The rockefeller university

The receptor-binding domain (RBD) of the SARS-CoV-2 spike (S) protein continues to evolve, facilitating antibody evasion. It remains unclear whether any conserved RBD epitopes persist across SARS-CoV-2 variants and whether vaccination and/or breakthrough infection (BTI) can elicit antibodies capable of targeting these conserved regions to counter future variants. Here, using a heterogeneous double-bait single B-cell sorting strategy, we identify a subset of antibodies with broad-spectrum RBD binding, including recognition of SARS-CoV-1 and emerging variants such as EG.5.1, BA.2.86, JN.1, and KP.2/3. These broadly binding antibodies (bbAbs) exhibit elevated levels of somatic hypermutation but are infrequently derived from clonally expanded B lymphocytes. Passive transfer of representative bbAbs reduces viral infection in a male hamster model. Structural analyses reveals that these bbAbs primarily target three distinct, highly conserved RBD epitopes, suggesting potential regions of future mutational pressure and highlighting the presence of conserved and immunogenic RBD conformations that may serve as a foundation for the development of broadly protective vaccines.

Membrane protein homo-oligomers named higher-order transient structures (HOTS) are formed through cohesive self-interactions in the range of a few kBT. The small magnitude of these interactions underlies the rapid reversibility of HOTS on the timescale of membrane signaling processes, permitting the dynamic modulation of signals. At the same time, weak interactions present an apparent paradox: HOTS should form only if the concentration of a particular protein is sufficiently high to produce oligomerization by mass action. And yet, HOTS are observed experimentally with membrane proteins present in cell membranes at concentrations of only a few per mu m2. In this study, we employ principles of statistical thermodynamics to explain how cells can alter the configurational entropy of the oligomerization reaction, thereby achieving HOTS formation at low concentrations of the protein in the membrane. We propose that this modification of the configurational entropy, a process we call configurational length scaling, is an important aspect of HOTS formation in cell membranes and possibly other cellular compartments.

Current methods for variant effect prediction do not differentiate between pathogenic variants resulting in different disease outcomes and are restricted in application due to a focus on variants with a single molecular consequence. We have developed Variant-to-Phenotype (V2P), a multi-task, multi-output machine learning model to predict variant pathogenicity conditioned on top-level Human Phenotype Ontology disease phenotypes (n = 23) for single nucleotide variants and insertions/deletions throughout the human genome. V2P leverages a unique approach for the modeling of variant effect that incorporates resultant disease phenotypes as output and during training to improve the quality of variant disease phenotype and effect predictions, simultaneously. We describe the architecture, training strategy, and biological features contributing to V2P's output, revealing initial characteristics underlying the relationship between disease genotype and phenotype. Moreover, we demonstrate the benefit of incorporating disease phenotypes for variant effect predictions by comparing V2P with several variant effect predictors across various high-quality evaluation datasets from manually curated databases and functional assays. Finally, we examine how V2P's predictions result in the successful identification of pathogenic variants in real and simulated patient sequencing data, outperforming other tested methods in initial comparisons. V2P offers a complete mapping of human genetic variants to disease-phenotypes, offering a uniquely conditioned set of variant effect characterizations.

Generation of in vitro human induced pluripotent cell (hiPSC)-derived skeletal muscle progenitor cells (SMPCs) holds great promise for regenerative medicine for skeletal muscle wasting diseases, for example Duchenne muscular dystrophy (DMD). While multiple approaches have been described to obtain SMPCs in vitro, hiPSC-derived SMPCs generated using transgene-free protocols are usually obtained in a low amount and resemble a more embryonal/fetal stage of differentiation. Here, we demonstrate that modulation of the JAK2/STAT3 signaling pathway during an in vitro skeletal muscle differentiation protocol increases the yield of PAX7+and CD54+human SMPCs (hSMPCs) and drives them to a higher maturation stage, in both human embryonic stem (ES) and patient-derived induced pluripotent cells (iPSCs). Importantly, the obtained SMPCs are able to differentiate into multinucleated myotubes in vitro and engraft in vivo. These findings reveal that modulation of the JAK2/STAT3 signaling pathway is a potential therapeutic avenue to generate SMPCs in vitro with potential for cell therapy approaches.

Although adenosine was identified in the brain many decades ago, our understanding of when, where, and how it functions has expanded rapidly in recent years, driven in part by innovative technological advances. Adenosine is now increasingly recognized as a key neuromodulator that dynamically regulates brain circuits important for sleep/wakefulness, movement, cognition, and homeostasis. In addition, growing attention has been directed toward the molecular mechanisms governing adenosine production and its downstream signaling pathways, both of which hold great promise as therapeutic targets for neuropsychiatric disorders and neurodegenerative diseases. This review highlights recent progress in detecting adenosine, unraveling its signaling pathways in vitro and in vivo, and understanding how it regulates brain function under physiological and pathological conditions.

Bacterial immune systems exhibit remarkable diversity and modularity, as a consequence of the continuous selective pressures imposed by phage predation. Despite recent mechanistic advances, the evolutionary origins of many antiphage immune systems remain elusive, especially for those that encode homologs of the structural maintenance of chromosomes (SMC) superfamily, which are essential for chromosome maintenance and DNA repair across domains of life. Here, we elucidate the structural basis and evolutionary emergence of Lamassu, a bacterial immune system family featuring diverse effectors but a core conserved SMC-like sensor. Using cryo-EM, we determined structures of the Vibrio cholerae Lamassu complex in both apo-and dsDNA-bound states, revealing unexpected stoichiometry and topological architectures. We further demonstrate how Lamassu specifically senses dsDNA ends in vitro and phage replication origins in vivo, thereby triggering the formation of LmuA tetramers that activate its Cap4 nuclease domain. Our findings reveal that Lamassu evolved via exaptation of the bacterial Rad50-Mre11 DNA repair system to form a compact, modular sensor for viral replication, exemplifying how cellular machinery can be co-opted for novel immune functions.

Background: Brodalumab, an anti-interleukin-17 receptor A antibody, is effective in psoriasis via action on the IL-17 pathway. Objective: This analysis of an exploratory intervention study (ESPRIT) in Japanese patients with moderate to severe plaque psoriasis examined the brodalumab efficacy by clinical changes, and modulation of skin inflammation via changes in skin gene expression and blood sample protein expression. Methods: Primary clinical endpoints were changes in PASI score and PASI score 0 achievement rate at Week 12. For molecular endpoints, biopsies of lesional, non-lesional and healthy volunteer skin were examined by RNA sequencing and RT-PCR. Blood sample serum was analyzed by Olink high-throughput proteomics. Results: Twenty healthy volunteers and 40 patients were enrolled; 37 underwent molecular profiling. Clinical assessment showed that the median baseline PASI score (19.0) significantly decreased to 0.4 at Week 12 (P < 0.0001), with more rapid decline in higher PASI responders. Molecular assessment demonstrated that differential expressed genes in lesional skin were suppressed equivalently to non-lesional skin, establishing the molecular improvement with brodalumab. The transcriptomes of Japanese and Western patients were similar, and top-upregulated genes included IL-17-inducible and cardiovascular disease-related genes, which were suppressed by brodalumab. Serum protein analysis identified 22 proteins elevated by psoriasis. Several inflammatory and cardiovascular risk proteins correlated with psoriasis severity and BMI, but at lower rates than in Western patients. Conclusions: In summary, the transcriptome and the proteome characteristics of Japanese and Western psoriasis patients were similar. Brodalumab rapidly improved skin and serum molecular levels and reduced cardiovascular disease risk factor expression.

In psoriatic lesions, interleukin (IL)-17C protein expression has been reported as high as 125 times that of IL-17A; as such, it is crucial to understand the role that IL-17C plays in psoriasis, inflammation, and treatment response. Overexpression or injection of IL-17C in mice results in increased epidermal thickening and inflammation, whereas psoriatic mice with IL-17C knockout have decreased disease severity compared with control littermates. In psoriasis, IL-17C likely acts as a critical inflammatory amplifier via a feed-forward mechanism, wherein IL-17-producing CD4+ helper T (TH17) cells and IL-17-producing CD8+ cytotoxic T (TC17) cells stimulate IL-17C expression in keratinocytes. Then, keratinocyte-derived IL-17C induces IL-17A expression in TH17 and TC17 cells. Additionally, keratinocyte-derived IL-17C propagates its own signaling in an autocrine manner. Furthermore, studies suggest that IL-17C acts as an early mediator of psoriasis. No approved therapies directly target IL-17C. Brodalumab is an IL-17 receptor (IL-17R) A antagonist that inhibits IL-17A, F, C, and E signaling and has a unique mechanism of action among biologic therapies for psoriasis. By way of IL-17RA blockade, brodalumab is the only approved therapy for psoriasis that inhibits IL-17C signaling. This unique mechanism of action is hypothesized to correlate with efficacy in patients with prior failures to anti-IL-17A therapies and relatively higher rates of early skin clearance compared with those of other biologic therapies. Clinical studies are needed to confirm these correlations. In summary, IL-17C is an inflammatory amplifier and early psoriatic mediator, and inhibition of IL-17C may be beneficial in psoriasis management.