It has been known that, the novel coronavirus, 2019-nCoV, which is considered similar to SARS-CoV and originated from Wuhan (China), invades human cells via the receptor angiotensin converting enzyme II (ACE2). Moreover, lung cells that have ACE2 expression may be the main target cells during 2019-nCoV infection. However, some patients also exhibit non-respiratory symptoms, such as kidney failure, implying that 2019-nCoV could also invade other organs. To construct a risk map of different human organs, we analyzed the single-cell RNA sequencing (scRNA-seq) datasets derived from major human physiological systems, including the respiratory, cardiovascular, digestive, and urinary systems. Through scRNA-seq data analyses, we identified the organs at risk, such as lung, heart, esophagus, kidney, bladder, and ileum, and located specific cell types (i.e., type II alveolar cells (AT2), myocardial cells, proximal tubule cells of the kidney, ileum and esophagus epithelial cells, and bladder urothelial cells), which are vulnerable to 2019-nCoV infection. Based on the findings, we constructed a risk map indicating the vulnerability of different organs to 2019-nCoV infection. This study may provide potential clues for further investigation of the pathogenesis and route of 2019-nCoV infection.

SummaryCitrus canker, caused by Xanthomonas citri subsp. citri (Xcc), is severely damaging to the global citrus industry. Targeted editing of host disease‐susceptibility genes represents an interesting and potentially durable alternative in plant breeding for resistance. Here, we report improvement of citrus canker resistance through CRISPR/Cas9‐targeted modification of the susceptibility gene CsLOB1 promoter in citrus. Wanjincheng orange (Citrus sinensis Osbeck) harbours at least three copies of the CsLOB1 G allele and one copy of the CsLOB1 − allele. The promoter of both alleles contains the effector binding element (EBEP thA4), which is recognized by the main effector PthA4 of Xcc to activate CsLOB1 expression to promote citrus canker development. Five pCas9/CsLOB1sgRNA constructs were designed to modify the EBEP thA4 of the CsLOB1 promoter in Wanjincheng orange. Among these constructs, mutation rates were 11.5%–64.7%. Homozygous mutants were generated directly from citrus explants. Sixteen lines that harboured EBEP thA4 modifications were identified from 38 mutant plants. Four mutation lines (S2‐5, S2‐6, S2‐12 and S5‐13), in which promoter editing disrupted CsLOB1 induction in response to Xcc infection, showed enhanced resistance to citrus canker compared with the wild type. No canker symptoms were observed in the S2‐6 and S5‐13 lines. Promoter editing of CsLOB1 G alone was sufficient to enhance citrus canker resistance in Wanjincheng orange. Deletion of the entire EBEP thA4 sequence from both CsLOB1 alleles conferred a high degree of resistance to citrus canker. The results demonstrate that CRISPR/Cas9‐mediated promoter editing of CsLOB1 is an efficient strategy for generation of canker‐resistant citrus cultivars.

Cancer immunotherapy has revolutionized cancer treatment, and it relies heavily on the comprehensive understanding of the immune landscape of the tumor microenvironment (TME). Here, we obtain a detailed immune cell atlas of esophageal squamous cell carcinoma (ESCC) at single-cell resolution. Exhausted T and NK cells, regulatory T cells (Tregs), alternatively activated macrophages and tolerogenic dendritic cells are dominant in the TME. Transcriptional profiling coupled with T cell receptor (TCR) sequencing reveal lineage connections in T cell populations. CD8 T cells show continuous progression from pre-exhausted to exhausted T cells. While exhausted CD4, CD8 T and NK cells are major proliferative cell components in the TME, the crosstalk between macrophages and Tregs contributes to potential immunosuppression in the TME. Our results indicate several immunosuppressive mechanisms that may be simultaneously responsible for the failure of immuno-surveillance. Specific targeting of these immunosuppressive pathways may reactivate anti-tumor immune responses in ESCC.

The intracellular delivery of biofunctional enzymes or therapeutic proteins through systemic administration is of great importance in therapeutic intervention of various diseases. However, current strategies face substantial challenges owing to various biological barriers, including susceptibility to protein degradation and denaturation, poor cellular uptake, and low transduction efficiency into the cytosol. Here, we developed a biomimetic nanoparticle platform for systemic and intracellular delivery of proteins. Through a biocompatible strategy, guest proteins are caged in the matrix of metal-organic frameworks (MOFs) with high efficiency (up to ∼94%) and high loading content up to ∼50 times those achieved by surface conjunction, and the nanoparticles were further decorated with the extracellular vesicle (EV) membrane with an efficiency as high as ∼97%. In vitro and in vivo study manifests that the EV-like nanoparticles can not only protect proteins against protease digestion and evade the immune system clearance but also selectively target homotypic tumor sites and promote tumor cell uptake and autonomous release of the guest protein after internalization. Assisted by biomimetic nanoparticles, intracellular delivery of the bioactive therapeutic protein gelonin significantly inhibits the tumor growth in vivo and increased 14-fold the therapeutic efficacy. Together, our work not only proposes a new concept to construct a biomimetic nanoplatform but also provides a new solution for systemic and intracellular delivery of protein.