The targeted degradation of membrane proteins would afford an attractive and general strategy for treating various diseases that remain difficult with the current proteolysis-targeting chimera (PROTAC) methodology. We herein report a covalent nanobody-based PROTAC strategy, termed GlueTAC, for targeted membrane protein degradation with high specificity and efficiency. We first established a mass-spectrometry-based screening platform for the rapid development of a covalent nanobody (GlueBody) that allowed proximity-enabled cross-linking with surface antigens on cancer cells. By conjugation with a cell-penetrating peptide and a lysosomal-sorting sequence, the resulting GlueTAC chimera triggered the internalization and degradation of programmed death-ligand 1 (PD-L1), which provides a new avenue to target and degrade cell-surface proteins.

Introduction Analysis of extracellular vesicles (EVs) derived from plasma or cerebrospinal fluid (CSF) has emerged as a promising biomarker platform for therapeutic monitoring in glioblastoma patients. However, the contents of the various subpopulations of EVs in these clinical specimens remain poorly defined. Here we characterize the relative abundance of miRNA species in EVs derived from the serum and cerebrospinal fluid of glioblastoma patients. Methods EVs were isolated from glioblastoma cell lines as well as the plasma and CSF of glioblastoma patients. The microvesicle subpopulation was isolated by pelleting at 10,000×g for 30 min after cellular debris was cleared by a 2,000×g (20 min) spin. The exosome subpopulation was isolated by pelleting the microvesicle supernatant at 120,000×g (120 min). qRT-PCR was performed to examine the distribution of miR-21, miR-103, miR-24, and miR-125. Global miRNA profiling was performed in select glioblastoma CSF samples. Results In plasma and cell line derived EVs, the relative abundance of miRNAs in exosome and microvesicles were highly variable. In some specimens, the majority of the miRNA species were found in exosomes while in other, they were found in microvesicles. In contrast, CSF exosomes were enriched for miRNAs relative to CSF microvesicles. In CSF, there is an average of one molecule of miRNA per 150-25,000 EVs. Conclusion Most EVs derived from clinical biofluids are devoid of miRNA content. The relative distribution of miRNA species in plasma exosomes or microvesicles is unpredictable. In contrast, CSF exosomes are the major EV compartment that harbor miRNAs.

Activating intra-tumor innate immunity might enhance tumor immune surveillance. Virotherapy is proposed to achieve tumor cell killing, while indirectly activating innate immunity. Here, we report that recombinant poliovirus therapy primarily mediates antitumor immunotherapy via direct infection of non-malignant tumor microenvironment (TME) cells, independent of malignant cell lysis. Relative to other innate immune agonists, virotherapy provokes selective, TBK1-IRF3 driven innate inflammation that is associated with sustained type-I/III interferon (IFN) release. Despite priming equivalent antitumor T cell quantities, MDA5-orchestrated TBK1-IRF3 signaling, but not NFκB-polarized TLR activation, culminates in polyfunctional and Th1-differentiated antitumor T cell phenotypes. Recombinant type-I IFN increases tumor-localized T cell function, but does not mediate durable antitumor immunotherapy without concomitant pattern recognition receptor (PRR) signaling. Thus, virus-induced MDA5-TBK1-IRF3 signaling in the TME provides PRR-contextualized IFN responses that elicit functional antitumor T cell immunity. TBK1-IRF3 innate signal transduction stimulates eventual function and differentiation of tumor-infiltrating T cells.

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Viruses naturally engage innate immunity, induce antigen presentation, and mediate CD8 T cell priming against foreign antigens. Polioviruses can provide a context optimal for generating antigen-specific CD8 T cells, as they have natural tropism for dendritic cells, preeminent inducers of CD8 T cell immunity; elicit Th1-promoting inflammation; and lack interference with innate or adaptive immunity. However, notorious genetic instability and underlying neuropathogenicity has hampered poliovirus-based vector applications. Here we devised a strategy based on the polio:rhinovirus chimera PVSRIPO, devoid of viral neuropathogenicity after intracerebral inoculation in human subjects, for stable expression of exogenous antigens. PVSRIPO vectors infect, activate, and induce epitope presentation in DCs in vitro; they recruit and activate DCs with Th1-dominant cytokine profiles at the injection site in vivo. They efficiently prime tumor antigen-specific CD8 T cells in vivo, induce CD8 T cell migration to the tumor site, delay tumor growth and enhance survival in murine tumor models.

Parkinson’s disease (PD) is characterized by a progressive loss of dopaminergic neurons and consequent dopamine (DA) deficit, and current treatment still remains a challenge. Although neural stem cells (NSCs) have been evaluated as appealing graft sources, mechanisms underlying the beneficial phenomena are not well understood. Here, we investigate whether human NSCs (hNSCs) transplantation could provide neuroprotection against DA depletion by recruiting endogenous cells to establish a favorable niche. Adult mice subjected to 1-methyl-4-phenyl-1,2,3,6-tetrahydropyridine (MPTP) were transplanted with hNSCs or vehicle into the striatum. Behavioral and histological analyses demonstrated significant neurorescue response observed in hNSCs-treated animals compared with the control mice. In transplanted animals, grafted cells survived, proliferated, and migrated within the astrocytic scaffold. Notably, more local astrocytes underwent de-differentiation, acquiring the properties of NSCs or neural precursor cells (NPCs) in mice given hNSCs. Additionally, we also detected significantly higher expression of host-derived growth factors in hNSCs-transplanted mice compared with the control animals, together with inhibition of local microglia and proinflammatory cytokines. Overall, our results indicate that hNSCs transplantation exerts neuroprotection in MPTP-insulted mice via regulating the host niche. Harnessing synergistic interaction between the grafts and host cells may help optimize cell-based therapies for PD.

and remdesivir to treat SARS-CoV-2 infection. [3] Meanwhile, researchers have also reported the development of effective neutralizing antibodies using techniques such as single B cell sequencing. [4] Nevertheless, one of the most promising strategies for COVID-19 prevention relies on vaccine development. There have already been more than 100 vaccines under development, including whole virus vaccines (attenuated, inactivated, or recombinant virus), subunit vaccines, DNA, and RNA vaccines. [5] For example, an inactivated SARS-CoV-2 whole virus vaccine from China showed efficacy in mice, rats, and monkeys. [6] Another recombinant adenovirus vaccine clinical trial (NCT04313127) has posted its phase 1 results with neutralizing antibodies and reported specific T cell responses. [7] Whole virus vaccines are expensive, dangerous during production, and may cause severe vaccine-related diseases. [8] Alternatively, using subunit vaccines with virus antigen protein should be a safer, more effective, and economic strategy. Recombinant expression of the antigen in organisms such as E. coli, yeast, or mammalian cells can facilitate the large-scale production. The receptor binding domain of SARS-CoV-2 spike protein (S-RBD) has been shown to mediate the entry of the virus into host cells via interacting with human angiotensin converting Prevention and intervention methods are urgently needed to curb the global pandemic of coronavirus disease-19 caused by severe acute respiratory syndrome coronavirus-2 (SARS-CoV-2). Herein, a general pro-antigen strategy for subunit vaccine development based on the reversibly formulated receptor binding domain of SARS-CoV-2 spike protein (S-RBD) is reported. Since the poor lymph node targeting and uptake of S-RBD by antigen-presenting cells prevent effective immune responses, S-RBD protein is formulated into a reversible nanogel (S-RBD-NG), which serves as a pro-antigen with enhanced lymph node targeting and dendritic cell and macrophage accumulation. Synchronized release of S-RBD monomers from the internalized S-RBD-NG pro-antigen triggers more potent immune responses in vivo. In addition, by optimizing the adjuvant used, the potency of S-RBD-NG is further improved, which may provide a generally applicable, safer, and more effective strategy for subunit vaccine development against SARS-CoV-2 as well as other viruses.

Background: Physicians play a unique role in scientific and clinical research, which is the cornerstone of evidence-based medical practice. In China, tertiary public hospitals link promotions and bonuses with publications. However, the weight placed on research in the clinician’s evaluation process and its potential impact on clinical practice have come under controversy. Despite the heated debate about physicians’ role in research, there is little empirical evidence about the relationship between physicians’ publications and their clinical outcomes. Method: This paper examines the association of the quantity and quality of tertiary hospitals’ attending physicians’ publications and inpatient readmission rates in China. We analyzed a 20% random sample of inpatient data from the Urban Employee Basic Medical Health Insurance scheme in one of the largest cities in China from January 2018 through October 2019. We assessed the relationship between the quantity and impact factor of physicians’ publications and 30-day inpatient readmission rates using logistic regression. There were 111,965 hospitalizations treated by 5794 physicians in our sample. Results: Having any first-author publications was not associated with the rate of readmission. Among internists, having clinical studies published in journals with an average impact factor of 3 or above was associated with lower readmission rates (OR = 0.849; 95% CI (0.740, 0.975)), but having basic science studies published in journals with an average impact factor of 3 or above was not associated with the rate of readmission. Among surgeons, having clinical studies published in journals with an average impact factor of 3 or above was likewise associated with lower readmission rates (OR = 0.708 (0.531, 0.946)), but having basic science studies published in journals with an average impact factor of 3 or above was associated with higher readmission rates (OR = 1.230 (1.051, 1.439)).