An RNA toolbox for cancer immunotherapy. Pastor Fernando,Berraondo Pedro,Etxeberria Iñaki,Frederick Josh,Sahin Ugur,Gilboa Eli,Melero Ignacio Nature reviews. Drug discovery Cancer immunotherapy has revolutionized oncology practice. However, current protein and cell therapy tools used in cancer immunotherapy are far from perfect, and there is room for improvement regarding their efficacy and safety. RNA-based structures have diverse functions, ranging from gene expression and gene regulation to pro-inflammatory effects and the ability to specifically bind different molecules. These functions make them versatile tools that may advance cancer vaccines and immunomodulation, surpassing existing approaches. These technologies should not be considered as competitors of current immunotherapies but as partners in synergistic combinations and as a clear opportunity to reach more efficient and personalized results. RNA and RNA derivatives can be exploited therapeutically as a platform to encode protein sequences, provide innate pro-inflammatory signals to the immune system (such as those denoting viral infection), control the expression of other RNAs (including key immunosuppressive factors) post-transcriptionally and conform structural scaffoldings binding proteins that control immune cells by modifying their function. Nascent RNA immunotherapeutics include RNA vaccines encoding cancer neoantigens, mRNAs encoding immunomodulatory factors, viral RNA analogues, interference RNAs and protein-binding RNA aptamers. These approaches are already in early clinical development with promising safety and efficacy results. 10.1038/nrd.2018.132
    mRNA vaccine-elicited antibodies to SARS-CoV-2 and circulating variants. Wang Zijun,Schmidt Fabian,Weisblum Yiska,Muecksch Frauke,Barnes Christopher O,Finkin Shlomo,Schaefer-Babajew Dennis,Cipolla Melissa,Gaebler Christian,Lieberman Jenna A,Oliveira Thiago Y,Yang Zhi,Abernathy Morgan E,Huey-Tubman Kathryn E,Hurley Arlene,Turroja Martina,West Kamille A,Gordon Kristie,Millard Katrina G,Ramos Victor,Da Silva Justin,Xu Jianliang,Colbert Robert A,Patel Roshni,Dizon Juan,Unson-O'Brien Cecille,Shimeliovich Irina,Gazumyan Anna,Caskey Marina,Bjorkman Pamela J,Casellas Rafael,Hatziioannou Theodora,Bieniasz Paul D,Nussenzweig Michel C Nature Here we report on the antibody and memory B cell responses of a cohort of 20 volunteers who received the Moderna (mRNA-1273) or Pfizer-BioNTech (BNT162b2) vaccine against SARS-CoV-2. Eight weeks after the second injection of vaccine, volunteers showed high levels of IgM and IgG anti-SARS-CoV-2 spike protein (S) and receptor-binding-domain (RBD) binding titre. Moreover, the plasma neutralizing activity and relative numbers of RBD-specific memory B cells of vaccinated volunteers were equivalent to those of individuals who had recovered from natural infection. However, activity against SARS-CoV-2 variants that encode E484K-, N501Y- or K417N/E484K/N501-mutant S was reduced by a small-but significant-margin. The monoclonal antibodies elicited by the vaccines potently neutralize SARS-CoV-2, and target a number of different RBD epitopes in common with monoclonal antibodies isolated from infected donors. However, neutralization by 14 of the 17 most-potent monoclonal antibodies that we tested was reduced or abolished by the K417N, E484K or N501Y mutation. Notably, these mutations were selected when we cultured recombinant vesicular stomatitis virus expressing SARS-CoV-2 S in the presence of the monoclonal antibodies elicited by the vaccines. Together, these results suggest that the monoclonal antibodies in clinical use should be tested against newly arising variants, and that mRNA vaccines may need to be updated periodically to avoid a potential loss of clinical efficacy. 10.1038/s41586-021-03324-6
    Safety and immunogenicity of the SARS-CoV-2 BNT162b1 mRNA vaccine in younger and older Chinese adults: a randomized, placebo-controlled, double-blind phase 1 study. Li Jingxin,Hui Aimin,Zhang Xiang,Yang Yumei,Tang Rong,Ye Huayue,Ji Ruiru,Lin Mei,Zhu Zhongkui,Türeci Özlem,Lagkadinou Eleni,Jia Siyue,Pan Hongxing,Peng Fuzhong,Ma Zhilong,Wu Zhenggang,Guo Xiling,Shi Yunfeng,Muik Alexander,Şahin Uğur,Zhu Li,Zhu Fengcai Nature medicine An effective vaccine is needed to end the severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) pandemic. Here, we assess the preliminary safety, tolerability and immunogenicity data from an ongoing single-center (in Jiangsu province, China), parallel-group, double-blind phase 1 trial of the vaccine candidate BNT162b1 in 144 healthy SARS-CoV-2-naive Chinese participants. These participants are randomized 1:1:1 to receive prime and boost vaccinations of 10 µg or 30 µg BNT162b1 or placebo, given 21 d apart, with equal allocation of younger (aged 18-55 years) and older adults (aged 65-85 years) to each treatment group (ChiCTR2000034825). BNT162b1 encodes the SARS-CoV-2 spike glycoprotein receptor-binding domain (RBD) and is one of several messenger RNA-based vaccine candidates under clinical investigation. Local reactions and systemic events were generally dose dependent, transient and mild to moderate. Fever was the only grade 3 adverse event. BNT162b1 induced robust interferon-γ T cell responses to a peptide pool including the RBD in both younger and older Chinese adults, and geometric mean neutralizing titers reached 2.1-fold (for younger participants) and 1.3-fold (for the older participants) that of a panel of COVID-19 convalescent human sera obtained at least 14 d after positive SARS-CoV-2 polymerase chain reaction test. In summary, BNT162b1 has an acceptable safety profile and produces high levels of humoral and T cell responses in an Asian population. 10.1038/s41591-021-01330-9
    Tailoring mRNA Vaccine to Balance Innate/Adaptive Immune Response. Linares-Fernández Sergio,Lacroix Céline,Exposito Jean-Yves,Verrier Bernard Trends in molecular medicine mRNA vaccine platforms present numerous advantages, such as versatility, rapid production, and induction of cellular and humoral responses. Moreover, mRNAs have inherent adjuvant properties due to their complex interaction with pattern recognition receptors (PRRs). This recognition can be either beneficial in activating antigen-presenting cells (APCs) or detrimental by indirectly blocking mRNA translation. To decipher this Janus effect, we describe the different innate response mechanisms triggered by mRNA molecules and how each element from the 5' cap to the poly-A tail interferes with innate/adaptive immune responses. Then, we emphasize the importance of some critical steps such as production, purification, and formulation as key events to further improve the quality of immune responses and balance innate and adaptive immunity. 10.1016/j.molmed.2019.10.002
    A core-shell structured COVID-19 mRNA vaccine with favorable biodistribution pattern and promising immunity. Yang Ren,Deng Yao,Huang Baoying,Huang Lei,Lin Ang,Li Yuhua,Wang Wenling,Liu Jingjing,Lu Shuaiyao,Zhan Zhenzhen,Wang Yufei,A Ruhan,Wang Wen,Niu Peihua,Zhao Li,Li Shiqiang,Ma Xiaopin,Zhang Luyao,Zhang Yujian,Yao Weiguo,Liang Xingjie,Zhao Jincun,Liu Zhongmin,Peng Xiaozhong,Li Hangwen,Tan Wenjie Signal transduction and targeted therapy Although inoculation of COVID-19 vaccines has rolled out globally, there is still a critical need for safe and effective vaccines to ensure fair and equitable supply for all countries. Here, we report on the development of a highly efficacious mRNA vaccine, SW0123 that is composed of sequence-modified mRNA encoding the full-length SARS-CoV-2 Spike protein packaged in core-shell structured lipopolyplex (LPP) nanoparticles. SW0123 is easy to produce using a large-scale microfluidics-based apparatus. The unique core-shell structured nanoparticle facilitates vaccine uptake and demonstrates a high colloidal stability, and a desirable biodistribution pattern with low liver targeting effect upon intramuscular administration. Extensive evaluations in mice and nonhuman primates revealed strong immunogenicity of SW0123, represented by induction of Th1-polarized T cell responses and high levels of antibodies that were capable of neutralizing not only the wild-type SARS-CoV-2, but also a panel of variants including D614G and N501Y variants. In addition, SW0123 conferred effective protection in both mice and non-human primates upon SARS-CoV-2 challenge. Taken together, SW0123 is a promising vaccine candidate that holds prospects for further evaluation in humans. 10.1038/s41392-021-00634-z
    Trivalent nucleoside-modified mRNA vaccine yields durable memory B cell protection against genital herpes in preclinical models. Awasthi Sita,Knox James J,Desmond Angela,Alameh Mohamad-Gabriel,Gaudette Brian T,Lubinski John M,Naughton Alexis,Hook Lauren M,Egan Kevin P,Tam Ying K,Pardi Norbert,Allman David,Luning Prak Eline T,Cancro Michael P,Weissman Drew,Cohen Gary H,Friedman Harvey M The Journal of clinical investigation Nucleoside-modified mRNA vaccines have gained global attention because of COVID-19. We evaluated a similar vaccine approach for preventing a chronic latent genital infection rather than an acute respiratory infection. We used animal models to compare an HSV-2 trivalent nucleoside-modified mRNA vaccine with the same antigens prepared as proteins with an emphasis on antigen-specific memory B cell responses and immune correlates of protection. In guinea pigs, serum neutralizing antibody titers were higher at one month and declined far less by eight months in mRNA- than protein-immunized animals. Both vaccines protected against death and genital lesions when infected one month after immunization; however, protection was more durable in the mRNA than protein group when infected after eight months, an interval representing >15% of the animal's lifespan. Serum and vaginal neutralizing antibody titers correlated with protection against infection as measured by genital lesions and vaginal virus titers two days post infection. In mice, the mRNA vaccine generated more antigen-specific memory B cells than the protein vaccine at early times post immunization that persisted for up to one year. High neutralizing titers and robust B cell immune memory likely explain the more durable protection by the HSV-2 mRNA vaccine. 10.1172/JCI152310
    Design of SARS-CoV-2 hFc-Conjugated Receptor-Binding Domain mRNA Vaccine Delivered Lipid Nanoparticles. Elia Uri,Ramishetti Srinivas,Rosenfeld Ronit,Dammes Niels,Bar-Haim Erez,Naidu Gonna Somu,Makdasi Efi,Yahalom-Ronen Yfat,Tamir Hadas,Paran Nir,Cohen Ofer,Peer Dan ACS nano Severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) has been identified as the causal agent of COVID-19 and stands at the center of the current global human pandemic, with death toll exceeding one million. The urgent need for a vaccine has led to the development of various immunization approaches. mRNA vaccines represent a cell-free, simple, and rapid platform for immunization, and therefore have been employed in recent studies toward the development of a SARS-CoV-2 vaccine. Herein, we present the design of an mRNA vaccine, based on lipid nanoparticles (LNPs)-encapsulated SARS-CoV-2 human Fc-conjugated receptor-binding domain (RBD-hFc). Several ionizable lipids have been evaluated in a luciferase (luc) mRNA reporter assay, and two leading LNPs formulations have been chosen for the subsequent RBD-hFc mRNA vaccine strategy. Intramuscular administration of LNP RBD-hFc mRNA elicited robust humoral response, a high level of neutralizing antibodies and a Th1-biased cellular response in BALB/c mice. The data in the current study demonstrate the potential of these lipids as promising candidates for LNP-based mRNA vaccines in general and for a COVID19 vaccine in particular. 10.1021/acsnano.0c10180
    Coordinate Induction of Humoral and Spike Specific T-Cell Response in a Cohort of Italian Health Care Workers Receiving BNT162b2 mRNA Vaccine. Agrati Chiara,Castilletti Concetta,Goletti Delia,Meschi Silvia,Sacchi Alessandra,Matusali Giulia,Bordoni Veronica,Petrone Linda,Lapa Daniele,Notari Stefania,Vanini Valentina,Colavita Francesca,Aiello Alessandra,Agresta Alessandro,Farroni Chiara,Grassi Germana,Leone Sara,Vaia Francesco,Capobianchi Maria Rosaria,Ippolito Giuseppe,Puro Vincenzo,On Behalf Of The Inmi Covid-Vaccine Study Group Microorganisms Vaccination is the main public health measure to reduce SARS-CoV-2 transmission and hospitalization, and a massive worldwide scientific effort resulted in the rapid development of effective vaccines. This work aimed to define the dynamics of humoral and cell-mediated immune response in a cohort of health care workers (HCWs) who received a two-dose BNT162b2-mRNA vaccination. The serological response was evaluated by quantifying the anti-RBD and neutralizing antibodies. The cell-mediated response was performed by a whole blood test quantifying Th1 cytokines (IFN-γ, TNF-α, IL-2), produced in response to spike peptides. The BNT162b2-mRNA vaccine induced both humoral and cell-mediated immune responses against spike peptides in virtually all HCWs without previous SARS-CoV-2 infection, with a moderate inverse relation with age in the anti-RBD response. Spike-specific T cells produced several Th1 cytokines (IFN-γ, TNF-α, and IL-2), which correlated with the specific-serological response. Overall, our study describes the ability of the BNT162b2 mRNA vaccine to elicit a coordinated neutralizing humoral and spike-specific T cell response in HCWs. Assessing the dynamics of these parameters by an easy immune monitoring protocol can allow for the evaluation of the persistence of the vaccine response in order to define the optimal vaccination strategy. 10.3390/microorganisms9061315
    A single-dose mRNA vaccine provides a long-term protection for hACE2 transgenic mice from SARS-CoV-2. Huang Qingrui,Ji Kai,Tian Siyu,Wang Fengze,Huang Baoying,Tong Zhou,Tan Shuguang,Hao Junfeng,Wang Qihui,Tan Wenjie,Gao George F,Yan Jinghua Nature communications The rapid expansion of the COVID-19 pandemic has made the development of a SARS-CoV-2 vaccine a global health and economic priority. Taking advantage of versatility and rapid development, three SARS-CoV-2 mRNA vaccine candidates have entered clinical trials with a two-dose immunization regimen. However, the waning antibody response in convalescent patients after SARS-CoV-2 infection and the emergence of human re-infection have raised widespread concerns about a possible short duration of SARS-CoV-2 vaccine protection. Here, we developed a nucleoside-modified mRNA vaccine in lipid-encapsulated form that encoded the SARS-CoV-2 RBD, termed as mRNA-RBD. A single immunization of mRNA-RBD elicited both robust neutralizing antibody and cellular responses, and conferred a near-complete protection against wild SARS-CoV-2 infection in the lungs of hACE2 transgenic mice. Noticeably, the high levels of neutralizing antibodies in BALB/c mice induced by mRNA-RBD vaccination were maintained for at least 6.5 months and conferred a long-term notable protection for hACE2 transgenic mice against SARS-CoV-2 infection in a sera transfer study. These data demonstrated that a single dose of mRNA-RBD provided long-term protection against SARS-CoV-2 challenge. 10.1038/s41467-021-21037-2
    mRNA vaccine: a potential therapeutic strategy. Wang Yang,Zhang Ziqi,Luo Jingwen,Han Xuejiao,Wei Yuquan,Wei Xiawei Molecular cancer mRNA vaccines have tremendous potential to fight against cancer and viral diseases due to superiorities in safety, efficacy and industrial production. In recent decades, we have witnessed the development of different kinds of mRNAs by sequence optimization to overcome the disadvantage of excessive mRNA immunogenicity, instability and inefficiency. Based on the immunological study, mRNA vaccines are coupled with immunologic adjuvant and various delivery strategies. Except for sequence optimization, the assistance of mRNA-delivering strategies is another method to stabilize mRNAs and improve their efficacy. The understanding of increasing the antigen reactiveness gains insight into mRNA-induced innate immunity and adaptive immunity without antibody-dependent enhancement activity. Therefore, to address the problem, scientists further exploited carrier-based mRNA vaccines (lipid-based delivery, polymer-based delivery, peptide-based delivery, virus-like replicon particle and cationic nanoemulsion), naked mRNA vaccines and dendritic cells-based mRNA vaccines. The article will discuss the molecular biology of mRNA vaccines and underlying anti-virus and anti-tumor mechanisms, with an introduction of their immunological phenomena, delivery strategies, their importance on Corona Virus Disease 2019 (COVID-19) and related clinical trials against cancer and viral diseases. Finally, we will discuss the challenge of mRNA vaccines against bacterial and parasitic diseases. 10.1186/s12943-021-01311-z
    The self-assembled nanoparticle-based trimeric RBD mRNA vaccine elicits robust and durable protective immunity against SARS-CoV-2 in mice. Sun Wenqiang,He Lihong,Zhang He,Tian Xiaodong,Bai Zhihua,Sun Lei,Yang Limin,Jia Xiaojuan,Bi Yuhai,Luo Tingrong,Cheng Gong,Fan Wenhui,Liu Wenjun,Li Jing Signal transduction and targeted therapy As COVID-19 continues to spread rapidly worldwide and variants continue to emerge, the development and deployment of safe and effective vaccines are urgently needed. Here, we developed an mRNA vaccine based on the trimeric receptor-binding domain (RBD) of the SARS-CoV-2 spike (S) protein fused to ferritin-formed nanoparticles (TF-RBD). Compared to the trimeric form of the RBD mRNA vaccine (T-RBD), TF-RBD delivered intramuscularly elicited robust and durable humoral immunity as well as a Th1-biased cellular response. After further challenge with live SARS-CoV-2, immunization with a two-shot low-dose regimen of TF-RBD provided adequate protection in hACE2-transduced mice. In addition, the mRNA template of TF-RBD was easily and quickly engineered into a variant vaccine to address SARS-CoV-2 mutations. The TF-RBD multivalent vaccine produced broad-spectrum neutralizing antibodies against Alpha (B.1.1.7) and Beta (B.1.351) variants. This mRNA vaccine based on the encoded self-assembled nanoparticle-based trimer RBD provides a reference for the design of mRNA vaccines targeting SARS-CoV-2. 10.1038/s41392-021-00750-w
    Construction and Immunogenicity of Modified mRNA-Vaccine Variants Encoding Influenza Virus Antigens. Starostina Ekaterina V,Sharabrin Sergei V,Antropov Denis N,Stepanov Grigory A,Shevelev Georgiy Yu,Lemza Anna E,Rudometov Andrey P,Borgoyakova Mariya B,Rudometova Nadezhda B,Marchenko Vasiliy Yu,Danilchenko Natalia V,Chikaev Anton N,Bazhan Sergei I,Ilyichev Alexander A,Karpenko Larisa I Vaccines Nucleic acid-based influenza vaccines are a promising platform that have recently and rapidly developed. We previously demonstrated the immunogenicity of DNA vaccines encoding artificial immunogens AgH1, AgH3, and AgM2, which contained conserved fragments of the hemagglutinin stem of two subtypes of influenza A-H1N1 and H3N2-and conserved protein M2. Thus, the aim of this study was to design and characterize modified mRNA obtained using the above plasmid DNA vaccines as a template. To select the most promising protocol for creating highly immunogenic mRNA vaccines, we performed a comparative analysis of mRNA modifications aimed at increasing its translational activity and decreasing toxicity. We used mRNA encoding a green fluorescent protein (GFP) as a model. Eight mRNA-GFP variants with different modifications (M0-M7) were obtained using the classic cap(1), its chemical analog ARCA (anti-reverse cap analog), pseudouridine (Ψ), N6-methyladenosine (m6A), and 5-methylcytosine (m5C) in different ratios. Modifications M2, M6, and M7, which provided the most intensive fluorescence of transfected HEK293FT cells were used for template synthesis when mRNA encoded influenza immunogens AgH1, AgH3, and AgM2. Virus specific antibodies were registered in groups of animals immunized with a mix of mRNAs encoding AgH1, AgH3, and AgM2, which contained either ARCA (with inclusions of 100% Ψ and 20% m6A (M6)) or a classic cap(1) (with 100% substitution of U with Ψ (M7)). M6 modification was the least toxic when compared with other mRNA variants. M6 and M7 RNA modifications can therefore be considered as promising protocols for designing mRNA vaccines. 10.3390/vaccines9050452
    Lipid Nanoparticle RBD-hFc mRNA Vaccine Protects hACE2 Transgenic Mice against a Lethal SARS-CoV-2 Infection. Elia Uri,Rotem Shahar,Bar-Haim Erez,Ramishetti Srinivas,Naidu Gonna Somu,Gur David,Aftalion Moshe,Israeli Ma'ayan,Bercovich-Kinori Adi,Alcalay Ron,Makdasi Efi,Chitlaru Theodor,Rosenfeld Ronit,Israely Tomer,Melamed Sharon,Abutbul Ionita Inbal,Danino Dganit,Peer Dan,Cohen Ofer Nano letters The COVID-19 pandemic led to development of mRNA vaccines, which became a leading anti-SARS-CoV-2 immunization platform. Preclinical studies are limited to infection-prone animals such as hamsters and monkeys in which protective efficacy of vaccines cannot be fully appreciated. We recently reported a SARS-CoV-2 human Fc-conjugated receptor-binding domain (RBD-hFc) mRNA vaccine delivered via lipid nanoparticles (LNPs). BALB/c mice demonstrated specific immunologic responses following RBD-hFc mRNA vaccination. Now, we evaluated the protective effect of this RBD-hFc mRNA vaccine by employing the K18 human angiotensin-converting enzyme 2 (K18-hACE2) mouse model. Administration of an RBD-hFc mRNA vaccine to K18-hACE2 mice resulted in robust humoral responses comprising binding and neutralizing antibodies. In correlation with this response, 70% of vaccinated mice withstood a lethal SARS-CoV-2 dose, while all control animals succumbed to infection. To the best of our knowledge, this is the first nonreplicating mRNA vaccine study reporting protection of K18-hACE2 against a lethal SARS-CoV-2 infection. 10.1021/acs.nanolett.1c01284