Biology subjects

Sun, M.

Publications and source records attributed to Sun, M..

At least 109 records · Page 6Linked to original sources

bioRxiv2023

Defense mechanism of a bacterial retron supramolecular assembly

Retrons are a class of multigene antiphage defense system typically consisting of a retron reverse transcriptase, a non-coding RNA, and a cognate effector. Although the triggers for several retron systems have been discovered recently, the full picture of how retron systems sense invading phages and mediate defense remains to be elucidated. Here, we focus on the retron Ec86 defense system and report its modes of activation and action. We identified a phage-encoded DNA cytosine methyltransferase (Dcm) as the trigger of the Ec86 system and show that Ec86 senses msDNA methylation and becomes activated. We further determined the structure of a tripartite retron Ec86 supramolecular assembly, which is primed for activation by Dcm, and demonstrated that the activated system confers defense through depletion of nucleoside derivatives. These findings emphasize the role of retrons being a second line of defense and highlight an emerging theme of anti-phage defense through supramolecular complex assemblies.

microbiology↗

bioRxiv2023

Therapeutic Prime/Pull Vaccination of HSV-2 Infected Guinea Pigs with the Ribonucleotide Reductase 2 (RR2) Protein and CXCL11 Chemokine Boosts Antiviral Local Tissue-Resident and Effector Memory CD4+ and CD8+ T Cells and Protects Against Recurrent Genital Herpes

Following acute herpes simplex virus type 2 (HSV-2) infection, the virus undergoes latency in sensory neurons of the dorsal root ganglia (DRG). Intermittent virus reactivation from latency and shedding in the vaginal mucosa (VM) causes recurrent genital herpes. While T-cells appear to play a role in controlling virus reactivation and reducing the severity of recurrent genital herpes, the mechanisms for recruiting these T-cells into DRG and VM tissues remain to be fully elucidated. The present study investigates the effect of CXCL9, CXCL10, and CXCL11 T-cell-attracting chemokines on the frequency and function of DRG- and VM-resident CD4+ and CD8+ T cells and its effect on the frequency and severity of recurrent genital herpes. HSV-2 latent-infected guinea pigs were immunized intramuscularly with the HSV-1 RR2 protein (Prime) and subsequently treated intravaginally with the neurotropic adeno-associated virus type 8 (AAV-8) expressing CXCL9, CXCL10, or CXCL11 T-cell-attracting chemokines (Pull). Compared to the RR2 therapeutic vaccine alone, the RR2/CXCL11 prime/pull therapeutic vaccine significantly increased the frequencies of functional tissue-resident (TRM cells) and effector (TEM cells) memory CD4+ and CD8+ T cells in both DRG and VM tissues. This was associated with less virus shedding in the healed genital mucosal epithelium and reduced frequency and severity of recurrent genital herpes. These findings confirm the role of local DRG- and VM-resident CD4+ and CD8+ TRM and TEM cells in reducing virus reactivation shedding and the severity of recurrent genital herpes and propose the novel prime/pull vaccine strategy to protect against recurrent genital herpes. IMPORTANCEThe present study investigates a novel prime/pull therapeutic vaccine strategy to protect against recurrent genital herpes in the guinea pig model. HSV-2 infected guinea pigs were vaccinated using a recombinantly expressed herpes tegument protein-RR2 (prime), followed by intravaginal treatment with the neurotropic adeno-associated virus type 8 (AAV-8) expressing CXCL9, CXCL10, or CXCL11 T-cell-attracting chemokines (pull). The RR2/CXCL11 prime/pull therapeutic vaccine elicited a significant reduction in virus shedding in the vaginal mucosa and decreased the severity and frequency of recurrent genital herpes. This protection was associated with increased frequencies of functional tissue-resident (TRM cells) and effector (TEM cells) memory CD4+ and CD8+ T cells infiltrating latently infected DRG tissues and the healed regions of the vaginal mucosa. These findings shed light on the role of tissue-resident (TRM cells) and effector (TEM cells) memory CD4+ and CD8+ T cells in DRG and vaginal mucosa (VM) tissues in protection against recurrent genital herpes and propose the prime/pull therapeutic vaccine strategy in combating genital herpes. TWEETA therapeutic RR2/CXCL11 prime/pull vaccine reduced recurrent genital herpes more effectively than therapeutic vaccination with a subunit HSV RR2 antigen alone.

immunology↗

bioRxiv2023

ERK signaling drives evolutionary expansion of the mammalian cerebral cortex

The molecular basis for cortical expansion during evolution remains largely unknown. Here, we found that FGF-extracellular signal-regulated kinase (ERK) signaling promotes the self-renewal and expansion of cortical radial glial (RG) cells. Furthermore, FGF-ERK signaling induces Bmp7 expression in cortical RG cells, which increases the length of the neurogenic period. We demonstrate that ERK signaling and SHH signaling mutually inhibit each other in cortical RG cells. We also provide evidence that ERK signaling is elevated in cortical RG cells during development and evolution. We conclude that the evolutionary expansion of the mammalian cortex, notably in human, is driven by ERK-BMP7-GLI3R signaling pathway in cortical RG cells, which participates in a positive feedback loop through antagonizing SHH signaling. We also propose that the molecular basis for cortical evolutionary dwarfism, exemplified by the lissencephalic mouse which originated from a larger and gyrencephalic ancestor, is due to mouse cortical RG cells receiving higher SHH signaling that antagonizes ERK signaling.

neuroscience↗

bioRxiv2023

3 Directional Inception-ResUNet: deep spatial feature learning for multichannel singing voice separation with distortion

Singing voice separation on robots faces the problem of interpreting ambiguous auditory signals. The acoustic signal, which the humanoid robot perceives through its onboard microphones, is a mixture of singing voice, music, and noise, with distortion, attenuation, and reverberation. In this paper, we used the 3 directional Inception-Resnet structure in the U-shaped encoding and decoding network to improve the utilization of the spatial and spectral information of the spectrograms. Multi-objectives were used to train the model: magnitude consistency loss, phase consistency loss, and magnitude correlation consistency loss. We recorded the singing voice and accompaniment derived from the MIR-1k datasets with NAO robots and synthesized the 10-channel datasets for training the model. The experimental results show that the proposed model trained by multi-objective reaches an average NSDR of 11.55db on the test datasets, which outperforms the comparison model. Author summaryThe mixture in the real singing voice separation is always mixed with noise and distortion. In this paper, the acoustic signals with distortion and noise perceived by the robot are used to study the separation of singing voices in real scenes. This paper described how to synthesize the training datasets, proposed a 3 directional Inception-ResUNet structure for multichannel singing voice separation, and adopted multi-objectives including magnitude correlation consistency loss to train the model. The experimental results showed that the magnitude correlation consistency loss reduces distortions, the proposed model achieves better performance than the compared models.

bioinformatics↗

bioRxiv2023

Long-read Transcriptome Landscapes of Primary and Metastatic Liver Cancers at Transcript Resolution

BackgroundThe liver is the sixth most common site of primary cancer in humans and is frequently colonized by metastases from cancers of other organs. Few studies have investigated the transcriptomic profiles of matched primary tumor and hepatic metastases of patients. Moreover, the read length of 100-200 bases in conventional short-read RNA sequencing is too short, which makes it difficult to directly infer the full-length transcript structure. To help develop effective treatments and improve survival, it is crucial to understand the complex and diverse molecular mechanisms of primary and metastatic liver cancers. MethodsNinety-five primary and secondary liver cancer patients who underwent hepatic resection were included with long-read sequencing isoform-sequencing and short-read RNA sequencing. We compared the transcriptome landscapes of primary and metastatic liver cancers and systematically investigated HCC, paired primary tumors and liver metastases, and matched non-tumor liver tissues. ResultsWe defined the full-length isoform-level transcriptome of human primary and metastatic liver cancers and identified isoform-level diversity in HCC and metastasis-associated transcriptome variations in metastatic liver cancers. Specific RNA transcripts and isoform switching events with clinical implications were profoundly discovered in liver cancer. Metastasis-specific transcripts that can predict the metastatic risk and identify the primary sites of cancers of unknown primary liver metastasis patients were defined. Additionally, we found that adjacent paracancerous liver tissues are abnormal and characterized the premetastatic immunological and metabolic alterations in the liver that favor the spread of cancer metastases. ConclusionsOur findings strongly highlight the powerfulness of full-length transcriptome profiling to yield novel biological insights into understanding the molecular basis of tumorigenesis and will further benefit the treatment of primary and metastatic liver cancers.

genomics↗

bioRxiv2023

A Cryptic Basic Groove formed by Ubiquitin and Histone H3 Mediates the Selective Recognition of H2AK119Ub Nucleosomes by Synovial Sarcoma X Breakpoint 1 Protein

The cancer-specific fusion oncoprotein SS18-SSX1 disturbs chromatin accessibility by hijacking the BAF complex from the promoters and enhancers to the polycomb-repressed chromatin regions. This process relies on the selective recognition of H2AK119Ub nucleosomes by SSX1. However, the mechanism by which SSX1 selective recognition of H2AK119Ub nucleosomes in the absence of ubiquitin (Ub)-binding capacity remains unknown. Here we report the cryo-EM structure of SSX1 bound to H2AK119Ub nucleosomes at 3.1 [A] resolution. Combined in vitro biochemical and cellular assays revealed that the Ub recognition by SSX1 is unique and depends on a cryptic basic groove formed by H3 and the Ub motif on the H2AK119 site. Moreover, this unorthodox binding mode of SSX1 induces DNA unwrapping at the entry/exit sites. Together, our results describe a unique mode of site-specific ubiquitinated nucleosome recognition that underlies the specific hijacking of the BAF complex to polycomb regions by SS18-SSX1 in synovial sarcoma.

molecular biology↗

bioRxiv2023

Upstream ribosome impediments activate roles of internal Shine-Dalgarno sequence for translation initiation in E. coli

The initiation of protein translation, one of the four phases of translation, had been proved to be the rate limiting step for translation. The specific interaction of bacterial 30S ribosomal subunit with Shine-Dalgarno sequence (SD) contributes the initiation significantly. It had been shown that SD-like sequence in coding region of mRNA, designated as internal SD, can direct translation initiation as regular SD does. The ribosome impediments were demonstrated to be one of the factors contributing the non-uniform translation elongation rate, but their effects on internal SD translation initiation role (ISTIR) remains unclear. To investigate effects of upstream ribosome impediments on ISTIR, a fragment consisting of pyruvate kinase (PK) gene, translation initiation needed mRNA elements (including an A/U-rich region, SD sequence and start codon AUG) and red fluorescent protein (RFP) gene was constructed and RFP expression levels representing translation initiation efficiency induced by internal SD was analyzed. Surprisingly, RFP expression was not detected with this primary construct, further experiments of inclusion of stem loop structure preceding to internal SD or co-expression of engineered RNA binding scaffold (ERBS) targeting to preceding sequence of internal SD could activate ISTIR. These results suggest that upstream ribosome impediments would activate ISTIR to initiate the downstream gene translation, which manifests the potential for developing new method to test interactions between RNA binding proteins and their target RNA molecules in vivo.

molecular biology↗

bioRxiv2023

A Multi-Epitope/CXCL11 Prime/Pull Coronavirus Mucosal Vaccine Boosts the Frequency and the Function of Lung-Resident CD4+ and CD8+ Memory T Cells and Protects Against COVID-19-like Symptoms and Death Caused by SARS-CoV-2 infection

The pandemic of the coronavirus disease 2019 (COVID-19) has created the largest global health crisis in almost a century. Following exposure to SARS-CoV-2, the virus particles replicate in the lungs, induce a "cytokine storm" and potentially cause life-threatening inflammatory disease. Low frequencies of function SARS-CoV-2-specific CD4+ and CD8+ T cells in the lungs of COVID-19 patients were associated with severe cases of COVID-19. The apparent low level of T cell-attracting CXCL9, CXCL10, and CXCL11 chemokines in infected lungs may not be sufficient enough to assure the sequestration and/or homing of CD4+ and CD8+ T cells from the circulation into infected lungs. We hypothesize that a Coronavirus vaccine strategy that boosts the frequencies of functional SARS-CoV-2-specific CD4+ and CD8+ T cells in the lungs would lead to better protection against SARS-CoV-2 infection, COVID19-like symptoms, and death. In the present study, we designed and pre-clinically tested the safety, immunogenicity, and protective efficacy of a novel multi-epitope//CXCL11 prime/pull mucosal Coronavirus vaccine. This prime/pull vaccine strategy consists of intranasal delivery of a lung-tropic adeno-associated virus type 9 (AAV-9) vector that incorporates highly conserved human B, CD4+ CD8+ cell epitopes of SARS-CoV-2 (prime) and pulling the primed B and T cells into the lungs using the T cell attracting chemokine, CXCL-11 (pull). We demonstrated that immunization of HLA-DR*0101/HLA-A*0201/hACE2 triple transgenic mice with this multi-epitope//CXCL11 prime/pull Coronavirus mucosal vaccine: (i) Increased the frequencies of CD4+ and CD8+ TEM, TCM, and TRM cells in the lungs; and (ii) reduced COVID19-like symptoms, lowered virus replication, and prevented deaths following challenge with SARS-CoV-2. These findings discuss the importance of bolstering the number and function of lung-resident memory CD4+ and CD8+ T cells for better protection against SARS-CoV-2 infection, COVID-19-like symptoms, and death.

immunology↗

bioRxiv2023

Enhancing anti-gastrointestinal cancer activities of CLDN18.2 CAR-T armored with novel synthetic NKG2D receptors Containing DAP10 and DAP12 signaling domains.

Chimeric antigen receptor (CAR) T therapies have shown remarkable efficacy in hematopoietic malignancies, but their therapeutic benefits in solid tumors have been limited due to heterogeneities in both antigen types and their expression levels on tumor cells. NK group 2 member D ligands (NKG2DLs) are extensively expressed on various tumors and absent on normal tissues, making them a promising target for cellular immunotherapy. DAP10 and DAP12 function as adaptor proteins in NK cells to transduce activating signals, and recent studies have revealed DAP10 and DAP12s additional role as a co-stimulatory signal in T cells. Our pre-clinical data showed that CAR-T targeting CLDN18.2 is highly effective in gastrointestinal (GI) cancers, but the heterogeneous expression of CLDN18.2 poses a treatment challenge. To complement this antigen deficiency, we demonstrated that NKG2DLs were extensively expressed in GI tumor tissues and formed an ideal dual target. Here, we reported a CLDN18.2 CAR design armored with synthetic NKG2D receptors (SNR) containing DAP10 and DAP12 signaling domains. This novel CAR-T showed improved cytotoxicity against tumor cells with heterogeneous expression of CLDN18.2. The possible underlined mechanism is that SNR promotes CAR-T memory formation and reduces their exhaustion, while also enhancing their expansion and ability to infiltrate immune-excluded tumors in vivo. Taken together, SNR with DAP10/12 signaling and their synergistic involvement, increased CAR-T function and overcame the antigen deficiency, providing a novel treatment modality for solid GI tumor.

immunology↗

bioRxiv2023

Evidence for conservation of a primordial 12-hour ultradian gene program in humans

While circadian rhythms are entrained to the once daily light-dark cycle of the sun, many marine organisms exhibit [~]12h ultradian rhythms corresponding to the twice daily movement of the tides. Although human ancestors emerged from circatidal environment millions of years ago, direct evidence of [~]12h ultradian rhythms in humans is lacking. Here, we performed prospective, temporal transcriptome profiling of peripheral white blood cells and identified robust [~]12h transcriptional rhythms from three healthy participants. Pathway analysis implicated [~]12h rhythms in RNA and protein metabolism, with strong homology to the circatidal gene programs previously identified in Cnidarian marine species. We further observed [~]12h rhythms of intron retention events of genes involved in MHC class I antigen presentation, synchronized to expression of mRNA splicing genes in all three participants. Gene regulatory network inference revealed XBP1, and GABP and KLF transcription factor family members as potential transcriptional regulators of human [~]12h rhythms. These results suggest that human [~]12h biological rhythms have a primordial evolutionary origin with important implications for human health and disease.

systems biology↗

bioRxiv2023

Deconstructing the brain bases of emotion regulation: A systems-identification approach using Bayes factors

Cognitive reappraisal is fundamental to cognitive therapies and everyday emotion regulation. Analyses using Bayes factors and an axiomatic systems-identification approach identified four reappraisal-related components encompassing distributed neural activity patterns across two independent fMRI studies (n=182 and n=176): (1) An anterior prefrontal system selectively involved in cognitive reappraisal; (2) A fronto-parietal-insular system engaged by both reappraisal and emotion generation, demonstrating a general role in appraisal; (3) A largely subcortical system activated during negative emotion generation but unaffected by reappraisal, including amygdala, hypothalamus, and periaqueductal gray; and (4) a posterior cortical system of negative emotion-related regions down-regulated by reappraisal. These systems covaried with individual differences in reappraisal success and were differentially related to neurotransmitter binding maps, implicating cannabinoid and serotonin systems in reappraisal. These findings challenge limbic-centric models of reappraisal and provide new systems-level targets for assessing and enhancing emotion regulation.

neuroscience↗

bioRxiv2023

Enriched zones of embedded ribonucleotides are associated with DNA replication and coding sequences in the human mitochondrial genome

Abundant ribonucleoside triphosphate (rNTP) incorporation in DNA by DNA polymerases in the form of ribonucleoside monophosphates (rNMPs) is a widespread phenomenon in nature, resulting in DNA structural change and genome instability. The rNMP distribution, characteristics, hotspots, and association with DNA metabolic processes in human mitochondrial DNA (hmtDNA) remain mostly unknown. Here, we utilize the ribose-seq technique to capture embedded rNMPs in mtDNA of six different human cell types with wild-type or mutant ribonuclease (RNase) H2 genotype. The rNMPs are preferentially embedded in the DNA of the light strand in most cell types studied, but not in the liver-tissue cells, in which the rNMPs are dominant on the heavy strand of hmtDNA. We uncover common rNMP hotspots and conserved rNMP-enriched zones across the entire hmtDNA, including in the replication-control region, which may result in the suppression of mtDNA replication. We also show that longer coding sequences have a significantly higher rNMP-embedment frequency per nucleotide. While the composition of the embedded rNMPs varies among the different cell types, by studying the genomic context of embedded rNMPs, we detected common rNMP-embedment patterns in hmtDNA. The genomic contexts of rNMPs found in hmtDNA are mainly distinct from those found in yeast mtDNA, highlighting a unique signature of rNTP incorporation by hmtDNA polymerase {gamma}.

genomics↗

bioRxiv2023

The Potential of Low Press and Hypoxia Environment in Assisting Pan-cancer Treatment

ObjectiveA low incidence and mortality rate of cancer has been observed in high-altitude regions, suggesting a potential positive effect of low press and hypoxia (LPH) environment on cancer. Based on this finding, our study aimed to construct a pan-cancer prognosis risk model using a series of ADME genes intervened by low oxygen, to explore the impact of LPH environment on the overall survival (OS) of various kinds of cancers, and to provide new ideas and approaches for cancer prevention and treatment. Datasets and MeasuresThe study used multiple sources of data to construct the pan-cancer prognosis risk model, including gene expression and survival data of 8,628 samples from the cancer genome atlas, and three gene expression omnibus databases were employed to validate the prediction efficiency of the prognostic model. The AltitudeOmics dataset was specifically used to validate the significant changes in model gene expression in LPH. To further identify the biomarkers and refine the model, various analytical approaches were employed such as single-gene prognostic analysis, weighted gene co-expression network analysis, and stepwise cox regression. And LINCS L1000, AutoDockTools, and STITCH were utilized to explore effective interacting drugs for model genes. Main Outcomes and ConclusionsThe study identified eight ADME genes with significant changes in the LPH environment to describe the prognostic features of pan-cancer. Lower risk scores calculated by the model were associated with better prognosis in 25 types of tumors, with a p-value of less than 0.05. The LPH environment was found to reduce the overall expression value of model genes, which could decrease the death risk of tumor prognosis. Additionally, it is found that the low-risk group had a higher degree of T cell infiltration based on immune infiltration analysis. Finally, drug exploration led to the identification of three potential model-regulating drugs. Overall, the study provided a new approach to construct a pan-cancer survival prognosis model based on ADME genes from the perspective of LPH and offered new ideas for future tumor prognosis research.

cancer biology↗

bioRxiv2023

Nanograms of SARS-CoV-2 Spike Protein Delivered by Exosomes Induce Potent Neutralization of Both Delta and Omicron Variants.

Exosomes are emerging as potent and safe delivery carriers for use in vaccinology and therapeutics. A better vaccine for severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) is needed to provide improved, broader, longer lasting neutralization of SARS-CoV-2, a more robust T cell response, enable widespread global usage, and further enhance the safety profile of vaccines given the likelihood of repeated booster vaccinations. Here, we use Capricors StealthX platform to engineer exosomes to express native SARS-CoV-2 spike Delta variant (STX-S) protein on the surface for the delivery of a protein-based vaccine for immunization against SARS-CoV-2 infection. The STX-S vaccine induced a strong immunization with the production of a potent humoral immune response as demonstrated by high levels of neutralizing antibody not only against the delta SARS-CoV-2 virus but also two Omicron variants (BA.1 and BA.5), providing broader protection than current mRNA vaccines. Additionally, both CD4+ and CD8+ T cell responses were increased significantly after treatment. Quantification of spike protein by ELISA showed that only nanograms of protein were needed to induce a potent immune response. This is a significantly lower dose than traditional recombinant protein vaccines with no adjuvant required, which makes the StealthX exosome platform ideal for the development of multivalent vaccines with a better safety profile. Importantly, our exosome platform allows novel proteins, or variants in the case of SARS-CoV-2, to be engineered onto the surface of exosomes in a matter of weeks, comparable with mRNA vaccine technology, but without the cold storage requirements. The ability to utilize exosomes for cellular delivery of proteins, as demonstrated by STX-S, has enormous potential to revolutionize vaccinology by rapidly facilitating antigen presentation at an extremely low dose resulting in a potent, broad antibody response.

immunology↗

bioRxiv2023

NuSAP participates in metaphase spindle length control in mammalians

Precise chromosome congression and segregation require proper assembly of a steady-state metaphase spindle, which is dynamic and maintained by continuous microtubule flux. NuSAP is a microtubule-stabilizing and -bundling protein that promotes chromosomedependent spindle assembly. However, its function in spindle dynamics remains unclear. Here, we demonstrate that NuSAP regulates the dynamics and length control of the metaphase spindle. Mechanistically, NuSAP facilitates kinetochore capture and spindle assembly via promoting Eg5 binding with microtubules. It also prevents excessive microtubule depolymerization through interacting with Kif2A and reduces its spindle-pole localization. NuSAP is phosphorylated by Aurora A at Ser-240 during mitosis, and this phosphorylation promotes its interaction with Kif2A on the spindle body and reduces its localization to the spindle poles, thus maintaining the proper spindle microtubule flux. NuSAP knockout resulted in shorter spindle formation with faster microtubule flux and chromosome misalignment. Taken together, we uncover that NuSAP participates in spindle assembly, dynamics, and metaphase spindle length control via affecting microtubule flux and Kif2A localization.

cell biology↗

bioRxiv2023

A multidimensional atlas of human glioblastoma organoids reveals highly coordinated molecular networks and effective drugs

Recent advances in the genomics of glioblastoma (GBM) led to the introduction of molecular neuropathology but failed to translate into treatment improvement. This is largely attributed to the genetic and phenotypic heterogeneity of GBM, which are considered the major obstacle to GBM therapy. Here, we use advanced human GBM organoid (LEGO: Laboratory Engineered Glioblastoma Organoid) and provide an unprecedented comprehensive characterization of LEGO models using single-cell transcriptome, DNA methylome, metabolome, lipidome, proteome, and phospho-proteome analysis. We discovered that genetic heterogeneity dictates functional heterogeneity across molecular layers and demonstrates that NF1 mutation drives mesenchymal signature. Most importantly, we found that glycerol lipid reprogramming is a hallmark of GBM, and several targets and drugs were discovered along this line. We also provide a genotype-based drug reference map using LEGO-based drug screen. This study provides novel human GBM models and a research path toward effective GBM therapy.

cancer biology↗

bioRxiv2023

Exosome based multivalent vaccine: achieving potent immunization, broaden reactivity and T cell response with nanograms of proteins without any adjuvant.

Current approved vaccines against severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) have focused solely on the spike protein to provide immunity. The first vaccines were developed rapidly using spike mRNA delivered by lipid nanoparticles but required ultra-low storage and have had limited immunity against variations in spike. Subsequently, protein-based vaccines were developed which offer broader immunity but require significant time for development and use of an adjuvant to boost immune response. Here, exosomes were used to deliver a bi-valent protein-based vaccine, in which two independent viral proteins were used. Exosomes were engineered to express either SARS-CoV-2 Delta spike (Stealth X-Spike, STX-S) or the more conserved nucleocapsid (Stealth X-Nucleocapsid, STX-N) protein on the surface. When administered as single product (STX-S or STX-N) or in combination (STX-S+N), both STX-S and STX-N induced a strong immunization with the production of a potent humoral and cellular immune response. Interestingly, these results were obtained with administration of only nanograms of protein and without adjuvant. In two independent animal models (mouse and rabbit), administration of nanograms of the STX-S+N vaccine resulted in increased antibody production, potent neutralizing antibodies with cross-reactivity to other variants of spike and strong T-cell responses. Importantly, no competition in immune response was observed, allowing for delivery of nucleocapsid with spike to offer improved SARS-CoV-2 immunity. These data show that the StealthXTM exosome platform has an enormous potential to revolutionize vaccinology by combining the advantages of mRNA and recombinant protein vaccines into a superior, rapidly generated, low dose vaccine resulting in potent, broader immunity.

immunology↗

bioRxiv2023

Multiomics atlas-assisted discovery of transcription factors enables specific cell state programming.

CD8+ T cells differentiate into diverse states that shape immune outcomes in cancer and chronic infection1-4. To systematically define the transcription factors (TFs) driving these states, we built a comprehensive atlas integrating transcriptional and epigenetic data across nine CD8+ T cell states and inferred TF activity profiles. Our analysis catalogued TF activity fingerprints, uncovering regulatory mechanisms governing selective cell state differentiation. Leveraging this platform, we focused on two transcriptionally similar but functionally opposing states critical in tumor and viral contexts: terminally exhausted T cells (TEXterm), which are dysfunctional5-8, and tissue-resident memory T cells (TRM), which are protective9-13. Global TF community analysis revealed distinct biological pathways and TF-driven networks underlying protective versus dysfunctional states. Through in vivo CRISPR screening integrated with single-cell RNA sequencing (in vivo Perturb-seq), we delineated several TFs that selectively govern TEXterm differentiation. We also identified HIC1 and GFI1 as shared regulators of TEXterm and TRM differentiation and KLF6 as a unique regulator of TRM. Importantly, we discovered novel TEXterm- selective TFs, including ZSCAN20 and JDP2, with no prior known function in T cells. Targeted deletion of these TFs enhanced tumor control and synergized with immune checkpoint blockade but did not interfere with TRM formation. Consistently, their depletion in human T cells reduces the expression of inhibitory receptors and improves effector function. By decoupling exhaustion TEX-selective from protective TRM programs, our platform enables more precise engineering of T cell states, accelerating the rational design of more effective cellular immunotherapies.

immunology↗