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Kuang, M.

Publications and source records attributed to Kuang, M..

7 recordsLinked to original sources

Socially regulated genes are spatially hyperconnected to enhancers in the ant brain

Caste identity in Harpegnathos saltator ants remains plastic beyond development and throughout adulthood. Adult Harpegnathos workers can become dominant reproductives, known as "gamergates," through a social caste transition that involves extensive transcriptional and cellular remodeling of the brain. To gain insight into the epigenetic regulation of this process, we generated comprehensive, caste-specific epigenomic atlases of the Harpegnathos brain, including chromatin accessibility, histone modifications, and 3D genome architecture. Using these data we refined the genome assembly, annotated enhancers, and linked them to target genes. We then identified candidate 3D-architectural factors, many of which were specifically upregulated in gamergate brains. Promoters of genes upregulated during the worker-gamergate transition formed an unusually high number of 3D chromatin contacts with their regulatory regions, and most of these contacts were already present in workers. We propose that the pre-existing hyper-connectivity of socially regulated genes is essential to adult brain plasticity and behavioral reprogramming.

genomics↗

Inhibiting B-cell-mediated Immunosuppression to Enhance the Immunotherapy Efficacy in Hepatocellular Carcinoma

BackgroundImmunotherapy is efficacious in hepatocellular carcinoma (HCC), but the benefits are limited to a minority of patients. Most HCC patients show resistance to immune checkpoint blockade (ICB). Agonists of the stimulator of interferon genes (STING), potent immune stimulators, showed limited effectiveness. Using preclinical models, we studied the mechanisms of resistance to ICB and STING agonism. MethodsMurine HCA-1 and RIL-175 HCCs were orthotopically grown in mice with underlying liver fibrosis, to mimic the presentation of human HCC. Established tumors were treated with a STING agonist (BMS-986301) or anti-PD1 ICB, and mice were followed to evaluate safety and efficacy, as well as the mechanisms of treatment resistance by RNA sequencing, flow cytometry, and immunofluorescence, B-cell depletion and T-cell immunoglobulin and mucin domain 1 (TIM-1) ICB. ResultsUnbiased analyses of transcriptomic data from murine HCC tissues from ICB-treated mice showed an increased abundance of intratumoral CD8+ T cells and B cells. STING agonism alone showed efficacy in the ICB-responsive RIL-175 HCC model but more limited efficacy in the ICB-resistant HCA-1 model. STING agonism increased circulating IL-10 and intratumoral infiltration by B-cells, including TIM-1+ B cells, and promoted the formation of tertiary lymphoid structure (TLS)-like structures, especially in the peritumoral areas. Strikingly, adding B cell depletion to ICB or STING agonism treatment significantly increased survival. Interestingly, unlike ICB, STING agonism also had a pronounced anti-metastatic activity. In addition, the combination of STING agonism and TIM-1 blockade augmented B cell differentiation and antigen presentation in vitro and improved the anti-tumor effects in murine HCC in vivo. This approach decreased the number of TIM-1+ B cells in the tumor and shifted B cells to higher expression of CD86 and MHC class II, enhancing the antigen presentation capability and further boosting the antitumor efficacy of CD8+ cytotoxic T cells. ConclusionOur findings demonstrate that B cells are associated with ICB- and STING-mediated therapy resistance, and that depleting B-cells or targeting TIM-1 enhances both innate and acquired therapeutic efficacy in HCC.

cancer biology↗

Distinct Single-cell Immune Ecosystems Distinguish True and De Novo HBV-related Hepatocellular Carcinoma Recurrences

Revealing differential tumor immune microenvironment (TIME) characteristics between true versus de novo hepatocellular carcinoma (HCC) recurrence could help optimal development and use of immunotherapies. Here, we studied the TIME of recurrent HBV-related HCCs by 5and VDJ single-cell and bulk RNA-sequencing, flow cytometry, and multiplexed immunofluorescence. Analyses of mutational profiles, evolutionary trajectories, and clonal architecture using whole-exome sequencing identified de novo versus true recurrences, some of which occurred before clinical diagnosis. The TIME of truly recurrent HCCs was characterized by an increased abundance in KLRB1+CD8+ T cells with memory phenotype and low cytotoxicity. In contrast, we found an enrichment in cytotoxic and exhausted CD8+ T cells in the TIME of de novo recurrent HCCs. Transcriptomic and interaction analyses showed an upregulated GDF15 expression level on HCC cells in proximity to dendritic cells, which may have dampened antigen presentation and inhibited anti-tumor immunity in the TIME of truly recurrent lesions. In contrast, we found that myeloid cells crosstalk with T cells mediated T cell exhaustion and immunosuppression in the TIME of de novo recurrent HCC. In conclusion, our results support genomic diagnosis and immune profiling for guiding immunotherapy implementation based on the type of HCC recurrence and TIME. HighlightsO_LITruly recurrent lesions are seeded before primary tumor diagnosis, and that de novo cancer can occur earlier than the clinically used 2-year limit. C_LIO_LIScRNA-seq unravels distinct immune ecosystems in true versus de novo HCC recurrences, highlighting the need for different immunotherapy strategies for two types of HCC recurrence. C_LIO_LICD8+ T cells in de novo recurrence displayed cytotoxic and exhausted phenotypes while those in truly recurrent lesions showed a memory phenotype with weak cytotoxicity. C_LIO_LIHCC cells expressing the inhibitory molecule GDF15 were in the proximity of DCs only in truly recurrent lesions. C_LIO_LIHigh GDF15 expression level was associated with truly recurrent HCC and worse prognosis. C_LI Graphical abstract O_FIG O_LINKSMALLFIG WIDTH=200 HEIGHT=186 SRC="FIGDIR/small/494526v1_ufig1.gif" ALT="Figure 1"> View larger version (71K): org.highwire.dtl.DTLVardef@1b76bf0org.highwire.dtl.DTLVardef@10f889aorg.highwire.dtl.DTLVardef@d16b52org.highwire.dtl.DTLVardef@dceb7a_HPS_FORMAT_FIGEXP M_FIG C_FIG

immunology↗

Accelerated mass transfer from frozen thin films during thin-film freeze-drying

Freeze-drying, or lyophilization, is widely used to produce pharmaceutical solids from temperature-sensitive materials but the process is time and energy inefficient. Herein, using E. coli as a model live organism, whose viability in dry powders is highly sensitive to the water content in the powders, we demonstrated that the drying rate of thin-film freeze-drying (TFFD) is significantly higher than that of the conventional shelf freeze-drying, likely because the large total surface area from the loosely stacked frozen thin films and the low thickness of the thin-films enable faster and more efficient mass transfer during freeze-drying. The highly porous nature and high specific surface area of the thin-film freeze-dried powders may have contributed to the faster mass transfer as well. Moreover, we demonstrated that TFFD can be applied to produce dry powders of E. coli and L. acidophilus with minimum bacterial viability loss (i.e., within one log reduction), and the L. acidophilus dry powder is suitable for intranasal delivery. It is concluded that TFFD technology is promising in addressing the time-and cost-inefficient issue of conventional shelf freeze-drying.

pharmacology and toxicology↗

Collateral cleavage of 28s rRNA by RfxCas13d causes death of mice

The CRISPR-Cas13 system is an RNA-guided RNA-targeting system, and has been widely used in transcriptome engineering with potentially important clinical applications. However, it is still controversial whether Cas13 exhibits collateral activity in mammalian cells. Here, we found that knocking down gene expression using RfxCas13d in the adult brain neurons caused death of mice, which was not resulted from the loss of target gene function or off-target effects. Mechanistically, we showed that RfxCas13d exhibited collateral activity in mammalian cells, which is positively correlated with the abundance of target RNA. The collateral activity of RfxCas13d could cleave 28s rRNA into two fragments, leading to translation attenuation and activation of the ZAK-JNK/p38-immediate early gene (IEG) pathway. These results provide new mechanistic insights into the collateral activity of RfxCas13d and warn that the biosafety of CRISPR-Cas13 system needs further evaluation before applying it to clinical treatments.

bioengineering↗

SARS-CoV-2 spike protein interacts with and activates TLR4

The onset of sepsis is an important feature of COVID19 and a main cause of death. It is unknown how SARS-CoV-2 infection results in viral sepsis in human. We recently found that SARS-CoV-2 provoked an anti-bacterial like response and activation of TLR4 pathway at the very early stage of infection in animal models. This abnormal immune response led to emergency granulopoiesis and sepsis. However, the original trigger of TLR4 signaling by SARS-CoV-2 is unknown. We here identified that the trimeric spike protein of SARS-CoV-2 could bind to TLR4 directly and robustly activate downstream signaling in monocytes and neutrophils. Moreover, specific TLR4 or NFKB inhibitor, or knockout of MyD88 could significantly block IL-1B induction by spike protein. We thus reveal that spike protein of SARS-CoV-2 functions as a potent stimulus causing TLR4 activation and sepsis related abnormal responses.

immunology↗

DLPAlign: A Deep Learning based Progressive Alignment for Multiple Protein Sequences

This paper proposed a novel and straightforward approach to improve the accuracy of progressive multiple protein sequence alignment. We trained a decision-making model based on the convolutional neural networks and bi-directional long short term memory networks, and based on this model, we progressively aligned the input sequences by calculating different posterior probability matrixes. To test the accuracy of this approach, we have implemented a multiple sequence alignment tool called DLPAlign and compared its performance with eleven leading alignment methods on three empirical alignment benchmarks (BAliBASE, OXBench and SABMark). Our results show that DLPAlign can get the best total-column scores on the three benchmarks. When evaluated against the 711 low similarity families with average PID [≤] 30%, DLPAlign improved about 2.8% over the second-best MSA software. Besides, we also compared the performance of DLPAlign and other alignment tools on a real-life application, namely protein secondary structure prediction on four protein sequences related to SARS-COV-2, and DLPAlign provides the best result in all cases.

bioinformatics↗