Immunostimulatory Potential Research Articles

Evaluation of immunomodulatory (humoral as well as cell-mediated) and cytokines (TNF-α & IL-10) regulating potential of Neolamarckia cadamba fruit extract in Wistar albino rats.

Current work has been designed to investigate the immunomodulatory efficacy with particular reference to humoral, cell-mediated and cytokine-modulating potential of hot aqueous extract of Neolamarckia cadamba (HAENC) fruits in Wistar albino rats. The effect of different concentrations of HAENC fruits over cell-mediated immune response was assessed using six groups (Gp-I as control, Gp-II with 20µg/mL, Gp-III with 50µg/mL, Gp-IV with 100µg/mL, Gp-V with 250µg/mL, and Gp-VI with 500µg/mL) of Wistar albino rats having six animals in each. The amount of tumor necrosis factor-α (TNF-α) and interleukin (IL)-10 was measured by sandwich ELISA with different concentrations of HAENC (50-500µg/mL) in splenocyte culture supernatant and their expression was determined by qRT-PCR Humoral immune response was determined by measuring the serum antibody titer of Wistar albino rats against Salmonella typhimurium 'O' antigen using four groups containing six animals each (Gp-I as control, Gp II, III & IV were respectively fed orally with 125, 250, and 500mg/Kg body weight using HAENC fruits). LC-MS analysis suggested the presence of cadambine, chlorogenic acid, cadambagenic acid, stearic acid, octadecanoic acid ethyl ether, and 7-hydroxy-5,2'-4'-trimethoxyflavonon in the extract based on their m/z ratio. The result suggested significant (p < 0.01) dose-dependent proliferation of Concanavalin A (Con A)-treated splenocytes, depicting cell-mediated immunostimulatory potential of HAENC fruits. A dose-dependent significant decrease (p < 0.01) was found in the amount of TNF-α and IL-10 was found to increase significantly (p < 0.01) as extract concentrations increased. TNF-α and IL-10 expressions were confirmed at the molecular level by qRT-PCR analysis of mRNA transcripts of TNF-α and IL-10 genes. Fold expression of TNF-α and IL-10 gene was 0.197 and 3.58 at 250µg/mL, 0.02 and 20.11 at 500µg/mL concentrations of HAENC respectively in comparison to control. Serum antibody titer was significantly increased (p < 0.01) in animals fed with different doses of HAENC fruits. The present study suggested the anti-inflammatory effect of HAENC fruits which also influences the networking of cytokines, implying that it may play a role in regulating the activity of the host's immune system and can serve as a potent herbal drug with immuno-stimulatory potential.

Nutrient availability regulates the secretion and function of immune cell-derived extracellular vesicles through metabolic rewiring.

Extracellular vesicle (EV)-based immunotherapeutics have emerged as promising strategy for treating diseases, and thus, a better understanding of the factors that regulate EV secretion and function can provide insights into developing advanced therapies. Here, we report that nutrient availability, even changes in individual nutrient components, may affect EV biogenesis and composition of immune cells [e.g., macrophages (Mφs)]. As a proof of concept, EVs from M1-Mφ under glutamine-depleted conditions (EVGLN-) had higher yields, functional compositions, and immunostimulatory potential than EVs from conventional GLN-present medium (EVGLN+). Mechanistically, the systemic metabolic rewiring (e.g., altered energy and redox metabolism) induced by GLN depletion resulted in up-regulated pathways related to EV biogenesis/cargo sorting (e.g., ESCRT) and immunostimulatory molecule production (e.g., NF-κB and STAT) in Mφs. This study highlights the importance of nutrient status in EV secretion and function, and optimizing metabolic states and/or integrating them with other engineering methods may advance the development of EV therapeutics.

The Immunomodulatory Effects of Fluorescein-Mediated Sonodynamic Treatment Lead to Systemic and Intratumoral Depletion of Myeloid-Derived Suppressor Cells in a Preclinical Malignant Glioma Model.

Fluorescein-mediated sonodynamic therapy (FL-SDT) is an extremely promising approach for glioma treatment, resulting from the combination of low-intensity focused ultrasound (FUS) with a sonosensitizer. In the present study, we evaluated the efficacy and immunomodulation of SDT with fluorescein as the sonosensitizer in immunocompetent GL261 glioma mice for the first time. In vitro studies demonstrated that the exposure of GL261 cells to FL-SDT induced immunogenic cell death and relevant upregulation of MHC class I, CD80 and CD86 expression. In vivo studies were then performed to treat GL261 glioma-bearing mice with FL-SDT, fluorescein alone, or FUS alone. Perturbation of the glioma-associated macrophage subset within the immune microenvironment was induced by all the treatments. Notably, a relevant depletion of myeloid-derived suppressor cells (MDSCs) and concomitant robust infiltration of CD8+ T cells were observed in the SDT-FL-treated mice, resulting in a significant radiological delay in glioma progression and a consequent improvement in survival. Tumor control and improved survival were also observed in mice treated with FL alone (median survival 41.5 days, p > 0.0001 compared to untreated mice), reflecting considerable modulation of the immune microenvironment. Interestingly, a high circulating lymphocyte-to-monocyte ratio and a very low proportion of MDSCs were predictive of better survival in FL- and FL-SDT-treated mice than in untreated and FUS-treated mice, in which elevated monocyte and MDSC frequencies correlated with worse survival. The immunostimulatory potential of FL-SDT treatment and the profound modulation of most immunosuppressive components within the microenvironment encouraged the exploration of the combination of FL-SDT with immunotherapeutic strategies.

STING agonists in cancer immunotherapy: a brief review

The “STimulator of INterferon Genes” (STING) represents the primary sensors of cytosolic double-stranded DNA (dsDNA). The STING cellular signaling pathway is considered an attractive pharmacological target for cancer immunotherapy due to its immunostimulatory potential. In fact, activation of the intracellular STING protein triggers the secretion of type I IFNs, which results in immune-mediated tumor elimination and generation of antitumor immune memory. Two types of STING agonists were developed: cyclic dinucleotides (CDNs) and non-nucleotide small molecule agonists. Preclinical studies of STING agonists have demonstrated remarkable results in many tumor models, resulting in complete and durable therapeutic responses in a majority of treated mice. This review provides a brief summary of the latest research findings on STING agonists, their delivery to the tumor and the strategies being employed to enhance their efficacy in cancer immunotherapy.

Bimetallic Gold–Iron Oxide Nanoparticles as Carriers of Methotrexate: Perspective Tools for Biomedical Applications

Bimetallic nanoparticles (BMNPs) combine unique and synergistic properties of two metals, allowing new specific applications. In this study, bimetallic AuFe nanoparticles and their conjugates with methotrexate (MTX) were obtained with an environmentally safe method of metal-vapor synthesis. The composition and electronic structure of the particles were investigated with X-ray photoelectron spectroscopy (XPS), energy dispersive X-ray (EDX) spectrum and X-ray absorption spectroscopy (XANES and EXAFS). The effects of BMNP-MTX conjugates on human primary cells and tumor cell lines were evaluated with neutral red uptake and MTT in vitro cytotoxicity assays. Bright-field microscopy analyses of tumor spheroid size and evaluations of tumor spheroid vitality based on SFDA AM staining were carried out. In vitro assays for an antibacterial activity evaluation of the generated samples were performed. The influence of BMNP-MTX on cytokine production with normal leukocytes was assessed using ELISA. X-ray analyses of the samples demonstrated that gold was in the ground state Au0 as well as Au+ and Au3+ states are present in small quantities, whereas iron existed as a mixture of non-histometric oxides with states close to Fe2+ and Fe3+. The modification of the AuFe system with MTX is accompanied by a threefold increase in the relative proportion of the Au+ state. BMNP-MTX conjugates demonstrated significant antitumor activity compared to the drug alone, which proves the ability of the generated nanoconjugates to improve the effectiveness of MTX therapy. This was confirmed by a marked reduction in the size and vitality of AuFe-MTX-treated 3D tumor spheroids. In addition to their selective antitumor activity, AuFe-MTX exhibited moderate antibacterial activity and induced sample-specific cytokine production with normal human leukocytes—which points to an immunostimulatory potential. The present findings indicate important and diverse biological properties of BMNP-MTX conjugates and thus highlight perspectives for their biomedical applications and new immune-specific abilities.

A review on unravelling the medicinal properties of magical mushrooms: Cordyceps militaris

Nowadays, the public and the scientific communities are choosing and looking for natural remedies as an alternative to the elaborate chemically synthesised drugs. As a result, due to its immunostimulatory potential, Cordyceps genus has grabbed attention from the scientific community in recent years. Various in vivo and in vitro investigations on the endo-parasitic fungi have shown its tremendous pharmaceutical potential owing to the various bioactive constituents. Pre-clinical studies have revealed its activities like anti-cancer, anti-diabetic, antioxidant, vasorelaxation, antihyperlipidemic, anticholesterolemic, hypotensive, anti-aging, anti-fatigue, kidney protection and aphrodisiac. Moreover, Cordyceps species are also related with stimulation of the immune system- stimulating inflammatory response mediated via mitogen activated protein (MAP) kinase pathway, stimulation of phagocytosis, and cytokine production such as interleukins (IL)-10, IL-12, and tumour necrosis factor alpha (TNF) etc. In the present review, we discuss the various bioactive compounds of the fungi such as nucleosides, alkaloids, flavonoids and their therapeutic potential. We also highlight its culturing methods and its current status in the global market.

Immuno-metabolic dendritic cell vaccine signatures associate with overall survival in vaccinated melanoma patients

Efficacy of cancer vaccines remains low and mechanistic understanding of antigen presenting cell function in cancer may improve vaccine design and outcomes. Here, we analyze the transcriptomic and immune-metabolic profiles of Dendritic Cells (DCs) from 35 subjects enrolled in a trial of DC vaccines in late-stage melanoma (NCT01622933). Multiple platforms identify metabolism as an important biomarker of DC function and patient overall survival (OS). We demonstrate multiple immune and metabolic gene expression pathway alterations, a functional decrease in OCR/OXPHOS and increase in ECAR/glycolysis in patient vaccines. To dissect molecular mechanisms, we utilize single cell SCENITH functional profiling and show patient clinical outcomes (OS) correlate with DC metabolic profile, and that metabolism is linked to immune phenotype. With single cell metabolic regulome profiling, we show that MCT1 (monocarboxylate transporter-1), a lactate transporter, is increased in patient DCs, as is glucose uptake and lactate secretion. Importantly, pre-vaccination circulating myeloid cells in patients used as precursors for DC vaccine generation are significantly skewed metabolically as are several DC subsets. Together, we demonstrate that the metabolic profile of DC is tightly associated with the immunostimulatory potential of DC vaccines from cancer patients. We link phenotypic and functional metabolic changes to immune signatures that correspond to suppressed DC differentiation.

Immunostimulatory potential of extruded plant-based meat: effect of extrusion moisture level on macrophage activation.

In this study, the effect of different moisture levels in extruded plant-based meat on macrophage immunostimulation, and the potential of this meat as a protein source and a solution to environmental and economic challenges associated with conventional meat was investigated. To determine the effects of the extruded plant-based meat, cell viability assay, enzyme-linked immunosorbent assay, flow cytometry, and western blotting were performed. Low-moisture (LMME) and high-moisture meat extracts (HMME) showed higher potential to activate macrophages and regulate cytokine production than raw material extract. Treatment with LMME and HMME resulted in increased expression of CD80, CD86, and MHC class I/II proteins, indicating their potential to activate macrophages. Western blotting suggested that the immune activation observed in a previous study of macrophages was because of the phosphorylation of MAPKs and NF-κB. These findings suggest that extruded plant-based meat can potentially be used as an immunostimulatory food ingredient.

Immunomodulatory effect of probiotic exopolysaccharides in a porcine in vitro co-culture model mimicking the intestinal environment on ETEC infection.

The aim of this study was to evaluate the immunomodulatory effect of EPS-L26 isolated from the probiotic strain Lactobacillus (Limosilactobacillus) reuteri L26 Biocenol™, in a model of infection with an enterotoxigenic E. coli (ETEC) by establishing monocultures consisting of the IPEC-J2 cell line or monocyte-derived dendritic cells (moDCs) and creating a 3D model of cell co-cultures established with IPEC-J2 cells and moDCs. The immunomodulatory and immunoprotective potential of used EPS-L26 was confirmed in monocultures in an experimental group of pretreated cells, where our study showed that pretreatment of cells with EPS-L26 and subsequent exposure to infection resulted in significantly down-regulated mRNA levels of genes encoding inflammatory cytokines compared to ETEC challenge in single cell cultures (in IPEC-J2, decreased mRNA levels for TNF-α, IL-6, IL-1β, IL-12p35; in moDCs, decreased mRNA levels for IL-1β). Similar to monocultures, we also demonstrated the immunostimulatory potential of the ETEC strain in the co-culture model on directly treated IPEC-J2 cells cultivated on insert chambers (apical compartment) and also on indirectly treated moDCs cultivated in the lower chamber (basolateral compartment), however in the co-culture model the expression of inflammatory cytokines was attenuated at the mRNA level compared to monocultures. Pretreatment of the cells on the insert chambers pointed to the immunoprotective properties of EPS-L26, manifested by decreased mRNA levels in both cell lines compared to ETEC challenge (in IPEC-J2 decreased mRNA levels for IL-12p35; in moDCs decreased mRNA levels for IL-1β, IL-6). Our results suggest intercellular communication via humoral signals derived from IPEC-J2 cells by influencing the gene expression of indirectly treated moDC cells located in the basolateral compartment.

Engineering Non-Human RNA Viruses for Cancer Therapy.

Alongside the development and progress in cancer immunotherapy, research in oncolytic viruses (OVs) continues advancing novel treatment strategies to the clinic. With almost 50 clinical trials carried out over the last decade, the opportunities for intervention using OVs are expanding beyond the old-fashioned concept of "lytic killers", with promising breakthrough therapeutic strategies focused on leveraging the immunostimulatory potential of different viral platforms. This review presents an overview of non-human-adapted RNA viruses engineered for cancer therapy. Moreover, we describe the diverse strategies employed to manipulate the genomes of these viruses to optimize their therapeutic capabilities. By focusing on different aspects of this particular group of viruses, we describe the insights into the promising advancements in the field of virotherapy and its potential to revolutionize cancer treatment.

Characterization of potential probiotic starter cultures of lactic acid bacteria isolated from Ethiopian fermented cereal beverages, Naaqe and Cheka.

To test the in vitro probiotic potential and starter culture capacity of lactic acid bacteria (LAB) isolated from Naaqe and Cheka, cereal-based Ethiopian traditional fermented beverages. 44 strains were isolated from spontaneously fermented Ethiopian cereal-based beverages, Naaqe and Cheka, with 24 putatively identified as LAB and 14 identified up to the species level. The species Limosilactobacillus fermentum (6/12; 50%) and Weissella confusa (5/12, 41.67%) were the predominant species identified from Naaqe, while the two Cheka isolates were Limosilactobacillus fermentum and Pediococcus pentosaceus. Six LAB strains inhibited eight of the nine gastrointestinal indicator key pathogens in Ethiopia, including Escherichia coli, Salmonella enterica subsp. enterica var. Typhimurium, Staphylococcus aureus, Shigella flexneri, and Listeria monocytogenes. Three of the LAB isolates exhibited strain-specific immunostimulation in human monocytes. Based on these probiotic properties and growth, six strains were selected for in situ evaluation in a mock fermentation of Naaqe and Cheka. During primary fermentations, L. fermentum 73B, P. pentosaceus 74D, L. fermentum 44B, Weissella confusa 44D, L. fermentum 82C and Weissella cibaria 83E and their combinations demonstrated higher pH-lowering properties and colony-forming unit counts compared to the control spontaneous fermentation. The same pattern was also observed in the secondary mock fermentation by the Naaqe LAB isolates. In this study, we selected six LAB strains with antipathogenic, immunostimulatory and starter culture potentials that can be used as autochthonous probiotic starters for Naaqe and Cheka fermentations, once their health benefit is ascertained in a clinical trial as a next step.

Immunostimulatory and antagonistic potential of the methanolic extract of Oedogonium intermedium SCB in Cirrhinus reba challenged with Aeromonas hydrophila

Immunostimulatory and antagonistic potential of the methanolic extract of Oedogonium intermedium SCB in Cirrhinus reba challenged with Aeromonas hydrophila

Cryptococcus neoformans requires the TVF1 gene for thermotolerance and virulence.

Cryptococcus neoformans is the primary causative agent of cryptococcosis. Since C. neoformans thrives in environments and its optimal growth temperature is 25-30°C, it needs to adapt to heat stress in order to cause infection in mammalian hosts. In this study, we aimed to investigate the role of an uncharacterized gene, CNAG_03308. Although the CNAG_03308 deletion strain grew as well as the parent strain KN99, it produced yeast cells with abnormal morphology at 37°C and failed to propagate at 39°C. Furthermore, the deletion strain exhibited slower growth at 37°C in the presence of congo red, which is a cell wall stressor. When cultured at 39°C, the deletion strain showed strong staining with fluorescent probes for cell wall chitin and chitosan, including FITC-labeled wheat germ agglutinin, Eosin Y, and calcofluor white. The transmission electron microscopy of the deletion strain revealed a thickened inner layer of the cell wall containing chitin and chitosan under heat stress. This cell-surface altered deletion strain induced dendritic cells to secrete more interleukin (IL)-6 and IL-23 than the control strains under heat stress. In a murine infection study, C57BL/6 mice infected with the deletion strain exhibited lower mortality and lower fungal burden in the lungs and brain compared to those infected with the control strains. Based on these findings, we concluded that CNAG_03308 gene is necessary for C. neoformans to adapt to heat stress both in vitro and in the host environment. Therefore, we designated the CNAG_03308 gene as TVF1, which stands for thermotolerance and virulence-related factor 1.

Cellular Export Fate of Liposomal Spherical Nucleic Acids.

Liposomal spherical nucleic acids (LSNAs) are useful structures for oligonucleotide-based cell modulation because of their biocompatibility and ability to readily enter cells without transfection agents. Understanding LSNA trafficking is key to developing applications, but while much is understood about LSNA cell uptake, little is known about their export fate. Here, we study LSNA export through pulse-chase studies with fluorophore-labeled LSNAs. Our findings show that the components of LSNAs are differentially exported by cells, with the phospholipids showing 90-100% export and the oligonucleotides showing 30-45% export over 24 h in RAW264.7 macrophages. Despite the increase in the level of uptake of LSNAs, these percentages are not significantly influenced by whether the materials are taken up as LSNAs or as the individual components. The exported oligonucleotide material consists of a full-length oligonucleotide with the phospholipid anchor modified by loss of a fatty acid. The exported liposome-derived phospholipids also had a fatty acid removed. Moreover, the exported oligonucleotide-lysophospholipid conjugates retain immunostimulatory potential. These findings indicate that after cellular entry LSNAs are degraded into lysophospholipids, something to which they are susceptible due to the presence of hydrolyzable ester bonds. The export percentage of the resultant materials over 24 h is independent of the amount imported, such that greater initial import leads to a similar fold increase in exported material. This work therefore reveals an intracellular feature of LSNAs and shows that the enhanced uptake achieved with LSNAs can be exploited to maximize the amount of material subsequently exported, suggesting avenues for leveraging pharmacologic effects from exported LSNA components.

Immunostimulatory activity of avocado oil in mice (Mus musculus)

Avocado fruit contains bioactive compounds that have the potential to act as an immunomodulator. This study aims to identify the ability of avocado oil as an immunomodulator based on the macrophage phagocytic activity and index of mice injected with nonpathogenic Staphylococcus aureus and to determine the most effective dose as an immunomodulator. This study used 30 male Deutschland Denken Yoken (DDY) mice, which were divided into five groups: placebo as negative control (mineral water), positive control (commercial immunomodulator containing Echinacea purpurea extract), and avocado oil 1 g/kg BW, 3 g/kg BW, and 5 g/kg BW. The treatment was carried out orally once a day for 14 days. Mice were induced by nonpathogenic Staphylococcus aureus on day 15 intraperitoneally, and after one hour, mice were euthanized to collect the peritoneal fluid. Peritoneal fluid smear preparations were made before active macrophages and phagocytosed Staphylococcus aureus were observed under a microscope. Phagocytic activity and phagocytic index were calculated. Avocado oil 5 g/kg BW showed the highest phagocytic activity and phagocytic index results with values of 71.00% ± 5.40% and 2.79 ± 0.14, respectively. Avocado oil enhances non-specific immune responses through macrophagephagocytic activity and index, demonstrating its immunostimulatory potential.

Chemotherapy-induced nanovaccines implement immunogenicity equivalence for improving cancer chemoimmunotherapy

Several chemoimmunotherapies have been approved by the FDA for the treatment of various cancers. Chemotherapy has the potential to improve the efficacy of immunotherapy by inducing immunogenic cell death (ICD) of tumor cells, promoting the release of tumor associated antigens (TAAs), tumor specific antigens (TSAs) and damage associated molecular patterns (DAMPs), and disrupting immunosuppressive microenvironments by tumor debulking. Unfortunately, systemic administration of chemotherapeutics carries side effects of blunting anti-cancer immune response through systemic immunosuppression, which deserves to be explored as an inner contradiction in chemoimmunotherapy. Here, we proposed the hypothesis of “immunogenicity equivalence” in chemoimmunotherapy that chemotherapeutics-induced immunogenic antigens and DAMPs in vitro that can subsequently be incorporated into nanovaccines, which will possess comparable immunostimulatory potential when compared to tumors treated with systemic chemotherapy in vivo. The proteomic analysis confirmed that our nanovaccines contained TAAs, TSAs and DAMPs. Improvement in treatment outcomes in tumor-bearing mice receiving anti-PD-1 and chemotherapy-induced nanovaccines was then observed. Furthermore, we demonstrated the feasibility of replacing long-term chemotherapy with nanovaccines in chemoimmunotherapy. Our nanovaccine strategy would be a general choice for formulating cancer vaccines in personalized medicine.

Immunostimulatory effects of marine algae extracts on in vitro antigen-presenting cell activation and in vivo immune cell recruitment.

Marine algae are photosynthetic eukaryotic organisms that are widely used as sources of food, cosmetics, and drugs. However, their biological and immunological effects on immune cells have not been fully elucidated. To unravel their immunological activity and broaden their application, we generated antigen-presenting cells (APCs), including dendritic cells (DCs) and macrophages, from mouse bone marrow cells and treated them with six different marine algae extracts (MAEs). We evaluated cell viability, activation marker expression, and pro-inflammatory cytokine production by APCs after 2 days of MAE treatment. All six MAEs significantly induced cytokine production of APCs, among which Pyropia yezoensis (PY), Peyssonnelia caulifera (PC), and Meristotheca papulosa (MP) extracts exhibited the strongest effect. Cladophora wrightiana var. minor (CW) extract moderately upregulated cytokine levels but increased the expression of activation markers on DCs. Moreover, PY, PC, MP, Sargassum pectinifera (SP), and Caulerpa okamurae (CO) pre-treated APCs effectively stimulated T-cell proliferation and cytokine production. Furthermore, the mice injected with MAEs exhibited higher cytokine (TNF-α, IL-6, and IL-1β) production as well as enhanced innate immune cell recruitment capacities (DCs, monocytes, neutrophils, and natural killer cells) in the peritoneal cavity of the mice compared to those of the non-treated mice. Therefore, all MAEs exhibited immunostimulatory potential, with PY, PC, CW, and MP extracts being the most effective in stimulating immune responses and cell activation. To the best of our knowledge, this is the first study to determine the immunomodulatory activities of six MAEs both in vitro and in vivo.

Evaluation of Radiosensitization and Cytokine Modulation by Differentially PEGylated Gold Nanoparticles in Glioblastoma Cells.

Glioblastoma (GBM) is known as the most aggressive type of malignant brain tumour, with an extremely poor prognosis of approximately 12 months following standard-of-care treatment with surgical resection, radiotherapy (RT), and temozolomide treatment. Novel RT-drug combinations are urgently needed to improve patient outcomes. Gold nanoparticles (GNPs) have demonstrated significant preclinical potential as radiosensitizers due to their unique physicochemical properties and their ability to pass the blood-brain barrier. The modification of GNP surface coatings with poly(ethylene) glycol (PEG) confers several therapeutic advantages including immune avoidance and improved cellular localisation. This study aimed to characterise both the radiosensitizing and immunomodulatory properties of differentially PEGylated GNPs in GBM cells in vitro. Two GBM cell lines were used, U-87 MG and U-251 MG. The radiobiological response was evaluated by clonogenic assay, immunofluorescent staining of 53BP1 foci, and flow cytometry. Changes in the cytokine expression levels were quantified by cytokine arrays. PEGylation improved the radiobiological efficacy, with double-strand break induction being identified as an underlying mechanism. PEGylated GNPs also caused the greatest boost in RT immunogenicity, with radiosensitization correlating with a greater upregulation of inflammatory cytokines. These findings demonstrate the radiosensitizing and immunostimulatory potential of ID11 and ID12 as candidates for RT-drug combination in future GBM preclinical investigations.

Phytoglycogen-dsRNA nanoparticles demonstrate differential cytotoxicity and immunostimulatory potential in two ovarian cancer cell lines

Ovarian cancer is a leading cause of cancer mortality in women, and novel treatments with improved efficacy are needed to fight ovarian cancer. Double-stranded (ds) RNA, including the synthetic polyinosinic cytidylic acid (poly (I:C), has shown promise as a cancer therapeutic. Phytoglycogen derived from sweet corn, nanodendrix (NDX) is a carrier for dsRNA. The responsiveness to NDX-delivered poly (I:C), NDX-poly (I:C), was tested in two ovarian cancer cell lines, SKOV-3 and OVCAR-3, previously identified as dsRNA-resistant and dsRNA-sensitive, respectively. NDX bound poly (I:C) at a w/w ratio of 2:1 NDX:poly (I:C) and poly (I:C)-NDX was tested for biological activity through uptake and two therapeutic modes of action, cytotoxicity, and immune stimulation. Immunocytochemistry demonstrated both cells bound to poly (I:C)-NDX. In OVCAR-3, poly (I:C)-NDX caused significant cell death, even at concentrations as low as 62.5 ng/mL; no cell death was observed with poly (I:C) alone at concentrations up to 5 μg/mL in SKOV-3 and 0.5 μg/mL in OVCAR-3. In both cell lines poly (I:C)-NDX stimulated the production of CXCL10 protein and transcripts, an innate immune chemokine, and at significantly higher levels than poly (I:C) alone. Interestingly, in response to poly (I:C)-NDX SKOV-3 produced a more robust immune response and higher levels of capase-3/-7 activation compared to OVCAR-3, despite showing no significant cell death. Poly (I:C)-NDX represents a robust and multifunctional therapy, potentiating poly (I:C) and sensitizing resistant cells. Additionally, the SKOV-3 and OVCAR-3 combination represents a powerful comparative model to help unravel dsRNA-mediated immune responses in ovarian cancer cells.

The Autoinducer N-Octanoyl-L-Homoserine Lactone (C8-HSL) as a Potential Adjuvant in Vaccine Formulations.

Autoinducers AI-1 and AI-2 play an important role in bacterial quorum sensing (QS), a form of chemical communication between bacteria. The autoinducer N-octanoyl-L-Homoserinehomoserine lactone (C8-HSL) serves as a major inter- and intraspecies communicator or 'signal', mainly for Gram-negative bacteria. C8-HSL is proposed to have immunogenic properties. The aim of this project is to evaluate C8-HSL as a potential vaccine adjuvant. For this purpose, a microparticulate formulation was developed. The C8-HSL microparticles (MPs) were formulated by a water/oil/water (W/O/W) double-emulsion solvent evaporation method using PLGA (poly (lactic-co-glycolic acid)) polymer. We tested C8-HSL MPs with two spray-dried bovine serum albumin (BSA)-encapsulated bacterial antigens: colonization factor antigen I (CFA/I) from Escherichia coli (E. coli.) and the inactive protective antigen (PA) from Bacillus anthracis (B. anthracis). We formulated and tested C8-HSL MP to determine its immunogenicity potential and its ability to serve as an adjuvant with particulate vaccine formulations. An in vitro immunogenicity assessment was performed using Griess's assay, which indirectly measures the nitric oxide radical (NOˑ) released by dendritic cells (DCs). The C8-HSL MP adjuvant was compared with FDA-approved adjuvants to determine its immunogenicity potential. C8-HSL MP was combined with particulate vaccines for measles, Zika and the marketed influenza vaccine. The cytotoxicity study showed that MPs were non-cytotoxic toward DCs. Griess's assay showed a comparable release of NOˑ from DCs when exposed to CFA and PA bacterial antigens. Nitric oxide radical (NOˑ) release was significantly higher when C8-HSL MPs were combined with particulate vaccines for measles and Zika. C8-HSL MPs showed immunostimulatory potential when combined with the influenza vaccine. The results showed that C8-HSL MPs were as immunogenic as FDA-approved adjuvants such as alum, MF59, and CpG. This proof-of-concept study showed that C8-HSL MP displayed adjuvant potential when combined with several particulate vaccines, indicating that C8-HSL MPs can increase the immunogenicity of both bacterial and viral vaccines.