IL-1 and IL-1ra are key regulators of the inflammatory response to RNA vaccines

Exaggerated Lung Inflammation Induced by Lung-Targeted mRNA-LNP Dampens Vaccines against Tuberculosis

The challenges in developing a tuberculosis (TB) vaccine stem from the complex life cycle of Mycobacterium tuberculosis (Mtb) and various bacterial proteins encoded by approximately 4000 genes. mRNA is easy to design and can accommodate multiple antigens, suggesting that it may be an effective TB vaccine technology. Here, we designed an mRNA encoding Ag85B and ESAT6 that was delivered by lung targeted lipid nanoparticles (LNPlung-mRNAA-E), intending to stimulate lung immunity to combat TB. To enhance the vaccine efficacy, we further cofabricated monophosphoryl lipid A (MPLA) with mRNA to evaluate the adjuvanted mRNA vaccine (LNPlung-mRNAA-E-MPLA). Both vaccines elicited robust CD4+ T cell response, resulting in markedly locally higher production of IFN-γ, TNF-α, and IL-2. As anticipated, the addition of MPLA further enhanced the immunogenicity of LNPlung-mRNAA-E. However, the Mtb challenge experiment showed that LNPlung-mRNAA-E-MPLA neither provided effective protection nor enhanced the immune protection primed by BCG (Bacillus Calmette-Guérin). The subsequent HE staining of the lung revealed that the LNPlung-mRNAA-E-MPLA induced pulmonary inflammation, leading to tissue damage. Moreover, the inflammatory cytokines including IL-6, IL-1β, and MCP-1 were significantly increased and the MPLA additive exacerbated the inflammatory process. Therefore, the lung targeted mRNA vaccine and MPLA adjuvant synergistically induced lung inflammation and weakened protection from Mtb infection. Thus, this work provides valuable implications for developing targeted lung vaccines: Addressing chronic lung inflammation induced by vaccine systems is critical for lung-targeted mRNA vaccines.

Biochemical and hematological reference intervals in rhesus and cynomolgus macaques and implications for vaccine and drug development

Nonhuman primates have a key role in the evaluation of novel therapeutics including vaccine and drug development. Monitoring biochemical and hematological parameters of macaques is critical to understand toxicity and safety, but general reference intervals following standardized guidelines remain to be determined. Here we compiled multiple internal datasets to define normal ranges of classical biochemical and hematological parameters in Indian and Chinese rhesus macaques as well as cynomolgus macaques. Furthermore, the combination of hematological data with phenotypic information of cells obtained by flow cytometry enabled analyses of specific immune cell subsets. We found that vaccination generally induced transient changes at 24 h in cell frequencies accompanied by fluctuation in selected liver enzymes and metabolites. However, most parameters remained within our identified reference intervals. These deviations did not lead to noticeable side effects. Fluctuation in selected biochemical and hematological parameters was accompanied with differentiation of CD14+CD16+ intermediate monocytes and upregulation of genes associated with interleukin-1 signaling. By contrast, two animals with noticeable side effects showed sustained deviations. This study provides insights into baseline and vaccine-induced biochemical and hematological profiles of healthy macaques, facilitating the interpretation of toxicity and safety assessments in preclinical trials of novel therapies.

EPIFEVER-2 investigators. Interleukin-1 receptor antagonist polymorphisms in women receiving epidural analgesia who develop maternal intrapartum fever: a prospective, multicentre Mendelian randomised study

BACKGROUND

Genetically predicted higher levels of the anti-inflammatory cytokine interleukin-1 receptor antagonist (IL1-Ra) might reduce the risk of developing epidural-related maternal fever, a phenomenon that occurs exclusively in women having epidural analgesia in labour. We hypothesised that in women having epidural analgesia, the absence of specific alleles that lower circulating levels of IL1-Ra would be associated with the development of epidural-related maternal fever, administration of intrapartum antibiotics, or both.

METHODS

We prospectively enrolled women ≥18 yr of age receiving epidural analgesia during labour, excluding those with pre-existing fever, antibiotic therapy, or immunodeficiency. Allele scores were constructed from genotyping the C-allele frequency at variants rs6743376 and rs1542176; more copies of each allele independently raise IL-1Ra. The composite primary outcome was maternal intrapartum fever (>38°C) or administration of intrapartum antibiotics after epidural placement. The exposure of interest was the IL1-Ra allele score, comparing 0 (lowest genetically predicted IL-1Ra levels) with ≥1 allele scores. Maternal fever and antibiotic administration were compared in women with 0 or ≥1 allele scores.

RESULTS

Of 624 women genotyped, 155 (24.8%) developed maternal fever or received antibiotics. Fever or antibiotic administration occurred in 19/74 (25.7%) labouring women with an IL-1Ra allele score of 0, compared with 136/550 (24.7%) women with IL-1Ra allele scores ≥1 (odds ratio 1.05, 95% confidence interval 0.60-1.83; P=0.89).

CONCLUSIONS

In women who receive epidural analgesia during labour, genetically predicted (higher) interleukin-1 receptor antagonist levels do not alter the incidence of maternal intrapartum fever or use of intrapartum antibiotics.

CLINICAL TRIAL REGISTRATION

ISRCTN99641204.

Nucleic acid vaccines: innovations, efficacy, and applications in at-risk populations

For more than two centuries, the field of vaccine development has progressed through the adaptation of novel platforms in parallel with technological developments. Building off the advantages and shortcomings of first and second-generation vaccine platforms, the advent of third-generation nucleic acid vaccines has enabled new approaches to tackle emerging infectious diseases, cancers, and pathogens where vaccines remain unavailable. Unlike traditional vaccine platforms, nucleic acid vaccines offer several new advantages, including their lower cost and rapid production, which was widely demonstrated during the COVID-19 pandemic. Beyond production, DNA and mRNA vaccines can elicit unique and targeted responses through specialized design and delivery approaches. Considering the growth of nucleic acid vaccine research over the past two decades, the evaluation of their efficacy in at-risk populations is paramount for refining and improving vaccine design. Importantly, the aging population represents a significant portion of individuals highly susceptible to infection and disease. This review seeks to outline the major impairments in vaccine-induced responses due to aging that may be targeted for improvement with design and delivery components encompassing mRNA and DNA vaccine formulations. Results of pre-clinical and clinical applications of these vaccines in aged animal models and humans will also be evaluated to outline current successes and limitations observed in these platforms.

cGAS mRNA-Based Immune Agonist Promotes Vaccine Responses and Antitumor Immunity

mRNA vaccines are a potent tool for immunization against viral diseases and cancer. However, the lack of a vaccine adjuvant limits the efficacy of these treatments. In this study, we used cGAS mRNA, which encodes the DNA innate immune sensor, complexed with lipid nanoparticles (LNP), to boost the immune response. By introducing specific mutations in human cGAS mRNA (hcGASK187N/L195R), we significantly enhanced cGAS activity, resulting in a more potent and sustained stimulator of interferon gene (STING)-mediated IFN response. cGAS mRNA-LNPs exhibited stimulatory effects on maturation, antigen engulfment, and antigen presentation by antigen-presenting cells, both in vitro and in vivo. Moreover, the hcGASK187N/L195R mRNA-LNP combination demonstrated a robust adjuvant effect and amplified the potency of mRNA and protein vaccines, which was a result of strong humoral and cell-mediated responses. Remarkably, the hcGASK187N/L195R mRNA-LNP complex, either alone or in combination with antigens, demonstrated exceptional efficacy in eliciting antitumor immunity. In addition to its immune-boosting properties, hcGASK187N/L195R mRNA-LNP exerted antitumor effects with IFNγ directly on tumor cells, further promoting tumor restriction. In conclusion, we developed a cGAS mRNA-based immunostimulatory adjuvant compatible with various vaccine forms to boost the adaptive immune response and cancer immunotherapies.

An Industry Perspective on the Use of Novel Excipients in Lipid Nanoparticles-Nonclinical Considerations

Nucleic acid drug delivery with lipid nanoparticle (LNP) formulations has enabled the development of novel therapeutics and vaccines. LNP formulations are composed of both naturally occurring and synthetic lipid excipients. This perspective shares current practices in the nonclinical safety assessment of novel lipid excipients contained in LNP formulations and identifies gaps in current regulatory guidance on this topic. There is no globally harmonized regulatory guidance for the nonclinical safety assessment of novel excipients or guidance specific to safety testing of novel excipients in LNPs. Given the complexity of these LNP formulations, most nonclinical safety studies to support development are conducted with the drug product or with a LNP that contains non-active cargo. Three case studies (Onpattro®, Comirnaty®, and SpikeVax®) highlight that specific assessments may differ depending on the encapsulated modality, the intended use (e.g., therapeutic versus preventative vaccine), dose, and frequency of dosing. These case studies also suggest that regulatory agencies are open to scientific rationale to justify why certain tests should or should not be performed. As more products are approved, it will be important to understand how precedents set for approved products can be leveraged and what additional unique strategies may be applied to ensure nonclinical safety assessments are predictive, relevant, and meaningful for human safety. Proactive alignment with regulatory authorities will be critical in this context, especially as new approaches are proposed. Guidance documents may need to be revised or created as more experience is acquired to reflect the unique considerations for these novel excipients.

Repurposing anti-viral subunit and mRNA vaccines T cell immunity for intratumoral immunotherapy against solid tumors

Intratumoral (IT) immunotherapy can stimulate the tumor microenvironment and enhance anti-tumor immunity. We investigated IT delivery of three licensed viral vaccines-Shingrix (VZV shingles), Gardasil-9 (HPV), and Spikevax (SARS-CoV-2)-in prevaccinated mice using the murine tumor model TC-1, which expresses HPV16 oncogenes E6 and E7. Shingrix IT injection often induced tumor regression and resistance to secondary challenge. Injecting a VZV glycoprotein E (gE)-derived MHC-II-restricted peptide with polyI:C also led to durable remission, highlighting the role of gE-specific CD4+ T cells. While Gardasil-9 IT injection alone was ineffective, combining a HPV L1-derived MHC-I-restricted peptide with polyI:C or Shingrix enhanced tumor regression. Both approaches elicited CD8+ T cells against the E7 tumor viral oncoprotein. Tumor microenvironment analysis revealed remodeling of the myeloid compartment, significant induction of IFN-γ, TNF-α, and CXCL9 and broad gene expression reprograming. In a dual-flank model, IT injection of Shingrix with an MHC-I-restricted E7 tumor-specific peptide eliminated primary and non-injected tumors. Finally, Spikevax IT injection showed modest tumor growth delay, while improved control was observed with a SARS-CoV-2 spike-derived MHC-I-restricted peptide and polyI:C. These results demonstrate the potential of licensed vaccines as promising platforms for IT immunotherapy, either alone or combined with vaccine- or tumor-derived MHC-I-restricted peptide epitopes.

Unleashing the power of nucleic acid therapeutics through efficient cytosolic delivery

The approval of siRNA-based therapy for liver disease in 2018 and the subsequent success of mRNA-based SARS-CoV-2 vaccines have inaugurated a new era in nucleic acid-based therapeutics. These breakthroughs underscore the transformative potential of nucleic acid-based therapeutics, which modulate gene function, correct genetic defects, or disrupt pathological molecular processes. Such advances represent a paradigm shift in modern medicine. Despite their immense promise, the clinical realization of nucleic acid-based therapies is fundamentally constrained by endosomal entrapment, a critical barrier that significantly limits therapeutic efficacy. Overcoming this obstacle is imperative to fully unlock the potential of these therapies. Designing effective strategies to facilitate the escape of nucleic acids from endosomes-or bypassing endosomal pathways altogether-remains a central challenge in the field. In this review, we provide a comprehensive and critical analysis of current approaches aimed at enhancing endosomal escape or circumventing endosomal entrapment. By highlighting both the successes and limitations of these strategies, we aim to offer valuable insights to inform the development of more efficient and clinically viable nucleic acid delivery systems, advancing the future of molecular medicine.

AAV vectors trigger DNA damage response-dependent pro-inflammatory signalling in human iPSC-derived CNS models and mouse brain

Adeno-associated viral (AAV) vector-based gene therapy is gaining foothold as treatment for genetic neurological diseases with encouraging clinical results. Nonetheless, dose-dependent adverse events have emerged in recent clinical trials through mechanisms that remain unclear. We have modelled here the impact of AAV transduction in cell models of the human central nervous system (CNS), taking advantage of induced pluripotent stem cells. Our work uncovers vector-induced innate immune mechanisms that contribute to cell death. While empty AAV capsids were well tolerated, the AAV genome triggered p53-dependent DNA damage responses across CNS cell types followed by the induction of inflammatory responses. In addition, transgene expression led to MAVS-dependent activation of type I interferon responses. Formation of DNA damage foci in neurons and gliosis were confirmed in murine striatum upon intraparenchymal AAV injection. Transduction-induced cell death and gliosis could be prevented by inhibiting p53 or by acting downstream on STING- or IL-1R-mediated responses. Together, our work identifies innate immune mechanisms of vector sensing in the CNS that can potentially contribute to AAV-associated neurotoxicity.

Highly immunogenic DNA/LION nanocarrier vaccine potently activates lymph nodes inducing long-lasting immunity in macaques

A SARS-CoV-2 spike DNA vaccine formulated with a cationic nanoparticle emulsion (LION) was tested in Rhesus macaques. It induced robust, long-lasting (>2 years) cellular and humoral immunity, including increased neutralization breadth. T cell responses were predominantly CD8+, in contrast to other DNA vaccines. A rapid transient cytokine/chemokine response was associated with expansion and trafficking of myeloid cells and lymphocytes. Increased proliferation and dynamic changes between blood and lymph node (LN) were found for monocyte-derived cells, dendritic cells, and B and T cells, resulting in activation of LN and expansion of germinal centers (GCs), likely critical in shaping long-lasting adaptive immunity. Significant GC expansion of B, CD4-, and CD8- cells, including the Tfc3 subset, reflects a balanced immune response, including antibody (Ab) development. DNA/LION vaccination activates myeloid and lymphoid cells in blood and LN and promotes effective antigen presentation, resulting in sustained antigen-specific cellular and humoral responses, emerging as an effective DNA vaccine delivery platform.

Ionizable lipid nanoparticles of mRNA vaccines elicit NF-κB and IRF responses through toll-like receptor 4

Ionizable lipid nanoparticles (LNP) that have enabled the success of messenger RNA (mRNA) vaccines have been shown to be immunostimulatory in the absence of mRNA. However, the mechanisms through which they activate innate immune cells is incompletely understood. Using a monocyte cell line, we compared the ability of three LNP formulations to activate transcription factors Nuclear Factor-kappa B (NF-κB) and Interferon Regulatory Factor (IRF). Comparison of signaling in knockout cell lines illustrated a role for Toll-like receptor (TLR) 4 in initiation of this signaling cascade and the contribution of the ionizable lipid component. Activation induced by empty LNPs was similar to that induced by LNPs containing mRNA, indicating that LNPs may provide the majority of innate stimulation for the mRNA vaccine platform. Our findings demonstrate that ionizable lipids within LNPs signal through TLR4 to activate NF-κB and IRF, identifying a mechanism for innate activation that can be optimized for adjuvant design.

Shared clinical and immunologic features of mRNA vaccines: preliminary results from a comparative clinical study

Introduction

Clinical trials do not typically assess underlying molecular mechanisms of vaccine immunogenicity or reactogenicity. We evaluated the reactogenicity and immunogenicity of 4 mRNA vaccines and potential contributing mechanisms and identified shared and unique clinical and immunologic features.

Methods

This ongoing, open-label, phase 1 trial randomized healthy adults (18-75 years) to receive a single dose of mRNA-1273.222 (bivalent COVID-19), mRNA-1345 (RSV), mRNA-1010 (influenza), and FLUAD (active influenza comparator) or 2 or 3 doses of mRNA-1647 (CMV). The primary objective was to assess the safety and reactogenicity of each study vaccine, with humoral immunogenicity (neutralizing antibody [nAb] responses) as the secondary objective. This interim analysis reports safety and reactogenicity in all study vaccines and humoral immunogenicity in single-dose vaccines (mRNA-1273.222, mRNA-1345, mRNA-1010, and FLUAD). Exploratory objectives included antigen-specific T-cell responses after single-dose mRNA-1345 or mRNA-1273.222, and soluble mediators of inflammation and innate immunity following vaccination in single-dose vaccine groups and two doses of mRNA-1647.

Results

At the interim analysis data cutoff (February 1, 2023), 302 participants received 1 dose of the study vaccines. Reactogenicity exhibited a consistent trend across vaccine groups; most solicited local and systemic adverse reactions within 7 days were mild or moderate in severity. There were no deaths or serious, severe, or treatment-related adverse events leading to study discontinuation. At Day 29, nAb titers against vaccine-specific antigens increased 2- to 8-fold versus baseline for all single-dose vaccine groups. In an exploratory analysis, mRNA-1273.222 and mRNA-1345 induced antigen-specific Th1-biased CD4+ and CD8+ T-cell responses at Day 29. The cytokine response analysis showed increased levels of IFN-γ, IL-6, IL-2Ra, CXCL9, IP-10, MCP-2, and MIP-1β on Day 2 following vaccination, with generally greater increases observed with mRNA vaccines versus FLUAD. Regardless of age and across mRNA vaccine groups, peak serum levels of IL-1Ra and MCP-1/MCP-2 on Day 2 weakly correlated with systemic reactogenicity scores (correlation coefficient range: 0.15-0.27).

Conclusions

The 4 mRNA vaccines had acceptable reactogenicity, demonstrated changes in serum biomarkers of innate immune activation, and were immunogenic. This suggests that the observed reactogenicity of mRNA vaccines may be related to shared features of the mRNA platform (LNP platform).

Clinical trial registration

ClinicalTrials.gov, identifier NCT05397223.

sa-mRNA influenza vaccine raises a higher and more durable immune response than mRNA vaccine in preclinical models

mRNA-based vaccines can be rapidly manufactured and have been demonstrated clinically to raise robust immune responses to COVID-19 and protect against severe COVID-19 disease. The clinical immunogenicity and efficacy of self-amplifying mRNA (sa-mRNA) vaccines have also been demonstrated, along with a longer duration of action than mRNA vaccines. However, a detailed understanding of differences between sa-mRNA and conventional mRNA vaccines with modified bases is lacking. Compared with a N1ψ-modified mRNA platform, when using an sa-mRNA approach, we observed a > 100-fold greater transfection efficiency for multiple antigens by sa-mRNA, all of which also showed high durability for gene-of-interest (GOI) production. The enhanced magnitude and durability of GOI expression by sa-mRNA compared with modified mRNA was also analysed in vivo using a luciferase reporter construct. In this experiment, sa-mRNA produced >100-fold cumulative bioluminescence compared with an mRNA construct. The elevation in GOI production translated into greater in vivo immunogenicity, where a 10-fold lower dose of sa-mRNA generated similar binding and neutralizing titers for the avian pandemic influenza H5N1 strain in both mouse and rat models. The sa-mRNA construct also generated comparable or higher antigen-specific CD8 T cell responses at 10-fold lower doses than mRNA. The lower doses of sa-mRNA generated a reduced elevation of reactogenic biomarkers while still generating similar or higher immunogenicity in rats and mice compared with modified mRNA. The current study suggests the potential of leveraging dose sparing, improved durability, enhanced immunogenicity, and possibly reduced reactogenicity of the sa-mRNA platform for vaccine applications.

Persistent epigenetic memory of SARS-CoV-2 mRNA vaccination in monocyte-derived macrophages

Immune memory plays a critical role in the development of durable antimicrobial immune responses. How precisely mRNA vaccines train innate immune cells to shape protective host defense mechanisms remains unknown. Here we show that SARS-CoV-2 mRNA vaccination significantly establishes histone H3 lysine 27 acetylation (H3K27ac) at promoters of human monocyte-derived macrophages, suggesting epigenetic memory. However, we found that two consecutive vaccinations were required for the persistence of H3K27ac, which matched with pro-inflammatory innate immune-associated transcriptional changes and antigen-mediated cytokine secretion. H3K27ac at promoter regions were preserved for six months and a single mRNA booster vaccine potently restored their levels and release of macrophage-derived cytokines. Interestingly, we found that H3K27ac at promoters is enriched for G-quadruplex DNA secondary structure-forming sequences in macrophage-derived nucleosome-depleted regions, linking epigenetic memory to nucleic acid structure. Collectively, these findings reveal that mRNA vaccines induce a highly dynamic and persistent training of innate immune cells enabling a sustained pro-inflammatory immune response.

Regulation of IL-17A-mediated hypersensitivity by extracellular vesicles and lipid nanoparticles carrying miR-451a

Extracellular vesicles (EVs), including exosomes, mediate intercellular communication by transporting functional molecules between donor cells and recipient cells, thereby regulating biological processes, such as immune responses. miR-451a, an immune regulatory microRNA, is highly abundant in circulating EVs; however, its precise physiological significance remains to be fully elucidated. Here, we demonstrate that miR-451a deficiency exacerbates delayed-type hypersensitivity (DTH) in mice. Notably, miR-451a knockout resulted in a significant increase in the number of interleukin (IL)-17A-expressing T helper 17 and γδ T cells infiltrating DTH-induced ear lesions. miR-451a deficiency also increased the number of γδ T cells in the secondary lymphoid tissues. Comprehensive analyses revealed that miR-451 deficiency promoted the expression of Rorc and γδ T cell-related genes following sensitization with allergens. Moreover, intravenous administration of wild-type EVs to miR-451a knockout mice increased cellular miR-451a levels in tissues and significantly attenuated the severity of DTH. Furthermore, synthetic lipid nanoparticles encapsulating miR-451a effectively mitigated DTH. Our findings indicate the importance of circulating miR-451a in the proliferation of γδ T cells and highlight the therapeutic potential of lipid nanoparticle-based microRNA delivery platforms for interventions in immune-related diseases.

Membrane-targeted immunogenic compositions using exosome mimetic approach for vaccine development against SARS-CoV-2 and other pathogens

The COVID-19 pandemic has underscored the urgent need for a vaccine strategy that is safe, effective, rapid, cost-efficient, and scalable for large-scale deployment during widespread infectious outbreaks. Here, we present a new vaccination strategy that meets these critical requirements. The SARS-CoV-2 S protein consists of the S1 and S2 subunits. The S2 subunit acts as the viral cell membrane fusion protein, and mutations in its C-terminal region facilitate the transport of the entire S protein to the cell membrane. When we expressed the SARS-CoV-2 S protein with a deletion of 21 amino acids from its C-terminal region in various cell types, we observed a dense presence of the protein in the cell membrane, as determined by IHC, dot blot, and ELISA. In the cell membrane-SARS-CoV-2 S protein complex, the cell membrane functions as an exosome mimic, carrying protein antigens (S protein) in their most natural form, as no further protocols are used to attach antigens to the membrane. We demonstrate that using the membrane-S protein component as a vaccine yields a more robust and protective immune response, with enhanced safety compared to mRNA-based or inactivated virus-based vaccines against SARS-CoV-2. Additionally, we show that fusing the transmembrane domain of the Vesicular Stomatitis Virus (VSV) G protein with the SARS-CoV-2 S1 protein effectively transports the S1 protein to the cell membrane, similar to SARS-CoV-2 S Δ21. We propose that designing the S2 subunit of the SARS-CoV-2 S protein, or its analogues such as the VSV-G protein, as carriers for fusing bacterial, viral, or tumor proteins with antigenic properties-and transporting them to the cell membrane-could result in a comprehensive vaccination protocol applicable to all bacteria, viruses, and even tumors.

In Vivo Engineered CAR-T Cell Therapy: Lessons Built from COVID-19 mRNA Vaccines

Chimeric antigen receptor T cell (CAR-T) therapy has revolutionized cancer immunotherapy but continues to face significant challenges that limit its broader application, such as antigen targeting, the tumor microenvironment, and cell persistence, especially in solid tumors. Meanwhile, the global implementation of mRNA vaccines during the COVID-19 pandemic has highlighted the transformative potential of mRNA and lipid nanoparticle (LNP) technologies. These innovations, characterized by their swift development timelines, precise antigen design, and efficient delivery mechanisms, provide a promising framework to address some limitations of CAR-T therapy. Recent advancements, including mRNA-based CAR engineering and optimized LNP delivery, have demonstrated the capacity to enhance CAR-T efficacy, particularly in the context of solid tumors. This review explores how mRNA-LNP technology can drive the development of in vivo engineered CAR-T therapies to address current limitations and discusses future directions, including advancements in mRNA design, LNP optimization, and strategies for improving in vivo CAR-T functionality and safety. By bridging these technological insights, CAR-T therapy may evolve into a versatile and accessible treatment paradigm across diverse oncological landscapes.

Intranasal prime-boost RNA vaccination elicits potent T cell response for lung cancer therapy

The rapid success of RNA vaccines in preventing SARS-CoV-2 has sparked interest in their use for cancer immunotherapy. Although many cancers originate in mucosal tissues, current RNA cancer vaccines are mainly administered non-mucosally. Here, we developed a non-invasive intranasal cancer vaccine utilizing circular RNA encapsulated in lipid nanoparticles to induce localized mucosal immune responses. This strategy elicited potent anti-tumor T cell responses in preclinical lung cancer models while mitigating the systemic adverse effects commonly associated with intravenous RNA vaccination. Specifically, type 1 conventional dendritic cells were indispensable for T cell priming post-vaccination, with both alveolar macrophages and type 1 conventional dendritic cells boosting antigen-specific T cell responses in lung tissues. Moreover, the vaccination facilitated the expansion of both endogenous and adoptive transferred antigen-specific T cells, resulting in robust anti-tumor efficacy. Single-cell RNA sequencing revealed that the vaccination reprograms endogenous T cells, enhancing their cytotoxicity and inducing a memory-like phenotype. Additionally, the intranasal vaccine can modulate the response of CAR-T cells to augment therapeutic efficacy against tumor cells expressing specific tumor-associated antigens. Collectively, the intranasal RNA vaccine strategy represents a novel and promising approach for developing RNA vaccines targeting mucosal malignancies.

Enhancement of NK Cell Cytotoxic Activity and Immunoregulatory Effects of a Natural Product Supplement Across a Wide Age Span: A 30-Day In Vivo Human Study

The purpose of this study was to examine whether supplementation of ultra- and nanofiltered colostrum-based products, combined with egg yolk extract, nicotinamide mononucleotide (NMN), quercetin, alpha-ketoglutarate, white button mushroom, and celery seed extracts (the formula was patented by 4Life Research Company, USA and named as AgePro), modulate the functional activity of natural killer (NK) cells in vivo. We found that this supplement, taken orally in two capsules twice a day for 30 days, significantly enhanced the cytotoxic activity of NK cells. This was evidenced by the increased NK cell-mediated killing of carboxyfluorescein diacetate succinimidyl ester (CFSE)-labeled K562 human myeloid leukemia cells. As expected, this effect was dependent on the ratio between the effector (E) (e.g., peripheral blood mononuclear cells (PBMCs)) and target (T) (e.g., K562) cells, illustrating maximal killing of K562 cells at a 50:1 E/T ratio. Of note, increased NK-mediated killing of K562 cells after taking AgePro correlated with increased perforin release, evidenced by the CD107a degranulation assay. In concordance with these findings, taking of AgePro for 1 month increased production of several cytokines and chemokines, including IL-1β, IL-1Rα, IL-6, IL-8, IL-10, IFN-γ, TNF-α, G-CSF, PDGF-AA, PDGF-AB/BB, GRO, MCP-1, MCP-3, and MIP-1α, in PBMCs co-cultured with K562 cells. Of note, increased production of the cytokines correlated with the activation state of PBMCs, as evidenced by increased expression of the surface activation markers (e.g., the interleukin-2 receptor alpha chain-CD25). A strong correlation was found between NK-based cytotoxic activity and the production of IL-1β, IL-6, TNF-α, and MIP-1α. Importantly, no increase in the aforementioned soluble factors and activation markers was detected in PBMCs cultured alone, thereby illustrating the potent immunoregulatory activity of AgePro only in the presence of the harmful target cells. Hematological parameters also remained unchanged over the entire study period. Collectively, we show herein the significant enhancement of the cytotoxic activity of NK cells against target tumor cells after taking AgePro for 1 month. Notably, this effect was observed for all age groups, including young, adult, and elderly participants. Moreover, a significant improvement in NK cytotoxic activity was also detected for participants with low basal (e.g., before taking AgePro) numbers of NK-mediated killing. The enhancement of NK-based cytotoxicity was associated with an increased release of several cytokines and chemokines involved in regulating a broad spectrum of mechanisms outside the cell-mediated cytotoxicity and killing of target cells. Of note, spontaneous activation of PBMCs, particularly NK cells, was not detected after taking AgePro. Given that spontaneous activation of autoreactive lymphocytes is a feature associated with autoimmunity and taking into account our data illustrating the AgePro-induced activation of NK cells detected only in the presence of the potentially harmful cells, we conclude that our innovative product exhibits potent immunoregulatory activity and high safety profile.

Association between vaccination, viral antibodies, and asthma prevalence in the U.S.: insights from NHANES (1999-2020)

Objective

This investigation aimed to explore the differences in asthma prevalence among various demographic groups in the U.S., focusing on factors related to vaccination and viral antibodies.

Methods

The study analyzed data from 37,445 individuals collected through the National Health and Nutrition Examination Survey between 1998 and 2020. Employing weighted sampling methods, the analysis considered the stratification and clustering typical of the survey's design. It particularly examined how age, race, income, smoke, education, and gender factors influence both the prevalence and severity of asthma.

Results

This study aims to elucidate disparities in asthma prevalence across the U.S. population by examining the roles of demographic characteristics and factors related to vaccination and viral antibodies. It revealed a significant correlation between asthma prevalence and patient demographics, including age, gender, income, smoke, education, and race. We found that asthma patients were mostly found in participants with lower economic level (2.7 vs. 2.87). Non-Hispanic black women age exhibited a higher likelihood of asthma, at 17.7%, compared to non-Hispanic whites and Mexican Americans. Asthma prevalence peaks between the ages of 20 and 30 and has shown a rising trend over the years. Regarding vaccinations, hepatitis A, hepatitis B, pneumococcal, and HPV vaccines were associated with an increased risk of asthma. Conversely, patients testing positive for hepatitis A virus and core hepatitis B virus antibodies demonstrated a lower prevalence of asthma. Additionally, asthmatic patients showed lower average measles virus and rubella antibodies levels, at 0.53 and 3.32, respectively, compared to non-asthmatic individuals. Notably, asthma incidence was lower in herpesvirus I-positive patients (OR: 0.895, CI, 0.809%-0.991%), while herpesvirus II-positive patients displayed a higher incidence of asthma (OR: 1.102, CI, 0.974%-1.246%).

Conclusion

The study findings underscore the significant prevalence of asthma and its correlation with population demographics, vaccination rates, and serum viral antibodies. These results highlight the importance of implementing tailored public health interventions.

Humoral immune response characteristics of vulnerable populations against SARS-CoV-2 strains EG.5 and JN.1 after infection with strains BA.5 and XBB

In this study, we compared the humoral immune characteristics of children, elderly individuals, and pregnant women in Guangzhou, China, who had been infected with the SARS-CoV-2 strains BA.5 and XBB against the currently predominant strains EG.5 and JN.1. It was discovered that the neutralizing antibody titers in children, elderly individuals, and pregnant women against strains EG.5 and JN.1 were low in individuals who had been infected with strain BA.5, irrespective of their vaccination status. There was a significant positive correlation between the neutralization titers against JN.1 and EG.5 in both the acute and convalescent phases of BA.5 infection. For XBB-infected patients, the sera in the acute stage exhibited a low neutralizing titer against EG.5 and JN.1, whereas the convalescent sera demonstrated a significantly higher neutralizing titer against the two viruses, particularly in infected individuals who had been vaccinated. For XBB-infected patients, there was a strong positive correlation between the serum neutralizing antibody titers against EG.5 and JN.1 in both the acute and recovery phases. This finding provides crucial information for judging the epidemic trend of COVID-19 and the development of vaccines, especially for developing customized vaccines and immune strategies for different populations.

Identification of Cell Receptors Responsible for Recognition and Binding of Lipid Nanoparticles

Effective delivery of lipid nanoparticles (LNPs) and their organ- or cell-type targeting are paramount for therapeutic success. Achieving this requires a comprehensive understanding of protein corona dynamics and the identification of cell receptors involved in the recognition and uptake of LNPs. We introduce a simple, fast, and in situ strategy by a biosensor-based "Fishing" method to uncover protein corona formation on LNPs and identify key receptors of human blood cells that are responsible for the recognition and binding of human plasma corona on the surface of LNPs. Unexpectedly, we observed a significant presence of immunoglobulins with high abundance, especially anti-PEG antibodies, within the LNP corona. These antibodies, along with complement opsonization, drive colony-stimulating factor 2 receptor β (CSF2RB)-mediated phagocytosis by human myeloid cells. These compositions of the human plasma corona and their interactions with neighboring proteins are critical for the recognition and binding of LNPs by cell receptors and cellular uptake. Our findings highlight the pivotal role of anti-PEG antibodies in the circulation and phagocytosis of LNPs in vivo. This approach offers profound insights into nanomaterial behavior in vivo, paving the way for the enhanced design and efficacy of LNP-based therapies.

Visualizing lipid nanoparticle trafficking for mRNA vaccine delivery in non-human primates

mRNA delivered using lipid nanoparticles (LNPs) has become an important subunit vaccine modality, but mechanisms of action for mRNA vaccines remain incompletely understood. Here, we synthesized a metal chelator-lipid conjugate enabling positron emission tomography (PET) tracer labeling of LNP/mRNA vaccines for quantitative visualization of vaccine trafficking in live mice and non-human primates (NHPs). Following intramuscular injection, we observed LNPs distributing through injected muscle tissue, simultaneous with rapid trafficking to draining lymph nodes (dLNs). Deltoid injection of LNPs mimicking human vaccine administration led to stochastic LNP delivery to three different sets of dLNs. LNP uptake in dLNs was confirmed by histology, and cellular analysis of tissues via flow cytometry identified antigen-presenting cells as the primary immune cell type responsible for early LNP uptake and mRNA translation. These results provide insights into the biodistribution of mRNA vaccines administered at clinically relevant doses, injection volumes, and injection sites in an important large animal model for vaccine development.

Poly(β-amino ester) polymer library with monomer variation for mRNA delivery

Non-viral vectors for mRNA delivery primarily include lipid nanoparticles (LNPs) and polymers. While LNPs are known for their high mRNA delivery efficiency, they can induce excessive immune responses and cause off-target effects, potentially leading to side effects. In this study, we aimed to explore polymer-based mRNA delivery systems as a viable alternative to LNPs, focusing on their mRNA delivery efficiency and potential application in mRNA vaccines. We created a library of poly(β-amino ester) (PBAE) polymers by combining various amine monomers and acrylate monomers. Through screening this polymer library, we identified specific polymer nanoparticles (PNPs) that demonstrated high mRNA expression efficiency, with sustained mRNA expression for up to two weeks. Furthermore, the PNPs showed mRNA expression only at the injection site and did not exhibit liver toxicity. Additionally, when assessing immune activation, the PNPs significantly induced T-cell immune activation and were effective in the plaque reduction neutralization test. These results suggest that polymer-based mRNA delivery systems not only hold potential for use in mRNA vaccines but also show promise for therapeutic applications.

Design, current states, and challenges of nanomaterials in anti-neuroinflammation: A perspective on Alzheimer's disease

Alzheimer's disease (AD), an age-related neurodegenerative disease, brings huge damage to the society, to the whole family and even to the patient himself. However, until now, the etiological factor of AD is still unknown and there is no effective treatment for it. Massive deposition of amyloid-beta peptide(Aβ) and hyperphosphorylation of Tau proteins are acknowledged pathological features of AD. Recent studies have revealed that neuroinflammation plays a pivotal role in the pathology of AD. With the rise of nanomaterials in the biomedical field, researchers are exploring how the unique properties of these materials can be leveraged to develop effective treatments for AD. This article has summarized the influence of neuroinflammation in AD, the design of nanoplatforms, and the current research status and inadequacy of nanomaterials in improving neuroinflammation in AD.

CD47 Knock-Out Using CRISPR-Cas9 RNA Lipid Nanocarriers Results in Reduced Mesenchymal Glioblastoma Growth In Vivo

Immune checkpoint (ICP) blockade has shown limited effectiveness in glioblastoma (GBM), particularly in the mesenchymal subtype, where interactions between immune cells and glioblastoma cancer stem cells (GSCs) drive immunosuppression and therapy resistance. Tailoring ICPs specific to GSCs can enhance the antitumor immune response. This study proposes the use of lipid nanoparticles (LNPs) encapsulating CRISPR RNAs as an in vivo screening tool for ICPs in a syngeneic model of mesenchymal GSCs. Using PD-L1 and CD47 to validate the proof of concept, intratumoral administration of LNPs in orthotopic tumors achieved efficient editing of ICPs, leading to enhanced immune cell infiltration within the tumor microenvironment. Targeting CD47 reduced tumor growth, suggesting improved cancer cell sensitization to the immune system post-ICP editing. The study positions LNPs as a robust tool for in vivo validation of ICPs as therapeutic targets in clinically relevant GBM models. LNPs could serve as a screening tool in patient-derived xenografts to identify and optimize ICP combinations, potentially expediting ICP translation and enhancing personalized GBM immunotherapies.

Vax-Innate: improving therapeutic cancer vaccines by modulating T cells and the tumour microenvironment

T cells have a critical role in mediating antitumour immunity. The success of immune checkpoint inhibitors (ICIs) for cancer treatment highlights how enhancing endogenous T cell responses can mediate tumour regression. However, mortality remains high for many cancers, especially in the metastatic setting. Based on advances in the genetic characterization of tumours and identification of tumour-specific antigens, individualized therapeutic cancer vaccines targeting mutated tumour antigens (neoantigens) are being developed to generate tumour-specific T cells for improved therapeutic responses. Early clinical trials using individualized neoantigen vaccines for patients with advanced disease had limited clinical efficacy despite demonstrated induction of T cell responses. Therefore, enhancing T cell activity by improving the magnitude, quality and breadth of T cell responses following vaccination is one current goal for improving outcome against metastatic tumours. Another major consideration is how T cells can be further optimized to function within the tumour microenvironment (TME). In this Perspective, we focus on neoantigen vaccines and propose a new approach, termed Vax-Innate, in which vaccination through intravenous delivery or in combination with tumour-targeting immune modulators may improve antitumour efficacy by simultaneously increasing the magnitude, quality and breadth of T cells while transforming the TME into a largely immunostimulatory environment for T cells.

Improving the Efficacy of Cancer mRNA Vaccines

mRNA vaccines consist of antigen-encoding mRNA, which produces the antigenic protein upon translation. Coupling antigen production with innate immune activation can generate a potent, antigen-specific T-cell response. Clinical reports have demonstrated the ability of mRNA vaccines to elicit an anticancer immune response against various tumor types. Here, we discuss strategies to enhance the potency of mRNA vaccines. We provide an overview of existing knowledge regarding the activation and trafficking mechanisms of mRNA vaccines and share optimization strategies to boost mRNA-mediated antigen production. In addition, we address methods to target mRNA vaccines to dendritic cells and lymph nodes, key initiators of the immune response. Finally, we review strategies for enhancing immune activation using adjuvants compatible with mRNA vaccines. mRNA vaccines offer unique advantages that can be utilized for oncology applications. However, significant work is needed to understand their underlying mechanisms and develop technologies to improve their effectiveness.

Linking vaccine adjuvant mechanisms of action to function

Vaccines deliver an immunogen in a manner designed to safely provoke an immune response, leading to the generation of memory T and B cells and long-lived antibody-producing plasma cells. Adjuvants play a critical role in vaccines by controlling how the immune system is exposed to the immunogen and providing inflammatory cues that enable productive immune priming. However, mechanisms of action underlying adjuvant function at the molecular, cell, and tissue levels are diverse and often poorly understood. Here, we review the current understanding of mechanisms of action underlying adjuvants used in subunit protein/polysaccharide vaccines and mRNA vaccines, discuss where possible how these mechanisms of action link to downstream effects on the immune response, and identify knowledge gaps that will be important to fill in order to enable the continued development of more effective adjuvants for challenging pathogens such as HIV and emerging threats.

Intratumoral administration of mRNA COVID-19 vaccine delays melanoma growth in mice

Immunotherapies are effective for cancer treatment but are limited in 'cold' tumor microenvironments due to a lack of infiltrating CD8+ T cells, key players in the anti-cancer immune response. The onset of the COVID-19 pandemic sparked the widespread use of mRNA-formulated vaccines and is well documented that vaccination induces a Th1-skewed immune response. Here, we evaluated the effects of an intratumoral injection of the mRNA COVID-19 vaccine in subcutaneous melanoma tumor mouse models. Tumor growth and survival studies following a single intratumoral injection of the COVID-19 vaccine showed significant tumor suppression and prolonged survival in established B16F10 subcutaneous tumor-bearing mice. mRNA vaccine treatment resulted in a significant increase in CD8+ T cell infiltration into the tumor microenvironment, as observed using intravital imaging and flow cytometry. Further tumor growth suppression was achieved using additional mRNA vaccine treatments. Combination administration of mRNA vaccine with immune checkpoint therapies demonstrated enhanced effects, further delaying tumor growth and improving the survival time of tumor-bearing mice. This study demonstrates that mRNA vaccines may be used as adjuvants for immunotherapies.

Interleukin-1 prevents SARS-CoV-2-induced membrane fusion to restrict viral transmission via induction of actin bundles

Innate immune responses triggered by severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) infection play pivotal roles in the pathogenesis of COVID-19, while host factors including proinflammatory cytokines are critical for viral containment. By utilizing quantitative and qualitative models, we discovered that soluble factors secreted by human monocytes potently inhibit SARS-CoV-2-induced cell-cell fusion in viral-infected cells. Through cytokine screening, we identified that interleukin-1β (IL-1β), a key mediator of inflammation, inhibits syncytia formation mediated by various SARS-CoV-2 strains. Mechanistically, IL-1β activates RhoA/ROCK signaling through a non-canonical IL-1 receptor-dependent pathway, which drives the enrichment of actin bundles at the cell-cell junctions, thus prevents syncytia formation. Notably, in vivo infection experiments in mice confirmed that IL-1β significantly restricted SARS-CoV-2 spread in the lung epithelium. Together, by revealing the function and underlying mechanism of IL-1β on SARS-CoV-2-induced cell-cell fusion, our study highlights an unprecedented antiviral function for cytokines during viral infection.

Shear Stress Conditioning Promotes a Pro-Inflammatory Response in Porcine Endocardial Endothelial Cells

PURPOSE

Discrete subaortic stenosis (DSS) is a congenital heart disease characterized by a narrowing of the passage below the aortic valve in the left ventricular outflow tract (LVOT) [1]. While endocardial endothelial cells (EECs) are known to play a role in DSS, the response of these cells to shear stress is not known. In this study, we hypothesize that the response of EECs to shear stress in the LVOT is a mediator of DSS.

METHODS

To test this hypothesis, we conditioned porcine EECs to controlled shear stress regimes using cone and plate bioreactors. Subsequently, we quantified the concentration of proinflammatory cytokine in the conditioned media using the Luminex assay. Bulk-RNA sequencing was used to quantify changes in the genotype of the shear stress conditioned EECs.

RESULTS

The expression of CD31 was knocked down and subsequently, the changes in release of shear stress induced proinflammatory cytokines released by EECs quantified using the Luminex assay. The results of these studies show that the inflammatory cytokines were highly selected in the conditioning medium, and under bioreactor treatment the cell activated the PI3K-AKT and TNF-a signaling, which also triggered the other immune cell responses though Th1, Th2 and Th17 cell differentiation pathways. Furthermore, CD31 was identified as a mediator of the pro-inflammatory response of shear stress conditioned EECs.

CONCLUSIONS

The studies provide a clear link between shear stress, and the subsequent proinflammatory response of EECs as a mediator of DSS.

Effects of increasing levels of rubber seed cake on growth performance, nutrient digestion metabolism, serum biochemical parameters, and rumen microbiota of Hu sheep

This study aimed to reveal the effects of increasing levels of rubber seed cake (RSC) on growth performance, nutrient digestion metabolism, serum biochemical parameters, and rumen microbiota in Hu sheep. In this study, 48 Hu sheep, weighing 17.01 ± 0.57 kg at 3 months of age, were randomly divided into four treatments: 0% rubber seed cake (RSC0%), 6% rubber seed cake (RSC6%), 12% rubber seed cake (RSC12%) and 18% rubber seed cake (RSC18%), with 12 sheep per group. Compared to the RSC0%, the ADG and DMI of the RSC6% and RSC12% were increased (P > 0.05). The apparent digestibility of OM and EE quadratically (P < 0.05) changed with the increase of RSC supplementation, with the greatest apparent digestibility of OM and EE observed in the RSC6% diet. With increased RSC supplementation, the N intake and fecal N increased linearly (P < 0.05), and the apparent digestibility of N reduced linearly (P < 0.05). As the increase of RSC supplementation, the serum levels of IgA, IgM, IgG, IL-4, T-AOC, and GSH-Px increased linearly (P < 0.05), and the serum level of IL-6 reduced linearly (P < 0.05). The serum level of IL-1β reduced quadratically (P < 0.05) with the increased RSC dose, and the serum level of SOD increased quadratically (P < 0.05) with the increased RSC dose. The ruminal NH3-N and the relative abundance of norank_Muribaculaceae quadratically (P < 0.05) changed with increased RSC supplementation, and the greatest relative abundance of norank_Muribaculaceae was observed in the RSC6% diet. In general, incorporating RSC into the diet of Hu sheep did not adversely affect growth performance and rumen fermentation characteristics. Supplementing with 6% RSC enhanced the relative abundance of norank_Muribaculacea in the rumen fluid and the immune and antioxidant capabilities. However, supplementing with 12 and 18% RSC might have negatively impacted nutrient digestion and metabolism. Therefore, this study recommended replacing corn and soybean meal with 6% RSC in the diet of Hu sheep.

Low-inflammatory lipid nanoparticle-based mRNA vaccine elicits protective immunity against H5N1 influenza virus with reduced adverse reactions

Messenger RNA vaccines based on lipid nanoparticles (mRNA-LNPs) are promising vaccine modalities. However, mRNA-LNP vaccines frequently cause adverse reactions such as swelling and fever in humans, partly due to the inflammatory nature of LNP. Modification of the ionizable lipids used in LNPs is one approach to avoid these adverse reactions. Here, we report the development of mRNA-LNP vaccines with better protective immunity and reduced adverse reactions using LNPs, which contain a disulfide (SS)-cleavable bond and pH-activated lipid-like materials with oleic acid (ssPalmO) as an ionizable lipid (LNPssPalmO). We used mRNA expressing H5N1 subtype high-pathogenicity avian influenza virus-derived hemagglutinin or neuraminidase to generate mRNA-LNP vaccines against H5N1 influenza. Compared with conventional LNPs, mRNA-LNPssPalmO induced comparable antigen-specific antibodies and better interferon-γ (IFN-γ)-producing T helper type 1 responses in mice. Both mRNA-LNPssPalmO and conventional mRNA-LNPs conferred strong protection against homologous H5N1 virus challenge. In addition, mRNA-LNPssPalmO showed better cross-protection against heterologous H5N1 virus challenge compared with conventional mRNA-LNPs. Furthermore, we observed that mRNA-LNPssPalmO induced less-inflammatory responses (e.g., inflammatory cytokine production, vascular hyperpermeability) and fewer adverse reactions (e.g., weight loss, fever) compared with conventional mRNA-LNPs. These results suggest that mRNA-LNPssPalmO would be a safe alternative to conventional vaccines to overcome mRNA-LNP vaccine hesitancy.

The role of IL-1 family cytokines in diabetic cardiomyopathy

Diabetic cardiomyopathy (DCM) is the primary cause of heart failure in patients with diabetes and is characterised by contractile dysfunction and left ventricular hypertrophy. The complex pathological and physiological mechanisms underlying DCM have contributed to a limited number of available treatment options. A substantial body of evidence has established that DCM is a low-grade inflammatory cardiovascular disorder, with the interleukin-1 (IL-1) family of cytokines playing crucial roles in initiating inflammatory responses and shaping innate and adaptive immunity. In this review, we aim to provide an overview of the underlying mechanisms of the IL-1 family and their relevance in DCM of various aetiologies. Furthermore, we highlighted potential therapeutic targets within the IL-1 family for the management of DCM.

Human embryonic stem cell-derived immunity-and-matrix-regulatory cells on collagen scaffold effectively treat rat corneal alkali burn

Corneal alkali burns (CAB) are a severe form of ocular injury that often leads to significant vision loss, with limited effective treatment options available beyond corneal transplantation. Immunity and matrix-regulatory cells (IMRCs) have emerged as a promising alternative due to their ability to modulate immune responses and support tissue repair. This study investigates the efficacy of IMRCs on collagen scaffolds (IMRCs-col) for treating CAB in a rat model. We developed a novel treatment combining IMRCs with a collagen scaffold to align with the ocular surface structure. In vitro analyses showed that IMRCs-col significantly upregulated the expression of immune regulatory molecules, including IL-1RA and SCF. Additionally, IMRCs-col effectively inhibited the production of pro-inflammatory cytokines (IL-8 and Gro-a/CXCL1) while promoting pro-regenerative cytokines (bFGF, HGF, and PDGF). In an animal model of CAB, IMRCs-col transplantation demonstrated substantial efficacy in restoring corneal opacity and reducing neovascularization. Histological examination revealed reduced inflammation and improved corneal tissue regeneration compared to untreated CAB. Enhanced activation of pathways associated with anti-inflammatory responses and tissue repair was observed at days 3, 7, and 21 post-treatment.

Variants and vaccines impact nasal immunity over three waves of SARS-CoV-2

Viral variant and host vaccination status impact infection with severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2), yet how these factors shift cellular responses in the human nasal mucosa remains uncharacterized. We performed single-cell RNA sequencing (scRNA-seq) on nasopharyngeal swabs from vaccinated and unvaccinated adults with acute Delta and Omicron SARS-CoV-2 infections and integrated with data from acute infections with ancestral SARS-CoV-2. Patients with Delta and Omicron exhibited greater similarity in nasal cell composition driven by myeloid, T cell and SARS-CoV-2hi cell subsets, which was distinct from that of ancestral cases. Delta-infected samples had a marked increase in viral RNA, and a subset of PER2+EGR1+GDF15+ epithelial cells was enriched in SARS-CoV-2 RNA+ cells in all variants. Prior vaccination was associated with increased frequency and activation of nasal macrophages. Expression of interferon-stimulated genes negatively correlated with coronavirus disease 2019 (COVID-19) severity in patients with ancestral and Delta but not Omicron variants. Our study defines nasal cell responses and signatures of disease severity across SARS-CoV-2 variants and vaccination.

Enhancing the immunogenicity of lipid-nanoparticle mRNA vaccines by adjuvanting the ionizable lipid and the mRNA

To elicit optimal immune responses, messenger RNA vaccines require intracellular delivery of the mRNA and the careful use of adjuvants. Here we report a multiply adjuvanted mRNA vaccine consisting of lipid nanoparticles encapsulating an mRNA-encoded antigen, optimized for efficient mRNA delivery and for the enhanced activation of innate and adaptive responses. We optimized the vaccine by screening a library of 480 biodegradable ionizable lipids with headgroups adjuvanted with cyclic amines and by adjuvanting the mRNA-encoded antigen by fusing it with a natural adjuvant derived from the C3 complement protein. In mice, intramuscular or intranasal administration of nanoparticles with the lead ionizable lipid and with mRNA encoding for the fusion protein (either the spike protein or the receptor-binding domain of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2)) increased the titres of antibodies against SARS-CoV-2 tenfold with respect to the vaccine encoding for the unadjuvanted antigen. Multiply adjuvanted mRNA vaccines may improve the efficacy, safety and ease of administration of mRNA-based immunization.

Unleashing the potential of natural protein based nanoparticles for the delivery of therapeutic nucleic Acid: A comprehensive review

Nucleic acid-based therapeutics represent a revolutionary approach in treating genetic disorders, offering unprecedented potential for addressing pathologies at their molecular level. However, effective cellular delivery remains a critical challenge hindering their clinical implementation. While existing delivery systems, including viral vectors and lipid nanoparticles, have shown utility, they face limitations in immunogenicity, cargo capacity, and manufacturing complexity. Natural protein-based nanoparticles, derived from proteins such as albumin, ferritin, and elastin, have emerged as promising alternative delivery systems. These carriers offer distinct advantages including reduced immunogenicity, enhanced biocompatibility, and optimal biodegradation profiles. Their engineerable nature enables precise control over particle size, surface charge, and ligand conjugation, facilitating selective cellular targeting and improved pharmacokinetics. Recent technological advances have expanded the application of protein nanoparticles across various nucleic acid modalities, including mRNA, siRNA, and plasmid DNA. Extensive research has characterized these systems through rigorous in vitro and in vivo studies, advancing our understanding of their biological behavior and clinical potential. Advanced engineering methodologies have further enhanced their optimization for specific therapeutic applications. This review examines the development and potential of protein-based nanoparticles in nucleic acid delivery, highlighting their advantages and addressing current challenges. By analyzing recent advances and clinical progress, we underscore their significant potential to enhance the safety, specificity, and efficacy of nucleic acid therapeutics, potentially revolutionizing the treatment of genetic disorders.

The type I IFN-IL-27 axis promotes mRNA vaccine-induced CD8 + T cell responses

The ability of lipid nanoparticle (LNP)-delivered mRNA vaccines to induce type I IFNs is critical to promote CD8 + T cell responses. The studies presented here indicate that immunization with nucleoside modified mRNA-LNP vaccines drives myeloid cell expression of the cytokine IL-27, which acts on antigen-specific CD8 + T cells to sustain T cell expansion. In vitro and in vivo studies revealed that type I IFN signaling is necessary for mRNA-LNP-induced IL-27 production, that immunization failed in IL-27 KO mice, and that immunization of IFNAR1-deficient mice with mRNA-LNP particles that also encode IL-27 mRNA restored antigen-specific CD8 + T cell responses. In addition, IL-27 mRNA-LNPs served as an adjuvant that improved cytolytic CD8 + T cell responses and the therapeutic efficacy of mRNA-LNPs to drive anti-pathogen and anti-tumor immunity. These studies highlight the central role of IL-27 in mRNA-LNP induced CD8 + T cell responses and the ability of this cytokine to augment the functionality of the CD8 + T cell response for prophylactic or therapeutic immunization.

Brucella abortus impairs T lymphocyte responsiveness by mobilizing IL-1RA-secreting omental neutrophils

Immune evasion strategies of Brucella, the etiologic agent of brucellosis, a global zoonosis, remain partially understood. The omentum, a tertiary lymphoid organ part of visceral adipose tissue, has never been explored as a Brucella reservoir. We report that B. abortus infects and replicates within murine omental macrophages. Throughout the chronic phase of infection, the omentum accumulates macrophages, monocytes and neutrophils. The maintenance of PD-L1+Sca-1+ macrophages, monocytes and neutrophils in the omentum depends on the wadC-encoded determinant of Brucella LPS. We demonstrate that PD-L1+Sca-1+ murine omental neutrophils produce high levels of IL-1RA leading to T cell hyporesponsiveness. These findings corroborate brucellosis patient analysis of whole blood displaying upregulation of PDL1 and Ly6E genes, and of serum exhibiting high levels of IL-1RA. Overall, the omentum, a reservoir for B. abortus, promotes bacterial persistence and causes CD4+ and CD8+ T cell immunosuppression by IL-1RA secreted by PD-L1+Sca-1+ neutrophils.

Impaired Hepatitis B and COVID-19 vaccination responses show strong concordance in hemodialysis patients with end stage renal disease

BACKGROUND

Patients with end stage renal disease (ESRD) undergoing hemodialysis are at increased risk for infection and impaired vaccination responses. We analyzed overlap and influencing factors of vaccination responses against severe acute respiratory syndrome corona virus disease 2 (SARS-CoV-2) and Hepatitis B virus (HBV).

METHODS

SARS-CoV-2 and HBV vaccination response was assessed in a cohort of German ESRD hemodialysis patients. Anti-HBs- and SARS-CoV-2 anti-S-IgG were analyzed by ELISA. Demographic and clinical data were extracted from clinical files.

RESULTS

Sixty-four patients with complete information on HBV and SARS-CoV-2 vaccination responses were included. More than one-third (35.4%) of non-responders upon HBV vaccination were identified. Unresponsiveness after HBV and poor response after SARS-CoV-2 vaccination showed strong overlap, and overall, 70.3% of patients were classified into concordant HBV/SARS vaccination response groups. HBV vaccination non-responsiveness, but not poor SARS-CoV-2 post-vaccination immunity was associated with obesity, while poor SARS-CoV-2 vaccination responses were associated increased age.

CONCLUSION

Our findings confirm previous reports on impaired vaccination response in hemodialysis patients and show that post-vaccination humoral responses against SARS-CoV-2 and HBV display strong overlap in this vulnerable patient group. These results may help to adapt vaccination strategies in this highly vulnerable population.

TRIAL REGISTRATION

German Clinical Trial Registry, DRKS00021152.

Exploring the impact of lipid nanoparticles on protein stability and cellular proteostasis

Lipid nanoparticles (LNPs) have become pivotal in advancing modern medicine, from mRNA-based vaccines to gene editing with CRISPR-Cas9 systems. Though LNPs based therapeutics offer promising drug delivery with satisfactory clinical safety profiles, concerns are raised regarding their potential nanotoxicity. Here, we explore the impacts of LNPs on protein stability in buffer and cellular protein homeostasis (proteostasis) in HepG2 cells. First, we show that LNPs of different polyethylene glycol (PEG) molar ratios to total lipid ratio boost protein aggregation propensity by reducing protein stability in cell lysate and blood plasma. Second, in HepG2 liver cells, these LNPs induce global proteome aggregation, as imaged by a cellular protein aggregation fluorescent dye (AggStain). Such LNPs induced proteome aggregation is accompanied by decrease in cellular micro-environmental polarity as quantified by a solvatochromic protein aggregation sensor (AggRetina). The observed local polarity fluctuations may be caused by the hydrophobic contents of LNPs that promote cellular proteome aggregation. Finally, we exploit RNA sequencing analysis (RNA-Seq) to reveal activation of unfolded protein response (UPR) pathway and other proteostasis genes upon LNPs treatment. Together, these findings highlight that LNPs may induce subtle proteome stress by compromising protein stability and proteostasis even without obvious damage to cell viability.

Autogene cevumeran with or without atezolizumab in advanced solid tumors: a phase 1 trial

Effective targeting of somatic cancer mutations to enhance the efficacy of cancer immunotherapy requires an individualized approach. Autogene cevumeran is a uridine messenger RNA lipoplex-based individualized neoantigen-specific immunotherapy designed from tumor-specific somatic mutation data obtained from tumor tissue of each individual patient to stimulate T cell responses against up to 20 neoantigens. This ongoing phase 1 study evaluated autogene cevumeran as monotherapy (n = 30) and in combination with atezolizumab (n = 183) in pretreated patients with advanced solid tumors. The primary objective was safety and tolerability; exploratory objectives included evaluation of pharmacokinetics, pharmacodynamics, preliminary antitumor activity and immunogenicity. Non-prespecified interim analysis showed that autogene cevumeran was well tolerated and elicited poly-epitopic neoantigen-specific responses, encompassing CD4+ and/or CD8+ T cells, in 71% of patients, most of them undetectable at baseline. Responses were detectable up to 23 months after treatment initiation. CD8+ T cells specific for several neoantigens constituted a median of 7.3% of circulating CD8+ T cells, reaching up to 23% in some patients. Autogene cevumeran-induced T cells were found within tumor lesions constituting up to 7.2% of tumor-infiltrating T cells. Clinical activity was observed, including one objective response in monotherapy dose escalation and in two patients with disease characteristics unfavorable for response to immunotherapy treated in combination with atezolizumab. These findings support the continued development of autogene cevumeran in earlier treatment lines. ClinicalTrials.gov registration: NCT03289962 .

Comparison of safety and immunogenicity in the elderly after receiving either Comirnaty or Spikevax monovalent XBB1.5 COVID-19 vaccine

BACKGROUND

The emergence of SARS-CoV-2 variants necessitates ongoing evaluation of vaccine performance. This study evaluates and compares the safety and immunogenicity of the Comirnaty and Spikevax monovalent XBB.1.5 COVID-19 vaccines in an elderly population.

METHODS

Altogether, 129 elderly individuals were recruited between 2 January and 3 February 2024, and received a booster dose of either Comirnaty (n=59) or Spikevax (n=70) monovalent XBB.1.5 COVID-19 vaccine. Blood samples were collected at before and one month after vaccination. Immunogenicity was assessed by measuring the percentage of IFNγ+CD4+ and IFNγ+CD8+ T cells, and neutralizing antibody titers (NT50) using a surrogate virus neutralization test (sVNT). Adverse reactions were recorded and analyzed.

FINDINGS

Both vaccines significantly increased the percentage of IFNγ+CD8+ T cells against XBB.1.5 and wild-type (WT) SARS-CoV-2 at one-month post-vaccination. Spikevax induced a significantly higher percentages of IFNγ+CD8+ and CD4+ T cells against XBB.1.5 than Comirnaty (p<0.001). The proportion of participants showing a positive T cell response to XBB1.5 after vaccination was higher in the Spikevax group (64.3% CD8, 71.4% CD4) than in the Comirnaty group (42.4% CD8, 57.6% CD4). Spikevax also elicited higher NT50 levels against XBB1.5, JN.1 and the latest variant KP.2 than Comirnaty (XBB1.5: p<0.01; KP.2: p<0.05). Fever was more common in the Spikevax group (fever: p=0.006). However, all side effects were short-term and resolved on their own.

INTERPRETATION

Both vaccines induce neutralizing antibody to XBB1.5, JN.1 and KP.2. Specifically, Spikevax induces higher cellular and humoral immune responses than Comirnaty in the elderly, but it is also associated with a higher incidence of fever. These findings can guide public health strategies for vaccinating the elderly population.

Regulating Immune Responses Induced by PEGylated Messenger RNA-Lipid Nanoparticle Vaccine

Messenger RNA (mRNA)-based therapeutics have shown remarkable progress in the treatment and prevention of diseases. Lipid nanoparticles (LNPs) have shown great successes in delivering mRNAs. After an mRNA-LNP vaccine enters a cell via an endosome, mRNA is translated into an antigen, which can activate adaptive immunity. mRNAs can bind to various pattern recognition receptors (PRRs), including toll-like receptors (TLRs), and increase the production of inflammatory cytokines. This review summarizes mechanisms of innate immunity induced by mRNAs. Polyethylene glycol (PEG) has been employed as a component of the mRNA-LNP vaccine. PEGylated nanoparticles display enhanced stability by preventing aggregation of particles. However, PEGylation can cause adverse reactions, including blood clearance (ABC) of nanoparticles via complement activation and anaphylaxis. Mechanisms of PEG-induced ABC phenomenon and anaphylaxis are presented and discussed. There have been studies aimed at reducing immune responses associated with PEG to make safe and effective vaccines. Effects of modifying or replacing PEG in reducing immune responses associated with PEGylated nanoparticles are also discussed. Modifying mRNA can induce immune tolerance, which can prevent hypersensitivity reactions induced by PEGylated mRNA-LNP vaccines. Current progress of immune tolerance induction in association with mRNA-LNP is also summarized. This review might be helpful for developing safe and effective PEGylated mRNA-LNP vaccines.

Lipid nanoparticles as adjuvant of norovirus VLP vaccine augment cellular and humoral immune responses in a TLR9- and type I IFN-dependent pathway

Norovirus (NoV) virus-like particles (VLPs) adjuvanted with aluminum hydroxide (Alum) are common vaccine candidates in clinical studies. Alum adjuvants usually inefficiently assist recombinant proteins to induce cellular immune responses. Thus, novel adjuvants are required to develop NoV vaccines that could induce both efficient humoral and robust cellular immune responses. Lipid nanoparticles (LNPs) are well-known mRNA delivery vehicles. Increasing evidence suggests that LNPs may have intrinsic adjuvant activity and can be used as adjuvants for recombinant protein vaccines; however, the underlying mechanism remains poorly understood. In this study, we compared the adjuvant effect of LNPs and Alum for a bivalent GI.1/GII.4 NoV VLP vaccine. Compared with Alum, LNP-adjuvanted vaccines induced earlier production of binding, blocking, and neutralizing antibodies and promoted a more balanced IgG2a/IgG1 ratio. It is crucial that LNP-adjuvanted vaccines induced stronger Th1-type cytokine-producing CD4+ T cell and CD8+ T cell responses than Alum. The adjuvant activity of LNPs depended on the ionizable lipid components. Mechanistically, LNPs activated innate immune responses in a type I IFN-dependent manner and were partially dependent on Toll-like receptor (TLR) 9, thus affecting the adaptive immune responses of the vaccine. This conclusion was supported by RNA-seq analysis and in vitro cell experiments and by the deeply blunted T cell responses in IFNαR1-/- mice immunized with LNP-adjuvanted vaccines. This study not only identified LNPs as a high quality adjuvant for NoV VLP vaccines, but also clarified the underlying mechanism of LNPs as a potent immunostimulatory component for improving protein subunit vaccines.IMPORTANCEWith the rapid development of mRNA vaccines, recurrent studies show that lipid nanoparticles (LNPs) have adjuvant activity. However, the mechanism of its adjuvant effect in protein vaccines remains unknown. In this study, we found that the LNP-adjuvanted norovirus bivalent virus-like particle vaccines led to durable antibody responses as well as Th1-type cytokine-producing CD4+ T cell and CD8+ T cell responses, which exceeded the efficiency of the conventional adjuvant aluminum hydroxide. Mechanistically, LNPs activated innate immune responses in a type I IFN-dependent manner and were partially dependent on Toll-like receptor 9, thus affecting the adaptive immune responses of the vaccine. This work unveils that LNPs as a potent immunostimulatory component may be ideal for generating CD8+ T cell and B cell responses for recombinant protein vaccines.

mRNA-LNPs induce immune activation and cytokine release in human whole blood assays across diverse health conditions

RNA medicines have become a promising platform for therapeutic use in recent years. Understanding the immunomodulatory effects of novel mRNA-lipid nanoparticles (LNPs) is crucial for future therapeutic development. An in vitro whole blood assay was developed to assess the impact of mRNA-LNPs on immune cell function, cytokine release, and complement activation. mRNA-LNPs significantly increased CD69 expression on T cells and natural killer cells, and CD80/CD86 on myeloid subsets, in a dose-dependent fashion. Furthermore, mRNA-LNPs elicited a robust release of pro-inflammatory cytokines, including tumor necrosis factor-α, interleukin (IL)-1β, monocyte chemoattractant protein-1, IL-6, and IP-10, indicating a potent immune response. Notably, mRNA-LNPs stimulate early cytokine production prior to triggering immune cell activation, suggesting a temporal and biological relationship. Moreover, mRNA-LNPs induce complement activation via the alternative pathway, as evidenced by increased serum sC5b-9, C3a, and Bb, which can amplify the inflammatory response and potentially impact safety. In vitro effects of mRNA-LNPs in whole blood of healthy human donors were compared with those from disease cohorts including systemic lupus erythematosus, type 2 diabetes mellitus, and cancer donors. The differences in mRNA-LNP effects on samples from healthy and diseased populations may impact therapeutic efficacy or toxicity, indicating a need for tailoring LNPs for specific target populations.

Interleukin-1α release during necrotic-like cell death generates myeloid-driven immunosuppression that restricts anti-tumor immunity

Necroptosis can promote antigen-specific immune responses, suggesting induced necroptosis as a therapeutic approach for cancer. Here we sought to determine the mechanism of immune activation but found the necroptosis mediators RIPK3 and MLKL dispensable for tumor growth in genetic and implantable models of breast or lung cancer. Surprisingly, inducing necroptosis within established breast tumors generates a myeloid suppressive microenvironment that inhibits T cell function, promotes tumor growth, and reduces survival. This was dependent upon the release of the nuclear alarmin interleukin-1α (IL-1α) by dying cells. Critically, IL-1α release occurs during chemotherapy and targeting this molecule reduces the immunosuppressive capacity of tumor myeloid cells and promotes CD8+ T cell recruitment and effector function. Neutralizing IL-1α enhances the efficacy of single agent paclitaxel or combination therapy with PD-1 blockade in preclinical models. Low IL1A levels correlates with positive patient outcome in several solid malignancies, particularly in patients treated with chemotherapy.

Delivery Aspects for Implementing siRNA Therapeutics for Blood Diseases

Hematological disorders result in significant health consequences, and traditional therapies frequently entail adverse reactions without addressing the root cause. A potential solution for hematological disorders characterized by gain-of-function mutations lies in the emergence of small interfering RNA (siRNA) molecules as a therapeutic option. siRNAs are a class of RNA molecules composed of double-stranded RNAs that can degrade specific mRNAs, thereby inhibiting the synthesis of underlying disease proteins. Therapeutic interventions utilizing siRNA can be tailored to selectively target genes implicated in diverse hematological disorders, including sickle cell anemia, β-thalassemia, and malignancies such as lymphoma, myeloma, and leukemia. The development of efficient siRNA silencers necessitates meticulous contemplation of variables such as the RNA backbone, stability, and specificity. Transportation of siRNA to specific cells poses a significant hurdle, prompting investigations of diverse delivery approaches, including chemically modified forms of siRNA and nanoparticle formulations with various biocompatible carriers. This review delves into the crucial role of siRNA technology in targeting and treating hematological malignancies and disorders. It sheds light on the latest research, development, and clinical trials, detailing how various pharmaceutical approaches leverage siRNA against blood disorders, mainly concentrating on cancers. It outlines the preferred molecular targets and physiological barriers to delivery while emphasizing the growing potential of various therapeutic delivery methods. The need for further research is articulated in the context of overcoming the shortcomings of siRNA in order to enrich discussions around siRNA's role in managing blood disorders and aiding the scientific community in advancing more targeted and effective treatments.