Immune Stimulation Research Articles

In silico Designing of a Multi-epitope-based Subunit Vaccine against SARS-CoV-2 (Delta Variant) by Exploiting Its Structural Proteins: A Reverse Vaccinomics and Immunoinformatics Approach

Background: The continuously emerging novel strains of SARS-CoV-2 remain a menace to the global population. The vicious delta variant (originated in India) is considered one of the most infectious/contagious variants of SARS-CoV-2. The transmission frequency of this variant is 225% higher than other variants, extending its prevalence and causing a massive surge in the COVID-19 pandemic. It is also the most ravenous variant among others. Objective: Though the delta variant has already disappeared, it could re-emerge/come out at any time with a more powerful strike than earlier. Therefore, to tackle such ferocity, this research is undertaken with a next-generation vaccine development strategy to design a multi-epitope-based subunit vaccine against the delta variant of SARS-CoV-2, which might boost the body's immunity. Materials and Methods: In the present investigation, reverse vaccinomics and immunoinformatics approaches were adopted to create an immune-stimulating prospective vaccine candidate having B cell, helper T cell (Th)/helper T lymphocyte (HTL), cytotoxic T cell (Tc)/cytotoxic T lymphocyte (CTL), and interferon-gamma (IFN-γ) inducing epitopes by exploiting the SARS-CoV-2 (delta variant) (GenBank: MZ724536.1) structural proteins: envelope glycoprotein (E), nucleocapsid phosphoprotein (N), surface glycoprotein (S), and membrane glycoprotein (M). The established vaccine construct was then completed by combining antigenic epitopes with adjuvants and linkers. Subsequently, the 3D model of the suggested vaccine was created and docked with an immune receptor (Toll-Like Receptor-4). A molecular dynamics (MD) simulation study was performed to confirm the binding stability between the vaccine conjugate and TLR4. Later, an immune simulation study was carried out to predict the in silico immune response of the vaccine candidate. To effectively express the developed vaccine in a bacterial system (E. coli), in silico codon optimization and cloning were done in an expression vector to manufacture it on a large scale. Results: According to the computational analysis, the vaccine candidate was found to be highly antigenic while maintaining favorable properties for the human body. Molecular docking and dynamics simulation study between the suggested vaccine construct and TLR4 immune receptor depicted it as extremely efficient and stable, ensuring a proper immunological response within the host cell. Eventually, an in silico immune simulation study of the vaccine candidate demonstrated a robust immune response to vaccine administration. Conclusion: We have hypothesized that the constructed vaccine model is benign, stable, and immunogenic, making it a promising/potent candidate for immune system stimulation against SARSCOV- 2 (DV). Hereof, wet lab-based investigations are needed to justify the competence of the novel vaccine candidate towards the delta variant along with other variants of SARS-CoV-2.

IL-7 promotes mRNA vaccine-induced long-term immunity.

Messenger RNA (mRNA) vaccines are a key technology in combating existing and emerging infectious diseases. However, improving the immunogenicity and durability of mRNA vaccines remains a challenge. To elicit optimal immune responses, integrating antigen-encoded mRNA and immunostimulatory adjuvants into a single formulation is a promising approach to enhancing the efficacy of mRNA vaccines. Here, we report an adjuvant strategy to enhance the efficacy of mRNA vaccines by co-loading mRNA encoding the antigen (rabies virus glycoprotein, RABV-G) and mRNA encoding IL-7 into lipid nanoparticles, achieving co-delivery to the same antigen-presenting cells. A single immunization with G&IL-7 mRNA vaccine elicited robust humoral immune responses in mice and conferred complete protection against RABV challenge. Notably, the high levels of neutralizing antibody induced by the G&IL-7 mRNA vaccine were maintained for at least 6months, providing mice with long-term significant and complete protection against RABV. Additionally, IL-7 also enhanced antibody responses against the SARS-CoV-2. These data demonstrate that IL-7 is a potent mRNA vaccine adjuvant that can provide the required immune stimulation in various mRNA vaccine formulations.

The Association between Allergies and Hematologic Tumors — A Review

Introduction: Dysfunctions of the immune system in allergic diseases and hematological malignancies are the subject of many studies due to the mechanisms that link them. Chronic inflammation created in the immune response in an allergic reaction has been associated with developing neoplastic diseases. Aim of the study: This review examines the potential correlation between Allergies and Hematologic Tumors: acute lymphoblastic leukemia, childhood leukemias, non-Hodgkin and Hodgkin lymphomas. Material and methods: An English-language literature review was conducted, analyzing studies from the PubMed database up to October 2024 regarding the correlation between Allergies and Hematologic Tumors. The review was performed using the PubMed database, with 50 works used. Conclusions: The relationship between allergies and hematological tumors is unclear. According to some studies, this relationship does not exist; some state, however, that allergic diseases show correlations with hematological malignancies. The results of these studies do not provide a clear answer to whether this is a positive or negative relationship. Some studies suggest that allergies reduce the risk of hematological malignancies, while others contradict this, suggesting that allergies may increase the risk of hematological tumors. The results of studies showing an increased risk of hematological malignancies in people suffering from allergies can be due to the hypothesis of antigenic stimulation, which may explain the mechanism of correlation between those diseases. This hypothesis suggests that chronic immune stimulation predisposes to hematologic malignancies such as multiple myeloma, non-Hodgkin's lymphoma (NHL), and leukemia by promoting the development of randomly occurring pro-oncogenic mutations in actively dividing immune cells. Different results on this potential correlation showed that further studies are necessary.

Mouse Testing Methods in Psychoneuroimmunology: Measuring Behavioral Responses.

The field of psychoneuroimmunology (PNI) aims to uncover the processes and consequences of nervous, immune, and endocrine system relationships. Behavior is a consequence of such interactions and manifests from a complex interweave of factors including immune-to-neural and neural-to-immune communication. Often the signaling molecules involved during a particular episode of neuroimmune activation are not known, but behavioral response provides evidence that bioactives such as neurotransmitters and cytokines are perturbed. Immunobehavioral phenotyping is a first-line approach when examining the neuroimmune system and its reaction to immune stimulation or suppression. Behavioral response is significantly more sensitive than direct measurement of a single specific bioactive and can quickly and efficiently rule in or out relevance of a particular immune challenge or therapeutic to neuroimmunity. Classically, immunobehavioral research was focused on sickness symptoms related to bacterial infection, but neuroimmune activation is now a recognized complication of diseases and disorders ranging from cancer to diabesity to Alzheimer's. Immunobehaviors include lethargy, loss of appetite, and disinterest in social activity/surrounding environment. In addition, neuroimmune activation can diminish physical activity, precipitate feelings of depression and anxiety, and impair cognitive and executive function. Provided is a detailed overview of behavioral tests frequently used to examine neuroimmune activation in mice with a special emphasis on pre-experimental conditions that can confound or prevent successful immunobehavioral experimentation.

Abstract PR012: A first-in-class EGFR-directed KRAS G12V selective inhibitor

Abstract The KRAS proto-oncogene encodes a small GTPase that is crucial for the activation of intracellular signaling pathways that control cell proliferation, survival and differentiation. KRAS is frequently mutated in cancer resulting in its constitutive activation and dysregulation of downstream signaling pathways that drive oncogenic transformation. KRAS G12V is the second most common KRAS mutation in cancer, and occurs frequently in lung, colon and pancreatic cancers. However, while significant advancements have been made in developing KRAS G12C, G12D and pan-KRAS inhibitors, there remain no direct KRAS G12V inhibitors in the clinic. Due to challenges targeting oncogenes with traditional small molecule approaches, RNA interference (RNAi) has become an attractive therapeutic approach for many oncogenes. RNAi has faced many obstacles as an effective cancer therapeutics, including the lack of cancer- specific tissue targeting, rapid oligonucleotide nuclease degradation and clearance from circulation, the need for endosomal escape, and unwanted immune stimulation. However, recently, the use of targetable ligands conjugated to chemically modified siRNAs have shown promise in circumventing these barriers. Here, we describe the development of EFTX-G12V, a fully-modified, mutant-selective siRNA conjugated to an EGFR ligand that shows improved tumor delivery and significant anti-tumor activity in lung and colon cancer models. We used a structure-activity relationship screening approach to identify a highly mutant-selective fully chemically modified siRNA that inhibits KRAS G12V expression at both the mRNA and protein level while completely sparing KRAS WT. Furthermore, this siRNA inhibited cancer cell growth in vitro and showed no off-target effects. To address the issue of tumor-specific delivery, we conjugated a non-mitogenic EGFR ligand to the siRNA and found enhanced delivery to tumors with varying levels of EGFR expression. EFTX-G12V significantly inhibited KRAS G12V mRNA and protein in vivo and showed significant anti-tumor activity in lung and colon xenograft models. Importantly, EFTX-G12V showed no off-target effects on WT KRAS in somatic tissues including kidney, skin and bladder. Unexpectedly, we found that mutant-selective targeting showed improved efficacy in comparison to a pan-KRAS siRNA. EFTX-G12V significantly inhibited tumor angiogenesis while pan-KRAS targeting had inconsistent effects suggesting that mutant-selective targeting has advantages within the tumor microenvironment. Together our findings represent a technologic advance in ligand-directed, mutant-selective oncogene targeting using RNAi and reveal new biologic insights in KRAS targeting that may have broader implications with regards to safety and efficacy. Citation Format: Lyla Stanland, Hayden Huggins, Alessandro Porrello, Yogitha Chareddy, Salma Azam, Jillian Perry, Pradeep Pallan, Kristina Whately, Lincy Edatt, Matthew Fleming, Jonah Im, Christina Gutierrez-Ford, Imani Simmons, Vandanaa Jayaprakash, Rani Sellers, Gabriela de la Cruz, Albert Wielgus, Martin Egli, Albert Bowers, Chad Pecot. A first-in-class EGFR-directed KRAS G12V selective inhibitor [abstract]. In: Proceedings of the AACR Special Conference in Cancer Research: RNAs as Drivers, Targets, and Therapeutics in Cancer; 2024 Nov 14-17; Bellevue, Washington. Philadelphia (PA): AACR; Mol Cancer Ther 2024;23(11_Suppl):Abstract nr PR012.

Intratumoral administration of poly-ICLC enhances the antitumor effects of anti-PD-1.

Immune checkpoint inhibitors are effective to treat hepatocellular carcinoma (HCC) yet only successful in a small part of patients. This study aimed to investigate whether poly-ICLC, an immune stimulant, can enhance the antitumor effects of anti-PD-1 on mouse HCC. We established two syngeneic HCC mouse models with BNL cells in BALB/c mice and Hep-55.1 C cells in C57BL/6 J mice. Mice with subcutaneous HCC tumors received one of five treatments: control, anti-PD-1, intratumoral (IT) poly-ICLC, anti-PD-1 plus intramuscular (IM) poly-ICLC, or anti-PD-1 plus IT poly-ICLC. Tumor volumes were measured, CD8+ T lymphocytes in tumors and spleen were analyzed, and interferon-γ activity was assessed by ELISpot. Immune cell types and abundance were evaluated with NanoString nCounter IO360 panels. Cotreatment with poly-ICLC significantly enhanced the antitumor effects of anti-PD-1, with IT administration being more effective than IM. IT poly-ICLC also induced more significant CD8+ T cell infiltration and interferon-γ activity in the tumor and spleen, and more upregulation of both interferon-γ and M1 macrophage signals in the tumor microenvironment while downregulating several cancer-promoting pathways. Combination therapy with poly-ICLC, especially through IT route, and anti-PD-1 provides significantly greater antitumor effects than anti-PD-1 monotherapy in syngeneic mouse models of HCC.

A pre- and postnatal immune challenge influences muscle growth and metabolism in weaned pigs.

The in-utero environment is key to both fetal and postnatal growth and development. The objective of this study was to determine if administration of an acute low-dose lipopolysaccharide (LPS) to gestating sows during mid to late gestation and post-weaning would alter the offsprings metabolomic profile of the longissimus dorsi (LD) and muscle ultrastructure. Pregnant Camborough sows were randomly assigned to receive LPS (LPS; n= 7) at a dose of 2.5 μg/kg or saline (CON; n = 7) on 78 ± 1.8 d of gestation. At weaning (21 ± 1.3 d of age), barrows (CON n = 17; LPS n = 17) from each treatment were selected to receive a secondary LPS. Barrows were administered the secondary LPS challenge at a dose of 10 μg/kg 7 d post weaning. Twenty-four h after the postnatal LPS dose, barrows (31 ± 1.3 d of age) were euthanized, and each LD was removed. The left LD was utilized for morphometric measurements. Two samples from the medial section of the right LD were preserved for immunohistochemical measurements and metabolomic analyses. Mass spectral data were deconvoluted, aligned, and annotated using MS-DIAL. Univariate and multivariate analyses were conducted using MetaboAnalyst. Pathway analysis was conducted and compared to the Homo sapiens pathway library. Morphometric and immunohistochemical measurements were analyzed using the MIXED procedure of SAS version 9.4. Significance for all analyses was declared at P ≤ 0.05 and tendencies were considered at P ≤ 0.10. Average diameter of myosin heavy chain (MHC) type I and IIB/X fibers was increased (P ≤ 0.048) in LPS offspring compared with CON. Average cross-sectional area was increased (P = 0.030) in MHC IIB/X fibers and tended to be increased (P = 0.080) in MHC I fibers of LPS offspring. There were no differences (P ≥ 0.186) between treatment groups for total nuclei or nuclei positive for MYF5, PAX7, or MYF5 and PAX7 nuclei. Metabolomic analyses identified 14 differentially expressed (P < 0.05) metabolites in the LD between treatment groups. There were 10 metabolites within the LD that tended (P ≤ 0.096) to differ between treatment groups. Thus, this study shows that in-utero immune stimulation using LPS in gestating sows and a subsequent LPS challenge postnatally alters the metabolomic profile and muscle ultrastructure of the LD in weaned pigs.

PaedVacCOVID - safety of the BNT162b2 vaccine against the SARS-CoV-2 in children with and without comorbidities aged 5 to 11 years.

Little is known about specific safety aspects in children with significant comorbidities receiving the mRNA vaccine BNT162b2, as approval studies did not address this population. This study's purpose is to evaluate safety and adverse events in these children compared to healthy children. In this prospective, multicentre, industry-independent cohort study, caregivers whose children received BNT162b2 were asked to participate in an online questionnaire. Potential side effects were evaluated in ten organ related categories. Frequency of symptoms was compared in both cohorts by bivariate analysis. From a total of 1,294 responses to the questionnaire, 793 data sets were included into the analysis (179 children with comorbidities and 614 healthy children). Responses were given at a median of 17 days after vaccination. Overall, safety of BNT162b2 was high in both cohorts. Psychological (OR: 3.56, [95% CI: 1.461 to 8.629]), pulmonary (OR: 7.14, [95% CI: 2.039 to 21.48]), gastrointestinal (OR: 2.35, [95% CI: 1.231 to 4.665]), neurological (OR: 1.74, [95% CI: 1.078 to 2.796]) and dermatological (OR: 2.28, [95% CI: 1.220 to 4.172]) side effects were increased in children with comorbidities over healthy controls. The higher rate of reported post-vaccination symptoms could either be due to a higher susceptibility for symptomatic effects following immune stimulation, or due to a trained awareness to health-related symptoms. The data emphasizes the importance to evaluate safety of the new mRNA COVID-19 vaccines not only in healthy children but also in children with comorbidities. To perform such evaluation should be made mandatory for pharmaceutical enterprises.

Bifunctional Metal–Organic Framework Synergistically Enhances Radiotherapy and Activates STING for Potent Cancer Radio‐Immunotherapy

AbstractThe activation of the stimulator of interferon genes (STING) protein by cyclic dinucleotide metabolites plays a critical role in antitumor immunity. However, synthetic STING agonists like 4‐(5,6‐dimethoxybenzo[b]thiophen‐2‐yl)‐4‐oxobutanoic acid (MSA‐2) exhibit suboptimal pharmacokinetics and fail to sustain STING activation in tumors for effective antitumor responses. Here, we report the design of MOF/MSA‐2, a bifunctional MSA‐2 conjugated nanoscale metal–organic framework (MOF) based on Hf6 secondary building units (SBUs) and hexakis(4′‐carboxy[1,1′‐biphenyl]‐4‐yl)benzene bridging ligands, for potent cancer radio‐immunotherapy. By leveraging the high‐Z properties of the Hf6 SBUs, the MOF enhances the therapeutic effect of X‐ray radiation and elicits potent immune stimulation in the tumor microenvironment. MOF/MSA‐2 further enhances radiotherapeutic effects of X‐rays by enabling sustained STING activation and promoting the infiltration and activation of immune cells in the tumors. MOF/MSA‐2 plus low‐dose X‐ray irradiation elicits strong STING activation and potent tumor regression, and when combined with an immune checkpoint inhibitor, effectively suppresses both primary and distant tumors through systemic immune activation.

Bifunctional Metal-Organic Framework Synergistically Enhances Radiotherapy and Activates STING for Potent Cancer Radio-Immunotherapy.

The activation of the stimulator of interferon genes (STING) protein by cyclic dinucleotide metabolites plays a critical role in antitumor immunity. However, synthetic STING agonists like 4-(5,6-dimethoxybenzo[b]thiophen-2-yl)-4-oxobutanoic acid (MSA-2) exhibit suboptimal pharmacokinetics and fail to sustain STING activation in tumors for effective antitumor responses. Here, we report the design of MOF/MSA-2, a bifunctional MSA-2 conjugated nanoscale metal-organic framework (MOF) based on Hf6 secondary building units (SBUs) and hexakis(4'-carboxy[1,1'-biphenyl]-4-yl)benzene bridging ligands, for potent cancer radio-immunotherapy. By leveraging the high-Z properties of the Hf6 SBUs, the MOF enhances the therapeutic effect of X-ray radiation and elicits potent immune stimulation in the tumor microenvironment. MOF/MSA-2 further enhances radiotherapeutic effects of X-rays by enabling sustained STING activation and promoting the infiltration and activation of immune cells in the tumors. MOF/MSA-2 plus low-dose X-ray irradiation elicits strong STING activation and potent tumor regression, and when combined with an immune checkpoint inhibitor, effectively suppresses both primary and distant tumors through systemic immune activation.

A B cell screen against endogenous retroviruses identifies glycan-reactive IgM that recognizes a broad array of enveloped viruses.

Endogenous retroviruses (ERVs), comprising a substantial portion of the vertebrate genome, are remnants of ancient genetic invaders. ERVs with near-intact coding potential reactivate in B cell-deficient mice. To study how B cells contribute to host anti-ERV immunity, we used an antigen-baiting strategy to enrich B cells reactive to ERV surface antigens. We identified ERV-reactive B-1 cells expressing germline-encoded natural IgM antibodies in naïve mice, the level of which further increases upon innate immune sensor stimulation. B cell receptor repertoire profiling of ERV-reactive B-1 cells revealed increased usage of the Igh VH gene that gives rise to glycan-specific antibodies targeting terminal N-acetylglucosamine moieties on ERV glycoproteins, which further engage the complement pathway to mediate anti-ERV responses. These same antibodies also recognize glycoproteins of other enveloped viruses but not self-proteins. These results reveal an innate antiviral mechanism of germline-encoded antibodies with broad reactivity to enveloped viruses, which constitutes a natural antibody repertoire capable of preventing the emergence of infectious ERVs.

A glucocorticoid-mediated immunoregulatory circuit integrated at brain levels: our early studies and a present view.

Background It was known since the 1940's that pharmacological administration of glucocorticoids can inhibit inflammatory and immune processes, and these hormones are still today among the most widely used therapeutic tools to treat diseases with immune components. However, it became clear later that endogenous glucocorticoids can either support or restrain immune processes. Summary Early studies showed that: a) endogenous levels of glucocorticoids can modulate immune cell activity; b) the immune response itself can stimulate the hypothalamus-pituitary-adrenal (HPA) axis to release glucocorticoids to levels that can exert immunoregulatory effects; c) immune products, later identified as cytokines, mediate this effect. On these bases, the existence of a glucocorticoid-mediated immunoregulatory circuit was proposed. It was also shown that increased levels of endogenous glucocorticoids exert protective effects during infections and other diseases with immune components. However, it was found in animal models and in humans that these effects can be blunted in several immune-linked diseases by defects at several levels, for example by glucocorticoid resistance or by adrenal insufficiency. Evidence was later provided that the glucocorticoid-mediated immunoregulatory circuit can also be activated by cytokines produced not only as consequence of immune stimulation but also following psycho/sensorial and physical stimuli. Thus, this circuit can be integrated at brain levels and, besides stimulating the HPA axis, cytokines can also affect synaptic plasticity, most likely via a tripartite synapse, with astrocytes as neuro-immune cells acting as the third component. Key Messages It is now well established that the glucocorticoid-mediated immunoregulatory circuit plays a central role in maintaining health. However, several variables can condition the efficacy of the effect of endogenous glucocorticoids. Furthermore, since cytokines and other immune products have many other neuro-endocrine and metabolic effects, other neuro-endocrine-immune circuits could simultaneously operate or become predominant during different pathologies. The consideration of these aspects might help to implement strategies to eventually decrease therapeutic doses of exogenous glucocorticoids.

Nucleus-Targeted Sonosensitizer Activates the cGAS-STING Pathway for Tumor Sonodynamic Immunotherapy.

A nucleus is crucial for both sonodynamic therapy (SDT) and antitumor immunity. However, how to burst ROS generation in situ, accurately damage a nucleus, and meanwhile activate a cGAS-STING pathway-induced innate immune response are still a great challenge. Here, we present TBzT-CPi, a small molecule with a D-A-π-A1 structure that simultaneously amplifies nucleus-targeted SDT and cGAS-STING pathway-dependent immune stimulation. TBzT-CPi could accumulate in the nucleus upon ultrasound irradiation and generate ROS in situ, which damages DNA and simultaneously triggers immunogenic cell death (ICD). Stirringly, nucleus-targeting SDT not only efficiently induces apoptosis in tumor cells but also modifies the immunosuppressive tumor microenvironment by activating cytotoxic T lymphocytes, maturing dendritic cells, and secreting cytokines. These findings pave the way for developing nucleus-targeting sonosensitizers for sonodynamic immunotherapy of cancer.

Chemical-Specific T Cell Tests Aim to Bridge a Gap in Skin Sensitization Evaluation

T cell activation is the final key event (KE4) in the adverse outcome pathway (AOP) of skin sensitization. However, validated new approach methodologies (NAMs) for evaluating this step are missing. Accordingly, chemicals that activate an unusually high frequency of T cells, as does the most prevalent metal allergen nickel, are not yet identified in a regulatory context. T cell reactivity to chemical sensitizers might be especially relevant in real-life scenarios, where skin injury, co-exposure to irritants in chemical mixtures, or infections may trigger the heterologous innate immune stimulation necessary to induce adaptive T cell responses. Additionally, cross-reactivity, which underlies cross-allergies, can only be assessed by T cell tests. To date, several experimental T cell tests are available that use primary naïve and memory CD4+ and CD8+ T cells from human blood. These include priming and lymphocyte proliferation tests and, most recently, activation-induced marker (AIM) assays. All approaches are challenged by chemical-mediated toxicity, inefficient or unknown generation of T cell epitopes, and a low throughput. Here, we summarize solutions and strategies to confirm in vitro T cell signals. Broader application and standardization are necessary to possibly define chemical applicability domains and to strengthen the role of T cell tests in regulatory risk assessment.

Outward depolarization of the microglia mitochondrial membrane potential following lipopolysaccharide exposure: a novel screening tool for microglia metabolomics

Microglia are non-electrogenic immune cells that respond rapidly to protect the central nervous system (CNS) from infections, injuries, or other forms of damage. Microglia mitochondria are essential for providing the requisite energy resources for immune regulation. While fluctuations in energy metabolism are regulated by mitochondria and are reflected in the mitochondrial membrane potential (ΔΨm), there remains a lack of innovation in microglia-centric tools that capitalize on this. In this study, live imaging of microglia in acute slices from EGFP reporter mice expressing EGFP under the control of the fractalkine receptor (CX3CR1) promoter is combined with loading a fluorescent reporter of ΔΨm. Depolarizations in the ΔΨm were recorded after administering the well-characterized immune stimulant lipopolysaccharide (LPS). Microglia ΔΨm increased in distinctive phases with a relatively steep slope following LPS exposure. Conversely, the ΔΨm of neurons showed minimal regulation, highlighting a distinct microglia ΔΨm response to immune stimuli. Analysis of the depolarization of the microglia ΔΨm in the soma, branches, and endfeet revealed progressive changes in each subcellular domain originating in the soma and progressing outward. The inverse agonist emapunil attenuated the depolarization of the ΔΨm across states in a domain-specific manner. These findings emphasize the contribution of mitochondrial membrane dynamics in regulating microglial responses to immune stimuli. Further, this work advances a novel drug screening strategy for the therapeutic regulation of metabolic activity in inflammatory conditions of the brain.

Dendritic cell maturation is induced by p53-armed oncolytic adenovirus via tumor-derived exosomes enhancing systemic antitumor immunity.

Dendritic cells (DCs) are crucial in cancer immunity, because they activate cytotoxic T cells by presenting tumor antigens. Recently, oncolytic virus therapy has been recognized as a systemic immune stimulator. We previously developed a telomerase-specific oncolytic adenovirus (OBP-301) and a p53-armed OBP-301 (OBP-702), demonstrating that these viruses strongly activate systemic antitumor immunity. However, their effects on DCs remained unclear. In the present study, the aim was to elucidate the mechanisms of DC activation by OBP-702, focusing particularly on tumor-derived exosomes. Exosomes (Exo53, Exo301, or Exo702) were isolated from conditioned media of human or murine pancreatic cancer cell lines (Panc-1, MiaPaCa-2, and PAN02) after treatment with Ad-p53, OBP-301, or OBP-702. Exo702 derived from Panc-1 and MiaPaCa-2 cells significantly upregulated CD86, CD80, CD83 (markers of DC maturation), and IFN-γ in DCs in vitro. Similarly, Exo702 derived from PAN02 cells upregulated CD86 and IFN-γ in bone marrow-derived DCs in a bilateral PAN02 subcutaneous tumor model. This DC maturation was inhibited by GW4869, an inhibitor of exosome release, and anti-CD63, an antibody targeting the exosome marker. Intratumoral injection of OBP-702 into PAN02 subcutaneous tumors significantly increased the presence of mature DCs and CD8-positive T cells in draining lymph nodes, leading to long-lasting antitumor effects through the durable activation of systemic antitumor immunity. In conclusion, tumor-derived exosomes play a significant role in DC maturation following OBP-702 treatment and are critical for the systemic activation of antitumor immunity, leading to the abscopal effect.

Phyllanthus-derived Naturally-occurring Products: An Overview of their Effects against Viruses in Cell Models

Background: Infectious diseases are considered a global public health problem, with viruses being the predominant infectious agents afflicting the human population. The most used control alternatives are the search and development of vaccines and drugs. Nevertheless, their efficacy has limitations related to the immune response stimulation, resistance mechanisms, costeffort ratio, development, and production. An alternative to these drawbacks is the search for compounds isolated from plants with antiviral and/or virucidal properties. The genus Phyllanthus is a plant group producing compounds that gathers an antiviral and virucidal spectrum on different biological models. However, there is no complete review of their properties against viruses in cell models. Objective: To compile and analyse the more relevant information on the antiviral and virucidal activity in cell models, phytochemical composition, and generalities of the genus Phyllanthus. Method: The information was assembled from a general search for articles in various databanks, and the information was organized, tabulated, and discussed. Results: The taxonomic classification of the genus Phyllanthus showed discrepancies between different authors and publications. The antiviral and virucidal effects of Phyllanthus naturallyoccurring compounds on cell models showed a broad spectrum and a high chemical diversity mainly related to phenols and polyphenols. Conclusion: Antiviral and virucidal properties of Phyllanthus-derived compounds showed promising results as controlling agents against viral infections in different cell models, particularly in the viral replication and translation processes. Further studies are required to elucidate the specific mechanisms involved in these natural alternatives to expand their efficient and effective applications.

Magnitude of antigen-specific T-cell immunity the month after completing vaccination series predicts the development of long-term persistence of antitumor immune response

BackgroundFor best efficacy, vaccines must provide long-lasting immunity. To measure longevity, memory from B and T cells are surrogate endpoints for vaccine efficacy. When antibodies are insufficient for protection, the...

Better, Faster, Stronger: Accelerating mRNA-Based Immunotherapies With Nanocarriers.

Messenger ribonucleic acid (mRNA) therapeutics are attracting attention as promising tools in cancer immunotherapy due to their ability to leverage the invivo expression of all known protein sequences. Even small amounts of mRNA can have a powerful effect on cancer vaccines by promoting the synthesis of tumor-specific antigens (TSA) or tumor-associated antigens (TAA) by antigen-presenting cells (APC). These antigens are then presented to T cells, eliciting strong antitumor immune stimulation. The potential of mRNA can be further enhanced by expressing immunomodulatory agents, such as cytokines, antibodies, and chimeric antigen receptors (CAR), enhancing tumor immunity. Recent research also explores mRNA-encoded tumor death inducers or tumor microenvironment (TME) modulators. Despite its promise, the clinical translation of mRNA-based anticancer strategies faces challenges, including inefficient targeted delivery invivo, failure of endosomal escape, and inadequate intracellular mRNA release, resulting in poor transfection efficiencies. Inspired by the approval of lipid nanoparticle-loaded mRNA vaccines against coronavirus disease 2019 (COVID-19) and the encouraging outcomes of mRNA-based cancer therapies in trials, innovative nonviral nanotechnology delivery systems have been engineered. These aim to advance mRNA-based cancer immunotherapies from research to clinical application. This review summarizes recent preclinical and clinical progress in lipid and polymeric nanomedicines for delivering mRNA-encoded antitumor therapeutics, including cytokines and antibody-based immunotherapies, cancer vaccines, and CAR therapies. It also addresses advanced delivery systems for direct oncolysis or TME reprogramming and highlights key challenges in translating these therapies to clinical use, exploring future perspectives, including the role of artificial intelligence and machine learning in their development.

P-type pilus PapG protein elicits toll-like receptor 2-mediated immune activation during cancer immunotherapy

The immune activation ability of FimH, an adhesion protein in pili of Escherichia coli (E. coli), has been recently reported. However, studies on the immune activity of PapG, another major pili terminal protein, have not been well explored. In this study, the immune stimulatory effect of purified recombinant PapG was evaluated. PapG treatment promoted dramatic changes in dendritic morphology of the bone marrow-derived dendritic cells (BMDCs) and induced upregulation of co-stimulatory molecule levels, major histocompatibility complex (MHC) I and II expression, and pro-inflammatory cytokine production in BMDCs. To identify the stimulatory receptor of PapG, an in silico study was performed. PapG exhibited strong binding affinity with murine toll-like receptor 2 (TLR2). In addition, PapG-induced activation of splenic DC and its subsets was unsuccessful in TLR2-knock out mice. Combination of PapG and ovalbumin (OVA) elicited OVA-specific T cell proliferation and cytokine production and cytotoxicity that consequently promoted anti-cancer immune responses against OVA-expressing B16 melanoma. Furthermore, PapG treatment induced activation of peripheral blood DCs and its subsets in humans in a TLR2 dependent manner. PapG-stimulated human conventional DC2 promoted syngeneic T cell proliferation and activation. The findings of this study demonstrated that PapG could be a useful immune stimulator for immunotherapy against cancer.