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
SARS-CoV-2 is responsible for development of COVID-19 in infected individuals, who can either exhibit mild symptoms or progress towards a life-threatening acute respiratory distress syndrome (ARDS). Exacerbated inflammation and dysregulated immune responses involving T and myeloid cells occur in COVID-19 patients with severe clinical progression. However, the differential contribution of specific subsets of dendritic cells and monocytes to ARDS is still poorly understood. In addition, the role of CD8+ T cells present in the lung of COVID-19 patients and relevant for viral control has not been characterized. Here, we have studied the frequencies and activation profiles of dendritic cells and monocytes present in the blood and lung of COVID-19 patients with different clinical severity in comparison with healthy individuals. Furthermore, these subpopulations and their association with antiviral effector CD8+ T cell subsets were also characterized in lung infiltrates from critical COVID-19 patients. Our results indicate that inflammatory transitional and non-classical monocytes and CD1c+ conventional dendritic cells preferentially migrate from blood to lungs in patients with severe COVID-19. Thus, this study increases the knowledge on specific myeloid subsets involved in the pathogenesis of COVID-19 disease and could be useful for the design of therapeutic strategies to fight SARS-CoV-2 infection.
Ildefonso Sánchez-Cerrillo, Pedro Landete, Beatriz Aldave, Santiago Sánchez-Alonso, Ana Sánchez-Azofra, Ana Marcos-Jiménez, Elena Ávalos, Ana Alcaraz-Serna, Ignacio de los Santos, Tamara Mateu-Albero, Laura Esparcia, Celia López-Sanz, Pedro Martínez-Fleta, Ligia Gabrie, Luciana del Campo Guerola, Hortensia de la Fuente, María J Calzada, Isidoro González-Álvaro, Arantzazu Alfranca, Francisco Sánchez-Madrid, Cecilia Muñoz-Calleja, Joan B. Soriano, Julio Ancochea, Enrique Martín-Gayo
Background: The recent failure of checkpoint-blockade therapies for glioblastoma multiforme (GBM) in late-phase clinical trials has directed interest towards adoptive cellular immunotherapies (ACT). In this open-label, first-in-human trial, we have assessed the safety and therapeutic potential of cytomegalovirus (CMV)-specific ACT in an adjuvant setting for patients with primary GBM, with an ultimate goal to prevent or delay recurrence and prolong overall survival. Methods: Twenty-eight patients with primary GBM were recruited to this prospective study, 25 of whom were treated with in vitro-expanded autologous CMV-specific T cells. Participants were monitored for safety, progression-free survival (PFS), overall survival (OS) and immune reconstitution. Results: No participants showed evidence of ACT-related toxicities. Of 25 evaluable participants, ten were alive at the completion of follow-up, while five were disease free. Reconstitution of CMV-specific T-cell immunity was evident and CMV-specific ACT may trigger bystander effect leading to additional T-cell responses to non-viral tumour-associated antigens through epitope spreading. Long-term follow-up of participants treated before recurrence showed significantly improved OS when compared to those who progressed before ACT (median 23 months, range 7–65 vs. median 14 months, range 5–19; p=0.018). Gene expression analysis of the ACT products indicated that a favourable T-cell gene signature was associated with improved long-term survival. Conclusion: Data presented in this study demonstrate that CMV-specific ACT can be safely used as an adjuvant therapy for primary GBM and, if offered before recurrence, this therapy may improve overall survival of GBM patients.Trial registration: anzctr.org.au: ACTRN12615000656538Funding Source:National Health & Medical Research Council (Australia) Trial registration: anzctr.org.au: ACTRN12615000656538 Funding Source: Philanthropic funding &National Health & Medical Research Council (Australia)
Corey Smith, Katie E. Lineburg, J. Paulo Martins, George Ambalathingal, Michelle A. Neller, Beth Morrison, Katherine K. Matthews, Sweera Rehan, Pauline Crooks, Archana Panikkar, Leone Beagley, Laetitia Le Texier, Sriganesh Srihari, David Walker, Rajiv Khanna
Although the control of bone-resorbing osteoclasts through osteocyte-derived RANKL is well defined, little is known about the regulation of osteoclasts by osteocyte death. Indeed, several skeletal diseases, such as bone fracture, osteonecrosis, and inflammation are characterized by excessive osteocyte death. Herein we show that osteoclasts sense damage-associated molecular patterns (DAMPs) released by necrotic osteocytes via macrophage-inducible C-type lectin (Mincle), which induced their differentiation and triggered bone loss. Osteoclasts showed robust Mincle expression upon exposure to necrotic osteocytes in vitro and in vivo. RNA sequencing and metabolic analyses demonstrated that Mincle activation triggers osteoclastogenesis via ITAM-based calcium signaling pathways, skewing osteoclast metabolism toward oxidative phosphorylation. Deletion of Mincle in vivo effectively blocked the activation of osteoclasts after induction of osteocyte death, improved fracture repair, and attenuated inflammation-mediated bone loss. Furthermore, in patients with osteonecrosis, Mincle was highly expressed at skeletal sites of osteocyte death and correlated with strong osteoclastic activity. Taken together, these data point to what we believe is a novel DAMP-mediated process that allows osteoclast activation and bone loss in the context of osteocyte death.
Darja Andreev, Mengdan Liu, Daniela Weidner, Katerina Kachler, Maria Faas, Anika Grüneboom, Ursula Schlötzer-Schrehardt, Luis E. Muñoz, Ulrike Steffen, Bettina Grötsch, Barbara Killy, Gerhard Krönke, Andreas M. Luebke, Andreas Niemeier, Falk Wehrhan, Roland Lang, Georg Schett, Aline Bozec
Emerging data indicate that complement and neutrophils contribute to the maladaptive immune response that fuels hyper-inflammation and thrombotic microangiopathy, thereby increasing COVID-19 mortality. Here, we investigated how complement interacts with the platelet/neutrophil extracellular traps (NETs)/thrombin axis, using COVID-19 specimens, cell-based inhibition studies and NETs/human aortic endothelial cell (HAEC) co-cultures. Increased plasma levels of NETs, tissue factor (TF) activity and sC5b-9 were detected in patients. Neutrophils of patients yielded high TF expression and released NETs carrying active TF. Treatment of control neutrophils with COVID-19 platelet-rich plasma generated TF-bearing NETs that induced thrombotic activity of HAEC. Thrombin or NETosis inhibition or C5aR1 blockade attenuated platelet-mediated NET-driven thrombogenicity. COVID-19 serum induced complement activation in vitro, consistent with high complement activity in clinical samples. Complement C3 inhibition with compstatin Cp40 disrupted TF expression in neutrophils. In conclusion, we provide a mechanistic basis for a pivotal role of complement and NETs in COVID-19 immunothrombosis. This study supports strategies against SARS-CoV-2 that exploit complement or NETosis inhibition.
Panagiotis Skendros, Alexandros Mitsios, Akrivi Chrysanthopoulou, Dimitrios C. Mastellos, Simeon Metallidis, Petros Rafailidis, Maria Ntinopoulou, Eleni Sertaridou, Victoria Tsironidou, Christina Tsigalou, Maria G. Tektonidou, Theocharis Konstantinidis, Charalampos Papagoras, Ioannis Mitroulis, Georgios Germanidis, John D. Lambris, Konstantinos Ritis