Blockage of CacyBP inhibits macrophage recruitment and improves anti-PD-1 therapy in hepatocellular carcinoma.

BACKGROUND: Despite remarkable advancements in cancer immunotherapy, the overall response rate to anti-programmed cell death-1 (anti-PD-1) therapy in hepatocellular carcinoma (HCC) patients remains low. Our previous study has demonstrated the critical role of CacyBP/SIP (Calcyclin-Binding Protein and Siah-1 Interacting Protein) as a regulator of HCC development and progression. However, the possible impact of CacyBP on the tumor immune microenvironment has not yet been clarified. METHODS: The expressions of CacyBP and Myd88 in HCC cell lines and tissues was detected by bioinformatics analysis, real-time quantitative PCR, western blotting and immunohistochemistry. The interaction between CacyBP and Myd88 was measured using co-immunoprecipitation and immunofluorescence. In vitro and in vivo assays were used to investigate the regulation of CacyBP on tumor-associated macrophages (TAMs). RESULTS: We identified that CacyBP was positively correlated with Myd88, a master regulator of innate immunity, and Myd88 was a novel binding substrate downstream of CacyBP in HCC. Additionally, CacyBP protected Myd88 from Siah-1-mediated proteasome-dependent degradation by competitively binding to its Toll/interleukin-1 receptor (TIR) domain. Inhibition of CacyBP-Myd88 signaling subsequently diminished HDAC1-mediated H3K9ac and H3K27ac modifications on the CX3CL1 promoter and reduced its transcription and secretion in HCC cells. Moreover, by using in vitro and in vivo strategies, we demonstrated that depletion of CacyBP impaired the infiltration of TAMs and the immunosuppressive state of the tumor microenvironment, further sensitizing HCC-bearing anti-PD-1 therapy. CONCLUSIONS: Our findings suggest that targeting CacyBP may be a novel treatment strategy for improving the efficacy of anti-PD-1 immunotherapy in HCC.

Characterization of a human-mouse chimeric monoclonal antibody targeting rabies virus glycoprotein.

At present, the horse or human rabies immunoglobulin (RIG) used for postexposure prevention of human rabies (PEP) has high cost and limited availability. It is strongly encouraged to replace RIG with equivalent or more effective and safer products. Mouse and human monoclonal antibodies have been shown to protect rodents from lethal rabies virus (RABV) attacks. In this study, we reported a human-mouse chimeric monoclonal antibody, 12-2A12, which showed a strong neutralization potency and a wide breadth against multiple street viruses of RABV in vitro. The antibody binded the viral glycoprotein (G) with nanomolar affinity. The complex structure of 12-2A12 bound to RABV G revealed that the antibody recognizes an epitope that partially overlaps with the recognition region for the nicotinic acetylcholine receptor (nAChR). The antibody therefore would interfere with the nAChR/G interaction to block the viral receptor binding. In addition, comparison of our complex structure with the G structure in the acidic state reveals a clear steric clash, highlighting that the antibody would further prevent the conformational changes of the viral glycoprotein that are essential for membrane fusion. In light of these functional and structural data, we believe that 12-2A12 might be developed to be included in an antibody cocktail for potential use in human rabies PEP.

COLEC10 Induces Endoplasmic Reticulum Stress by Occupying GRP78 and Inhibits Hepatocellular Carcinoma.

Collectin subfamily member 10 (COLEC10), a C-type lectin mainly expressed in the liver, is involved in the development of hepatocellular carcinoma (HCC). However, its underlying molecular mechanism in HCC progression remains unknown. In this study, reduced COLEC10 expression in tumor tissues was validated using various HCC cohorts and was associated with poor patient prognosis. COLEC10 overexpression attenuated HCC cell growth and migration abilities in vitro and in vivo. We identified that COLEC10 was a novel interactor of 78-kDa glucose-regulated protein (GRP78), a master modulator of the unfolded protein response in the endoplasmic reticulum (ER). COLEC10 overexpression potentiated ER stress in HCC cells, as demonstrated by elevated expression levels of phosphorylated protein kinase RNA-like ER kinase, phosphorylated inositol-requiring protein 1α, activating transcription factor 4, DNA damage-inducible transcript 3, and X-box-binding protein 1s. The ER in COLEC10-overexpressing cells also showed a dilated and fragmented pattern. Mechanistically, COLEC10 overexpression increases GRP78 occupancy through direct binding by the C-terminal carbohydrate recognition domain in the ER, which released and activated the ER stress transducers protein kinase RNA-like ER kinase and phosphorylated inositol-requiring protein 1α, triggering the unfolded protein response activity. COLEC10-overexpressing HCC cells generated a relatively high reactive oxygen species level and switched to apoptotic cell death under sorafenib-treated conditions. Our study provides the first novel view that COLEC10 inhibits HCC progression by regulating GRP78-mediated ER stress signaling and may serve as a promising therapeutic and prognostic biomarker.

Pseudotyped Viruses.

Pseudotyped viruses have been constructed for many viruses. They can mimic the authentic virus and have many advantages compared to authentic viruses. Thus, they have been widely used as a surrogate of authentic virus for viral function analysis, detection of neutralizing antibodies, screening viral entry inhibitors, and others. This chapter reviewed the progress in the field of pseudotyped viruses in general, including the definition and the advantages of pseudotyped viruses, their potential usage, different strategies or vectors used for the construction of pseudotyped viruses, and factors that affect the construction of pseudotyped viruses.

Retrospective immunogenicity analysis of seasonal flu H3N2 vaccines recommended in the past ten years using immunized animal sera.

BACKGROUND: Influenza A (H3N2) virus (A/H3N2) has complex antigenic evolution, resulting in frequent vaccine strain updates. We aimed to evaluate the protective effect of the vaccine strains on the circulating strains from past ten years and provide a basis for finding a broader and more efficient A/H3N2 vaccine strain. METHODS: Eighty-four representative circulating A/H3N2 strains were selected from 65,791 deposited sequences in 2011-2020 and pseudotyped viruses were constructed with the VSV vector. We immunized guinea pigs with DNA vaccine containing the A/H3N2 components of the vaccine strains from 2011 to 2021 and tested neutralizing antibody against the pseudotyped viruses. We used a hierarchical clustering method to classify the eighty-four representative strains into different antigenic clusters. We also immunized animals with monovalent vaccine stock of the vaccine strains for the 2020-2021 and 2021-2022 seasons and tested neutralizing antibody against the pseudotyped viruses. FINDINGS: The vaccine strains PE/09, VI/11 and TE/12 induced higher levels of neutralizing antibody against representative strains circulating in recommended year and the year immediately prior whereas vaccine strains HK/14, HK/19 and CA/20 induced poor neutralization against all representative strains. The representative strains were divided into five antigenic clusters (AgV), which were not identical to gene clades. The AgV5 strains were most difficult to be protected among the five clusters. Compared with single-dose immunization, three doses of monovalent vaccine stock (HK/19 or CA/20) could induce stronger and broader neutralizing antibodies against strains in each of the antigenic clusters. INTERPRETATION: The protective effect of vaccine strains indicated that the accurate selection of A/H3N2 vaccine strains must remain a top priority. By increasing the frequency of immunization, stronger and broader neutralizing antibodies against strains in all antigenic clusters were induced, which provides direction for a new immunization strategy. FUNDING: This work was supported by a grant from National Key R&D Program of China (No. 2021YFC2301700).

Analysis of the evolution, infectivity and antigenicity of circulating rabies virus strains.

Rabies virus has existed for thousands of years and is circulating in many species. In the present study, a total of 2896 rabies viruses isolated worldwide were phylogenetically classified into ten clusters based on the G gene sequence, and these clusters showed a close relationship with the hosts and regions that they were isolated from. Eighty-three representative G sequences were selected from ten clusters and were used to construct pseudoviruses using the VSV vector. The phylogenetic relationships, infectivity and antigenicity of the representative 83 pseudotyped rabies viruses were comprehensively analyzed. Eighty three pseudoviruses were divided into four antigentic clusters (GAgV), of which GAgV4 showed poor neutralization to all immunized sera. Further analysis showed that almost all strains in the GAgV4 were isolated from wild animals in the America, especially bats and skunks. No significant relationship in terms of phylogeny, infectivity and antigenicity was proved. Amino acid mutations at residues 231and 436 can affect the infectivity, while mutations at residues 113, 164 and 254 may affect the sensitivity to immunized animal sera, especially residue 254. We recommend close monitoring of infectivity and antigenicity, which should be more precise than simple genetic analysis.

Patience and climate change mitigation: Global evidence.

Complex policy problems such as climate mitigation have an economic, political, and social dimension. We focus on one of the social dimensions of climate change mitigation: the link between society-wide patience (future orientation) and adoption of public policies to combat global greenhouse gas emissions. Theoretically, future-oriented societies are more likely to accept current costs in exchange for long-run benefits posed by climate change mitigation than impatient (present-oriented) ones, cooperate in efforts to combat climate change, and support future-oriented governments. We evaluate this claim using evidence from a cross-section of countries. Controlling for other theoretically relevant factors, we find that patient societies are more likely to adopt public policies to mitigate climate change.