Zhu et al. report that intravenous immunoglobulin targets activated neutrophils in Kawasaki disease and multisystem inflammatory syndrome in children (MIS-C). The cover image is an artist’s rendering of immunoglobulin. Image credit: Kateryna Kon/Shutterstock.
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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.
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
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.
Vito Luigi Colona, Michela Bianocolella, Antonio Novelli, Giuseppe Novelli
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.
Maria Jose Ortuno, Marc Schneeberger, Anoj Ilanges, François Marchildon, Kyle Pellegrino, Jeffrey M. Friedman, Patricia Ducy
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).
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
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.
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
JCI This Month is a digest of the research, reviews, and other features published each month.
Animals, plants, and bacteria all display behavioral patterns that coincide with Earth’s light and dark cycles. These oscillating behaviors are the manifestation of the molecular circadian clock, a highly conserved network that maintains a near 24-hour rhythm even in the absence of light. In mammals, light signals are transmitted via the superchiasmatic nucleus (SCN) in the hypothalamus to synchronize peripheral clocks and coordinate physiological functions with the organism’s active period. This collection of reviews, curated by Amita Sehgal, considers the critical role of the circadian system in human health. Technology, work, and social obligations can disrupt optimal sleep and wake schedules, leaving humans vulnerable to diseases affecting the heart, brain, metabolism, and more. Sleep disorders as well as normal variations in human chronotype may exacerbate circadian disruptions, with profound consequences. These reviews emphasize that ongoing efforts to understand the complexities of human circadian rhythm will be essential for developing chronotherapies and other circadian-based interventions.