Combination therapy with oncolytic virus and T cells or mRNA vaccine amplifies antitumor effects.

Antitumor therapies based on adoptively transferred T cells or oncolytic viruses have made significant progress in recent years, but the limited efficiency of their infiltration into solid tumors makes it difficult to achieve desired antitumor effects when used alone. In this study, an oncolytic virus (rVSV-LCMVG) that is not prone to induce virus-neutralizing antibodies was designed and combined with adoptively transferred T cells. By transforming the immunosuppressive tumor microenvironment into an immunosensitive one, in B16 tumor-bearing mice, combination therapy showed superior antitumor effects than monotherapy. This occurred whether the OV was administered intratumorally or intravenously. Combination therapy significantly increased cytokine and chemokine levels within tumors and recruited CD8+ T cells to the TME to trigger antitumor immune responses. Pretreatment with adoptively transferred T cells and subsequent oncolytic virotherapy sensitizes refractory tumors by boosting T-cell recruitment, down-regulating the expression of PD-1, and restoring effector T-cell function. To offer a combination therapy with greater translational value, mRNA vaccines were introduced to induce tumor-specific T cells instead of adoptively transferred T cells. The combination of OVs and mRNA vaccine also displays a significant reduction in tumor burden and prolonged survival. This study proposed a rational combination therapy of OVs with adoptive T-cell transfer or mRNA vaccines encoding tumor-associated antigens, in terms of synergistic efficacy and mechanism.

Orchestrated codelivery of peptide antigen and adjuvant to antigen-presenting cells by using an engineered chimeric peptide enhances antitumor T-cell immunity.

The intrinsic pharmacokinetic limitations of traditional peptide-based cancer vaccines hamper effective cross-presentation and codelivery of antigens and adjuvants, which are crucial for inducing robust antitumor CD8+ T-cell responses. Here, we report the development of a versatile strategy that simultaneously addresses the different pharmacokinetic challenges of soluble subunit vaccines composed of antigens and CpG to modulate vaccine efficacy via translating an engineered chimeric peptide, eTAT, as an intramolecular adjuvant. Linking antigens to eTAT enhanced cytosolic delivery of the antigens. This, in turn, led to improved activation and lymph node-trafficking of antigen-presenting cells and antigen cross-presentation, thus promoting antigen-specific T-cell immune responses. Simple mixing of eTAT-linked antigens and CpG significantly enhanced codelivery of antigens and CpG to the antigen-presenting cells, and this substantially augmented the adjuvant effect of CpG, maximized vaccine immunogenicity and elicited robust and durable CD8+ T-cell responses. Vaccination with this formulation altered the tumor microenvironment and exhibited potent antitumor effects, with generally further enhanced therapeutic efficacy when used in combination with anti-PD1. Altogether, the engineered chimeric peptide-based orchestrated codelivery of antigen and adjuvant may serve as a promising but simple strategy to improve the efficacy of peptide-based cancer vaccines.

Differential genetic mutations and immune cell infiltration in high- and low-risk STAD: Implications for prognosis and immunotherapy efficacy.

This study investigates genetic mutations and immune cell dynamics in stomach adenocarcinoma (STAD), focusing on identifying prognostic markers and therapeutic targets. Analysis of TCGA-STAD samples revealed C > A as the most common single nucleotide variant (SNV) in both high and low-risk groups. Key mutated driver genes included TTN, TP53 and MUC16, with frame-shift mutations more prevalent in the low-risk group and missense mutations in the high-risk group. Interaction analysis of hub genes such as C1QA and CD68 showed significant correlations, impacting immune cell infiltration patterns. Using ssGSEA, we found higher immune cell infiltration (B cells, CD4+ T cells, CD8+ T cells, DC cells, NK cells) in the high-risk group, correlated with increased risk scores. xCell algorithm results indicated distinct immune infiltration levels between the groups. The study's risk scoring model proved effective in prognosis prediction and immunotherapy efficacy assessment. Key molecules like CD28, CD27 and SLAMF7 correlated significantly with risk scores, suggesting potential targets for high-risk STAD patients. Drug sensitivity analysis showed a negative correlation between risk scores and sensitivity to certain treatments, indicating potential therapeutic options for high-risk STAD patients. We also validated the carcinogenic role of RPL14 in gastric cancer through phenotypic experiments, demonstrating its influence on cancer cell proliferation, invasion and migration. Overall, this research provides crucial insights into the genetic and immune aspects of STAD, highlighting the importance of a risk scoring model for personalized treatment strategies and clinical decision-making in gastric cancer management.

Swine pseudorabies virus attenuated vaccine reprograms the kidney cancer tumor microenvironment and synergizes with PD-1 blockade.

The global incidence rate of kidney cancer (KC) has been steadily increasing over the past 30 years. With the aging global population, kidney cancer has become an escalating concern that necessitates vigilant surveillance. Nowadays, surgical intervention remains the optimal therapeutic approach for kidney cancer, while the availability of efficacious treatments for advanced tumors remains limited. Oncolytic viruses, an emerging form of immunotherapy, have demonstrated encouraging anti-neoplastic properties and are progressively garnering public acceptance. However, research on oncolytic viruses in kidney cancer is relatively limited. Furthermore, given the high complexity and heterogeneity of kidney cancer, it is crucial to identify an optimal oncolytic virus agent that is better suited for its treatment. The present study investigates the oncolytic activity of the Pseudorabies virus live attenuated vaccine (PRV-LAV) against KC. The findings clearly demonstrate that PRV-LAV exhibits robust oncolytic activity targeting KC cell lines. Furthermore, the therapeutic efficacy of PRV-LAV was confirmed in both a subcutaneous tumor-bearing nude mouse model and a syngeneic mouse model of KC. Combined RNA-seq analysis and flow cytometry revealed that PRV-LAV treatment substantially enhances the infiltration of a diverse range of lymphocytes, including T cells, B cells, macrophages, and NK cells. Additionally, PRV-LAV treatment enhances T cell activation and exerts antitumor effects. Importantly, the combination of PRV-LAV with anti-PD-1 antibodies, an approved drug for KC treatment, synergistically enhances the efficacy against KC. Overall, the discovery of PRV-LAV as an effective oncolytic virus holds significant importance for improving the treatment efficacy and survival rates of KC patients.

MHC class II regulation of CD8+ T cell tolerance and implications in autoimmunity and cancer immunotherapy.

Major histocompatibility complex (MHC) class II-reactive CD8+ T cells are found in humans and animals, but little is known about their identity, development, and function. In this study, we discover a group of CD8+ T cells reactive to both MHC class I and II molecules in MHC class II-deficient mice. We clone their T cell receptors (TCRs) and analyze their development and function. In wild-type animals, thymocytes bearing those TCRs are purged by negative selection. In the absence of MHC class II, they develop into mature CD8+ T cells. When encountering MHC class II in the periphery, they undergo robust activation and proliferation, attack self-tissues, and cause lethal autoimmune diseases. In adoptive T cell therapy, those CD8+ T cells are able to efficiently control MHC class II-expressing tumors. This study opens the door to investigation of dual-reactive CD8+ T cells, their development and selection in the thymus, and the perils and promises when their normal development and selection are compromised.

The potential of swine pseudorabies virus attenuated vaccine for oncolytic therapy against malignant tumors.

BACKGROUND: Oncolytic viruses are now well recognized as potential immunotherapeutic agents against cancer. However, the first FDA-approved oncolytic herpes simplex virus 1 (HSV-1), T-VEC, showed limited benefits in some patients in clinical trials. Thus, the identification of novel oncolytic viruses that can strengthen oncolytic virus therapy is warranted. Here, we identified a live-attenuated swine pseudorabies virus (PRV-LAV) as a promising oncolytic agent with broad-spectrum antitumor activity in vitro and in vivo. METHODS: PRV cytotoxicity against tumor cells and normal cells was tested in vitro using a CCK8 cell viability assay. A cell kinase inhibitor library was used to screen for key targets that affect the proliferation of PRV-LAV. The potential therapeutic efficacy of PRV-LAV was tested against syngeneic tumors in immunocompetent mice, and against subcutaneous xenografts of human cancer cell lines in nude mice. Cytometry by time of flight (CyTOF) and flow cytometry were used to uncover the immunological mechanism of PRV-LAV treatment in regulating the tumor immune microenvironment. RESULTS: Through various tumor-specific analyses, we show that PRV-LAV infects cancer cells via the NRP1/EGFR signaling pathway, which is commonly overexpressed in cancer. Further, we show that PRV-LAV kills cancer cells by inducing endoplasmic reticulum (ER) stress. Moreover, PRV-LAV is responsible for reprogramming the tumor microenvironment from immunologically naïve ("cold") to inflamed ("hot"), thereby increasing immune cell infiltration and restoring CD8+ T cell function against cancer. When delivered in combination with immune checkpoint inhibitors (ICIs), the anti-tumor response is augmented, suggestive of synergistic activity. CONCLUSIONS: PRV-LAV can infect cancer cells via NRP1/EGFR signaling and induce cancer cells apoptosis via ER stress. PRV-LAV treatment also restores CD8+ T cell function against cancer. The combination of PRV-LAV and immune checkpoint inhibitors has a significant synergistic effect. Overall, these findings point to PRV-LAV as a serious potential candidate for the treatment of NRP1/EGFR pathway-associated tumors.

The impact of the Hedgehog signal pathway on the tumor immune microenvironment of gastric adenocarcinoma by integrated analysis of scRNA-seq and RNA-seq datasets.

The Hedgehog signaling is a highly conserved pathway to regulate cell growth and proliferation, and plays an essential role in stomach adenocarcinoma (STAD) and other cancer types. However, previous studies were primarily conducted in terms of mRNA or vitro cell culture. It would be more convincing to integrate single-cell RNA sequencing (scRNA-seq) data because it is a more precise approach for genomic research. The expression profile, genetic alteration, and activity of the Hedgehog signaling pathway were investigated in both scRNA-seq and RNA-seq datasets of STAD. Communications between cancer cells and fibroblasts were determined by the cell-chat algorithm, and the Hedgehog-related gene signature was constructed to predict the survival of STAD. Patients were categorized into high- and low-risk groups according to the median of the signature. Further analysis explored the difference in survival outcome, tumor immune microenvironment (TIME), and drug sensitivity between the two groups, aiming to guide the use of chemotherapy and immunotherapy in STAD patients. Hedgehog signal pathway was over-activated in STAD. GAS1, GLI1, and SCEBU2 were recognized as hub genes in the prognostic signature of STAD, and served as robust risk factors to induce a poor survival outcome. Patients in the high-risk group demonstrated an exhausted TIME pattern, with rather low sensitivity toward molecular-targeted drugs. This study depicted the influence of the Hedgehog pathway on the survival outcome, TIME, and drug sensitivity of STAD, and provides novel insights for the treatment of STAD.

Combination therapy of therapeutic antibody and vaccine or entecavir in HBV carrier mice.

Chronic infection with the hepatitis B virus (HBV) is a leading causes of liver cirrhosis and hepatocellular carcinoma. However, managing HBV treatments is challenging due to the lack of effective monotherapy. Here, we present two combination approaches, both of which aim to target and enhance the clearance of HBsAg and HBV-DNA. The first approach involves the use of antibodies to continuously suppress HBsAg, followed by the administration of a therapeutic vaccine in a sequential manner. This approach results in better therapeutic outcomes compared to the use of these treatments individually. The second approach involves combining antibodies with ETV, which effectively overcomes the limitations of ETV in suppressing HBsAg. Thus, the combination of therapeutic antibodies, therapeutic vaccines, and other existing drugs is a promising strategy for the development of novel strategies to treat hepatitis B.

Potential Regulators of the Senescence-Associated Secretory Phenotype During Senescence and Aging.

Senescent cells express and secrete a variety of extracellular modulators that include cytokines, chemokines, proteases, growth factors, and some enzymes associated with extracellular matrix remodeling, defined as the senescence-associated secretory phenotype (SASP). SASP reinforces senescent cell cycle arrest, stimulates and recruits immune cells for immune-mediated clearance of potentially tumorigenic cells, limits or induces fibrosis, and promotes wound healing and tissue regeneration. On the other hand, SASP mediates chronic inflammation leading to the destruction of tissue structure and function and stimulating the growth and survival of tumor cells. SASP is highly heterogeneous and the role of SASP depends on the context. The regulation of SASP occurs at multiple levels including chromatin remodeling, transcription, mRNA translation, intracellular trafficking, and secretion. Several SASP modulators have already been identified setting the stage for future research on their clinical applications. In this review, we summarize in detail the potential signaling pathways that trigger and regulate SASP production during aging and senescence.

Cross-species tropism and antigenic landscapes of circulating SARS-CoV-2 variants.

Mutations in the severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) spike receptor-binding domain (RBD) may alter viral host tropism and affect the activities of neutralizing antibodies. Here, we investigated 153 RBD mutants and 11 globally circulating variants of concern (VOCs) and variants of interest (VOIs) (including Omicron) for their antigenic changes and cross-species tropism in cells expressing 18 ACE2 orthologs. Several RBD mutations strengthened viral infectivity in cells expressing ACE2 orthologs of non-human animals, particularly those less susceptible to the ancestral strain. The mutations surrounding amino acids (aas) 439-448 and aa 484 are more likely to cause neutralization resistance. Strikingly, enhanced cross-species infection potential in the mouse and ferret, instead of the neutralization-escape scores of the mutations, account for the positive correlation with the cumulative prevalence of mutations in humans. These findings present insights for potential drivers of circulating SARS-CoV-2 variants and provide informative parameters for tracking and forecasting spreading mutations.

Efficient intracellular delivery of proteins by a multifunctional chimaeric peptide in vitro and in vivo.

Protein delivery with cell-penetrating peptide is opening up the possibility of using targets inside cells for therapeutic or biological applications; however, cell-penetrating peptide-mediated protein delivery commonly suffers from ineffective endosomal escape and low tolerance in serum, thereby limiting in vivo efficacy. Here, we present an intracellular protein delivery system consisting of four modules in series: cell-penetrating peptide, pH-dependent membrane active peptide, endosome-specific protease sites and a leucine zipper. This system exhibits enhanced delivery efficiency and serum tolerance, depending on proteolytic cleavage-facilitated endosomal escape and leucine zipper-based dimerisation. Intravenous injection of protein phosphatase 1B fused with this system successfully suppresses the tumour necrosis factor-α-induced systemic inflammatory response and acetaminophen-induced acute liver failure in a mouse model. We believe that the strategy of using multifunctional chimaeric peptides is valuable for the development of cell-penetrating peptide-based protein delivery systems, and facilitate the development of biological macromolecular drugs for use against intracellular targets.

CDK-associated Cullin 1 Promotes Cell Proliferation and Inhibits Cell Apoptosis in Human Glioblastoma.

BACKGROUND: Glioma is the most common intracranial primary tumour of adult humans, and its pathological mechanism and molecular characteristics are still under investigation. CDK-associated cullin 1 (CACUL1) has been shown to regulate colorectal carcinoma, lung cancer, and gastric cancer development. OBJECTIVE: This study aims to explore the role of CACUL1 in the pathogenesis of human glioma. METHODS: CACUL1 levels in human glioma tissue microarrays were detected by immunohistochemistry analysis. Two glioblastoma cell lines, namely, U87 and U251, were transfected with CACUL1 siRNA, and cell proliferation, cell cycle, cell apoptosis, and regulating molecules, including cyclinE1, cyclinA2, CDK2, p21, Bcl2, and Bax were assessed by CCK8, flow cytometry, and Western blot. RESULTS: CACUL1 expression in glioma tissue was significantly higher than that in normal brain tissue. CACUL1 knockdown impeded cell proliferation, induced cell apoptosis, and caused G1/S transition arrest in glioblastoma cells. The cell cycle-related proteins CDK2, cyclinE1, and cyclinA2 were dramatically decreased in the CACUL1 siRNA group compared to the non-targeting siRNA group in both U87 and U251 cells, while the CDK inhibitory protein p21 was increased in U87 cells. Additionally, the Bcl-2/Bax ratio was significantly decreased. CONCLUSION: CACUL1 can promote cell proliferation and suppress apoptosis of glioma cells and might serve as a potential oncogene for gliomas.

Inflammation-related adverse reactions following vaccination potentially indicate a stronger immune response.

Concerns about vaccine safety are an important reason for vaccine hesitancy, however, limited information is available on whether common adverse reactions following vaccination affect the immune response. Data from three clinical trials of recombinant vaccines were used in this post hoc analysis to assess the correlation between inflammation-related solicited adverse reactions (ISARs, including local pain, redness, swelling or induration and systematic fever) and immune responses after vaccination. In the phase III trial of the bivalent HPV-16/18 vaccine (Cecolin®), the geometric mean concentrations (GMCs) for IgG anti-HPV-16 and -18 (P<0.001) were significantly higher in participants with any ISAR following vaccination than in those without an ISAR. Local pain, induration, swelling and systemic fever were significantly correlated with higher GMCs for IgG anti-HPV-16 and/or anti-HPV-18, respectively. Furthermore, the analyses of the immunogenicity bridging study of Cecolin® and the phase III trial of a hepatitis E vaccine yielded similar results. Based on these results, we built a scoring model to quantify the inflammation reactions and found that the high score of ISAR indicates the strong vaccine-induced antibody level. In conclusion, this study suggests inflammation-related adverse reactions following vaccination potentially indicate a stronger immune response.

Preparation and functional evaluation of monoclonal antibodies targeting Hepatitis B Virus Polymerase.

HBV pol plays a critical role in the replication of hepatitis B virus (HBV). Previous studies conducted on HBV pol have produced limited evidence on HBV pol expression due to the lack of effective detection methods. The present study used the HBV pol (159-406 aa) protein as a target to screen for specific monoclonal antibodies that recognize HBV pol and subsequently evaluate their diagnostic and therapeutic value. Four antibodies (P3, P5, P12, P20) against HBV pol were obtained. Among them, the P20 antibody indicated optimal binding with HBV pol as demonstrated by Western blotting (WB) in a cell model transfected with the HBV genome. We also expressed P5 and P12 antibodies in mouse liver cells by transfection and the results indicated significant antiviral effects caused by these two antibodies especially P12. In summary, the present study established an antibody which was denoted P20. This antibody can be used to detect HBV pol expression by four HBV genomes via WB analysis. In addition, the antibody denoted P12 could exert antiviral effects via intracellular expression, which may provide a promising approach for the treatment of chronic hepatitis B.

Specific determination of hepatitis B e antigen by antibodies targeting precore unique epitope facilitates clinical diagnosis and drug evaluation against hepatitis B virus infection.

Hepatitis B e antigen (HBeAg) is a widely used marker both for chronic hepatitis B (CHB) clinical management and HBV-related basic research. However, due to its high amino acid sequence homology to hepatitis B core antigen (HBcAg), most of available anti-HBe antibodies are cross-reactive with HBcAg resulting in high interference against accurate measurement of the status and level of HBeAg. In the study, we generated several monoclonal antibodies (mAbs) targeting various epitopes on HBeAg and HBcAg. Among these mAbs, a novel mAb 16D9, which recognizes the SKLCLG (aa -10 to -5) motif on the N-terminal residues of HBeAg that is absent on HBcAg, exhibited excellent detection sensitivity and specificity in pairing with another 14A7 mAb targeting the HBeAg C-terminus (STLPETTVVRRRGR, aa141 to 154). Based on these two mAbs, we developed a novel chemiluminescent HBeAg immunoassay (NTR-HBeAg) which could detect HBeAg derived from various HBV genotypes. In contrast to widely used commercial assays, the NTR-HBeAg completely eliminated the cross-reactivity with secreted HBcAg from precore mutant (G1896A) virus in either cell culture or patient sera. The improved specificity of the NTR-HBeAg assay enables its applicability in cccDNA-targeting drug screening in cell culture systems and also provides an accurate tool for clinical HBeAg detection.

SARS-CoV-2 spike produced in insect cells elicits high neutralization titres in non-human primates.

The current coronavirus disease 2019 (COVID-19) pandemic was the result of the rapid transmission of a highly pathogenic coronavirus, severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2), for which there is no efficacious vaccine or therapeutic. Toward the development of a vaccine, here we expressed and evaluated as potential candidates four versions of the spike (S) protein using an insect cell expression system: receptor binding domain (RBD), S1 subunit, the wild-type S ectodomain (S-WT), and the prefusion trimer-stabilized form (S-2P). We showed that RBD appears as a monomer in solution, whereas S1, S-WT, and S-2P associate as homotrimers with substantial glycosylation. Cryo-electron microscopy analyses suggested that S-2P assumes an identical trimer conformation as the similarly engineered S protein expressed in 293 mammalian cells but with reduced glycosylation. Overall, the four proteins confer excellent antigenicity with convalescent COVID-19 patient sera in enzyme-linked immunosorbent assay (ELISA), yet show distinct reactivities in immunoblotting. RBD, S-WT and S-2P, but not S1, induce high neutralization titres (>3-log) in mice after a three-round immunization regimen. The high immunogenicity of S-2P could be maintained at the lowest dose (1 µg) with the inclusion of an aluminium adjuvant. Higher doses (20 µg) of S-2P can elicit high neutralization titres in non-human primates that exceed 40-times the mean titres measured in convalescent COVID-19 subjects. Our results suggest that the prefusion trimer-stabilized SARS-CoV-2 S-protein from insect cells may offer a potential candidate strategy for the development of a recombinant COVID-19 vaccine.

The Effect of Vascular Endothelial Growth Factor on Bone Marrow Mesenchymal Stem Cell Engraftment in Rat Fibrotic Liver upon Transplantation.

BACKGROUND: According to existing related experiments and research reports, stem cell transplantation therapy has been shown to have a positive effect on the recovery of liver fibrosis/cirrhosis, but for some reason, this therapy still cannot be widely used in clinical work. One of the reasons that cannot be ignored is the low quantity of exogenous stem cells transplanted into the liver in vivo. Thus, we investigated whether the use of the vascular endothelial growth factor (VEGF) can increase the number of stem cell transplants and improve the efficacy of stem cell transplantation therapy. METHODS: Using a Sprague-Dawley rat liver fibrosis model, we transplanted into fibrosis liver allograft bone marrow mesenchymal stem cells (BMSCs) which were labelled with chlormethylbenzamido-1,1-dioctadecyl-3,3,3'3'-tetramethylin-docarbocyamine (CM-DiI) or injected VEGF adenovirus solution through the tail vein or conducted the above two operations simultaneously. The cell surface receptor profile of BMSC was examined by flow cytometry and immunofluorescence staining. Hepatic sinusoidal vascular leakage was measured with Evan's blue dye assay. Paraffin section staining, immunofluorescent staining, RT-qPCR (quantitative reverse transcription polymerase chain reaction), and Western blot were used to evaluate hepatic pathological changes and physiology function. RESULT: The in vivo study indicated that, comparing with other groups of rats, the rats with combined treatment of BMSC transplantation and VEGF injection exhibited obvious reduction in liver fibrosis. Evan's blue dye assay suggests that after injecting with VEGF adenovirus solution, the rat's hepatic sinusoidal permeability would be increased. We confirmed the expression of very late antigen-4 (VLA4, integrin α 4 ß 1) on rat BMSCs and the elevated expression of vascular adhesion molecule-1 (VCAM-1) in the hepatic sinusoidal endothelial cells. In addition, the analysis of CM-DiI-labeled BMSCs showed that the BMSC+VEGF group exhibited better cell engraftment and that the engrafted cells were mainly distributed in the hepatic parenchyma. Furthermore, compared with the other situation, it is best to reconstitute the liver secretion and regeneration function of rats after combined application of VEGF and BMSC. CONCLUSION: We showed that VEGF promotes the engraftment of BMSCs in liver fibrosis, enhances liver regeneration, and improves liver function. These outcomes may be related to the increasing hepatic sinusoidal endothelium permeability and VCAM-1-increased expression.