway involved in their function in CHB patients.
Shirin Nkongolo, Deeqa Mahamed, Adrian Kuipery, Juan D. Sanchez Vasquez, Samuel C. Kim, Aman Mehrotra, Anjali Patel, Christine Hu, Ian McGilvray, Jordan J. Feld, Scott Fung, Diana Chen, Jeffrey J. Wallin, Anuj Gaggar, Harry L.A. Janssen, Adam J. Gehring
Understanding the regulatory mechanisms of PD-L1 expression in tumors provides key clues for improving immune checkpoint blockade efficacy or developing novel oncoimmunotherapy. Here, we showed that the FDA-approved sodium-glucose cotransporter-2 (SGLT2) inhibitor canagliflozin dramatically suppressed PD-L1 expression and enhanced T cell–mediated cytotoxicity. Mechanistic study revealed that SGLT2 colocalized with PD-L1 at the plasma membrane and recycling endosomes and thereby prevented PD-L1 from proteasome-mediated degradation. Canagliflozin disturbed the physical interaction between SGLT2 and PD-L1 and subsequently allowed the recognition of PD-L1 by Cullin3SPOP E3 ligase, which triggered the ubiquitination and proteasome-mediated degradation of PD-L1. In mouse models and humanized immune-transformation models, either canagliflozin treatment or SGLT2 silencing significantly reduced PD-L1 expression and limited tumor progression — to a level equal to the PD-1 mAb — which was correlated with an increase in the activity of antitumor cytotoxic T cells. Notably, prolonged progression-free survival and overall survival curves were observed in the group of PD-1 mAb–treated patients with non–small cell lung cancer with high expression of SGLT2. Therefore, our study identifies a regulator of cell surface PD-L1, provides a ready-to-use small-molecule drug for PD-L1 degradation, and highlights a potential therapeutic target to overcome immune evasion by tumor cells.
Ling Ding, Xi Chen, Wenxin Zhang, Xiaoyang Dai, Hongjie Guo, Xiaohui Pan, Yanjun Xu, Jianguo Feng, Meng Yuan, Xiaomeng Gao, Jian Wang, Xiaqing Xu, Sicheng Li, Honghai Wu, Ji Cao, Qiaojun He, Bo Yang