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Lnc-H19-derived protein shapes the immunosuppressive microenvironment of glioblastoma. Cell reports. Medicine The immunosuppressive tumor microenvironment (TME) is a prominent feature of glioblastoma (GBM), the most lethal primary brain cancer resistant to current immunotherapies. The mechanisms underlying GBM-TME remain to be explored. We report that long non-coding RNA (LncRNA) H19 encodes an immune-related protein called H19-IRP. Functionally separated from H19 RNA, H19-IRP promotes GBM immunosuppression by binding to the CCL2 and Galectin-9 promoters and activating their transcription, thereby recruiting myeloid-derived suppressor cells (MDSCs) and tumor-associated macrophages (TAMs), leading to T cell exhaustion and an immunosuppressive GBM-TME. H19-IRP, overexpressed in clinical GBM samples, acts as a tumor-associated antigen (TAA) presented by major histocompatibility complex class I (MHC-I). A circular RNA vaccine targeting H19-IRP (circH19-vac) triggers a potent cytotoxic T cell response against GBM and inhibits GBM growth. Our results highlight the unrevealed function of H19-IRP in creating immunosuppressive GBM-TME by recruiting MDSCs and TAMs, supporting the idea of targeting H19-IRP with cancer vaccine for GBM treatment. 10.1016/j.xcrm.2024.101806
Organ- and Cell-Selective Delivery of mRNA In Vivo Using Guanidinylated Serinol Charge-Altering Releasable Transporters. Journal of the American Chemical Society Selective RNA delivery is required for the broad implementation of RNA clinical applications, including prophylactic and therapeutic vaccinations, immunotherapies for cancer, and genome editing. Current polyanion delivery relies heavily on cationic amines, while cationic guanidinium systems have received limited attention due in part to their strong polyanion association, which impedes intracellular polyanion release. Here, we disclose a general solution to this problem in which cationic guanidinium groups are used to form stable RNA complexes upon formulation but at physiological pH undergo a novel charge-neutralization process, resulting in RNA release. This new delivery system consists of guanidinylated serinol moieties incorporated into a charge-altering releasable transporter (GSer-CARTs). Significantly, systematic variations in structure and formulation resulted in GSer-CARTs that exhibit highly selective mRNA delivery to the lung (∼97%) and spleen (∼98%) without targeting ligands. Illustrative of their breadth and translational potential, GSer-CARTs deliver circRNA, providing the basis for a cancer vaccination strategy, which in a murine model resulted in antigen-specific immune responses and effective suppression of established tumors. 10.1021/jacs.4c02704
A novel nanoplatform-based circCSNK1G3 affects CBX7 protein and promotes glioma cell growth. International journal of biological macromolecules Bioenvironmental and biological factors have the potential to contribute to the development of glioma, a type of brain tumor. Recent studies have suggested that a unique circular RNA called circCSNK1G3 could play a role in promoting the growth of glioma cells. It does this by stabilizing a specific microRNA called miR-181 and reducing the expression of a tumor-suppressor gene known as chromobox protein homolog 7 (CBX7). To further investigate circCSNK1G3 and its effects on glioma, we utilized a nanoplatform called adeno-associated virus (AAV)-RNAi.To explore the functional implications of circCSNK1G3, we employed siRNA to silence its expression. Along with these effects, the silencing of circCSNK1G3 led to a depletion of miR-181d and an upregulation of CBX7. When we introduced miR-181d mimics, which artificially increase the levels of miR-181d, the anti-glioma cell activity induced by circCSNK1G3 siRNA was almost completely reversed. Conversely, inhibiting miR-181d mimicked the effects of circCSNK1G3 silencing. Moreover, when we overexpressed circCSNK1G3 in glioma cells, we observed an elevation of miR-181d and a depletion of CBX7. We found that the growth of A172 xenografts (tumors) carrying circCSNK1G3 shRNA was significantly inhibited. In these xenograft tissues, we detected a depletion of circCSNK1G3 and miR-181d, as well as an upregulation of CBX7. 10.1016/j.ijbiomac.2024.134025
Circular RNA-based neoantigen vaccine for hepatocellular carcinoma immunotherapy. MedComm mRNA vaccines are regarded as a highly promising avenue for next-generation cancer therapy. Nevertheless, the intricacy of production, inherent instability, and low expression persistence of linear mRNA significantly restrict their extensive utilization. Circular RNAs (circRNAs) offer a novel solution to these limitations due to their efficient protein expression ability, which can be rapidly generated in vitro without the need for extra modifications. Here, we present a novel neoantigen vaccine based on circRNA that induces a potent anti-tumor immune response by expressing hepatocellular carcinoma-specific tumor neoantigens. By cyclizing linearRNA molecules, we were able to enhance the stability of RNA vaccines and form highly stable circRNA molecules with the capacity for sustained protein expression. We confirmed that neoantigen-encoded circRNA can promote dendritic cell (DC) activation and enhance DC-induced T-cell activation in vitro, thereby enhancing T-cell killing of tumor cells. Encapsulating neoantigen-encoded circRNA within lipid nanoparticles for in vivo expression has enabled the creation of a novel circRNA vaccine platform. This platform demonstrates superior tumor treatment and prevention in various murine tumor models, eliciting a robust T-cell immune response. Our circRNA neoantigen vaccine offers new options and application prospects for neoantigen immunotherapy in solid tumors. 10.1002/mco2.667
Restoring expression of tumour suppressor PTEN by engineered circular RNA-enhanced Osimertinib sensitivity in non-small cell lung cancer. Clinical and translational medicine 10.1002/ctm2.1792
CircRNA based multivalent neuraminidase vaccine induces broad protection against influenza viruses in mice. NPJ vaccines Developing broad-spectrum influenza vaccines is crucial for influenza control and potential pandemic preparedness. Here, we reported a novel vaccine design utilizing circular RNA (circRNA) as a delivery platform for multi-subtype neuraminidases (NA) (influenza A N1, N2, and influenza B Victoria lineage NA) immunogens. Individual NA circRNA lipid nanoparticles (LNP) elicited robust NA-specific antibody responses with neuraminidase inhibition activity (NAI), preventing the virus from egressing and infecting neighboring cells. Additionally, the administration of circRNA LNP induced cellular immunity in mice. To achieve a universal influenza vaccine, we combined all three subtypes of NA circRNA-LNPs to generate a trivalent circRNA vaccine. The trivalent vaccine elicited a balanced antibody response against all three NA subtypes and a Th1-biased immune response in mice. Moreover, it protected mice against the lethal challenge of matched and mismatched H1N1, H3N2, and influenza B viruses, encompassing circulating and ancestral influenza virus strains. This study highlights the potential of delivering multiple NA antigens through circRNA-LNPs as a promising strategy for effectively developing a universal influenza vaccine against diverse influenza viruses. 10.1038/s41541-024-00963-4
Chemical and topological design of multicapped mRNA and capped circular RNA to augment translation. Nature biotechnology Protein and vaccine therapies based on mRNA would benefit from an increase in translation capacity. Here, we report a method to augment translation named ligation-enabled mRNA-oligonucleotide assembly (LEGO). We systematically screen different chemotopological motifs and find that a branched mRNA cap effectively initiates translation on linear or circular mRNAs without internal ribosome entry sites. Two types of chemical modification, locked nucleic acid (LNA) N-methylguanosine modifications on the cap and LNA + 5 × 2' O-methyl on the 5' untranslated region, enhance RNA-eukaryotic translation initiation factor (eIF4E-eIF4G) binding and RNA stability against decapping in vitro. Through multidimensional chemotopological engineering of dual-capped mRNA and capped circular RNA, we enhanced mRNA protein production by up to tenfold in vivo, resulting in 17-fold and 3.7-fold higher antibody production after prime and boost doses in a severe acute respiratory syndrome coronavirus 2 vaccine setting, respectively. The LEGO platform opens possibilities to design unnatural RNA structures and topologies beyond canonical linear and circular RNAs for both basic research and therapeutic applications. 10.1038/s41587-024-02393-y
A single-dose circular RNA vaccine prevents Zika virus infection without enhancing dengue severity in mice. Nature communications Antibody-dependent enhancement (ADE) is a potential concern for the development of Zika virus (ZIKV) vaccines. Cross-reactive but poorly neutralizing antibodies, usually targeting viral pre-membrane or envelope (E) proteins, can potentially enhance dengue virus (DENV) infection. Although E domain III (EDIII) contains ZIKV-specific epitopes, its immunogenicity is poor. Here, we show that dimeric EDIII, fused to human IgG1 Fc fragment (EDIII-Fc) and encoded by circular RNA (circRNA), induces better germinal center reactions and higher neutralizing antibodies compared to circRNAs encoding monomeric or trimeric EDIII. Two doses of circRNAs encoding EDIII-Fc and ZIKV nonstructural protein NS1, another protective antigen, prevent lethal ZIKV infection in neonates born to immunized C57BL/6 mice and in interferon-α/β receptor knockout adult C57BL/6 mice. Importantly, a single-dose optimized circRNA vaccine with improved antigen expression confers potent and durable protection without inducing obvious DENV ADE in mice, laying the groundwork for developing flavivirus vaccines based on circRNAs encoding EDIII-Fc and NS1. 10.1038/s41467-024-53242-0
Hypoxia-driven M2-polarized macrophages facilitate the epithelial-mesenchymal transition of glioblastoma via extracellular vesicles. Theranostics M2-like tumor-associated macrophages (TAMs) promote the malignant progression of glioblastomas. However, the mechanisms responsible for this phenomenon remain unclear. RT-PCR, Western blot and flow cytometry were used to evaluate the polarization status of macrophages. RT-PCR, western blot or/and immunohistochemistry was used to determine the expression of circ_0003137, PTBP1, PLOD3 and epithelial-mesenchymal transition (EMT) markers. Transwell assay was used to assess migration and invasion ability of tumor cells. RNA sequencing, bioinformatic analysis and Pearson correlation coefficient was performed to explore the relation between PTBP1 and circ_003137/PLOD3. experiment was used to determine the role of sh-circ_0003137-loaded nanoplatform. Hypoxia promoted the polarization of macrophages towards M2-like TAMs in an HIF1α dependent manner. Then, M2-like TAMs could transport circ_0003137 enriched extracellular vesicles (EVs) to glioblastoma cells, upregulating circ_0003137 in glioblastoma cells. The circ_0003137 overexpression promoted the EMT of glioblastoma cells and . Mechanistically, circ_0003137 physically binds to polypyrimidine tract binding protein 1 (PTBP1), enhancing the stability of procollagen-lysine, 2-oxoglutarate 5-dioxygenase 3 (PLOD3) and promoting the EMT of glioblastoma cells. Moreover, a liposome-based nanoplatform that delivers shRNAs was established and used to encapsulate sh-circ_0003137. The fluorescence microscope tracer and cell co-culture assays demonstrated that the nanoplatform encapsulated with sh-circ_0003137 was stable and could penetrate the blood-brain barrier (BBB), finally reaching the central nervous system (CNS). The intracranial tumor model showed that injecting the sh-circ_0003137-loaded nanoplatform via the tail vein significantly inhibited glioblastoma progression and improved the nude mice's survival. Hypoxia can drive macrophage polarization towards M2-like TAMs. Polarized M2-like TAMs can transport circ_0003137 to glioblastoma cells through EVs. Then, circ_0003137 promotes the EMT of glioblastomas by targeting the PTBP1/PLOD3 axis. Hence, targeting circ_0003137 might be a novel therapeutic strategy against glioblastoma. 10.7150/thno.95766
CXCL13 promotes broad immune responses induced by circular RNA vaccines. Proceedings of the National Academy of Sciences of the United States of America Antibody responses induced by current vaccines for influenza and SARS-CoV-2 often lack robust cross-reactivity. As hubs where diverse immune cells converge and interact, the alterations in the immune microenvironment within lymph nodes (LNs) are intricately linked to immune responses. Herein, we designed a lipid nanoparticle (LNP) loaded with circular RNA (circRNA) and targeted to LNs, in which CXCL13 was directly integrated into antigen-encoding circRNA strands. We demonstrated that CXCL13 alters the transcriptomic profiles of LNs, especially the upregulation of IL-21 and IL-4. Meanwhile, CXCL13 promotes the formation of germinal center and elicits robust antigen-specific T cell responses. With the codelivery of CXCL13 and the antigen, CXCL13 enhances cross-reactive antibodies against influenza virus and SARS-CoV-2, achieving protection against both homologous and heterologous influenza virus challenges in a mouse model. Notably, the targeted modification of LNP surfaces with antibodies helps address some of the challenges associated with lyophilized LNP vaccines, which is crucial for the long-term storage of LNP-circRNA vaccines. Overall, the circRNA-based antigen-CXCL13 coexpression system developed herein provides a simple and robust platform that enhances the magnitude and breadth of antibody responses against multiple viral glycoproteins, highlighting the potential utility of CXCL13 in inducing broad immune responses. 10.1073/pnas.2406434121
Nanocarriers Targeting Circular RNA ADARB1 Boost Radiosensitivity of Nasopharyngeal Carcinoma through Synergically Promoting Ferroptosis. ACS nano Nasopharyngeal carcinoma (NPC) is a common malignant tumor of the head and neck, prevalent in regions such as Southern China and Southeast Asia. Radiotherapy serves as the primary clinical treatment for this carcinoma. However, resistance to radiotherapy is a fundamental cause of treatment failure and patient mortality, with the underlying mechanisms yet to be fully elucidated. We identified a recently characterized circular RNA, circADARB1, which is markedly upregulated in NPC tissues and closely associated with poor prognosis and radiotherapy resistance. Both in vitro and in vivo experiments demonstrated that circADARB1 inhibited ferroptosis, thereby inducing radiotherapy resistance in NPC cells. Building on these findings, we synthesized a biomimetic nanomaterial consisting of semiconducting polymer nanoparticles wrapped in cell membranes, designed to deliver both siRNA targeting circADARB1 and iron ions. The application of this nanomaterial not only efficiently suppressed the expression of circADARB1 and boosted intracellular iron concentrations, but also enhanced ferroptosis induced by radiotherapy, improving the radiosensitivity of NPC cells. Furthermore, our study revealed that circADARB1 upregulated the expression of heat shock protein HSP90B1, which repaired misfolded SLC7A11 and GPX4 proteins triggered by radiotherapy, thereby preserving their stability and biological functions. Mechanistically, SLC7A11 facilitated cysteine transportation into cells and glutathione synthesis, while GPX4 employed glutathione to mitigate intracellular lipid peroxidation induced by radiotherapy, shielding cells from oxidative damage and inhibiting ferroptosis, and ultimately leading to radiotherapy resistance in NPC cells. Our investigation elucidates molecular mechanisms with substantial clinical relevance, highlights the promising application prospects of nanotechnology in precision cancer therapy. 10.1021/acsnano.4c07676
Circular RNA Signatures of Human Healing and Nonhealing Wounds. The Journal of investigative dermatology Venous ulcers (VUs) have complex and obscure pathogenicity, and effective VU therapies are still lacking. Circular RNAs (circRNAs) have emerged as powerful gene regulators with important roles in health and disease. In this study, we used paired total RNA and small RNA sequencing to profile circRNAs, protein-coding mRNAs, and microRNAs expression in a unique collection of clinical samples: healthy skin and acute wounds at inflammatory and proliferative phases and wound-edge VU biopsies. We unravel a dynamically changed expression pattern of circRNAs during human skin repair and their abnormal expression signature in VU, which are presented as a searchable web resource (www.xulandenlab.com/humanwounds-circrna). We analyzed the coexpression relationship between the circRNAs and mRNAs with weighted correlation network analysis and constructed circRNA‒mRNA‒microRNA networks. This allowed us to expose the regulatory networks specific to the inflammatory and proliferative phases of wound repair and VU, the biological processes the circRNAs may regulate, and the circRNAs that could sponge microRNAs in human wounds. Importantly, we found that hsa-CHST15_0003 and hsa-TNFRSF21_0001, two circRNAs upregulated in VU, hampered epidermal keratinocyte migration while promoting proliferation by modulating gene networks underpinning these cellular processes. This study paves the way to decipher the functional significance of circRNAs in tissue repair. 10.1016/j.jid.2022.03.024
Circular RNA hsa_circ_0004812 impairs IFN-induced immune response by sponging miR-1287-5p to regulate FSTL1 in chronic hepatitis B. Zhang Liangdong,Wang Zichao Virology journal BACKGROUND:The present study aims to explore the functions of circular RNA hsa_circ_0004812 in chronic hepatitis B (CHB) and its underlying molecular mechanisms. METHODS:The expression of circular RNA (circRNA)_0004812 was examined using qRT-PCR and Western blot in blood and liver tissues from CHB patients and healthy volunteers. In the in vitro study, the expression levels of circular RNA hsa_circ_0004812, miR-1287-5p, interferon (IFN)-α, IFN-β were determined using qRT-PCR and Western blotting in HBV-infected hepatoma cells, respectively. Luciferase and biotin pull-down assays were used to investigate the interactions between miR-1287-5p and circ_0004812. RESULTS:Levels of circ_0004812 were upregulated in CHB patients and HBV-infected hepatoma cells. Knockdown of circ_0004812 increased the expression of IFN-α and IFN-β in HBV-infected Huh7 cells. MiR-1287-5p was identified as a target of circ_0004812 whose overexpression inhibited the expression of miR-1287-5p. Additionally, circ_0004812 promoted the expression of Follistatin-related protein (FSTL) 1 through inhibiting miR-1287-5p. Circ_0004812/miR-1287-5p/FSTL1 axis regulated HBV-induced immune suppression. CONCLUSION:Circ_0004812 was identified as a potential target for CHB infection. Circ_0004812 promoted the expression of FSTL1 by inhibiting miR-1287-5p. 10.1186/s12985-020-01314-0
Circular RNA hsa_circ_0068252 Functions in Cisplatin Resistance and Immune Response via miR-1304-5p/PD-L1 Axis in Non-Small Cell Lung Cancer. Chemotherapy BACKGROUND:Research suggests that circRNAs play important roles in non-small cell lung cancer (NSCLC). The function of hsa_circ_0068252 in NSCLC, especially in cisplatin (DDP) resistance and the mechanisms, was explored in this study. METHODS:NSCLC patient samples and two NSCLC cell lines along with corresponding DDP-resistant cell lines were used. Expression levels of circ_0068252 were detected. SiRNA for circ_0068252 and inhibitor for miRNA were used in all functional analyses. A co-culture system of NSCLC cells with CD8+ T cells was used. The cellular location of circ_0068252 was detected and its target miRNA was predicted and verified. Finally, the mechanism responsible for circ_0068252 function on PD-L1 was analyzed using luciferase reporter assay in the two DDP-resistant cell lines, as well as in the co-culture system. The cytotoxicity of T cells was detected by lactate dehydrogenase assay. RESULTS:Our findings revealed that a high level of circ_0068252 was correlated with poor prognosis of NSCLC and DDP resistance. Knockdown of circ_0068252 could promote the sensitivity of DDP-resistant NSCLC cells to DDP. Moreover, knockdown of circ_0068252 could regulate the immune microenvironment which was mediated via CD8+ T cells. Finally, circ_0068252 could up-regulate PD-L1 expression by adsorbing miR-1304-5p. CONCLUSION:The circ_0068252/miR-1304-5p/PD-L1 signal axis participates in the regulation of DDP resistance and immune escape of NSCLC cells. Our results suggest that circ_0068252 may be a potential diagnostic marker and therapeutic target for DDP-resistant NSCLC. 10.1159/000525231
Circular RNA PRMT5 knockdown enhances cisplatin sensitivity and immune response in non-small cell lung cancer by regulating miR-138-5p/MYH9 axis. Xu Yanping,Zhao Rongping,Wang Hua,Jiang Jianwei,Wang Zhenwei,Wang Jiayuan,Zhang Wei,Li Min Journal of B.U.ON. : official journal of the Balkan Union of Oncology PURPOSE:To explore the role and molecular mechanism of circRNA protein arginine methyltransferase-5 (circ-PRMT5) in regulating cisplatin (DDP) resistance and immune response of non-small cell lung cancer (NSCLC). METHODS:The expression of circ-PRMT5, miR-138-5p and myosin heavy chain 9 (MYH9) was determined by quantitative real-time polymerase chain reaction (qRT-PCR) and western blot analyses. Cell Counting Kit-8 (CCK-8) assay, flow cytometry, transwell assay, and western blot assay were utilized to evaluate DDP sensitivity. Interleukin 2 (IL-2), tumor necrosis factor alpha (TNF-α) and transforming growth factor β (TGF-β) production were measured by enzyme-linked immunosorbent assay (ELISA) to assess immune system's ability. A xenograft tumor model was established to explore the role of circ-PRMT5 in DDP resistance in vivo. The interaction between miR-138-5p and circ-PRMT5 or MYH9 was predicted by starBase and verified by dual-luciferase reporter assay. RESULTS:Circ-PRMT5 and MYH9 were upregulated and miR-138-5p was downregulated in DDP-resistant NSCLC tissues and cells. Circ-PRMT5 knockdown enhanced DDP sensitivity of NSCLC cells by inhibiting cell viability, migration and invasion and inducing apoptosis. Circ-PRMT5 knockdown also increased immune response by promoting the levels of IL-2 and TNF-a and decreasing the production of TGF-β. Moreover, circ-PRMT5 interference improved DDP sensitivity of NSCLC in vivo. MiR-138-5p was a direct target of circ-PRMT5 and its knockdown abated the effects of circ-PRMT5 downregulation on DDP resistance and immune response. CONCLUSION:Circ-PRMT5 knockdown increased DDP sensitivity and immune response of NSCLC cells by regulating miR-138-5p/MYH9 axis, hinting potential value of circ-PRMT5 in the diagnosis and treatment for NSCLC.
Circular RNA as a source of neoantigens for cancer vaccines. Journal for immunotherapy of cancer BACKGROUND:The effectiveness of somatic neoantigen-based immunotherapy is often hindered by the limited number of mutations in tumors with low to moderate mutation burden. Focusing on microsatellite-stable colorectal cancer (CRC), this study investigates the potential of tumor-associated circular RNAs (circRNAs) as an alternative source of neoepitopes in CRC. METHODS:Tumor-associated circRNAs in CRC were identified using the MiOncoCirc database and ribo-depletion RNA sequencing of paired clinical normal and tumor samples. Candidate circRNA expression was validated by quantitative real-time PCR (RT-qPCR) using divergent primers. TransCirc database was used for translation prediction. Human leukocyte antigen binding affinity of open reading frames from potentially translatable circRNA was predicted using pVACtools. Strong binders from messenger RNA-encoded proteins were excluded using BlastP. The immunogenicity of the candidate antigens was functionally validated through stimulation of naïve CD8 T cells against the predicted neoepitopes and subsequent analysis of the T cells through enzyme-linked immunospot (ELISpot) assay, intracellular cytokine staining (ICS) and granzyme B (GZMB) reporter. The cytotoxicity of T cells trained with antigen peptides was further tested using patient-derived organoids. RESULTS:We identified a neoepitope from circRAPGEF5 that is upregulated in CRC tumor samples from MiOncoCirc database, and two neoepitopes from circMYH9, which is upregulated across various tumor samples from our matched clinical samples. The translation potential of candidate peptides was supported by Clinical Proteomic Tumor Analysis Consortium database using PepQuery. The candidate peptides elicited antigen-specific T cells response and expansion, evidenced by various assays including ELISpot, ICS and GZMB reporter. Furthermore, T cells trained with circMYH9 peptides were able to specifically target and eliminate tumor-derived organoids but not match normal organoids. This observation underscores the potential of circRNAs as a source of immunogenic neoantigens. Lastly, circMYH9 was enriched in the liquid biopsies of patients with CRC, thus enabling a detection-to-vaccination treatment strategy for patients with CRC. CONCLUSIONS:Our findings underscore the feasibility of tumor-associated circRNAs as an alternative source of neoantigens for cancer vaccines targeting tumors with moderate mutation levels. 10.1136/jitc-2023-008402
Tumor-Tailored Ionizable Lipid Nanoparticles Facilitate IL-12 Circular RNA Delivery for Enhanced Lung Cancer Immunotherapy. Advanced materials (Deerfield Beach, Fla.) The advancement of message RNA (mRNA) -based immunotherapies for cancer is highly dependent on the effective delivery of RNA (Ribonucleic) payloads using ionizable lipid nanoparticles (LNPs). However, the clinical application of these therapies is hindered by variable mRNA expression among different cancer types and the risk of systemic toxicity. The transient expression profile of mRNA further complicates this issue, necessitating frequent dosing and thus increasing the potential for adverse effects. Addressing these challenges, a high-throughput combinatorial method is utilized to synthesize and screen LNPs that efficiently deliver circular RNA (circRNA) to lung tumors. The lead LNP, H1L1A1B3, demonstrates a fourfold increase in circRNA transfection efficiency in lung cancer cells over ALC-0315, the industry-standard LNPs, while providing potent immune activation. A single intratumoral injection of H1L1A1B3 LNPs, loaded with circRNA encoding interleukin-12 (IL-12), induces a robust immune response in a Lewis lung carcinoma model, leading to marked tumor regression. Immunological profiling of treated tumors reveals substantial increments in CD45 leukocytes and enhances infiltration of CD8 T cells, underscoring the ability of H1L1A1B3 LNPs to modulate the tumor microenvironment favorably. These results highlight the potential of tailored LNP platforms to advance RNA drug delivery for cancer therapy, broadening the prospects for RNA immunotherapeutics. 10.1002/adma.202400307
Circular RNA vaccines against SARS-CoV-2 and emerging variants. Cell As the emerging variants of SARS-CoV-2 continue to drive the worldwide pandemic, there is a constant demand for vaccines that offer more effective and broad-spectrum protection. Here, we report a circular RNA (circRNA) vaccine that elicited potent neutralizing antibodies and T cell responses by expressing the trimeric RBD of the spike protein, providing robust protection against SARS-CoV-2 in both mice and rhesus macaques. Notably, the circRNA vaccine enabled higher and more durable antigen production than the 1mΨ-modified mRNA vaccine and elicited a higher proportion of neutralizing antibodies and distinct Th1-skewed immune responses. Importantly, we found that the circRNA vaccine induced effective neutralizing antibodies against the Omicron but not the Delta variant. In contrast, the circRNA vaccine protected against both Delta and Omicron or functioned as a booster after two doses of either native- or Delta-specific vaccination, making it a favorable choice against the current variants of concern (VOCs) of SARS-CoV-2. 10.1016/j.cell.2022.03.044
Circular RNA vaccine induces potent T cell responses. Proceedings of the National Academy of Sciences of the United States of America Circular RNAs (circRNAs) are a class of RNAs commonly found across eukaryotes and viruses, characterized by their resistance to exonuclease-mediated degradation. Their superior stability compared to linear RNAs, combined with previous work showing that engineered circRNAs serve as efficient protein translation templates, make circRNA a promising candidate for RNA medicine. Here, we systematically examine the adjuvant activity, route of administration, and antigen-specific immunity of circRNA vaccination in mice. Potent circRNA adjuvant activity is associated with RNA uptake and activation of myeloid cells in the draining lymph nodes and transient cytokine release. Immunization of mice with engineered circRNA encoding a protein antigen delivered by a charge-altering releasable transporter induced innate activation of dendritic cells, robust antigen-specific CD8 T cell responses in lymph nodes and tissues, and strong antitumor efficacy as a therapeutic cancer vaccine. These results highlight the potential utility of circRNA vaccines for stimulating potent innate and T cell responses in tissues. 10.1073/pnas.2302191120
Circular RNA cancer vaccines drive immunity in hard-to-treat malignancies. Theranostics Messenger RNA (mRNA) vaccine outperforms other kinds of cancer immunotherapy due to its high response rates, easy preparation, and wide applicability, which is considered as one of the most promising forms of next-generation cancer therapies. However, the inherent instability and insufficient protein expression duration of mRNA limit the efficacy and widespread application of the vaccine. Here, we first tested the possibility of a novel circular RNA (circRNA) platform for protein expression and compare its duration with linear RNA. Then, we developed a lipid nanoparticle (LNP) system for circRNA delivery and . Next, the innate and adaptive immune response of circRNA-LNP complex was evaluated . The anti-tumor efficacy of circRNA-LNP was further confirmed in three tumor models. Finally, the possibility of combination therapy with circRNA-LNP and adoptive cell transfer therapy was further investigated in a late-stage tumor model. We successfully increased the stability of the RNA vaccine by circularizing the linear RNA molecules to form highly stable circRNA molecules which exhibited durable protein expression ability. By encapsulating the antigen-coding circRNA in LNP enabling expression, we established a novel circRNA vaccine platform, which was capable of triggering robust innate and adaptive immune activation and showed superior anti-tumor efficacy in multiple mouse tumor models. Overall, our circRNA vaccine platform provides a novel prospect for the development of cancer RNA vaccines in a wide range of hard-to-treat malignancies. 10.7150/thno.77350
N6-Methyladenosine Modification Controls Circular RNA Immunity. Molecular cell Circular RNAs (circRNAs) are prevalent in eukaryotic cells and viral genomes. Mammalian cells possess innate immunity to detect foreign circRNAs, but the molecular basis of self versus foreign identity in circRNA immunity is unknown. Here, we show that N6-methyladenosine (mA) RNA modification on human circRNAs inhibits innate immunity. Foreign circRNAs are potent adjuvants to induce antigen-specific T cell activation, antibody production, and anti-tumor immunity in vivo, and mA modification abrogates immune gene activation and adjuvant activity. mA reader YTHDF2 sequesters mA-circRNA and is essential for suppression of innate immunity. Unmodified circRNA, but not mA-modified circRNA, directly activates RNA pattern recognition receptor RIG-I in the presence of lysine-63-linked polyubiquitin chain to cause filamentation of the adaptor protein MAVS and activation of the downstream transcription factor IRF3. CircRNA immunity has considerable parallel to prokaryotic DNA restriction modification system that transforms nucleic acid chemical modification into organismal innate immunity. 10.1016/j.molcel.2019.07.016