The rockefeller university

'Intrinsic immunity' is often used to refer to mechanisms of host defense operating in nonleukocytic cells. This term can refer to the intrinsic capacity of an individual cell to fend off invading microbes without help from other cells or of a group of similar cells to fend off invading microbes without help from other cell types. The intrinsic capacity of individual cells to defend themselves against invading microbes without assistance has received little attention and is the topic of this review. We also focus on nonleukocytic cells and on humans, the only species in which intrinsic immunity has been shown by genetic means to be essential for homeostasis in natural conditions at wholebody level. We review recent progress in our understanding of the type I interferon-independent intrinsic immunity of individual nonleukocytic cells, as inferred from human inborn errors of intrinsic immunity manifesting as infection or autoinflammation.

The recent Society for Molecular Biology and Evolution Satellite Meeting on De Novo Gene Birth, hosted at Texas A&M University on November 6 to 9, 2023, represented the first-ever opportunity for scientists studying the evolution and biology of de novo genes to gather through a dedicated meeting and discuss about groundbreaking discoveries in this emerging and exciting field of gene evolution. In this perspective, we discuss recent advances and major open questions in de novo gene emergence and evolution that were presented at the SMBE satellite meeting, as well as some of the key recent findings published before or since the conference. These key themes include de novo gene identification, function, and evolution, what we are learning about de novo genes from experimental analyses of random peptides, de novo gene birth and microproteins, and the role of de novo genes in human disease.

Pseudomonas aeruginosa is a leading cause of nosocomial infections, including pneumonia and urinary tract infections, and the primary cause of morbidity and mortality in cystic fibrosis patients. The emergence of multidrug-resistant strains makes these infections life-threatening. To overcome this challenge, lysocins can be employed as novel antipseudomonals. Lysocins use components of the pyocin antimicrobial system to deliver bacteriophage lysins to their peptidoglycan substrate in Pseudomonas. Peptidoglycan cleavage causes membrane destabilization, cytoplasmic leakage, and disruption of the proton motive force, thereby killing the cell. In our previous proof-of-concept study, the PyS2-GN4 lysocin killed only one-third of P. aeruginosa strains due to the targeted receptor. This limitation can now be circumvented by engineering second-generation lysocins that bind and translocate through highly conserved Pseudomonas-specific receptors. One lysocin, PyS5-I-GN4, uses a single domain from pyocin S5 to deliver the GN4 lysin through the conserved ferric pyochelin transporter, consequently killing 95% of multidrug-resistant clinical isolates tested. Importantly, PyS5-I-GN4 displayed antibiofilm properties and was bactericidal in serum and lung surfactant. Serum inactivation observed for lysins is not seen for lysocins, making this approach more effective for treating systemic Gram-negative bacterial infections. Despite its broadened pseudomonal strain coverage, PyS5-I-GN4 demonstrated narrow-spectrum antibacterial activity toward P. aeruginosa only and lacked cytotoxicity toward human cells. A single dose of lysocin was protective and reduced bacteria multiple log10-fold in the lungs and secondary organs in a neutropenic murine lung infection model. These findings support lysocins as therapeutics for P. aeruginosa and provide insight into designing future constructs for other Gram-negative pathogens.

Eukaryotic ribosomal small subunit (SSU) assembly requires the SSU processome, a nucleolar precursor containing the RNA chaperone U3 small nucleolar RNA (snoRNA). The underlying molecular mechanisms of SSU processome maturation, remodelling, disassembly and RNA quality control, and the transitions between states remain unknown owing to a paucity of intermediates1, 2-3. Here we report 16 native SSU processome structures alongside genetic data, revealing how two helicases, the Mtr4-exosome and Dhr1, are controlled for accurate and unidirectional ribosome biogenesis. Our data show how irreversible pre-ribosomal RNA degradation by the redundantly tethered RNA exosome couples the transformation of the SSU processome into a pre-40S particle, during which Utp14 can probe evolving surfaces, ultimately positioning and activating Dhr1 to unwind the U3 snoRNA and initiate nucleolar pre-40S release. This study highlights a paradigm for large dynamic RNA-protein complexes in which irreversible RNA degradation drives compositional changes and communicates these changes to govern enzyme activity while maintaining overall quality control.

Antibodies play a crucial role in adaptive immunity. They develop as B cell receptors (BCRs): membrane-bound forms of antibodies that are expressed on the surfaces of B cells. BCRs are refined through affinity maturation, a process of somatic hypermutation (SHM) and natural selection, to improve binding to an antigen. Computational models of affinity maturation have developed from two main perspectives: molecular evolution and language modeling. The molecular evolution perspective focuses on nucleotide sequence context to describe mutation and selection; the language modeling perspective involves learning patterns from large data sets of protein sequences. In this paper, we compared models from both perspectives on their ability to predict the course of antibody affinity maturation along phylogenetic trees of BCR sequences. This included models of SHM, models of SHM combined with an estimate of selection, and protein language models. We evaluated these models for large human BCR repertoire data sets, as well as an antigen-specific mouse experiment with a pre-rearranged cognate naive antibody. We demonstrated that precise modeling of SHM, which requires the nucleotide context, provides a substantial amount of predictive power for predicting the course of affinity maturation. Notably, a simple nucleotide-based convolutional neural network modeling SHM outperformed state-of-the-art protein language models, including one trained exclusively on antibody sequences. Furthermore, incorporating estimates of selection based on a custom deep mutational scanning experiment brought only modest improvement in predictive power. To support further research, we introduce EPAM (Evaluating Predictions of Affinity Maturation), a benchmarking framework to integrate evolutionary principles with advances in language modeling, offering a road map for understanding antibody evolution and improving predictive models.

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.