Chronic viral infections are often established by the exploitation of immune regulatory mechanisms that result in non-functional T cell responses. Viruses that establish persistent infections remain a serious threat to human health. Sphingosine kinase (SphK) 2 generates sphingosine 1-phosphate, which is a molecule known to regulate multiple cellular processes. However, little is known about SphK2’s role during the host immune responses to viral infection. Here, we demonstrate that SphK2 functions during lymphocytic choriomeningitis virus Cl 13 (LCMV Cl 13) infection to limit T cell immune pathology, which subsequently aids in the establishment of virus-induced immunosuppression and the resultant viral persistence. The infection of Sphk2-deficient (Sphk2-/-) mice with LCMV Cl 13 led to the development of nephropathy and mortality via T cell-mediated immunopathology. Following LCMV infection, Sphk2-/- CD4+ T cells displayed increased activity and proliferation, and these cells promoted overactive LCMV Cl 13-specific CD8+ T cell responses. Notably, oral instillation of an SphK2-selective inhibitor promoted protective T cell responses and accelerated the termination of LCMV Cl 13 persistence in mice. Thus, SphK2 is indicated as an immunotherapeutic target for the control of persistent viral infections.
Caleb J. Studstill, Curtis J. Pritzl, Young-Jin Seo, Dae Young Kim, Chuan Xia, Jennifer J. Wolf, Ravi Nistala, Madhuvanthi Vijayan, Yong-Bin Cho, Kyung Won Kang, Sang-Myeong Lee, Bumsuk Hahm
Regulatory T (Treg) cells require Foxp3 expression and induction of a specific DNA hypomethylation signature during development, after which Treg cells persist as a self-renewing population that regulates immune system activation. Whether maintenance DNA methylation is required for Treg cell lineage development and stability and how methylation patterns are maintained during lineage self-renewal remain unclear. Here, we demonstrate that the epigenetic regulator Uhrf1 is essential for maintenance of methyl-DNA marks that stabilize Treg cellular identity by repressing effector T cell transcriptional programs. Constitutive and induced deficiency of Uhrf1 within Foxp3+ cells resulted in global yet non-uniform loss of DNA methylation, derepression of inflammatory transcriptional programs, destabilization of the Treg cell lineage, and spontaneous inflammation. These findings support a paradigm in which maintenance DNA methylation is required in distinct regions of the Treg cell genome for both lineage establishment and stability of identity and suppressive function.
Kathryn A. Helmin, Luisa Morales-Nebreda, Manuel A. Torres Acosta, Kishore R. Anekalla, Shang-Yang Chen, Hiam Abdala-Valencia, Yuliya Politanska, Paul Cheresh, Mahzad Akbarpour, Elizabeth M. Steinert, Samuel E. Weinberg, Benjamin D. Singer
The transcription factor interferon regulatory factor 5 (IRF5) is a central mediator of innate and adaptive immunity. Genetic variations within IRF5 associate with risk of systemic lupus erythematosus (SLE) and mice lacking Irf5 are protected from lupus onset and severity, but how IRF5 functions in the context of SLE disease progression remains unclear. Using the NZB/W F1 model of murine lupus, we show that murine Irf5 becomes hyper-activated before clinical onset. In SLE patients, IRF5 hyper-activation correlated with dsDNA titers. To test whether IRF5 hyper-activation is a targetable function, we developed novel inhibitors that are cell permeable, non-toxic and selectively bind to the inactive IRF5 monomer. Preclinical treatment of NZB/W F1 mice with inhibitor attenuated lupus pathology by reducing serum ANA, dsDNA titers and the number of circulating plasma cells, which alleviated kidney pathology and improved survival. Clinical treatment of MRL/lpr and pristane-induced mice with inhibitor led to significant reductions in dsDNA levels and improved survival. In ex vivo human studies, the inhibitor blocked SLE serum-induced IRF5 activation in healthy immune cells and reversed basal IRF5 hyper-activation in SLE immune cells. Altogether, this study provides the first in vivo clinical support for treating SLE patients with an IRF5 inhibitor.
Su Song, Saurav De, Victoria Nelson, Samin Chopra, Margaret LaPan, Kyle Kampta, Shan Sun, Mingzhu He, Cherrie D. Thompson, Dan Li, Tiffany Shih, Natalie Tan, Yousef Al-Abed, Eugenio Capitle, Cynthia Aranow, Meggan Mackay, William L. Clapp, Betsy J. Barnes
Human natural killer cell deficiency (NKD) arises from inborn errors of immunity that lead to impaired NK cell development, function, or both. Through the understanding of the biological perturbations in individuals with NKD, requirements for the generation of terminally mature functional innate effector cells can be elucidated. Here, we report a cause of NKD resulting from compound heterozygous mutations in minichromosomal maintenance complex member 10 (MCM10) that impaired NK cell maturation in a child with fatal susceptibility to CMV. MCM10 has not been previously associated with monogenic disease and plays a critical role in the activation and function of the eukaryotic DNA replisome. Through evaluation of patient primary fibroblasts, modeling patient mutations in fibroblast cell lines, and MCM10 knockdown in human NK cell lines, we have shown that loss of MCM10 function leads to impaired cell cycle progression and induction of DNA damage–response pathways. By modeling MCM10 deficiency in primary NK cell precursors, including patient-derived induced pluripotent stem cells, we further demonstrated that MCM10 is required for NK cell terminal maturation and acquisition of immunological system function. Together, these data define MCM10 as an NKD gene and provide biological insight into the requirement for the DNA replisome in human NK cell maturation and function.
Emily M. Mace, Silke Paust, Matilde I. Conte, Ryan M. Baxley, Megan M. Schmit, Sagar L. Patil, Nicole C. Guilz, Malini Mukherjee, Ashley E. Pezzi, Jolanta Chmielowiec, Swetha Tatineni, Ivan K. Chinn, Zeynep Coban Akdemir, Shalini N. Jhangiani, Donna M. Muzny, Asbjørg Stray-Pedersen, Rachel E. Bradley, Mo Moody, Philip P. Connor, Adrian G. Heaps, Colin Steward, Pinaki P. Banerjee, Richard A. Gibbs, Malgorzata Borowiak, James R. Lupski, Stephen Jolles, Anja K. Bielinsky, Jordan S. Orange
Background: Marked progress is achieved in understanding the physiopathology of COVID-19 that caused global pandemics. However, CD4+ T cell population that is critical for antibody response in COVID-19 is poorly understood. Methods: In this study, we provided a comprehensive analysis of peripheral CD4+ T cells of 13 COVID-19 convalescent patients, as defined as confirmed free of SARS-CoV-2 for 2-4 weeks, using flow cytometry, magnetic chemiluminescence enzyme antibody immunoassay and correlated the data with clinical characteristics. Results: We observed that relative to healthy individuals, convalescent patients displayed an altered peripheral CD4+ T cell spectrum. Specifically, consistent with other viral infections, cTFH1 cell associated with SARS-CoV-2 targeting antibodies, which was found to skew with disease severity as more severe individuals showed higher frequency of TEM and TFH-EM cells but a lower frequency of TCM, TFH-CM and TNaive cells, relative to mild and moderate patients. Interestingly, higher frequency of cTFH-EM cells correlated with lower number of recorded admission blood oxygen level in convalescent patients. These observations might constitute residual effects by which COVID-19 can impact the homeostasis of CD4+ T cells in the long-term and explain the highest ratio of class-switched virus-specific antibody producing individuals found in our severe COVID-19 cohort. Conclusion: Together, our study demonstrated close connection between CD4+ T cells and antibody production in COVID-19 convalescents.Funding: This study was supported by Six Talent Peaks Project in Jiangsu Province and the National Natural Science Foundation of China (NSFC) grants 81970759.
Fang Gong, Yaping Dai, Ting Zheng, Liang Cheng, Dan Zhao, Hao Wang, Min Liu, Hao Pei, Tengchuan Jin, Di Yu, Pengcheng Zhou
Proteins created from recurrent fusion genes like CBFB-MYH11 are prevalent in acute myeloid leukemia (AML), often necessary for leukemogenesis, persistent throughout the disease course, and highly leukemia specific, making them attractive neoantigen targets for immunotherapy. A nonameric peptide derived from a prevalent CBFB-MYH11 fusion protein was found to be immunogenic in HLA-B*40:01+ donors. High-avidity CD8+ T cell clones isolated from healthy donors killed CBFB-MYH11+ HLA-B*40:01+ AML cell lines and primary human AML samples in vitro. CBFB-MYH11–specific T cells also controlled CBFB-MYH11+ HLA-B*40:01+ AML in vivo in a patient-derived murine xenograft model. High-avidity CBFB-MYH11 epitope–specific T cell receptors (TCRs) transduced into CD8+ T cells conferred antileukemic activity in vitro. Our data indicate that the CBFB-MYH11 fusion neoantigen is naturally presented on AML blasts and enables T cell recognition and killing of AML. We provide proof of principle for immunologically targeting AML-initiating fusions and demonstrate that targeting neoantigens has clinical relevance even in low–mutational frequency cancers like fusion-driven AML. This work also represents a first critical step toward the development of TCR T cell immunotherapy targeting fusion gene–driven AML.
Melinda A. Biernacki, Kimberly A. Foster, Kyle B. Woodward, Michael E. Coon, Carrie Cummings, Tanya M. Cunningham, Robson G. Dossa, Michelle Brault, Jamie Stokke, Tayla M. Olsen, Kelda Gardner, Elihu Estey, Soheil Meshinchi, Anthony Rongvaux, Marie Bleakley
Background: Patients with diffuse midline gliomas (DMG), including diffuse intrinsic pontine glioma (DIPG), have dismal outcomes. We previously described the H3.3K27M mutation as a shared neoantigen in HLA-A*02.01+ H3.3K27M+ DMGs. Within the Pacific Pediatric Neuro-Oncology Consortium, we assessed safety and efficacy of an H3.3K27M-targeted peptide vaccine. Patients and Methods: Newly diagnosed patients aged 3-21 years with HLA-A*02.01+ and H3.3K27M+ status were enrolled into Stratum A (DIPG) and Stratum B (non-pontine DMG). Vaccine was administered in combination with poly-ICLC every three weeks for eight cycles, followed by once every six weeks. Immuno-monitoring and imaging occurred every three months. Imaging was centrally reviewed. Immunological responses were assessed in peripheral blood mononuclear cells using mass cytometry. Results: 19 patients enrolled in Stratum A (median age=11 years) and 10 in Stratum B (median age=13 years). There were no grade 4 treatment-related adverse events (TRAE). Injection site reaction was the most commonly reported TRAE. Overall survival (OS) at 12 months was 40% (95% CI, 22% to 73%) for Stratum A and 39% (95% CI, 16% to 93%) for Stratum B. The median OS was 16.1 months in patients exhibiting an expansion of H3.3K27M-reactive CD8+ T-cells compared to 9.8 months for their counterparts (p=0.05). DIPG patients with below-median baseline levels of myeloid-derived suppressor cells had prolonged OS compared to their counterparts (p<0.01). Immediate pre-treatment dexamethasone administration inversely associated with H3.3K27M-reactive CD8+ T-cell responses. Conclusion: Administration of the H3.3K27M-specific vaccine is well tolerated. Patients with H3.3K27M-specific CD8+ immunological responses demonstrated prolonged OS compared to non-responders.
Sabine Mueller, Jared M. Taitt, Javier E. Villanueva-Meyer, Erin R. Bonner, Takahide Nejo, Rishi R Lulla, Stewart Goldman, Anu Banerjee, Susan N. Chi, Nicholas S. Whipple, John R. Crawford, Karen Gauvain, Kellie J. Nazemi, Payal B. Watchmaker, Neil D. Almeida, Kaori Okada, Andres M. Salazar, Ryan D. Gilbert, Javad Nazarian, Annette M. Molinaro, Lisa H. Butterfield, Michael D. Prados, Hideho Okada
Epstein-Barr virus-induced gene 3 (EBI3) is a subunit common to IL-27, IL-35, and IL-39. Here, we explore an intracellular role of EBI3 independent of function as cytokines. EBI3-deficient naive CD4+ T cells had reduced IFN-γ production and failed to induce T cell-dependent colitis in mice. Similarly reduced IFN-γ production was observed in vitro in EBI3-deficient CD4+ T cells differentiated under pathogenic Th17 polarizing conditions with IL-23. This is because the induction of expression of one of IL-23 receptor (R) subunits, IL-23Rα, but not another IL-23R subunit, IL-12Rβ1, was selectively decreased at the protein level but not the mRNA level. EBI3 augmented IL-23Rα expression via binding to the chaperone molecule calnexin and to IL-23Rα in a peptide-dependent manner, but not glycan-dependent manner. Indeed, EBI3 failed to augment the IL-23Rα expression in the absence of endogenous calnexin. Moreover, EBI3 poorly augmented the expression of G149R, an IL-23Rα variant that protects against the development of human colitis, because binding of EBI3 to the variant was reduced. Taking together with the result that EBI3 expression is inducible in T cells, the present results suggest that EBI3 plays a critical role in augmenting IL-23Rα protein expression via calnexin under inflammatory conditions.
Izuru Mizoguchi, Mio Ohashi, Hideaki Hasegawa, Yukino Chiba, Naoko Orii, Shinya Inoue, Chiaki Kawana, Mingli Xu, Katsuko Sudo, Koji Fujita, Masahiko Kuroda, Shin-ichi Hashimoto, Kouji Matsushima, Takayuki Yoshimoto
BACKGROUND. COVID-19 patients develop pneumonia generally associated to lymphopenia and severe inflammatory response due to uncontrolled cytokine release. These mediators are transcriptionally regulated by the JAK-STAT signaling pathways, which can be disabled by small molecules. METHODS. A group of subjects (n = 20) was treated with baricitinib according to an off-label use of the drug. The study was designed as an observational longitudinal trial and approved by the local ethical committee. The patients were treated with baricitinib 4 mg twice daily for 2 days, followed by 4 mg per day for the remaining 7 days. Changes in the immune phenotype and expression of pSTAT3 in blood cells were evaluated and correlated with serum-derived cytokine levels and antibodies anti-SARS-CoV-2. In a single treated patient, we evaluated also the alteration of myeloid cell functional activity. RESULTS. We provided evidences that baricitinib-treated patients have a marked reduction in serum levels of interleukin (IL)-6, IL-1β and tumor necrosis factor (TNF)-α, a rapid recovery in circulating T and B cell frequencies, and increased antibody production against SARS-CoV-2 spike protein, which were clinically associated with a reduction in oxygen flow need and progressive increase in the P/F. CONCLUSION. Baricitinib prevented the progression towards a severe/extreme form of the viral disease by modulating the patients’ immune landscape and these changes were associated with a safer and favorable clinical outcome of patients with COVID-19 pneumonia. TRIAL REGISTRATION. The ClinicalTrials.gov identifier of this project is protocol NCT04438629. FUNDING. This work was supported by Fondazione Cariverona (ENACT Project) and Fondazione TIM.
Vincenzo Bronte, Stefano Ugel, Elisa Tinazzi, Antonio Vella, Francesco De Sanctis, Stefania Canè, Veronica Batani, Rosalinda Trovato, Alessandra Fiore, Varvara Petrova, Francesca Hofer, Roza Maria Barouni, Chiara Musiu, Simone Caligola, Laura Pinton, Lorena Torroni, Enrico Polati, Katia Donadello, Simonetta Friso, Francesca Pizzolo, Manuela Iezzi, Federica Facciotti, Pier Giuseppe Pelicci, Daniela Righetti, Paolo Bazzoni, Mariaelisa Rampudda, Andrea C. Comel, Walter Mosaner, Claudio Lunardi, Oliviero Olivieri
The transcription factor, Mef2d, is important in the regulation of differentiation and adaptive responses in many cell types. Among T cells, Mef2d gains new functions in Foxp3+ T-regulatory (Treg) cells as a result of its interactions with the transcription factor, Foxp3, and its release from canonical partners, like histone/protein deacetylases. Though not necessary for the generation and maintenance of Tregs, Mef2d is required for the expression of IL-10, Ctla-4 and Icos, and for the acquisition of an effector Treg phenotype. At these loci, Mef2d acts both synergistically and additively to Foxp3, and down-stream of Blimp1. Mice with the conditional deletion in Tregs of the gene encoding Mef2d are unable to maintain long-term allograft survival despite costimulation blockade and have enhanced antitumor immunity in syngeneic models, but they display only minor evidence of autoimmunity when maintained under normal conditions. The role played by Mef2d in sustaining effector Foxp3+ Treg functions without abrogating their basal actions suggests its suitability for drug discovery efforts in cancer therapy.
Eros Di Giorgio, Liqing Wang, Yan Xiong, Tatiana Akimova, Lanette M. Christensen, Rongxiang Han, Arabinda Samanta, Matteo Trevisanut, Tricia R. Bhatti, Ulf H. Beier, Wayne W. Hancock