Role of NLRP3 inflammasome in nanoparticle adjuvant-mediated immune response.

The nucleotide-binding oligomerization domain (NOD)-like receptor (NLR) family pyrin domain-containing 3 (NLRP3) inflammasome is pivotal in orchestrating the immune response induced by nanoparticle adjuvants. Understanding the intricate mechanisms underlying the activation of NLRP3 inflammasome by these adjuvants is crucial for deciphering their immunomodulatory properties. This review explores the involvement of the NLRP3 inflammasome in mediating immune responses triggered by nanoparticle adjuvants. It delves into the signaling pathways and cellular mechanisms involved in NLRP3 activation, highlighting its significance in modulating the efficacy and safety of nanoparticle-based adjuvants. A comprehensive grasp of the interplay between NLRP3 inflammasome and nanoparticle adjuvants holds promise for optimizing vaccine design and advancing immunotherapeutic strategies.

In vitro mRNA-S maternal vaccination induced altered immune regulation at the maternal-fetal interface.

BACKGROUND: Maternal-fetal immunology is intricate, and the effects of mRNA-S maternal vaccination on immune regulation at the maternal-fetal interface require further investigation. Our study endeavors to elucidate these immunological changes, enhancing our comprehension of maternal and fetal health outcomes. By analyzing immune profiles and cytokine responses, we aim to provide valuable insights into the impact of mRNA-S vaccination on the delicate balance of immune regulation during pregnancy, addressing critical questions in the field of reproductive pharmacology. OBJECTIVES: This investigation sought to examine the prospective influence of mRNA-S-based vaccines and extracellular vesicles (EVs) containing the Spike (S) protein at the maternal-fetal interface. Our primary emphasis was on evaluating their effects on maternal decidua cells and fetal chorion trophoblast cells (hFM-CTCs). METHODS: We validated the generation of EVs containing the S protein from small human airway epithelial cell lines (HSAECs) following mRNA-S vaccine exposure. We assessed the expression of angiotensin-converting enzyme 2 (ACE2) gene and protein in fetal membranes and the placenta, with specific attention to decidual cells and fetal membrane chorion cells. To assess cellular functionality, these cells were exposed to both recombinant S protein and EVs loaded with S proteins (eSPs). RESULTS: Our findings revealed that cells and EVs subjected to mRNA-S-based vaccination exhibited altered protein expression levels of S proteins. At the feto-maternal interface, both placental and fetal membrane tissues demonstrated similar ACE-2 expression levels. Among individual cellular layers, syncytiotrophoblast cells in the placenta and chorion cells in the fetal membrane exhibited elevated ACE-2 expression. Notably, EVs derived from HSAECs activated the MAPK pathway in decidual cells. Additionally, decidual cells displayed a substantial increase in gene expression of chemokines like CXCL-10 and CXCL-11, as well as proinflammatory cytokines such as IL-6 in response to eSPs. However, the levels of Ccl-2 and IL-1ß remained unchanged in decidual cells under the same conditions. Conversely, hFM-CTCs demonstrated significant alterations in the proinflammatory cytokines and chemokines with respect to eSPs. CONCLUSION: In conclusion, our study indicates that mRNA-S-based maternal vaccination during pregnancy may influence the maternal-fetal interface's COVID-19 interaction and immune regulation. Further investigation is warranted to assess safety and implications.

Innate and Adaptive Immune Parameters following mRNA Vaccination in Mice.

The COVID-19 pandemic has raised the standard regarding the current vaccine development pace, as several messenger RNA (mRNA)-lipid nanoparticle (LNP) vaccines have proved their ability to induce strong immunogenicity and protective efficacy. We developed 1-methylpseudouridine-containing mRNA-LNP vaccines, expressing either the more conserved SARS-CoV-2 nucleoprotein (mRNA-N) or spike protein (mRNA-S), both based on the prototypic viral sequences. When combining both mRNA-S and mRNA-N together (mRNA-S+N), the vaccine showed high immunogenicity and broad protection against different SARS-CoV-2 variants, including wildtype, Delta, BA.1, BA.5, and BQ.1. To better understand the mechanisms behind this broad protection obtained by mRNA-S+N, we analyzed innate and adaptive immune parameters following vaccination in mice. Compared to either mRNA-S or mRNA-N alone, mice vaccinated with mRNA-S+N exhibited an increase in the innate immune response, as depicted by the higher cytokine (IL-6 and chemokine (MCP-1) levels. In addition, lymph node immunophenotyping showed the maturation and activation of dendritic cells and natural killer cells, respectively. To understand the adaptive immune response, RNA-Seq analyses of the lung and spleen samples of the vaccinated mice were performed in parallel and revealed a stronger immune gene-expression profile in the lung than that in the spleen. Compared to mRNA-S alone, mRNA-S+N vaccination elicited higher levels of expression for genes involved in multiple immune pathways, including T cells, cytokine signaling, antigen presentation, B cells, and innate immunity. Together, our studies provide immunological insights into the mechanisms of broad protection conferred by dual mRNA vaccination against SARS-CoV-2 variants.

The next-generation DNA vaccine platforms and delivery systems: advances, challenges and prospects.

Vaccines have proven effective in the treatment and prevention of numerous diseases. However, traditional attenuated and inactivated vaccines suffer from certain drawbacks such as complex preparation, limited efficacy, potential risks and others. These limitations restrict their widespread use, especially in the face of an increasingly diverse range of diseases. With the ongoing advancements in genetic engineering vaccines, DNA vaccines have emerged as a highly promising approach in the treatment of both genetic diseases and acquired diseases. While several DNA vaccines have demonstrated substantial success in animal models of diseases, certain challenges need to be addressed before application in human subjects. The primary obstacle lies in the absence of an optimal delivery system, which significantly hampers the immunogenicity of DNA vaccines. We conduct a comprehensive analysis of the current status and limitations of DNA vaccines by focusing on both viral and non-viral DNA delivery systems, as they play crucial roles in the exploration of novel DNA vaccines. We provide an evaluation of their strengths and weaknesses based on our critical assessment. Additionally, the review summarizes the most recent advancements and breakthroughs in pre-clinical and clinical studies, highlighting the need for further clinical trials in this rapidly evolving field.

Pharmacological targets at the lysosomal autophagy-NLRP3 inflammasome crossroads.

Many aspects of cell homeostasis and integrity are maintained by the nucleotide-binding oligomerization domain (NOD)-like receptor (NLR) family pyrin domain-containing 3 (NLRP3) inflammasome. The NLRP3 oligomeric protein complex assembles in response to exogenous and endogenous danger signals. This inflammasome has also been implicated in the pathogenesis of a range of disease conditions, particularly chronic inflammatory diseases. Given that NLRP3 modulates autophagy, which is also a key regulator of inflammasome activity, excessive inflammation may be controlled by targeting this intersecting pathway. However, specific niche areas of NLRP3-autophagy interactions and their reciprocal regulatory mechanisms remain underexplored. Consequently, we lack treatment methods specifically targeting this pivotal axis. Here, we discuss the potential of such strategies in the context of autoimmune and metabolic diseases and propose some research avenues.

Monovalent SARS-COV-2 mRNA vaccine using optimal UTRs and LNPs is highly immunogenic and broadly protective against Omicron variants.

The emergence of highly transmissible severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) variants of concern (VOCs) that are resistant to the current COVID-19 vaccines highlights the need for continued development of broadly protective vaccines for the future. Here, we developed two messenger RNA (mRNA)-lipid nanoparticle (LNP) vaccines, TU88mCSA and ALCmCSA, using the ancestral SARS-CoV-2 spike sequence, optimized 5' and 3' untranslated regions (UTRs), and LNP combinations. Our data showed that these nanocomplexes effectively activate CD4+ and CD8+ T cell responses and humoral immune response and provide complete protection against WA1/2020, Omicron BA.1 and BQ.1 infection in hamsters. Critically, in Omicron BQ.1 challenge hamster models, TU88mCSA and ALCmCSA not only induced robust control of virus load in the lungs but also enhanced protective efficacy in the upper respiratory airways. Antigen-specific immune analysis in mice revealed that the observed cross-protection is associated with superior UTRs [Carboxylesterase 1d (Ces1d)/adaptor protein-3ß (AP3B1)] and LNP formulations that elicit robust lung tissue-resident memory T cells. Strong protective effects of TU88mCSA or ALCmCSA against both WA1/2020 and VOCs suggest that this mRNA-LNP combination can be a broadly protective vaccine platform in which mRNA cargo uses the ancestral antigen sequence regardless of the antigenic drift. This approach could be rapidly adapted for clinical use and timely deployment of vaccines against emerging and reemerging VOCs.

BRD4 as a potential target for human papillomaviruses associated cancer.

Around 99% of cervical cancer and 5%-10% of human cancer are associated with human papillomaviruses (HPV). Notably, the life-cycle of HPV begins by low-level infection of the basal cells of the stratified epithelium, where the viral genomes are replicated and passed on to the daughter proliferating basal cells. The production of new viral particles remains restricted to eventually differentiated cells. HPVs support their persistent infectious cycle by hijacking pivotal pathways and cellular processes. Bromodomain-containing protein 4 (BRD4) is one of the essential cellular factors involved in multiple stages of viral transcription and replication. In this review, we demonstrate the role of BRD4 in the multiple stages of HPV infectious cycle. Also, we provide an overview of the intense research about the cellular functions of BRD4, the mechanism of action of bromodomain and extra terminal inhibitors, and how it could lead to the development of antiviral/anticancer therapies.

Next-Generation Vaccines Against COVID-19 Variants: Beyond the Spike Protein.

Vaccines are among the most effective medical countermeasures against infectious diseases. The current Coronavirus disease 2019 (COVID-19) pandemic, caused by severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2), has spurred the scientific strategies to fight against the disease. Since 2020, a great number of vaccines based on different platforms have been in development in response to the pandemic, among which mRNA, adenoviral vector, and subunit vaccines have been clinically approved for use in humans. These first-generation COVID-19 vaccines largely target the viral spike (S) protein and aim for eliciting potent neutralizing antibodies. With the emergence of SARS-CoV-2 variants, especially the highly transmissible Omicron strains, the S-based vaccine strategies have been faced constant challenges due to strong immune escape by the variants. The coronavirus nucleocapsid (N) is one of the viral proteins that induces strong T-cell immunity and is more conserved across different SARS-CoV-2 variants. Inclusion of N in the development of COVID-19 vaccines has been reported. Here, we briefly reviewed and discussed COVID-19 disease, current S-based vaccine strategies, and focused on the immunobiology of N protein in SARS-CoV-2 host immunity, as well as the next-generation vaccine strategies involving N protein, to combat current and emerging SARS-CoV-2 variants.

Corrigendum: IL-3 produced by T cells is crucial for basophil extravasation in hapten- induced allergic contact dermatitis.

[This corrects the article DOI: 10.3389/fimmu.2023.1151468.].

Biochanin A Ameliorates Nephropathy in High-Fat Diet/Streptozotocin-Induced Diabetic Rats: Effects on NF-kB/NLRP3 Axis, Pyroptosis, and Fibrosis.

Nephropathy is the most prevalent microvascular disorder in diabetes mellitus. Oxidative stress and inflammatory cascade provoked by the persistent hyperglycemic milieu play integral roles in the aggravation of renal injury and fibrosis. We explored the impact of biochanin A (BCA), an isoflavonoid, on the inflammatory response, nod-like receptor protein 3 (NLRP3) inflammasome activation, oxidative stress, and fibrosis in diabetic kidneys. A high-fat-diet/streptozotocin (HFD/STZ)-induced experimental model of diabetic nephropathy (DN) was established in Sprague Dawley rats, and in vitro studies were performed in high-glucose-induced renal tubular epithelial (NRK-52E) cells. Persistent hyperglycemia in diabetic rats was manifested by perturbation of renal function, marked histological alterations, and oxidative and inflammatory renal damage. Therapeutic intervention of BCA mitigated histological changes, improved renal function and antioxidant capacity, and suppressed phosphorylation of nuclear factor-kappa B (NF-κB) and nuclear factor-kappa B inhibitor alpha (IκBα) proteins. Our in vitro data reveal excessive superoxide generation, apoptosis, and altered mitochondrial membrane potential in NRK-52E cells that were cultured in a high-glucose (HG) environment were subsided by BCA intervention. Meanwhile, the upregulated expressions of NLRP3 and its associated proteins, the pyroptosis-indicative protein gasdermin-D (GSDMD) in the kidneys, and HG-stimulated NRK-52E cells were significantly ameliorated by BCA treatment. Additionally, BCA blunted transforming growth factor (TGF)-ß/Smad signaling and production of collagen I, collagen III, fibronectin, and alfa-smooth muscle actin (α-SMA) in diabetic kidneys. Our results indicate the plausible role of BCA in attenuating DN, presumably through modulation of the apoptotic cascade in renal tubular epithelial cells and the NF-κB/NLRP3 axis.

IL-3 produced by T cells is crucial for basophil extravasation in hapten-induced allergic contact dermatitis.

Basophils have been recognized as a characterized cellular player for Th2 immune responses implicated in allergic diseases, but the mechanisms responsible for basophil recruitment to allergic skin remain not well understood. Using a hapten fluorescein isothiocyanate (FITC)-induced allergic contact dermatitis (ACD) mouse model, we show that basophils in FITC-treated IL-3-knockout mice are defective in crossing the vascular endothelium to enter the inflamed skin. By generating mice in which IL-3 is selectively ablated in T cells, we further demonstrate that IL-3 produced by T cells mediates basophil extravasation. Moreover, basophils sorted from FITC-treated IL-3-knockout mice exhibit a decreased expression of integrins Itgam, Itgb2, Itga2b and Itgb7, which are potentially implicated in extravasation process. Interestingly, we observed that these basophils had a reduced expression of retinaldehyde dehydrogenase 1 family member A2 (Aldh1a2), an enzyme responsible for the production of retinoic acid (RA), and administration of all-trans RA restored partially the extravasation of basophils in IL-3-knockout mice. Finally, we validate that IL-3 induces the expression of ALDH1A2 in primary human basophils, and provide further evidence that IL-3 stimulation induces the expression of integrins particularly ITGB7 in an RA-dependent manner. Together, our data propose a model that IL-3 produced by T cells activates ALDH1A2 expression by basophils, leading to the production of RA, which subsequently induces the expression of integrins crucially implicated in basophil extravasation to inflamed ACD skin.

Recent Advances in the Lipid Nanoparticle-Mediated Delivery of mRNA Vaccines.

Lipid nanoparticles (LNPs) have recently emerged as one of the most advanced technologies for the highly efficient in vivo delivery of exogenous mRNA, particularly for COVID-19 vaccine delivery. LNPs comprise four different lipids: ionizable lipids, helper or neutral lipids, cholesterol, and lipids attached to polyethylene glycol (PEG). In this review, we present recent the advances and insights for the design of LNPs, as well as their composition and properties, with a subsequent discussion on the development of COVID-19 vaccines. In particular, as ionizable lipids are the most critical drivers for complexing the mRNA and in vivo delivery, the role of ionizable lipids in mRNA vaccines is discussed in detail. Furthermore, the use of LNPs as effective delivery vehicles for vaccination, genome editing, and protein replacement therapy is explained. Finally, expert opinion on LNPs for mRNA vaccines is discussed, which may address future challenges in developing mRNA vaccines using highly efficient LNPs based on a novel set of ionizable lipids. Developing highly efficient mRNA delivery systems for vaccines with improved safety against some severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) variants remains difficult.

THEME: "Vaccines and Vaccine Adjuvants/Immunomodulators for Infectious Diseases".

The discovery of vaccines has enabled the successful prevention of many deadly infectious diseases, decreased the overall mortality rate, and improved life expectancy worldwide [...].

Tocilizumab-treated convalescent COVID-19 patients retain the cross-neutralization potential against SARS-CoV-2 variants.

Although tocilizumab treatment in severe and critical coronavirus disease 2019 (COVID-19) patients has proven its efficacy at the clinical level, there is little evidence supporting the effect of short-term use of interleukin-6 receptor blocking therapy on the B cell sub-populations and the cross-neutralization of SARS-CoV-2 variants in convalescent COVID-19 patients. We performed immunological profiling of 69 tocilizumab-treated and non-treated convalescent COVID-19 patients in total. We observed that SARS-CoV-2-specific IgG1 titers depended on disease severity but not on tocilizumab treatment. The plasma of both treated and non-treated patients infected with the ancestral variant exhibit strong neutralizing activity against the ancestral virus and the Alpha, Beta, and Delta variants of SARS-CoV-2, whereas the Gamma and Omicron viruses were less sensitive to seroneutralization. Overall, we observed that, despite the clinical benefits of short-term tocilizumab therapy in modifying the cytokine storm associated with COVID-19 infections, there were no modifications in the robustness of B cell and IgG responses to Spike antigens.

Three Members of Transmembrane-4-Superfamily, TM4SF1, TM4SF4, and TM4SF5, as Emerging Anticancer Molecular Targets against Cancer Phenotypes and Chemoresistance.

There are six members of the transmembrane 4 superfamily (TM4SF) that have similar topology and sequence homology. Physiologically, they regulate tissue differentiation, signal transduction pathways, cellular activation, proliferation, motility, adhesion, and angiogenesis. Accumulating evidence has demonstrated, among six TM4SF members, the regulatory roles of transmembrane 4 L6 domain family members, particularly TM4SF1, TM4SF4, and TM4SF5, in cancer angiogenesis, progression, and chemoresistance. Hence, targeting derailed TM4SF for cancer therapy has become an emerging research area. As compared to others, this review aimed to present a focused insight and update on the biological roles of TM4SF1, TM4SF4, and TM4SF5 in the progression, metastasis, and chemoresistance of various cancers. Additionally, the mechanistic pathways, diagnostic and prognostic values, and the potential and efficacy of current anti-TM4SF antibody treatment were also deciphered. It also recommended the exploration of other interactive molecules to be implicated in cancer progression and chemoresistance, as well as potential therapeutic agents targeting TM4SF as future perspectives. Generally, these three TM4SF members interact with different integrins and receptors to significantly induce intracellular signaling and regulate the proliferation, migration, and invasion of cancer cells. Intriguingly, gene silencing or anti-TM4SF antibody could reverse their regulatory roles deciphered in different preclinical models. They also have prognostic and diagnostic value as their high expression was detected in clinical tissues and cells of various cancers. Hence, TM4SF1, TM4SF4, and TM4SF5 are promising therapeutic targets for different cancer types preclinically and deserve further investigation.

Dual spike and nucleocapsid mRNA vaccination confer protection against SARS-CoV-2 Omicron and Delta variants in preclinical models.

Emergence of SARS-CoV-2 variants of concern (VOCs), including the highly transmissible Omicron and Delta strains, has posed constant challenges to the current COVID-19 vaccines that principally target the viral spike protein (S). Here, we report a nucleoside-modified messenger RNA (mRNA) vaccine that expresses the more conserved viral nucleoprotein (mRNA-N) and show that mRNA-N vaccination alone can induce modest control of SARS-CoV-2. Critically, combining mRNA-N with the clinically proven S-expressing mRNA vaccine (mRNA-S+N) induced robust protection against both Delta and Omicron variants. In the hamster models of SARS-CoV-2 VOC challenge, we demonstrated that, compared to mRNA-S alone, combination mRNA-S+N vaccination not only induced more robust control of the Delta and Omicron variants in the lungs but also provided enhanced protection in the upper respiratory tract. In vivo CD8+ T cell depletion suggested a potential role for CD8+ T cells in protection conferred by mRNA-S+N vaccination. Antigen-specific immune analyses indicated that N-specific immunity, as well as augmented S-specific immunity, was associated with enhanced protection elicited by the combination mRNA vaccination. Our findings suggest that combined mRNA-S+N vaccination is an effective approach for promoting broad protection against SARS-CoV-2 variants.

IFN-γ Induces PD-L1 Expression in Primed Human Basophils.

Programmed death-ligand 1 (PD-L1) plays a key role in maintaining immune tolerance and also in immune evasion of cancers and pathogens. Though the identity of stimuli that induce PD-L1 in various human innate cells and their function are relatively well studied, data on the basophils remain scarce. In this study, we have identified one of the factors, such as IFN-γ, that induces PD-L1 expression in human basophils. Interestingly, we found that basophil priming by IL-3 is indispensable for IFN-γ-induced PD-L1 expression in human basophils. However, priming by other cytokines including granulocyte-macrophage colony-stimulating factor (GM-CSF) and thymic stromal lymphopoietin (TSLP) was dispensable. Analyses of a published microarray data set on IL-3-treated basophils indicated that IL-3 enhances IFNGR2, one of the chains of the IFNGR heterodimer complex, and CD274, thus providing a mechanistic insight into the role of IL-3 priming in IFN-γ-induced PD-L1 expression in human basophils.

Therapeutic potential of mangiferin against kidney disorders and its mechanism of action: A review.

There is a swing in research developments concerning the utilization of natural products as effective pharmacotherapeutic agents due to their comparatively lower toxicities than synthetic compounds. Among natural products, mangiferin is a natural C-glucosyl xanthonoid polyphenol with remarkable pharmacological activities. Emerging evidence indicates the therapeutic benefits of mangiferin against various kidney disorders, including renal injury, diabetic nephropathy, renal fibrosis, hyperuricemic nephropathy, and lupus nephritis, in experimental animal models. The mangiferin induced antioxidant response resulting in vital functions, such as protection against renal inflammation, inhibits renal cell apoptosis, activates autophagy, causes immunomodulation, regulates renal urate transporters and modulates cell signalling pathways. The purpose of this review provide a brief overview of the in vitro/in vivo reno-protective effect of mangiferin and the underlying mechanism(s) in protecting against kidney disorders. Understanding the pharmacological actions of mangiferin is prominence due to its excellent therapeutic potential in managing kidney disorders. Thus, in addition to this review, in-silico molecular docking is performed against nuclear factor kappa B (NF-κB) and soluble epoxide hydrolase (sEH) to study the mechanism of action of mangiferin. It is believed that mangiferin is a safe reno-protective molecule. The observed positive effects are attributed to the inhibition of inflammation caused by NF-κB and sEH upregulation and oxidative stress activation. Studies on the efficacy and safety of mangiferin in clinical trials are further warranted to confirm its medicinal potential as therapeutic agent for kidney disorders in humans.

SARS-CoV-2 Induces Cytokine Responses in Human Basophils.

Basophils play a key role in the orientation of immune responses. Though the interaction of SARS-CoV-2 with various immune cells has been relatively well studied, the response of basophils to this pandemic virus is not characterized yet. In this study, we report that SARS-CoV-2 induces cytokine responses and in particular IL-13, in both resting and IL-3 primed basophils. The response was prominent under IL-3 primed condition. However, either SARS-CoV-2 or SARS-CoV-2-infected epithelial cells did not alter the expression of surface markers associated with the activation of basophils, such as CD69, CD13 and/or degranulation marker CD107a. We also validate that human basophils are not permissive to SARS-CoV-2 replication. Though increased expression of immune checkpoint molecule PD-L1 has been reported on the basophils from COVID-19 patients, we observed that SARS-CoV-2 does not induce PD-L1 on the basophils. Our data suggest that basophil cytokine responses to SARS-CoV-2 might help in reducing the inflammation and also to promote antibody responses to the virus.