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Singh, M.

Publications and source records attributed to Singh, M..

At least 73 records · Page 4Linked to original sources

Sertraline enhances bacterial control by improving the pharmacodynamic -pharmacokinetic properties of frontline TB drugs

Given the need for innovative interventions for tackling the burden of TB, host directed therapies have emerged as a promising alternative in recent times. The combination of sertraline with frontline TB drugs has shown excellent promise in the murine models of infection in imparting better bacterial control and increasing host survival. We tested if the addition of sertraline worked to increase bacterial clearance in the random bred guinea pig model of TB infection that mimics the inter individual heterogeneity observed in the human response to infection. The combination of sertraline and frontline TB drugs effectively reduced bacterial burdens in the tissues of guinea pigs significantly better than the drugs alone with a marked betterment of lung histopathology. In order to evaluate the effect of sertraline on the pharmacodynamic properties of TB drugs, concentrations of the drugs were estimated in tissues at different time intervals over a period of 24h of administration to rats. Overall, addition of sertraline did not alter TB drug distribution or clearance from the animals, although enriching drug amounts transiently between 3-6 h in the different tissues. We thus highlight the advantage of an adjunct TB therapy with the inclusion of sertraline, an FDA approved antidepressant, in improving the PKPD of TB drugs and imparting better infection control in diverse models of infection.

microbiology↗

Ploidy alters root anatomy and shapes the evolution of wheat polyploids

Polyploidization played a crucial role in crop domestication and modern agriculture. While increased cell size in polyploids is known to enhance plant biomass and vigor, its impact on soil exploration remains poorly understood. Using wheat as a model, we identify a ploidy-induced belowground domestication syndrome, characterized by (a) increased root cortical cell size reducing root respiration, nitrogen content, and phosphorus content; (b) enlarged metaxylem vessels, increasing axial hydraulic conductance; and (c) blunter root tips, limiting penetration ability in compacted soils. Our empirical and in silico experiments show that reduced root respiration and reduced cellular nutrient content in wheat polyploids improved nutrient use and acquisition efficiency under suboptimal nitrogen and phosphorus availability. These adaptations would have been advantageous in nutrient-depleted agroecosystems of the Pre-Pottery Neolithic B (PPNB) Fertile Crescent, where continuous cultivation depleted soil fertility over time. Functional-structural modeling indicates that larger cortical cells in wheat polyploids increase vacuolar occupancy, reducing root metabolic costs. Enhanced axial hydraulic conducta nce may have improved water transport, an advantage in irrigated PPNB agroecosystems. However, polyploids have blunter root tips, which reduces their penetration ability in compacted soils, making them less suited for native soils with greater mechanical impedance. We propose that root anatomical changes driven by ploidy played an important role in adaptations of wheat domesticates to PPNB agriculture. One-Sentence SummaryPolyploidy induced changes in root anatomy may have improved adaptation of wheat to Neolithic agroecosystems.

plant biology↗

Palbociclib CDK4/6- and Crizotinib MET/ALK/ROS1-inhibitors Synergize to Enhance Senescence and Immune Recognition in Melanoma Cells Independently of BRAF/NRAS Status

"Pro-senescence therapy", which triggers both permanent cell cycle arrest and an immune response, has been proposed as a strategy for cancer treatment, but is still controversial. To assess this strategy in melanoma, we performed a high throughput microscopy-based senescence screen utilizing a panel of melanoma cell lines with different driver mutations and a collection of clinical and experimental drugs. We found that vemurafenib and trametinib, which inhibit BRAFV600E and MEK1/2, respectively, induced senescence in some but not all BRAF-mutant cell lines. In contrast, palbociclib, BKM-120 and crizotinib, which inhibit CDK4/6, PI3K, and MET/ALK/ROS1, respectively, triggered senescence in most cell lines, irrespective of BRAF/NRAS mutation status, and overcame intrinsic and acquired vemurafenib resistance. The combination of palbociclib and crizotinib synergized to further enhance the senescence response in all cell lines irrespective of BRAF/NRAS mutation status, increased the expression of SASP factors, such as IL-1 and {beta}, and HLA class I and other markers for recognition by NK and T cells. Further, this combination caused a significant increase in CD8+ T cells and pro-inflammatory macrophages in the tumor microenvironment and a marked reduction of mouse melanoma tumor growth that was dependent on CD8+ T cells, suggesting increased immune surveillance. Our findings suggest that pro-senescence therapy based on concomitant inhibition of both CDK4/6 and MET/ALK/ROS1 could be developed further as an alternative treatment strategy for melanoma. Significance: Pro-senescence therapy based on combined targeting of CDK4/6 with palbociclib and MET/ALK/ROS1 with crizotinib inhibits melanoma tumor growth through anti-tumor immune response activation, providing an alternative treatment strategy for melanoma.

cancer biology↗

Integrated genetic screening reveals FEN1 as a driver of stemness and temozolomide resistance in glioblastoma

Glioblastoma (GBM) is a lethal brain tumor with limited response to standard of care chemoradiotherapy. In this study, we conducted genome-wide CRISPR knockout screening in patient-derived glioblastoma stem cells (GSCs) to identify genetic dependencies of cell survival and therapy resistance. Our screening identified flap endonuclease 1 (FEN1) as a key driver of GSC survival, with enhanced dependency under temozolomide (TMZ) treatment. Genetic perturbation of FEN1 reduced GSC self-renewal and proliferation in vitro, and prolonged survival in a patient-derived xenograft model of GBM. FEN1 inhibition (FEN1i) preferentially affected highly aggressive or recurrent GBM models compared with less aggressive GBMs and healthy neural stem cells. Moreover, FEN1 inhibition synergized with TMZ only in these aggressive FEN1i-sensitive GSCs, providing cancer-selective killing and TMZ sensitization in the most untreatable of GBMs. Mechanistically, FEN1i-sensitive GSCs exhibited greater proliferation and sphere formation, while stalling their proliferation conferred resistance to FEN1 inhibition. Single-cell transcriptomics further linked FEN1 expression to stemness and the DNA damage response, elucidating broader determinants of FEN1 dependency. These findings establish FEN1 as a promising therapeutic target in GBM, offering a strategy for both selective targeting and enhancement of TMZ efficacy in aggressive cancers. Statement of SignificanceThis study identifies FEN1 as a key vulnerability of glioblastoma stem cells, revealing its role in therapy resistance and stemness, and proposes FEN1 inhibition as a strategy to enhance temozolomide efficacy.

cancer biology↗

DNA2 and FANCM function in two distinctive pathways in disrupting TERRA R-loops and suppressing replication stress at ALT telomeres

Cancers maintain their telomeres through two main telomere maintenance mechanisms (TMMs): 85-90% of cancers rely on telomerase, while 10-15% of cancers adopt the Alternative Lengthening of Telomere (ALT) pathway. Previously, we and others reported that FANCM, one of the Fanconi Anemia proteins, plays a critical role in suppressing replication stress and DNA damage at ALT telomeres by actively disrupting TERRA R-loops [1-4]. Here, we showed that inactivation of DNA2 in ALT-positive (ALT+) cells, but not in telomerase-positive (TEL+) cells, induces a robust increase of replication stress and DNA damage at telomeres, which leads to a pronounced increase of many ALT properties, including telomere dysfunction-induced foci (TIFs), ALT-associated PML bodies (APBs), and C-circles. We further demonstrated that depletion of DNA2 induces a pronounced increase of TERRA R-loops and a decrease in replication efficiency at ALT telomeres. Most importantly, we uncovered a strong additive genetic interaction between DNA2 and FANCM in the ALT pathway. Furthermore, co-depletion of DNA2 and FANCM causes synthetic lethality in ALT+ cells, but not in TEL+ cells, suggesting that targeting DNA2 and FANCM could be a viable strategy to treat ALT+ cancers. Finally, utilizing the single-molecule telomere assay via optical mapping (SMTA-OM) technology, we thoroughly characterized genome-wide changes in DNA2 deficient cells and FANCM deficient cells and found that most chromosome arms manifested increased telomere length. Unexpectedly, we uncovered many chromosome arm-specific telomere changes in those cells, suggesting that telomeres at different chromosome arms may regulate and respond to replication stress differently. Collectively, our study not only shed new light on the molecular mechanisms of the ALT pathway, but also discovered a new strategy for targeting ALT+ cancer.

cancer biology↗

Glycogen metabolism acts in neurons to support glycolytic plasticity

Glycogen is the largest energy reserve in the brain, but the specific role of glycogen in supporting neuronal energy metabolism in vivo is not well understood. We established a system in C. elegans to dynamically probe glycolytic states in single cells of living animals via the use of the glycolytic sensor HYlight and determined that neurons can dynamically regulate glycolysis in response to activity or transient hypoxia. We performed an RNAi screen and identified that PYGL-1, an ortholog of the human glycogen phosphorylase, is required in neurons for glycolytic plasticity. We determined that neurons employ at least two mechanisms of glycolytic plasticity: glycogen-dependent glycolytic plasticity (GDGP) and glycogen-independent glycolytic plasticity (GIGP). We uncover that GDGP is employed under conditions of mitochondrial dysfunction, such as transient hypoxia or in mutants for mitochondrial function. We find that the ability of neurons to plastically regulate glycolysis through cell-autonomous GDGP is important for sustaining the synaptic vesicle cycle. Together, our study reveals that, in vivo, neurons can directly use glycogen as a fuel source to sustain glycolytic plasticity and synaptic function.

neuroscience↗

YPEL controls synapse development through p62-Nrf2 antioxidant pathway in Drosophila neuromuscular junction

The Yippee-like (YPEL) genes are highly conserved among all eukaryotic species, yet the molecular and cellular pathways that YPEL regulate are poorly understood. Human and animal studies suggest that YPEL is involved in nervous system functions. Here we report that YPEL is necessary for synapse development in neuromuscular junction and motor functions in Drosophila. YPEL interacts with the Drosophila p62, Refractory to sigma P, which forms cytoplasmic proteinaceous bodies for selective autophagy and signaling. YPEL overexpression decreased p62 bodies, while increased p62 bodies were observed in YPEL mutant neurons. Suppressing p62 bodies by reducing p62 gene dosage significantly alleviated both synaptic and locomotion defects in YPEL mutants, suggesting that YPEL acts through p62 for synapse development. On the other hand, suppressing p62 bodies via autophagy did not restore synapse development in YPEL mutants. Interestingly, reduced levels of reactive oxygen species were found in YPEL mutants, which is consistent with the role of p62 in promoting the nuclear factor erythroid 2-related factor 2 (Nrf2) antioxidant pathway. Overexpressing Drosophila Nrf2, Cap n collar (Cnc), phenocopied the synaptic and locomotion deficits in YPEL mutants. Importantly, both synaptic and locomotion defects were completely rescued by knocking down Cnc in YPEL mutant motor neurons. Taken together, our study demonstrates that YPEL negatively controls p62 - Nrf2 antioxidant pathway for neuromuscular synapse development and locomotion.

neuroscience↗

Chromosome-level genome assembly of Tamarindus indica

Tamarindus indica is the sole member of the genus Tamarindus of the Leguminosae family. It is a multipurpose horticultural plant, with every part of the plant finding importance in food, medicine, and other industries. To gain an understanding of genome structure and evolution, we reported the first high-quality genome assembly of T. indica anchored to 12 chromosomes with N50 of [~]56 Mb. Supported by comprehensive transcriptome data, we reported >48,000 protein-coding genes. Through phylogenetic and evolutionary analysis, we uncovered an independent whole-genome duplication event in T. indica and highlighted the expression divergence of segmentally duplicated genes and their role in the better adaptivity of the plant. Our study thus provides first insights into its genomic organization, evolutionary history, and WGD event and thus becomes an important resource for future genetic and biotechnological studies to understand essential pathways and assist breeding programs for trait enhancements.

genomics↗

Sirtuin 2 controls global protein synthesis by regulating Rheb-GTPase

Upregulated global protein synthesis is associated with the development and progression of several diseases and disorders. Strategies like calorie restriction and pharmacological inhibition of protein synthesis, have exhibited health-promoting effects. However, the complex molecular events that regulate global protein synthesis are not completely understood. Here, we report that SIRT2, a histone deacylase, negatively regulates global protein synthesis by inhibiting the mTORC1 pathway via deacetylating Rheb and promoting Rheb degradation. Our in vitro results suggest that SIRT2 deficiency increases protein synthesis, whereas SIRT2 overexpression suppresses protein synthesis. SIRT2-deficient mice exhibit age-associated and neurohormone-induced cardiac hypertrophy. Here, we report increased global protein synthesis in the hearts of young SIRT2-deficient mice, which may contribute to the development of cardiac hypertrophy. Conversely, cardiac-specific overexpression of SIRT2 reduces global protein synthesis in mice hearts. Mechanistically, SIRT2 binds to and deacetylates Rheb at K151 residue to enhance ubiquitin-proteosome-mediated degradation of Rheb. Depletion of Rheb rescues the increased protein synthesis in SIRT2-inhibited conditions. Our findings suggest that SIRT2 activation can be a potential therapeutic for treating diseases associated with increased protein synthesis.

cell biology↗

Antagonistic Regulation of LINE-1/Alu Elements and Their Repressor APOBEC3B in Cellular Senescence

Long Interspersed Nuclear Elements-1 (LINE-1 or L1) make up approximately 21% of the human genome, with some L1 loci containing intact open reading frames (ORFs) that facilitate retrotransposition. Because retrotransposition can have deleterious effects leading to mutations and genomic instability, L1 activity is typically suppressed in somatic cells through transcriptional and post-transcriptional mechanisms. However, L1 elements are derepressed in senescent cells causing age-associated inflammation. Despite the recognition of L1 activity as a hallmark of aging, the underlying molecular mechanisms governing L1 derepression in these cells are not fully understood. In this study, we employed high throughput sequencing datasets and validated our findings through independent experiments to investigate the regulation of L1 elements in senescent cells. Our results reveal that both replicative and oncogene-induced senescence are associated with reduced expression of the cytidine deaminase APOBEC3B, a known suppressor of L1 retrotransposition. Consequently, senescent cells exhibited diminished levels of C-to-U editing of full-length L1 elements. Moreover, Ribo-seq profiling indicated that progression to senescence is not only associated with increased L1 transcription, but also translation of L1 ORFs. In summary, our results suggest that the depletion of APOBEC3B contributes to enhanced activity of L1 in senescent cells and promotion of L1-induced DNA damage and aging.

genomics↗

IL-1R1 Blockade Enhances CD40 Agonist-Mediated Immune Responses but Fails to Increase Efficacy or Mitigate Hepatotoxicity in Pancreatic Cancer

Pancreatic ductal adenocarcinoma (PDAC) has a poor survival rate and limited treatments. Agonistic CD40 antibodies are promising, but clinical trials have shown only modest efficacy and significant hepatotoxicity. We previously reported that IL-1 pathway blockade enhances agonistic CD40 antibody efficacy against melanoma by depleting polymorphonuclear myeloid-derived suppressor cells (PMN-MDSCs; CD11b+Ly6C+Ly6G+). Because PMN-MDSCs also cause liver toxicity, we investigated the impact of IL-1R1 blockade on the efficacy and toxicity of agonistic CD40 antibody therapy in PDAC. Agonistic CD40 antibody therapy induced immune activation and significantly prolonged survival in orthotopic PDAC-bearing mice. IL-1R1 blockade monotherapy downregulated innate and adaptive immune response and exacerbated tumor growth. Although combination therapy upregulated several immune-related pathways and boosted innate and adaptive immune responses. IL-1R1 blockade failed to improve the overall antitumor efficacy of agonistic CD40 antibody therapy and exacerbated liver toxicity. Ly6G+ cell depletion in mice reduced the efficacy of agonistic CD40 antibody therapy, suggesting that Ly6G immune cells (PMN-MDSCs or neutrophils) exhibit an antitumor rather than immunosuppressive role in PDAC. Our findings underscore the complex role of IL-1 signaling in modulating immune responses in PDAC and caution against pursuing IL-1R1 blockade, either as monotherapy or combined with agonistic CD40 antibodies, in clinical trials for PDAC.

cancer biology↗

Immunogenicity and protective efficacy of an intranasal neuraminidase-based influenza virus vaccine adjuvanted with bacterial cell membrane-derived adjuvants

Influenza virus neuraminidase (NA) has emerged as a promising vaccine candidate due to its relatively stable antigenic structure and the ability of NA-specific antibodies to provide cross-protection within influenza virus subtypes. Since the influenza virus causes respiratory infections in humans, developing mucosal vaccines to protect the entry site of the virus is of high importance. Recombinant NA requires adjuvants to induce a protective immune response after mucosal administration. In the current study, we analyze the immunogenicity and protective efficacy of a recombinant NA-based influenza virus vaccine administered intranasally in combination with adjuvants consisting of outer membrane proteins from Neisseria meningitidis complexed with exogenous lipopolysaccharides (LPS) from Shigella flexneri or endogenous LPS from N. meningitidis. We evaluated the local and systemic humoral and cellular immune responses to adjuvanted recombinant N1 NA, analyzing the dynamics of local follicular T-helper (Tfh) cells and germinal center B cells (GCB) in nasal-associated lymphoid tissue (NALT) and tissue-resident memory T cells in lungs, as well as the levels of IgA and IgG in the upper and lower respiratory tracts. Finally, we performed a heterologous challenge study to test the ability of the investigated vaccine formulations to induce cross-protection. The study demonstrates that bacterial cell membrane-derived adjuvants significantly improve the immunogenicity and protective efficacy of the recombinant N1 NA-based influenza vaccine leading to protection against clade 2.3.4.4b H5N1 challenge. This finding supports the potential of these adjuvanted vaccines in providing effective mucosal immunity against influenza virus.

microbiology↗

Striatal cell-type specific stability and reorganization underlying agency and habit

Goal-directed behavior is guided by learned action-outcome associations, allowing actions to adapt when outcomes change. With repetition, behavioral control shifts toward habit, enabling more automatic action execution, but reducing flexibility to outcome changes. Here, we used longitudinal, cellular-resolution calcium imaging, chemogenetics, instrumental conditioning, and the outcome devaluation test to ask how dorsomedial striatum D1+ and D2/A2A+ neurons contribute to the formation of goal-directed behavior and habit. DMS D1+ neurons stably encode instrumental actions, carry information about behavioral engagement and organization, and develop and maintain action-reward representational similarity and conjunctive activation with learning. Correspondingly, these neurons are critical for action-outcome learning and goal-directed decision making. In contrast, one ensemble of DMS A2A+ neurons transiently encodes actions during early action-outcome learning and another slowly starts to encode actions as habits form. Similarly, DMS A2A+ neurons transiently mediate action-outcome learning and become dispensable for goal-directed decision making. Thus, action-outcome associations are learned through DMS D1+ and A2A+ neuronal activity but only DMS D1+ neurons maintain support of adaptive, goal-directed decision making. Habit formation is associated with reorganization of A2A+ neuronal encoding. These data reveal a cell-type-specific dissociation between stable v. reorganizing striatal action representations paralleled by persistent v. transient contributions to goal-directed control.

neuroscience↗

Implications of diabetes mellitus on pathophysiology of Tuberculosis: Role of AGE-RAGE Axis and Glycated Proteins

Chronic hyperglycemia in diabetes mellitus promotes the formation of advanced glycation end products (AGEs) via non-enzymatic glycation of plasma proteins. AGEs and their receptor RAGE are central to diabetic complications, as they activate inflammatory pathways and oxidative stress. We studied the AGE-RAGE axis in uncontrolled diabetic individuals having pulmonary TB (PTB+DM), uncontrolled diabetic individuals with no infection (DM), and pulmonary TB patients (PTB). Levels of AGEs and RAGE were measured across these groups and compared to controls. The results showed significantly higher AGEs and RAGE levels in the diabetic milieu, reflecting chronic hyperglycemia. These AGEs were shown to be associated with impaired macrophage function, evidenced by reduced phagocytic capacity. Increased AGEs correlated with disease severity in tuberculosis patients co-affected by diabetes, indicating compromised immune responses. RAGE expression also showed a higher trend in TB patients, although not statistically significant, potentially influencing infection outcomes. Glycated calmodulin was also elevated in diabetic and TB-diabetes comorbid patients and negatively correlated with nitric oxide (NO) levels, suggesting that calmodulin glycation hinders NO production in diabetic conditions. Molecular dynamic studies revealed that glycosylation disrupts calmodulins interaction with inducible nitric oxide synthase (iNOS), potentially explaining the decreased NO levels in TB-diabetes comorbid patients. These findings underscore the detrimental impact of AGEs and RAGE in diabetic immune dysregulation, highlighting the need for therapeutic strategies to mitigate their effects on macrophage function and restore immune responses. HighlightsO_LIWe conducted this study to examine how hyperglycemia-driven AGEs and RAGE contribute to immune dysfunction and disease severity in diabetic and TB-diabetes patients. C_LIO_LIHigh AGEs and RAGE impairs macrophage function, decreasing phagocytic capacity and worsening disease severity in TB-diabetes comorbidity. C_LIO_LIGlycosylation disrupts calmodulins interaction with iNOS, contributing to lower NO levels and weakened immune responses in TB-diabetes comorbidity. C_LIO_LIThe AGE-RAGE axis should be studied further for these comorbid conditions to assess and improve macrophage function and restore immune responses. C_LI

immunology↗

Eukaryotic Translation Initiation Factor Loaded Extracellular Vesicles Promotes Macrophage Cholesterol Metabolism in ovarian cancer

Tumor-driven immune suppression poses a significant impediment to the success of immunotherapy in ovarian cancer. Among the various mechanisms contributing to immune suppression, intracellular communication facilitated by tumor-derived extracellular vesicles (EVs) within the tumor microenvironment (TME) emerges as a pivotal factor influencing tumor growth. We discovered that EVs from both ovarian tumor cell lines and the plasma of ovarian cancer patients are encapsulated with eukaryotic translation initiation factor 4E (eIF4E). Our study revealed a new mechanism showing how these EVs are loaded with eIF4E and its impact on ovarian cancer progression. We also demonstrated that eIF4E-containing EVs (eIF4E-EVs) alter protein translation in macrophages, contributing to anti-tumor immune response. Treatment of macrophages with eIF4E-EVs induces an immunosuppressive phenotype marked by the release of cytokines such as IL-6 and an elevated expression of Programmed death-ligand 1 (PD-L1). Notably, eIF4E-packaged EVs enhance the expression of 3-hydroxy-3-methyl-glutaryl-coenzyme A reductase (HMGCR) a pivotal enzyme in cholesterol biosynthesis, resulting in increased cholesterol levels within macrophages. Inhibition of HMGCR or reduction of cholesterol in macrophages effectively restores their antitumor activity by decreasing PD-L1 on macrophages. Analysis of tumor tissue from ovarian cancer patients revealed a positive correlation between HMGCR and TAM in ovarian cancer. In summary, we have characterized the mechanism of how eIF4E loaded EVs induced cholesterol synthesis, creating an immunosuppressive environment by upregulating PD-L1 expression in macrophages.

cancer biology↗

Integrative Computational Framework, Dyscovr, Links Mutated Driver Genes to Expression Dysregulation Across 19 Cancer Types

Mutations within cancer driver genes induce widespread transcriptional changes that reflect altered cellular states and can reveal associated genetic vulnerabilities. However, it remains challenging to determine which genes are dysregulated as a consequence of cancer alterations, and of these, which represent therapeutic opportunities. Here, we present Dyscovr, an integrative computational framework that leverages somatic mutation, gene expression, copy number alteration, methylation, and clinical data from primary tumors to identify driver-associated transcriptional changes. Dyscovr then uses these transcriptional changes as a biologically grounded starting point, integrating them with cancer cell line data to prioritize genes whose inhibition is predicted to reduce viability either specifically in driver-mutant contexts or in combination with driver inhibition. Applied both pan-cancer and across 19 tumor types, Dyscovr uncovers hundreds of such conditional vulnerabilities. As a case study, we newly implicate--and experimentally validate--KBTBD2 as a gene whose inhibition enhances the efficacy of PI3K inhibitors in PIK3CA-mutant breast cancer cell lines. The Dyscovr software (github.com/Singh-Lab/Dyscovr) and predictions (dyscovr.princeton.edu) provide a platform and resource for linking mutated driver genes to conditional genetic vulnerabilities and for prioritizing these relationships for experimental and therapeutic investigation.

systems biology↗

Working Memory Bridges Cognition, Emotion, and Brain Structure: A Multilayer Network Analysis of the Human Connectome Project-Young Adult

Multilayer network analyses allow for the exploration of complex relationships across different modalities. Specifically, this study employed a novel method that integrates psychometric networks with structural covariance networks to explore the relationships between cognition, emotion and the brain. Psychological (NIH Toolbox Cognition Battery and NIH Toolbox Emotion Battery) and anatomical MRI (cortical volume) data were extracted from the Human Connectome Project Young Adult dataset (n = 1109). Partial correlation networks with graphical lasso regularisation and extended Bayesian information criterion tuning were used to model a psychometric bi-layer network consisting of seven cognitive nodes and four emotion nodes, as well as a neuro-psychometric tri-layer network consisting of these same nodes in addition to 24 brain nodes from the central executive and salience networks. Bridge strength centrality was used to identify nodes that bridged between layers. For the bi-layer network, it was found that stress was the only bridge node. For the tri-layer network, six bridge nodes were identified, with the left insula emerging as the most central. These findings demonstrate the utility of multilayer networks in integrating psychological and neurobiological data for the potential identification of targets to improve psychological wellbeing.

neuroscience↗

Deep Mining of the Human Antibody Repertoire Identifies Frequent and Immunogenetically Diverse CDRH3 Topologies Targetable by Vaccination

Germline targeting vaccination strategies against highly variable pathogens such as HIV aim to elicit broadly neutralizing antibodies (bnAbs) with particular immunogenetic or structural features. The V2 apex of the HIV Env protein is a promising target for a class of bnAbs that contain conserved structural motifs in the heavy chain complementarity determining region 3 (CDRH3). Here, we show that these structural motifs are targetable by vaccination by characterizing V2 apex axe-like CDRH3s in the human repertoire and developing new immunogens capable of engaging them. We determined the frequency and diversity of axe-like CDHR3s in healthy human donors using a series of structural informatics approaches, finding these precursors in nearly 90% of donors. Axe-targeting immunogens based on the HIV Env Q23.17 bound axe-like precursors in cryo-EM structures, induced V2 apex-specific antibody responses in humanized mice, and induced axe-like heterologous neutralizing antibodies in rhesus macaques infected with a germline-targeted simian-human immunodeficiency virus. These results illustrate a new structure-guided immunoinformatic vaccine design paradigm that can be employed to elicit immunogenetically diverse yet structurally conserved classes of antibodies. Significance StatementMany broadly neutralizing antibodies (bnAbs) utilize modes of epitope recognition dominated by the antibody complementarity determining region 3 (CDRH3). The CDRH3 is the most diverse part of the antibody, posing a challenge for germline targeting vaccine designs that aim to elicit antibodies with particular immunogenetic features. Vaccine design strategies that accommodate CDRH3 variability are therefore needed. Many HIV Env V2 apex bnAbs share "axe-like" CDRH3 microfolds that arise from diverse immunogenetic origins. Here we determined the frequency in humans of B cells with such CDRH3 topologies and designed immunogens to engage their precursors. This work opens a path toward vaccines that engage specific structural classes of B cells, thereby advancing the rational design of immunogens for HIV and other pathogens.

immunology↗