T-cell receptor-specific immunotherapeutics drive selective in vivo HIV and CMV-specific T-cell expansion in humanized mice

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Abstract

To delineate the in vivo role of different costimulatory signals in activating and expanding highly functional virus-specific cytotoxic CD8+ T cells, we designed synTacs, infusible biologics which recapitulate antigen-specific T-cell activation signals delivered by antigen-presenting cells. We constructed synTacs consisting of dimeric Fc-domain scaffolds linking CD28- or 4-1BB-specific ligands to HLA-A2 MHC molecules covalently-tethered to HIV- or CMV-derived peptides. Treatment of HIV-infected donor PBMCs with synTacs bearing HIV- or CMV-derived peptides induced vigorous and selective ex vivo expansion of highly functional HIV- and/or CMV-specific CD8+ T cells, respectively, with potent anti-viral activities. Intravenous injection of HIV or CMV-specific synTacs into immunodeficient mice intrasplenically engrafted with donor PBMCs markedly and selectively expanded HIV-specific (32-fold) or CMV-specific (46-fold) human CD8+ T cells populating their spleens, respectively. Notably, these expanded HIV or CMV-specific CD8+ T cells directed potent in vivo suppression of HIV or CMV infections, respectively, in the humanized mice providing strong rationale for consideration of synTac-based approaches as a therapeutic strategy to cure HIV and treat CMV and other viral infections. The synTac platform flexibility supports facile delineation of in vivo effects of different costimulatory signals on patient-derived virus-specific CD8+ T cells, enabling optimization of individualized therapies, including HIV cure strategies.

Authors

Mengyan Li, Scott J. Garforth, Kaitlyn E. O’Connor, Hang Su, Danica M. Lee, Alev Celikgil, Rodolfo J. Chaparro, Ronald D. Seidel, R. Brad Jones, Ravit Arav-Boger, Steven C. Almo, Harris Goldstein

Will GWAS eventually allow the identification of genomic biomarkers for COVID-19 severity and mortality?

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Abstract

Genome-wide association studies (GWAS) involve testing genetic variants across the genomes of many individuals to identify genotype-phenotype associations. GWAS have enabled the identification of numerous genomic biomarkers in various complex human diseases including infectious ones. However, few of these studies are relevant for clinical practice or at the bedside. In this issue of the JCI, Nakanishi et al. characterized the clinical implications of a major genetic risk factor for COVID-19 severity and its age-dependent effect, using individual-level data in a large international multi-center consortium. This study indicates that a common COVID-19 genetic risk factor (rs10490770) associates with increased risks of morbidity and mortality, suggesting potential implications for future clinical risk management. How can the genomic biomarkers identified by GWAS be associated with the clinical outcomes of an infectious disease? In this commentary, we evaluate the advantages and limitations of this approach.

Authors

Vito Luigi Colona, Michela Bianocolella, Antonio Novelli, Giuseppe Novelli

Melanocortin 4 receptor stimulation prevents anti-depressant-associated weight gain in mice caused by long-term fluoxetine exposure

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Abstract

Contrasting with the predicted anorexigenic effect of increasing brain serotonin signaling, long-term use of selective serotonin reuptake inhibitors (SSRIs) antidepressants correlates with body weight gain. This adverse outcome increases the risk of transitioning to obesity and interferes with treatment compliance. Here we show that orally administered fluoxetine (Flx), a widely prescribed SSRI, increased body weight by enhancing food intake in healthy mice at two different time points and through two distinct mechanisms. Within hours, Flx decreased the activity of a subset of brainstem serotonergic neurons by triggering autoinhibitory signaling through the Htr1a receptor. Upon longer treatment Flx blunted Htr2c expression/signaling, decreased the phosphorylation of Creb and Stat3 and dampened the production of POMC/α-MSH in hypothalamic neurons, thereby increasing food intake. Accordingly, exogenous stimulation of the melanocortin 4 receptor (MC4R) by co-treating mice with Flx and lipocalin-2, an anorexigenic hormone signaling through this receptor, normalized feeding and body weight. Flx and other SSRIs also inhibit CREB/STAT3 phosphorylation in a human neuronal cell line suggesting that these non-canonical effects could also occur in long-term users of SSRIs. By defining the molecular basis of the long-term SSRIs-associated weight gain this study proposes a therapeutic strategy to counter it.

Authors

Maria Jose Ortuno, Marc Schneeberger, Anoj Ilanges, François Marchildon, Kyle Pellegrino, Jeffrey M. Friedman, Patricia Ducy

Visual percepts evoked with an Intracortical 96-channel microelectrode array inserted in human occipital cortex

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Abstract

BACKGROUND. A long-held dream of scientists is to transfer information directly to the visual cortex of blind individuals, thereby restoring a rudimentary form of sight. However, no clinically available cortical visual prosthesis yet exists. METHODS.We implanted an intracortical microelectrode array consisting of 96 electrodes in the visual cortex of a 57-year-old person with complete blindness for a six- month period. We measured thresholds and the characteristics of the visual percepts elicited by intracortical microstimulation. RESULTS. Implantation and subsequent explantation of intracortical microelectrodes were carried out without complications. The mean stimulation threshold for single electrodes was 66.8 ± 36.5 μA. We consistently obtained high-quality recordings from visually deprived neurons and the stimulation parameters remained stable over time. Simultaneous stimulation via multiple electrodes were associated with a significant reduction in thresholds (p<0.001, ANOVA test) and evoked discriminable phosphene percepts, allowing the blind participant to identify some letters and recognize object boundaries. Furthermore, we observed a learning process that helped the subject to recognize complex patterns over time. CONCLUSIONS. Our results demonstrate the safety and efficacy of chronic intracortical microstimulation via a large number of electrodes in human visual cortex, showing its high potential for restoring functional vision in the blind. TRIAL REGISTRATION. ClinicalTrials.gov identifier NCT02983370. FUNDING. Funding was provided by grant RTI2018-098969-B-100 from the Spanish Ministerio de Ciencia Innovación y Universidades, by grant PROMETEO/2019/119 from the Generalitat Valenciana (Spain), by the Bidons Egara Research Chair of the University Miguel Hernández (Spain) and by the John Moran Eye Center of the University of Utah (US).

Authors

Eduardo Fernández, Arantxa Alfaro, Cristina Soto-Sánchez, Pablo González-López, Antonio M. Lozano Ortega, Sebastian Peña, María Dolores Grima, Alfonso Rodil, Bernardeta Gómez, Xing Chen, Pieter R. Roelfsema, John D. Rolston, Tyler S. Davis, Richard A. Normann

Inhibition of estrogen signaling in myeloid cells increases tumor immunity in melanoma

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Abstract

Immune checkpoint inhibitors (ICB) have significantly prolonged patient survival across multiple tumor types, particularly in melanoma. Interestingly, gender specific differences in response to ICB have been observed with males getting more benefit than females, although the mechanism(s) underlying this difference are unknown. Mining published transcriptomic datasets, we determined that response to ICBs is influenced by the functionality of intratumoral macrophages. This puts into context our observation that estrogens (E2) working through the estrogen receptor (ERα) stimulate melanoma growth in murine models by skewing macrophage polarization towards an immune-suppressive state that promotes CD8+ T cell dysfunction/exhaustion and ICB resistance. This activity was not evident in mice harboring a macrophage specific depletion of ERα confirming a direct role for estrogen signaling within myeloid cells in establishing an immunosuppressed state. Inhibition of ERα using fulvestrant, a selective estrogen receptor downregulator (SERD) decreases tumor growth, stimulates adaptive immunity and increases the antitumor efficacy of ICBs. Further, a gene signature that reads on ER activity in macrophages predicted survival in ICB treated melanoma patients. These results highlight the importance of E2/ER as a regulator of intratumoral macrophage polarization; an activity that can be therapeutically targeted to reverse immune suppression and increase ICB efficacy.

Authors

Binita Chakraborty, Jovita Byemerwa, Jonathan H. Shepherd, Corinne N. Haines, Robert Baldi, Weida Gong, Wen Liu, Debarati Mukherjee, Sandeep Artham, Felicia Lim, Yeeun Bae, Olivia Brueckner, Kendall Heetderks, Suzanne E. Wardell, Brent A. Hanks, Charles M. Perou, Ching-Yi Chang, Donald P. McDonnell

Cross-protective immunity following coronavirus vaccination and coronavirus infection

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Abstract

Although Severe Acute Respiratory Syndrome Coronavirus 2 (SARS-CoV-2) vaccines have shown efficacy against SARS-CoV-2, it is unknown if coronavirus vaccines can also protect against other coronaviruses that may infect humans in the future. Here, we show that coronavirus vaccines elicit cross-protective immune responses against heterologous coronaviruses. In particular, we show that a Severe Acute Respiratory Syndrome Coronavirus 1 (SARS-CoV-1) vaccine developed in 2004 and known to protect against SARS-CoV-1, confers robust heterologous protection against SARS-CoV-2 in mice. Similarly, prior coronavirus infections conferred heterologous protection against distinct coronaviruses. Cross-reactive immunity was also reported in Coronavirus Disease 2019 (COVID-19) patients and humans who received SARS-CoV-2 vaccines, and transfer of plasma from these individuals into mice improved protection against coronavirus challenges. These findings provide the first demonstration that coronavirus vaccines (and prior coronavirus infections) can confer broad protection against heterologous coronaviruses, providing a rationale for universal coronavirus vaccines.

Authors

Tanushree Dangi, Nicole Palacio, Sarah Sanchez, Mincheol Park, Jake Class, Lavanya Visvabharathy, Thomas Ciucci, Igor J. Koralnik, Justin M. Richner, Pablo Penaloza-MacMaster

Inhibition of phosphodiesterase type 9 reduces obesity and cardiometabolic syndrome in mice

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Abstract

Central obesity with cardiometabolic syndrome (CMS) is a major global contributor to human disease, and effective therapies are needed. Here, we show inhibiting cyclic-GMP selective phosphodiesterase-9A (PDE9-I) in both ovariectomized female or male mice suppresses pre-established severe diet-induced obesity/CMS with or without superimposed mild cardiac pressure-load. PDE9-I reduces total body, inguinal, hepatic, and myocardial fat, stimulating mitochondrial activity in brown and white fat, and improving CMS, without significantly altering activity or food intake. PDE9 localized at mitochondria, and its inhibition in vitro stimulated lipolysis and mitochondrial respiration in adipocytes and myocytes coupled to PPARα-dependent gene regulation. PPARα upregulation was required to achieve the lipolytic, anti-obesity, and metabolic effects of PDE9-I. All these PDE9-I induced changes were not observed in obese/CMS non-ovariectomized females, indicating a strong sexual dimorphism. We found that PPARα chromatin binding was re-oriented away from fat-metabolism regulating genes when stimulated in the presence of co-activated estrogen receptor-alpha, and this may underly the dimorphism. These findings have translational relevance given that PDE9-I is already being studied in humans for indications including heart failure, and efficacy against obesity/CMS would enhance its therapeutic utility.

Authors

Sumita Mishra, Nandhini Sadagopan, Brittany Dunkerly-Eyring, Susana Rodriguez, Dylan C. Sarver, Ryan P. Ceddia, Sean A. Murphy, Hildur Knutsdottir, Vivek P. Jani, Deepthi Ashok, Christian U. Oeing, Brian O'Rourke, Jon A. Gangoiti, Dorothy D. Sears, G. William Wong, Sheila Collins, David Kass

Exceptionally potent human monoclonal antibodies are effective for prophylaxis and therapy of tetanus in mice

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Abstract

Human monoclonal antibodies were used here to study the mechanism of neuron intoxication by tetanus neurotoxin and to evaluate them as a safe preventive and therapeutic substitute of hyperimmune sera for tetanus in mice. By screening memory B cells of immune donors, we selected two monoclonal antibodies specific for tetanus neurotoxin with exceptionally high neutralizing activities, which were extensively characterized both structurally and functionally. We found that these antibodies interfere with the binding and translocation of the neurotoxin into neurons by interacting with two epitopes, whose definition pinpoints crucial events in the cellular pathogenesis of tetanus. This information explains the unprecedented neutralization ability of these antibodies, which were found to be exceptionally potent in preventing experimental tetanus when injected in mice long before the neurotoxin. Moreover, their Fab derivatives neutralized tetanus neurotoxin in post-exposure experiments, suggesting their potential therapeutic use via intrathecal injection. As such, these human monoclonal antibodies, as well as their Fab derivatives, meet all requirements for being considered for prophylaxis and therapy of human tetanus and are ready for clinical trials.

Authors

Marco Pirazzini, Alessandro Grinzato, Davide Corti, Sonia Barbieri, Oneda Leka, Francesca Vallese, Marika Tonellato, Chiara Silacci-Fregni, Luca Piccoli, Eaazhisai Kandiah, Giampietro Schiavo, Giuseppe Zanotti, Antonio Lanzavecchia, Cesare Montecucco

Phase 2a clinical trial of complement C3 inhibitor AMY-101 in adults with periodontal inflammation

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Abstract

BACKGROUND. Gingivitis and periodontitis are prevalent inflammatory diseases of the periodontal tissues. Current treatments are often ineffective or do not prevent disease recurrence. Uncontrolled complement activation and resulting chronic gingival inflammation is a hallmark of periodontal diseases. We determined efficacy and safety of a complement 3-targeted therapeutic, AMY-101, locally administered in adults with periodontal inflammation. METHODS. Thirty-two patients with gingival inflammation were enrolled into a randomized, placebo-controlled, double-blind, split-mouth design phase 2a trial, after dose-escalation study to select safe and effective dose with additional 8 patients. Half of the mouth was randomly assigned to AMY-101 (0.1mg/site) or placebo injections at sites of inflammation, administered on days 0, 7 and 14 and evaluated for safety and efficacy outcomes at days 28, 60 and 90. The primary efficacy outcome was change in gingival inflammation, measured by modified gingival index (MGI), and secondary outcomes included changes in bleeding-on-probing (BOP), amount of plaque, pocket depth, clinical attachment level, and gingival crevicular fluid levels of matrix metalloproteinases (MMPs) over 90 days. RESULTS. A once-per-week intragingival injection of AMY-101 for 3 weeks was safe and well-tolerated in all participants resulting in significant (P<0.001) reductions in clinical indices measuring gingival inflammation (MGI and BOP). AMY-101 significantly (P<0.05) reduced MMP-8 and MMP-9 levels, indicators of inflammatory tissue destruction. These therapeutic effects persisted for at least 3 months post-treatment. CONCLUSION. AMY-101 causes significant and sustainable reduction in gingival inflammation without adverse events and merits further investigation for the treatment of periodontitis and other oral or peri-implant inflammatory conditions. TRIAL REGISTRATION. ClinicalTrials.gov: NCT03694444. FUNDING. Amyndas Pharmaceuticals. Amyndas contributed to the design and conducts of the clinical trial and in the writing of the manuscript.

Authors

Hatice Hasturk, George Hajishengallis, John D. Lambris, Dimitrios C. Mastellos, Despina Yancopoulou

Inhibiting serotonin signaling through HTR2B in visceral adipose tissue improves obesity related insulin resistance

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Abstract

Insulin resistance is a cornerstone of obesity related complications such as type 2 diabetes, metabolic syndrome, and non-alcoholic fatty liver disease. A high rate of lipolysis is known to be associated with insulin resistance, and inhibiting adipose tissue lipolysis improves obesity-related insulin resistance. Here, we demonstrate that inhibition of 5-HT signaling through serotonin receptor 2B (HTR2B) in adipose tissues ameliorates insulin resistance by reducing lipolysis in visceral adipocytes. Chronic high-fat diet (HFD) feeding increased Htr2b expression in eWAT, resulting in the increased HTR2B signaling in visceral white adipose tissue. Moreover, HTR2B expression in white adipose tissue was increased in obese humans and positively correlated with metabolic parameters. We further found that adipocyte-specific Htr2b-knockout mice are resistant to high-fat diet (HFD)-induced insulin resistance, visceral adipose tissue inflammation, and hepatic steatosis. Enhanced 5-HT signaling through HTR2B directly activated lipolysis through phosphorylation of hormone sensitive lipase in visceral adipocytes. Moreover, treatment with a selective HTR2B antagonist attenuated HFD-induced insulin resistance, visceral tissue inflammation, and hepatic steatosis. Thus, adipose HTR2B signaling could be a potential therapeutic target for treatment of obesity-related insulin resistance.

Authors

Won Gun Choi, Wonsuk Choi, Tae Jung Oh, Hye-Na Cha, Inseon Hwang, Yun Kyung Lee, Seung Yeon Lee, Hyemi Shin, Ajin Lim, Dongryeol Ryu, Jae Myoung Suh, So-Young Park, Sung Hee Choi, Hail Kim