The single-cell epigenomic and transcriptional landscape of immunity to influenza vaccination.

Emerging evidence indicates a fundamental role for the epigenome in immunity. Here, we mapped the epigenomic and transcriptional landscape of immunity to influenza vaccination in humans at the single-cell level. Vaccination against seasonal influenza induced persistently diminished H3K27ac in monocytes and myeloid dendritic cells (mDCs), which was associated with impaired cytokine responses to Toll-like receptor stimulation. Single-cell ATAC-seq analysis revealed an epigenomically distinct subcluster of monocytes with reduced chromatin accessibility at AP-1-targeted loci after vaccination. Similar effects were observed in response to vaccination with the AS03-adjuvanted H5N1 pandemic influenza vaccine. However, this vaccine also stimulated persistently increased chromatin accessibility at interferon response factor (IRF) loci in monocytes and mDCs. This was associated with elevated expression of antiviral genes and heightened resistance to the unrelated Zika and Dengue viruses. These results demonstrate that vaccination stimulates persistent epigenomic remodeling of the innate immune system and reveal AS03's potential as an epigenetic adjuvant.

Induction of ferroptosis in human keratinocyte HaCaT cells by squalene hydroperoxide: Possible prevention of skin ferroptosis by botanical extracts.

Ever since the proposal of ferroptosis, it has been studied as a nonapoptotic cell death caused by iron ion-dependent phospholipid (PL) peroxidation. We previously showed that treatment of human hepatoma cell line HepG2 with prepared PL hydroperoxide (PLOOH) resulted in ferroptosis. However, in human sebum, the major hydroperoxide is not PLOOH but squalene hydroperoxide (SQOOH), and to our knowledge, it is not established yet whether SQOOH induces ferroptosis in the skin. In this study, we synthesized SQOOH and treated human keratinocyte HaCaT cells with SQOOH. The results showed that SQOOH induces ferroptosis in HaCaT cells in the same way that PLOOH causes ferroptosis in HepG2 cells. Some natural antioxidants (botanical extracts) could inhibit the ferroptosis in both the cell types. Consequently, future research focus would revolve around the involvement of SQOOH-induced ferroptosis in skin pathologies as well as the prevention and treatment of skin diseases through inhibition of ferroptosis by botanical extracts.

A novel amphiphilic squalene-based compound with open-chain polyethers reduces malignant melanoma metastasis in-vitro and in-vivo.

Squalene (SQ) is a well-known antioxidant and anti-inflammatory agent that provides promising anti-aging and UV-protective roles on human skin. However, its strong hydrophobic nature, accompanied by issues such as poor solubility and limited tissue permeation, has created challenges for scientists to investigate its untapped potential in more complex conditions, including cancer progression. The present study assessed the potent anti-metastatic properties of a newly synthesized amphiphilic ethylene glycol SQ derivative (SQ-diEG) in melanoma, the most fatal skin cancer. In vitro and in vivo experiments have discovered that SQ-diEG may exert its potential on melanoma malignancy through the mitochondria-mediated caspase activation apoptotic signaling pathway. The potent anti-metastatic effect of SQ-diEG was observed in vitro using highly proliferative and aggressive melanoma cells. Administration of SQ-diEG (25 mg/kg) significantly decreased the tumor burden on the lung and inhibited the metastasis-associated proteins and gene markers in B16F10 lung colonization mice model. Furthermore, global gene profiling also revealed a promising role of SQ-diEG in tumor microenvironment. We anticipated that the amphiphilic nature of the SQ compound bearing ethylene glycol oligomers could potentially augment its ability to reach the pathology site, thus enhancing its therapeutic potential in melanoma.

Differentially Expressed Genes in Response to a Squalene-Supplemented Diet Are Accurate Discriminants of Porcine Non-Alcoholic Steatohepatitis.

Squalene is the major unsaponifiable component of virgin olive oil, the fat source of the Mediterranean diet. To evaluate its effect on the hepatic transcriptome, RNA sequencing was carried out in two groups of male Large White x Landrace pigs developing nonalcoholic steatohepatitis by feeding them a high fat/cholesterol/fructose and methionine and choline-deficient steatotic diet or the same diet with 0.5% squalene. Hepatic lipids, squalene content, steatosis, activity (ballooning + inflammation), and SAF (steatosis + activity + fibrosis) scores were analyzed. Pigs receiving the latter diet showed hepatic squalene accumulation and twelve significantly differentially expressed hepatic genes (log2 fold change < 1.5 or <1.5) correlating in a gene network. These pigs also had lower hepatic triglycerides and lipid droplet areas and higher cellular ballooning. Glutamyl aminopeptidase (ENPEP) was correlated with triglyceride content, while alpha-fetoprotein (AFP), neutralized E3 ubiquitin protein ligase 3 (NEURL3), 2'-5'-oligoadenylate synthase-like protein (OASL), and protein phosphatase 1 regulatory inhibitor subunit 1B (PPP1R1B) were correlated with activity reflecting inflammation and ballooning, and NEURL3 with the SAF score. AFP, ENPEP, and PPP1R1B exhibited a remarkably strong discriminant power compared to those pathological parameters in both experimental groups. Moreover, the expression of PPP1R1B, TMEM45B, AFP, and ENPEP followed the same pattern in vitro using human hepatoma (HEPG2) and mouse liver 12 (AML12) cell lines incubated with squalene, indicating a direct effect of squalene on these expressions. These findings suggest that squalene accumulated in the liver is able to modulate gene expression changes that may influence the progression of non-alcoholic steatohepatitis.

Anti-Inflammatory and Antioxidant Properties of Squalene in Copper Sulfate-Induced Inflammation in Zebrafish (Danio rerio).

Long-term or excessive oxidative stress can cause serious damage to fish. Squalene can be added to feed as an antioxidant to improve the body constitution of fish. In this study, the antioxidant activity was detected by 2,2-diphenyl-1-acrylhydrazyl (DPPH) test and fluorescent probe (dichloro-dihydro-fluorescein diacetate). Transgenic Tg (lyz: DsRed2) zebrafish were used to evaluate the effect of squalene on CuSO4-induced inflammatory response. Quantitative real-time reverse transcription polymerase chain reaction was used to examine the expression of immune-related genes. The DPPH assay demonstrated that the highest free radical scavenging exerted by squalene was 32%. The fluorescence intensity of reactive oxygen species (ROS) decreased significantly after 0.7% or 1% squalene treatment, and squalene could exert an antioxidative effect in vivo. The number of migratory neutrophils in vivo was significantly reduced after treatment with different doses of squalene. Moreover, compared with CuSO4 treatment alone, treatment with 1% squalene upregulated the expression of sod by 2.5-foldand gpx4b by 1.3-fold to protect zebrafish larvae against CuSO4-induced oxidative damage. Moreover, treatment with 1% squalene significantly downregulated the expression of tnfa and cox2. This study showed that squalene has potential as an aquafeed additive to provide both anti-inflammatory and antioxidative properties.

Analysis of Antidiabetic Activity of Squalene via In Silico and In Vivo Assay.

Squalene has been tested widely in pharmacological activity including anticancer, antiinflammatory, antioxidant, and antidiabetic properties. This study aims to examine antidiabetic activity of squalene in silico and in vivo models. In the in silico model, the PASS server was used to evaluate squalene antidiabetic properties. Meanwhile, the in vivo model was conducted on a Type 2 Diabetes Mellitus (T2DM) with the rats separated into three groups. These include squalene (160 mg/kgbw), metformin (45 mg/kgbw), and diabetic control (DC) (aquades 10 mL/kgbw) administered once daily for 14 days. Fasting Blood Glucose Level (FBGL), Dipeptidyl Peptidase IV (DPPIV), leptin, and Superoxide Dismutase (SOD) activity were measured to analysis antidiabetic and antioxidant activity. Additionally, the pancreas was analysed through histopathology to examine the islet cell. The results showed that in silico analysis supported squalene antidiabetic potential. In vivo experiment demonstrated that squalene decreased FBGL levels to 134.40 ± 16.95 mg/dL. The highest DPPIV level was in diabetic control- (61.26 ± 15.06 ng/mL), while squalene group showed the lowest level (44.09 ± 5.29 ng/mL). Both metformin and squalene groups showed minor pancreatic rupture on histopathology. Leptin levels were significantly higher (p < 0.05) in diabetic control group (15.39 ± 1.77 ng/mL) than both squalene- (13.86 ± 0.47 ng/mL) and metformin-treated groups (9.22 ± 0.84 ng/mL). SOD activity were higher in both squalene- and metformin-treated group, particularly 22.42 ± 0.27 U/mL and 22.81 ± 0.08 U/mL than in diabetic control (21.88 ± 0.97 U/mL). In conclusion, in silico and in vivo experiments provide evidence of squalene antidiabetic and antioxidant properties.

Systems analysis of human vaccine adjuvants.

The discovery and wide spread use of vaccines have saved millions of lives in the past few decades. Vaccine adjuvants represent an integral part of the modern vaccines. Despite numerous efforts, however, only a handful of vaccine adjuvants is currently available for human use. A comprehensive understanding of the mechanisms of action of adjuvants is pivotal to harness the potential of existing and new adjuvants in mounting desirable immune responses to counter human pathogens. Decomposing the host response to vaccines and its components at systems level has recently been made possible owing to the recent advancements in Omics technology and cutting edge immunological assays powered by systems biology approaches. This approach has begun to shed light on the molecular signatures of several human vaccines and adjuvants. This review is an attempt to provide an overview of the recent efforts in systems analysis of vaccine adjuvants that are currently in clinic.

Correlates of adjuvanticity: A review on adjuvants in licensed vaccines.

After decades of slow progress, the last years have seen a rapid acceleration of the development of adjuvanted vaccines which have lately been approved for human use. These adjuvants consist of different components, e.g. aluminium salts, emulsions such as MF59 and AS03, Toll-like receptor (TLR) agonists (CpG ormonophosphoryl lipid A (MPL) adsorbed on aluminium salts as in AS04) or combination of immunopotentiators (QS-21 and MPL in AS01). Despite their distinctive features, most of these adjuvants share some key characteristics. For example, they induce early activation (although at different levels) of innate immunity which then translates into higher antibody and cellular responses to the vaccine antigens. In addition, most of these adjuvants (e.g. MF59, AS03, AS04) clearly induce a wider breadth of adaptive responses able to confer protection against, for example, heterovariants of the influenza viruses (MF59, AS03) or against human papillomavirus strains not contained in the vaccine (AS04). Finally, the use of some of these adjuvants has contributed to significantly enhance the immune response and the efficacy and effectiveness of vaccines in the elderly who experience a waning of the immune responsiveness to infection and vaccination, as shown for MF59- or AS03-adjuvanted influenza vaccines and AS01-adjuvanted herpes zoster vaccine. These results, together with the track record of acceptable safety profiles of the adjuvanted vaccines, pave the way for the development of novel vaccines at the extremes of age and against infections with a high toll of morbidity and mortality. Here, we review the mechanisms associated with the performance of those adjuvanted vaccines in animal models and in humans through recent advances in systems vaccinology and biomarker discovery. We also provide some perspectives on remaining knowledge gaps but also on opportunities that could accelerate the development of new vaccines.

Squalene through Its Post-Squalene Metabolites Is a Modulator of Hepatic Transcriptome in Rabbits.

Squalene is a natural bioactive triterpene and an important intermediate in the biosynthesis of sterols. To assess the effect of this compound on the hepatic transcriptome, RNA-sequencing was carried out in two groups of male New Zealand rabbits fed either a diet enriched with 1% sunflower oil or the same diet with 0.5% squalene for 4 weeks. Hepatic lipids, lipid droplet area, squalene, and sterols were also monitored. The Squalene administration downregulated 9 transcripts and upregulated 13 transcripts. The gene ontology of transcripts fitted into the following main categories: transporter of proteins and sterols, lipid metabolism, lipogenesis, anti-inflammatory and anti-cancer properties. When the results were confirmed by RT-qPCR, rabbits receiving squalene displayed significant hepatic expression changes of LOC100344884 (PNPLA3), GCK, TFCP2L1, ASCL1, ACSS2, OST4, FAM91A1, MYH6, LRRC39, LOC108176846, GLT1D1 and TREH. A squalene-enriched diet increased hepatic levels of squalene, lanosterol, dihydrolanosterol, lathosterol, zymostenol and desmosterol. Strong correlations were found among specific sterols and some squalene-changed transcripts. Incubation of the murine AML12 hepatic cell line in the presence of lanosterol, dihydrolanosterol, zymostenol and desmosterol reproduced the observed changes in the expressions of Acss2, Fam91a1 and Pnpla3. In conclusion, these findings indicate that the squalene and post-squalene metabolites play important roles in hepatic transcriptional changes required to protect the liver against malfunction.

Media Supplementation with Mannitol and Biotin Enhances Squalene Production of Thraustochytrium ATCC 26185 through Increased Glucose Uptake and Antioxidative Mechanisms.

Media supplementation with exogenous chemicals is known to stimulate the accumulation of important lipids produced by microalgae and thraustochytrids. However, the roles of exogenous chemicals in promoting and preserving the terpenoids pool of thraustochytrids have been rarely investigated. Here, we realized the effects of two media supplements-mannitol and biotin-on the biomass and squalene production by a thraustochytrid strain (Thraustochytrium sp. ATCC 26185) and elucidated their mechanism of action. A significant change in the biomass was not evident with the exogenous addition of these supplements. However, with mannitol (1 g/L) supplementation, the ATCC 26185 culture achieved the best concentration (642 ± 13.6 mg/L) and yield (72.9 ± 9.6 mg/g) of squalene, which were 1.5-fold that of the control culture (non-supplemented). Similarly, with biotin supplementation (0.15 mg/L), the culture showed 459 ± 2.9 g/L and 55.7 ± 3.2 mg/g of squalene concentration and yield, respectively. The glucose uptake rate at 24 h of fermentation increased markedly with mannitol (0.31 g/Lh-1) or biotin (0.26 g/Lh-1) supplemented culture compared with non-supplemented culture (0.09 g/Lh-1). In addition, the reactive oxygen species (ROS) level of culture supplemented with mannitol remained alleviated during the entire period of fermentation while it alleviated after 24 h with biotin supplementation. The ∆ROS with mannitol was better compared with biotin supplementation. The total antioxidant capacity (T-AOC) of the supplemented culture was more than 50% during the late stage (72-96 h) of fermentation. Our study provides the potential of mannitol and biotin to enhance squalene yield and the first lines of experimental evidence for their protective role against oxidative stress during the culture of thraustochytrids.

Investigation of squalene-doxorubicin distribution and interactions within single cancer cell using Raman microspectroscopy.

Intracellular distribution of doxorubicin (DOX) and its squalenoylated (SQ-DOX) nanoparticles (NPs) form in murine lung carcinoma M109 and human breast carcinoma MDA-MB-231 cells was investigated by Raman microspectroscopy. Pharmacological data showed that DOX induced higher cytotoxic effect than SQ-DOX NPs. Raman data were obtained using single-point measurements and imaging on the whole cell areas. These data showed that after DOX treatment at 1 µM, the spectral features of DOX were not detected in the M109 cell cytoplasm and nucleus. However, the intracellular distribution of SQ-DOX NPs was higher than DOX in the same conditions. In addition, SQ-DOX NPs were localized into both cell cytoplasm and nucleus. After 5 µM treatment, Raman bands of DOX at 1211 and 1241 cm-1 were detected in the nucleus. Moreover, the intensity ratio of these bands decreased, indicating DOX intercalation into DNA. However, after treatment with SQ-DOX NPs, the intensity of these Raman bands increased. Interestingly, with SQ-DOX NPs, the intensity of 1210/1241 cm-1 ratio was higher suggesting a lower fraction of intercalated DOX in DNA and higher amount of non-hydrolyzed SQ-DOX. Raman imaging data confirm this subcellular localization of these drugs in both M109 and MDA-MB-231 cells. These finding brings new insights to the cellular characterization of anticancer drugs at the molecular level, particularly in the field of nanomedicine.

Non-Polar Lipids as Regulators of Membrane Properties in Archaeal Lipid Bilayer Mimics.

The modification of archaeal lipid bilayer properties by the insertion of apolar molecules in the lipid bilayer midplane has been proposed to support cell membrane adaptation to extreme environmental conditions of temperature and hydrostatic pressure. In this work, we characterize the insertion effects of the apolar polyisoprenoid squalane on the permeability and fluidity of archaeal model membrane bilayers, composed of lipid analogues. We have monitored large molecule and proton permeability and Laurdan generalized polarization from lipid vesicles as a function of temperature and hydrostatic pressure. Even at low concentration, squalane (1 mol%) is able to enhance solute permeation by increasing membrane fluidity, but at the same time, to decrease proton permeability of the lipid bilayer. The squalane physicochemical impact on membrane properties are congruent with a possible role of apolar intercalants on the adaptation of Archaea to extreme conditions. In addition, such intercalant might be used to cheaply create or modify chemically resistant liposomes (archeaosomes) for drug delivery.

In vitro estimation of superfluid critical extracts of some plants for their antimicrobial potential, phytochemistry, and GC-MS analyses.

BACKGROUND: Along with swift economic evolution and continuous amelioration of lifestyle, people at present are paying more attention to health issues. Synthetic drugs will be compensated with other natural ones that belong to natural origin. Plants have always been considered as sources of several compounds that are used in many fields, especially human and animal health, starting from boosting immunity to the treatment of infectious diseases caused by some pathogenic microbes such as bacteria, fungi as well as viruses. This study aimed to incorporate some types of plants within the antimicrobial portfolio through the examination of different six plants which were Cichorium intybus, Cinnamomum camphora, Commiphora myrrha, Foeniculum vulgare, Nerium oleander, and Spartium junceum. As well, attempting to identify the active constituents of their extracts using GC-MS. MATERIALS AND METHODS: All selected plants were analyzed to determine their phytochemical composition such as phenolics, alkaloids, flavonoids, terpenoids, and so on. The extraction step was done by sophisticated equipment called supercritical fluid extractor SFE through adjustment of specific conditions include temperature, time, flow rate and pressure to change the behavior of CO2. Testing the antimicrobial activity of each plant extract via agar well diffusion method through the formation of clear zones against a wide range of test microorganisms including both Gram-positive and Gram-negative bacteria as well as yeasts. Finally, attempting to primarily identify the constituents of each plant extract using GC-MS. RESULTS AND DISCUSSION: The crude extract of F. vulgare showed the highest potency against C. albicans, E. faecalis and S. typhimurium, it contains some unique compounds such as squalene, eugenol and isoeugenol while, Extract of C. intybus showed a moderate activity especially against C. lipolytica and MRSA and it includes Vitamin A like compound which indicates antioxidant property. CONCLUSION: Conclusively, fennel gave a promising result as a good wide spectrum antimicrobial agent because it contains some compounds act as antimicrobial agents such as eugenol which was used as food preservatives in addition to squalene which acts as an antioxidant and antimycotic agent so, it will be useful especially while it was used in highly purified form excluding all undesirable subcomponents.

Investigation of the Effects of Squalene and Squalene Epoxides on the Homeostasis of Coenzyme Q10 in Rats by UPLC-Orbitrap MS.

Squalene has been used as a dietary supplement for a long history due to its potential cancer-preventive function. However, the mechanism has not been investigated in detail yet. Therefore, the aim of this study is to see if the plasma coenzyme Q10 (CoQ10) level will be altered by gavage of squalene and oxidosqualenes to rats. In the present work, a sensitive and simple high-performance analytical method based on ultra-high-performance liquid chromatography coupled with an Orbitrap mass spectrometry (UPLC-Orbitrap-MS) was developed for the quantification of CoQ10 in rat plasma. Coenzyme Q9 (CoQ9) was employed as the internal standard. CoQ10 was determined after acetonitrile-mediated plasma protein precipitation using UPLC-Orbitrap-MS in negative ion mode. Intragastric administration of squalene and the two squalene epoxides into rats once daily for several days elevated the level of CoQ10 in their plasma, but there was no significant difference between high-dose (286 mg/kg) and low-dose (143 mg/kg) groups. Intragastric administration of squalene once a day for 5 consecutive days and oxidosqualenes once a day for 3 consecutive days is necessary for reaching the steady-state level of CoQ10. Our present findings indicate that squalene and oxidosqualenes may be useful for stimulating the synthesis of CoQ10 in rats.

Identification of plant genes putatively involved in the perception of fungal ergosterol-squalene.

Trichoderma biocontrol strains establish a complex network of interactions with plants, in which diverse fungal molecules are involved in the recognition of these fungi as nonpathogenic organisms. These molecules act as microbial-associated molecular patterns that trigger plant responses. Previous studies have reported the importance of ergosterol produced by Trichoderma spp. for the ability of these fungi to induce plant growth and defenses. In addition, squalene, a sterol biosynthetic intermediate, seems to play an important role in these interactions. Here, we analyzed the effect of different concentrations of ergosterol and squalene on tomato (Solanum lycopersicum) growth and on the transcription level of defense- and growth-related genes. We used an RNA-seq strategy to identify several tomato genes encoding predicted pattern recognition receptor proteins or WRKY transcription factors, both of which are putatively involved in the perception and response to ergosterol and squalene. Finally, an analysis of Arabidopsis thaliana mutants lacking the genes homologous to these tomato candidates led to the identification of a WRKY40 transcription factor that negatively regulates salicylic acid-related genes and positively regulates ethylene- and jasmonate-related genes in the presence of ergosterol and squalene.

The cholesterol ester cycle regulates signalling complexes and synapse damage caused by amyloid-ß.

Cholesterol is required for the formation and function of some signalling platforms. In synaptosomes, amyloid-ß (Aß) oligomers, the causative agent in Alzheimer's disease, bind to cellular prion proteins (PrPC) resulting in increased cholesterol concentrations, translocation of cytoplasmic phospholipase A2 (cPLA2, also known as PLA2G4A) to lipid rafts, and activation of cPLA2 The formation of Aß-PrPC complexes is controlled by the cholesterol ester cycle. In this study, Aß activated cholesterol ester hydrolases, which released cholesterol from stores of cholesterol esters and stabilised Aß-PrPC complexes, resulting in activated cPLA2 Conversely, cholesterol esterification reduced cholesterol concentrations causing the dispersal of Aß-PrPC complexes. In cultured neurons, the cholesterol ester cycle regulated Aß-induced synapse damage; cholesterol ester hydrolase inhibitors protected neurons, while inhibition of cholesterol esterification significantly increased Aß-induced synapse damage. An understanding of the molecular mechanisms involved in the dispersal of signalling complexes is important as failure to deactivate signalling pathways can lead to pathology. This study demonstrates that esterification of cholesterol is a key factor in the dispersal of Aß-induced signalling platforms involved in the activation of cPLA2 and synapse degeneration.

A clinically applicable adjuvant for an atherosclerosis vaccine in mice.

Vaccination with MHC-II-restricted peptides from Apolipoprotein B (ApoB) with complete and incomplete Freund's adjuvant (CFA/IFA) is known to protect mice from atherosclerosis. This vaccination induces antigen-specific IgG1 and IgG2c antibody responses and a robust CD4 T cell response in lymph nodes. However, CFA/IFA cannot be used in humans. To find a clinically applicable adjuvant, we tested the effect of vaccinating Apoe-deficient mice with ApoB peptide P6 (TGAYSNASSTESASY). In a broad screening experiment, Addavax, a squalene-based oil-in-water adjuvant similar to MF59, was the only adjuvant that showed similar efficacy as CFA/IFA. This was confirmed in a confirmation experiment for both the aortic arch and whole aorta analyzed by en face analysis after atherosclerotic lesion staining. Mechanistically, restimulated peritoneal cells from mice immunized with P6 in Addavax released significant amounts of IL-10. Unlike P6 in CFA/IFA, vaccination with P6 in Addavax did not induce any detectable IgG1 or IgG2c antibodies to P6. These data suggest that squalene-based adjuvants such as MF59 are good candidate adjuvants for developing a clinically effective atherosclerosis vaccine.

The Adjuvant Effect of Squalene, an Active Ingredient of Functional Foods, on Doxorubicin-Treated Allograft Mice.

Many functional foods or physiologically active ingredients derived from plants and animals are actively being investigated for their role in chronic disease prevention. Squalene (SQ) is found as active ingredient in the functional foods predominantly present in olive oil and shark liver oil. It is known that during chemotherapy anticancer drugs induce inflammation. SQ has been thought to prevent and suppress inflammation; however, there is little direct evidence available. We examined the adjuvant effect of SQ on tumor-transplanted mice along with anticancer drug doxorubicin (DOX). SQ significantly suppressed the DOX-induced increase in prostaglandin E2 (PGE2) concentration (P < 0.05) in plasma of tumor-bearing mice. SQ inhibited the numbers of writhing response (P < 0.05), formalin-induced pain and decreased COX-2 and substance P expression in the tumor tissue compared to control mice and also enhanced the antitumor efficacy of DOX in allograft mice. Thus, SQ reduces inflammation through modulation of PGE2 production indicating its potential as an adjuvant during chemotherapy in tumor-bearing mice.

Efficacy and safety of a non-mineral oil adjuvanted injectable vaccine for the protection of Atlantic salmon (Salmo salar L.) against Flavobacterium psychrophilum.

Flavobacterium psychrophilum is the causative agent of Rainbow Trout Fry Syndrome which has had a major impact on global salmonid aquaculture. Recent outbreaks in Atlantic salmon in Scotland and Chile have added to the need for a vaccine to protect both salmon and trout. At present no licensed vaccines are available in Europe, leaving antibiotics as the only course of action to contain disease outbreaks. Outbreaks generally occur in fry at temperatures between 10 and 15 °C. Recently outbreaks in larger fish have given added impetus to the development of a vaccine which can provide long term protection from this highly heterogeneous pathogen. Most fish injectable vaccines are formulated with oil emulsion adjuvants to induce strong and long lasting immunity, but which are known to cause side effects. Alternative adjuvants are currently sought to minimise these adverse effects. The current study was performed to assess the efficacy of a polyvalent, whole cell vaccine containing formalin-inactivated F. psychrophilum to induce protective immunity in Atlantic salmon. The vaccine was formulated with an adjuvant containing squalene and aluminium hydroxide, and was compared to a vaccine formulated with a traditional oil adjuvant, Montanide ISA 760VG, and a non-adjuvanted vaccine. Duplicate groups of salmon (23.5 ± 6.8 g) were vaccinated with each of the vaccine formulations or phosphate buffered saline by intraperitoneal injection. Fish were challenged by intramuscular injection with F. psychrophilum six weeks post-vaccination to test the efficacy of the vaccines. Cumulative mortality reached 70% in the control salmon, while the groups of salmon that received vaccine had significantly lower mortality than the controls (p = 0.0001), with no significant difference in survival between vaccinated groups. The squalene/alum adjuvant was safe, more readily metabolised by the fish and induced less histopathological changes than the traditional oil adjuvant.

Evaluation of Oxasqualenoids from the Red Alga Laurencia viridis against Acanthamoeba.

Acanthamoeba genus is a widely distributed and opportunistic parasite with increasing importance worldwide as an emerging pathogen in the past decades. This protozoan has an active trophozoite stage, a cyst stage, and is dormant and very resistant. It can cause Acanthamoeba keratitis, an ocular sight-threatening disease, and granulomatous amoebic encephalitis, a chronic, very fatal brain pathology. In this study, the amoebicidal activity of sixteen Laurencia oxasqualenoid metabolites and semisynthetic derivatives were tested against Acanthamoeba castellanii Neff. The results obtained point out that iubol (3) and dehydrothyrsiferol (1) possess potent activities, with IC50 values of 5.30 and 12.83 µM, respectively. The hydroxylated congeners thyrsiferol (2) and 22-hydroxydehydrothyrsiferol (4), active in the same value range at IC50 13.97 and 17.00 µM, are not toxic against murine macrophages; thus, they are solid candidates for the development of new amoebicidal therapies.