Synthetic hemozoin as a nanocarrier for cross-presentation.

It is known that conventional antigen presentation involves phagocytosis of antigens followed by its internalization in endocytic compartments and presentation of epitopes through MHC class II molecules for CD4 T cells. However, since 1976 a cross-presentation pathway has been studied, in which CD8 T cells are activated via MHC class I with antigens acquired through phagocytosis or endocytosis by dendritic cells (DCs). Among some important molecules involved in the cross-presentation, the C-type lectin receptor of the Dectin-1 cluster (CLECs), particularly the CLEC9A receptor, not only is expressed in dendritic cells but also presents a pivotal role in this context. In special, CLEC12A has been highlighted as a malaria pigment hemozoin (HZ) receptor. During Plasmodium infection, hemozoin crystals defend the parasite against heme toxicity within erythrocytes, as well as the released native HZ elicits pro-inflammatory responses and can induce cross-presentation. Particularly, this crystal can be synthesized from hematin anhydride and mimics the native form, and the gaps generated between the nanocrystal domains during its synthesis allow for substance coupling followed by its coating. Therefore, this study aimed to assess whether synthetic hemozoin (sHz) or hematin anhydride could be a nanocarrier and promote cross-presentation in dendritic cells. Firstly, it was verified that sHz can carry coated and coupled antigens, the compounds can associate to LAMP1-positive vesicles and decrease overall intracellular pH, which can potentially enhance the cross-presentation of ovalbumin and Leishmania infantum antigens. Thus, this study adds important data in the molecular intricacies of antigen presentation by showing not only the sHz immunomodulatory properties but also its potential applications as an antigen carrier.

C-Phycocyanin Prevents Oxidative Stress, Inflammation, and Lung Remodeling in an Ovalbumin-Induced Rat Asthma Model.

Asthma is a chronic immunological disease related to oxidative stress and chronic inflammation; both processes promote airway remodeling with collagen deposition and matrix thickening, causing pulmonary damage and lost function. This study investigates the immunomodulation of C-phycocyanin (CPC), a natural blue pigment purified from cyanobacteria, as a potential alternative treatment to prevent the remodeling process against asthma. We conducted experiments using ovalbumin (OVA) to induce asthma in Sprague Dawley rats. Animals were divided into five groups: (1) sham + vehicle, (2) sham + CPC, (3) asthma + vehicle, (4) asthma + CPC, and (5) asthma + methylprednisolone (MP). Our findings reveal that asthma promotes hypoxemia, leukocytosis, and pulmonary myeloperoxidase (MPO) activity by increasing lipid peroxidation, reactive oxygen and nitrogen species, inflammation associated with Th2 response, and airway remodeling in the lungs. CPC and MP treatment partially prevented these physiological processes with similar action on the biomarkers evaluated. In conclusion, CPC treatment enhanced the antioxidant defense system, thereby preventing oxidative stress and reducing airway inflammation by regulating pro-inflammatory and anti-inflammatory cytokines, consequently avoiding asthma-induced airway remodeling.

Improved biodistribution and enhanced immune response of subunit vaccine using a nanostructure formed by self-assembly of ascorbyl palmitate.

New adjuvant strategies are needed to improve protein-based subunit vaccine immunogenicity. We examined the potential to use nanostructure of 6-O-ascorbyl palmitate to formulate ovalbumin (OVA) protein and an oligodeoxynucleotide (CpG-ODN) (OCC). In mice immunized with a single dose, OCC elicited an OVA-specific immune response superior to OVA/CpG-ODN solution (OC). Rheological studies demonstrated OCC's self-assembling viscoelastic properties. Biodistribution studies indicated that OCC prolonged OVA and CpG-ODN retention at injection site and lymph nodes, reducing systemic spread. Flow-cytometry assays demonstrated that OCC promoted OVA and CpG-ODN co-uptake by Ly6ChiCD11bhiCD11c+ monocytes. OCC and OC induced early IFN-γ in lymph nodes, but OCC led to higher concentration. Conversely, mice immunized with OC showed higher serum IFN-γ concentration compared to those immunized with OCC. In mice immunized with OCC, NK1.1+ cells were the IFN-γ major producers, and IFN-γ was essential for OVA-specific IgG2c switching. These findings illustrate how this nanostructure improves vaccine's response.

Nanogel-Mediated antigen delivery: Biocompatibility, immunogenicity, and potential for tailored vaccine design across species.

Nanotechnology has emerged as a promising avenue for enhancing the efficacy of vaccine delivery systems. This study investigates the utilization of nanogels as carriers for the model antigen ovalbumin, with a focus on in vivo assessments in equine and murine models. Nanogels, owing to their biocompatibility and tunable physicochemical properties, offer a versatile platform for efficient antigen encapsulation and controlled release. The encapsulation efficiency and physicochemical characteristics of ovalbumin-loaded nanogels were comprehensively characterized. In vitro biocompatibility was evaluated, finding excellent properties of these nanogels. In vivo evaluations were conducted on both equine and murine subjects, assessing immunogenicity through antibody and splenic cell response. Furthermore, the study propose the potential use of nanogels in tailoring immune responses through the modulation of antigen release kinetics. The results obtained in the in vitro assays showed an increase in the uptake of nanogels by APCs compared to free antigen (OVA). In mice, an absence of inflammatory response in the inoculation site was observed, without systemic damage in the evaluated organs. In addition, non-significant humoral response was found nor cellular proliferation and proinflammatory cytokine production, compared with a traditional adjuvant as aluminum hydroxide, in both animal models. These findings allow further insights into nanogel-based delivery systems and offer valuable insights into their application in various animal models. In conclusion, this research establishes the utility of nanogels as effective carriers for antigens-based vaccines, with interesting biocompatibility properties and highly taken affinity by antigen-presenting cells, without inducing inflammation at the injection site. The study underscores the potential of nanogel technology in revolutionizing vaccine design and highlights the importance of tailored approaches for diverse target species.

A single dose of angiotensin-(1-7) resolves eosinophilic inflammation and protects the lungs from a secondary inflammatory challenge.

OBJECTIVE: Angiotensin-(1-7) [Ang-(1-7)] is a pro-resolving mediator. It is not known whether the pro-resolving effects of Ang-(1-7) are sustained and protect the lung from a subsequent inflammatory challenge. This study sought to investigate the impact of treatment in face of a second allergic or lipopolysaccharide (LPS) challenge. METHODS: Mice, sensitized and challenged with ovalbumin (OVA), received a single Ang-(1-7) dose at the peak of eosinophilic inflammation, 24 h after the final OVA challenge. Subsequently, mice were euthanized at 48, 72, 96, and 120 h following the OVA challenge, and cellular infiltrate, inflammatory mediators, lung histopathology, and macrophage-mediated efferocytic activity were evaluated. The secondary inflammatory stimulus (OVA or LPS) was administered 120 h after the last OVA challenge, and subsequent inflammatory analyses were performed. RESULTS: Treatment with Ang-(1-7) resulted in elevated levels of IL-10, CD4+Foxp3+, Mres in the lungs and enhanced macrophage-mediated efferocytic capacity. Moreover, in allergic mice treated with Ang-(1-7) and then subjected to a secondary OVA challenge, inflammation was also reduced. Similarly, in mice exposed to LPS, Ang-(1-7) effectively prevented the lung inflammation. CONCLUSION: A single dose of Ang-(1-7) resolves lung inflammation and protect the lung from a subsequent inflammatory challenge highlighting its potential therapeutic for individuals with asthma.

Comparison of treatment efficacy of omega-3 fish oil and montelukast in ovalbumin-protease-induced allergic rhinitis model in rats.

OBJECTIVES: Montelukast is a well-known leukotriene receptor antagonist commonly used in treating allergic rhinitis and asthma. Omega-3 fatty acid is also known as an antiallergic and immunomodulator molecule. This study aimed to elucidate the efficacy of systemic montelukast and omega-3 fatty acid treatment in allergic rhinitis models in Wistar Hannover rats. METHODS: This research was conducted on 28 healthy Wistar Hannover rats weighing 250-350 g. After establishing the allergic rhinitis model, nasal symptoms were observed and scored, and the nasal mucosa of all rats was investigated histologically. Light microscopy was utilized to evaluate the degree of ciliary loss, goblet cell hyperplasia, vascular congestion, vascular proliferation, inflammatory cell infiltration, eosinophil infiltration, and hypertrophy in chondrocytes. RESULTS: As a result of the analysis of the data obtained from the study, it was determined that typical allergic rhinitis symptoms such as nasal scratching and sneezing were significantly reduced in the rats in the montelukast and omega-3 treated group, and these symptoms did not increase after repeated intranasal OVA-protease applications. Histological examinations after fish oil treatment did not reveal typical inflammatory changes in allergic rhinitis. None of the rats in the montelukast and omega-3 groups had any increase in goblet cells, whereas 14.3% of the rats in the control group and 28.6% of the rats in the allergic rhinitis group had mild increase. Last but not least, 71.4% of rats in the allergic rhinitis group had a moderate increase. The difference between the groups was statistically significant (p < 0.001). CONCLUSION: Regarding the outcomes of this research, it was observed that w-3 fatty acids had antiallergic effects, both histopathological and clinical, in the allergic rhinitis model. We believe that further randomized controlled trials incorporating larger cohorts are warranted to verify the use of omega-3 fatty acids in treating allergic rhinitis. The level of evidence of this article is Level 2.

Display of FliC131 on the Surface of Lactococcus lactis as a Strategy to Increase its Adjuvanticity for Mucosal Immunization.

Research on innovative mucosal adjuvants is essential to develop new vaccines for safe mucosal application. In this work, we propose the development of a Lactococcus lactis that expresses a variant of flagellin on its surface (FliC131*), to increase the adjuvanticity of the living cell and cell wall-derived particles (CWDP). We optimized the expression of FliC131*, and confirmed its identity and localization by Western blot and flow cytometry. We also generated CWDP containing FliC131* (CDWP-FliC131*) and evaluated their storage stability. Lastly, we measured the human TLR5 stimulating activity in vitro and assessed the adjuvanticity in vivo using ovalbumin (OVA) as a model antigen. As a result, we generated L. lactis/pCWA-FliC131*, that expresses and displays FliC131* on its surface, obtained the corresponding CWDP-FliC131*, and showed that both activated hTLR5 in vitro in a dose-dependent manner. Furthermore, CWDP-FliC131* retained this biological activity after being lyophilized and stored for a year. Finally, intranasal immunization of mice with OVA plus live L. lactis/pCWA-FliC131* or CWDP-FliC131* induced OVA-specific IgG and IgA in serum, intestinal lavages, and bronchoalveolar lavages. Our work demonstrates the potential of this recombinant L. lactis with an enhanced adjuvant effect, prompting its further evaluation for the design of novel mucosal vaccines.

Morita-Baylis-Hillman adduct 2-(3-hydroxy-1-methyl-2-oxoindolin-3-il) acrylonitrile (CISACN) ameliorates the pulmonary allergic inflammation in CARAS model by increasing IFN-γ/IL-4 ratio towards the Th1 immune response.

Combined allergic rhinitis and asthma syndrome (CARAS) is an airway-type 2 immune response with a profuse inflammatory process widely affecting the world population. Due to the compromise of quality of life and the lack of specific pharmacotherapy, the search for new molecules becomes relevant. This study aimed to evaluate the effectiveness of the Morita-Bailys-Hillman adduct (CISACN) treatment in the CARAS experimental model. Female BALB/c mice were ovalbumin (OVA) -sensitized and -challenged and treated with CISACN. The treatment decreased the eosinophil migration to the nasal and lung cavities and tissues and the goblet cell hyperplasia/hypertrophy, attenuated airway hyperactivity by reducing the hyperplasia/hypertrophy of the smooth muscle and the extracellular matrix's thickness. Also, the treatment reduced the clinical signs of rhinitis as nasal rubbing and sneezing in a histamine-induced nasal hyperreactivity assay. The immunomodulatory effect of CISACN was by reducing OVA-specific IgE serum level, and IL-33, IL-4, IL-13, and TGF-ß production, dependent on IFN-γ increase. Furthermore, the effect of CISACN on lung granulocytes was by decreasing the p-p38MAPK/p65NF-κB signaling pathway. Indeed, CISACN reduced the p38MAPK and p65NF-κB activation. These data demonstrated the anti-inflammatory and immunomodulatory effects of the CISACN with scientific support to become a pharmacological tool to treat airway inflammatory diseases.

Encapsulation of propolis extract in ovalbumin protein particles: characterization and in vitro digestion.

The encapsulation of propolis has shown promising results for the protection of bioactive compounds, local and gradual release and masking the astringent taste. Ovoalbumin is a protein of animal origin found in large amounts in egg whites, which has good properties as a wall material for particles.The objective of this study was to microencapsulate propolis by spray drying. The best condition for microencapsulation was achieved with 4% ovalbumin at 120 °C, where there was the greatest encapsulation efficiency (88.20%) and spherical shape. However, the increase of ovalbumin concentration resulted lower yields (< 52%). As for the scanning electron microscopy (SEM), the increase of ovalbumin concentration caused an increase of the size with average diameter and formation of spherical microcapsules. The phenolic compounds were already released in the gastric fluid condition (stomach).

New phosphodiesterase-4 inhibitors present airways relaxant activity in a guinea pig acute asthma model.

Asthma is a disease characterized by chronic inflammation and hyper responsiveness of airways. We aimed to assess the relaxant potential of phosphodiesterase-4 (PDE4) inhibitors N-sulfonilhidrazonic derivatives on non-asthmatic and asthmatic guinea pig trachea. Firstly, guinea pigs were sensitized and challenged with ovalbumin, and then morphological, and contractile changes were evaluated resulting from asthma, followed by evaluation of relaxant effect of derivatives on guinea pig trachea and the cAMP levels measurement by ELISA. It has been evidenced hypertrophy of airway smooth muscle, inflammatory infiltrate, and vascular abnormalities. Moreover, only sensitized tracheal rings were responsive to OVA. Contractile response to histamine, but not to carbachol, was greater in sensitized animals, however the relaxant response to aminophylline and isoprenaline were the same in non-asthmatics and asthmatics. N-sulfonilhidrazonic derivatives presented equipotent relaxant action independent of epithelium, with exception of LASSBio-1850 that presented a low efficacy (< 50%) and LASSBio-1847 with a 4-fold higher potency on asthmatics. LASSBio-1847 relaxant curve was impaired in the presence of propranolol and potentiated by isoprenaline in both groups. Furthermore, relaxation was potentiated 54- and 4-fold by forskolin in non-asthmatics and asthmatics, respectively. Likewise, LASSBio-1847 potentiated relaxant curve of aminophylline 147- and 4-fold in both groups. The PKA inhibitor H-89 impaired the relaxant potency of the derivative. Finally, LASSBio-1847 increased tracheal intracellular cAMP levels similarly to rolipram, selective PDE4 inhibitor, in both animals. LASSBio-1847 showed to be promising to relax guinea pig trachea from non-sensitized and sensitized guinea pigs by activation of ß2-adrenergic receptors/AC/cAMP pathway.

Investigating the Effects of a New Peptide, Derived from the Enterolobium contortisiliquum Proteinase Inhibitor (EcTI), on Inflammation, Remodeling, and Oxidative Stress in an Experimental Mouse Model of Asthma-Chronic Obstructive Pulmonary Disease Overlap (ACO).

The synthesized peptide derived from Enterolobium contortisiliquum (pep3-EcTI) has been associated with potent anti-inflammatory and antioxidant effects, and it may be a potential new treatment for asthma-COPD overlap-ACO). Purpose: To investigate the primary sequence effects of pep3-EcTI in an experimental ACO. BALB/c mice were divided into eight groups: SAL (saline), OVA (ovalbumin), ELA (elastase), ACO (ovalbumin + elastase), ACO-pep3-EcTI (treated with inhibitor), ACO-DX (treated with dexamethasone), ACO-DX-pep3-EcTI (treated with dexamethasone and inhibitor), and SAL-pep3-EcTI (saline group treated with inhibitor). We evaluated the hyperresponsiveness to methacholine, exhaled nitric oxide, bronchoalveolar lavage fluid (BALF), mean linear intercept (Lm), inflammatory markers, tumor necrosis factor (TNF-α), interferon (IFN)), matrix metalloproteinases (MMPs), growth factor (TGF-ß), collagen fibers, the oxidative stress marker inducible nitric oxide synthase (iNOS), transcription factors, and the signaling pathway NF-κB in the airways (AW) and alveolar septa (AS). Statistical analysis was conducted using one-way ANOVA and t-tests, significant when p < 0.05. ACO caused alterations in the airways and alveolar septa. Compared with SAL, ACO-pep3-EcTI reversed the changes in the percentage of resistance of the respiratory system (%Rrs), the elastance of the respiratory system (%Ers), tissue resistance (%Gtis), tissue elastance (%Htis), airway resistance (%Raw), Lm, exhaled nitric oxide (ENO), lymphocytes, IL-4, IL-5, IL-6, IL-10, IL-13, IL-17, TNF-α, INF-γ, MMP-12, transforming growth factor (TGF)-ß, collagen fibers, and iNOS. ACO-DX reversed the changes in %Rrs, %Ers, %Gtis, %Htis, %Raw, total cells, eosinophils, neutrophils, lymphocytes, macrophages, IL-1ß, IL-6, IL-10, IL-13, IL-17, TNF-α, INF-γ, MMP-12, TGF-ß, collagen fibers, and iNOS. ACO-DX-pep3-EcTI reversed the changes, as was also observed for the pep3-EcTI and the ACO-DX-pep3-EcTI. Significance: The pep3-EcTI was revealed to be a promising strategy for the treatment of ACO, asthma, and COPD.

In vitro anti-inflammatory activity and ameliorative effects on gastric ulcers of Licania rigida benth seed extract.

Licania rigida Benth., a Brazilian endemic plant, has been traditionally used for treating inflammation and stomach pain. This work investigates the anti-inflammatory and gastroprotective activities of the ethanolic extract from L. rigida seeds (EELr) by in vitro and in vivo methods. The phytochemical profile was determined and the in vitro antioxidant activity was investigated by radical scavenging and thiobarbituric acid reactive substances methods. The ovalbumin denaturation method was used with sodium diclofenac as standard for the in vitro anti-inflammatory activity assessment. Acetylsalicylic acid was used to induce gastric ulcers in male mice and then to evaluate the preventive and therapeutic gastroprotective effect of EELr, using omeprazole as the reference drug. The extract exhibited relevant amount of phenolic compounds and flavonoids, in particular, demonstrating in vitro antioxidant capacity. EELr was able to inhibit almost 60% of ovalbumin denaturation at a concentration considered low. It also prevented the decrease of biochemical markers for oxidative stress such as superoxide dismutase (SOD) and reduced glutathione (GSH) in the stomach and SOD and catalase (CAT) in the liver. EELr also significantly decreased the number of lesions as well as reduced the ulcerated area when used as therapy. The observed effect may be due to its phenolic compounds, such as chlorogenic acid, caffeic acid and tannins, as previously reported. EELr is a potential source of compounds with anti-inflammatory activity, protects the liver from oxidative damage and improves healing of aspirin-induced ulcers. This work contributes to the knowledge of L. rigida species.

Effects of a Peptide Derived from the Primary Sequence of a Kallikrein Inhibitor Isolated from Bauhinia bauhinioides (pep-BbKI) in an Asthma-COPD Overlap (ACO) Model.

(1) There are several patients with asthma-COPD overlap (ACO). A peptide derived from the primary sequence of a kallikrein inhibitor isolated from Bauhinia bauhinioides (pep-BbKI) has potent anti-inflammatory and antioxidant effects. Purpose: To investigate the effects of pep-BbKI treatment in an ACO model and compare them with those of corticosteroids. (2) BALB/c mice were divided into groups: SAL (saline), OVA (ovalbumin), ELA (elastase), ACO (ovalbumin + elastase), ACO-pep-BbKI (treated with inhibitor), ACO-DX (dexamethasone treatment), ACO-DX-pep-BbKI (both treatments), and SAL-pep-BbKI (saline group treated with inhibitor). We evaluated: hyperresponsiveness to methacholine, bronchoalveolar lavage fluid (BALF), exhaled nitric oxide (eNO), IL-1ß, IL-4, IL-5, IL-6, IL-10, IL-13, IL-17, IFN-γ, TNF-α, MMP-9, MMP-12, TGF-ß, collagen fibers, iNOS, eNO, linear mean intercept (Lm), and NF-κB in airways (AW) and alveolar septa (AS). (3) ACO-pep-BbKI reversed ACO alterations and was similar to SAL in all mechanical parameters, Lm, neutrophils, IL-5, IL-10, IL-17, IFN-γ, TNF-α, MMP-12 (AW), collagen fibers, iNOS (AW), and eNO (p > 0.05). ACO-DX reversed ACO alterations and was similar to SAL in all mechanical parameters, Lm, total cells and differentials, IL-1ß(AS), IL-5 (AS), IL-6 (AS), IL-10 (AS), IL-13 (AS), IFN-γ, MMP-12 (AS), TGF-ß (AS), collagen fibers (AW), iNOS, and eNO (p > 0.05). SAL was similar to SAL-pep-BbKI for all comparisons (p > 0.05). (4) Pep-BbKI was similar to dexamethasone in reducing the majority of alterations of this ACO model.

IL-22 Is Deleterious along with IL-17 in Allergic Asthma but Is Not Detrimental in the Comorbidity Asthma and Acute Pneumonia.

There is evidence that IL-22 and IL-17 participate in the pathogenesis of allergic asthma. To investigate the role of IL-22, we used IL-22 deficient mice (IL-22 KO) sensitized and challenged with ovalbumin (OVA) and compared with wild type (WT) animals exposed to OVA. IL-22 KO animals exposed to OVA showed a decreased number and frequency of eosinophils, IL-5 and IL-13 in the airways, reduced mucus production and pulmonary inflammation. In addition, IL-22 KO animals exhibited a decreased percentage and number of lung CD11c+CD11b+ cells and increased apoptosis of eosinophils. Th17 cell transfer generated from IL-22 KO to animals previously sensitized and challenged with OVA caused a reduction in eosinophil frequency and number in the airways compared to animals transferred with Th17 cells generated from WT mice. Therefore, IL-22 is deleterious with concomitant secretion of IL-17. Our findings show a pro-inflammatory role for IL-22, confirmed in a model of allergen-free and allergen-specific immunotherapy. Moreover, during the comorbidity asthma and pneumonia that induces neutrophil inflammation, IL-22 was not detrimental. Our results show that targeting IL-22 would negatively affect the survival of eosinophils, reduce the expansion or migration of CD11c+CD11b+ cells, and negatively regulate allergic asthma.

Obesity-induced hyperglycemia impairs oral tolerance induction and aggravates food allergy.

Obesity and type 2 diabetes (T2D) have been found to be associated with abnormalities in several organs, including the intestine. These conditions can lead to changes in gut homeostasis, compromising tolerance to luminal antigens and increasing susceptibility to food allergies. The underlying mechanisms for this phenomenon are not yet fully understood. In this study, we investigated changes in the intestinal mucosa of diet-induced obese mice and found that they exhibited increased gut permeability and reduced Treg cells frequency. Upon oral treatment with ovalbumin (OVA), obese mice failed to develop oral tolerance. However, hyperglycemia treatment improved intestinal permeability and oral tolerance induction in mice. Furthermore, we observed that obese mice exhibited a more severe food allergy to OVA, and this allergy was alleviated after treatment with a hypoglycemic drug. Importantly, our findings were translated to obese humans. Individuals with T2D had higher serum IgE levels and downregulated genes related to gut homeostasis. Taken together, our results suggest that obesity-induced hyperglycemia can lead to a failure in oral tolerance and to exacerbation of food allergy. These findings shed light on the mechanisms underlying the relationship among obesity, T2D, and gut mucosal immunity, which could inform the development of new therapeutic approaches.

Metformin Counteracts the Deleterious Effects of Methylglyoxal on Ovalbumin-Induced Airway Eosinophilic Inflammation and Remodeling.

Exposure to methylglyoxal (MGO) increases the levels of receptor for advanced glycation end products (RAGE) and reactive-oxygen species (ROS) in mouse airways, exacerbating the inflammatory responses. Metformin scavenges MGO in plasma of diabetic individuals. We investigated if amelioration by metformin of eosinophilic inflammation reflects its ability to inactivate MGO. Male mice received 0.5% MGO for 12 weeks together or not with 2-week treatment with metformin. Inflammatory and remodeling markers were evaluated in bronchoalveolar lavage fluid (BALF) and/or lung tissues of ovalbumin (OVA)-challenged mice. MGO intake elevated serum MGO levels and MGO immunostaining in airways, which were reduced by metformin. The infiltration of inflammatory cells and eosinophils and levels of IL-4, IL-5 and eotaxin significantly increased in BALF and/or lung sections of MGO-exposed mice, which were reversed by metformin. The increased mucus production and collagen deposition by MGO exposure were also significantly decreased by metformin. In MGO group, the increases of RAGE and ROS levels were fully counteracted by metformin. Superoxide anion (SOD) expression was enhanced by metformin. In conclusion, metformin counteracts OVA-induced airway eosinophilic inflammation and remodeling, and suppresses the RAGE-ROS activation. Metformin may be an option of adjuvant therapy to improve asthma in individuals with high levels of MGO.

Maternal stress increases risk of allergic lung inflammation in adult mice.

BACKGROUND: Allergies are increasing worldwide. The presence of atopic diseases in the mother propagates the onset of allergic diseases in the offspring with a considerably stronger penetrance than atopic diseases of the father. Such observation challenges genetic predispositions as the sole cause of allergic diseases. Epidemiological studies suggest that caregiver stress in the perinatal period may predispose offspring to asthma. Only one group has studied the link between prenatal stress and neonatal asthma susceptibility in a murine model. OBJECTIVES: We aimed to study if the neonatal increased risk of developing allergic lung inflammation persists after puberty and if there are sex differences in susceptibility. METHODS: Pregnant BALB/c mice were subjected to a single restraint stress exposure at day 15 of gestation. Pups were separated by gender and subjected to a well-known sub-optimal asthma model after puberty. RESULTS: Adult mice born to stressed dams were more susceptible to developing allergic pulmonary inflammation since an increase in the number of eosinophils in bronchoalveolar lavage (BAL), a greater peribronchial and perivascular infiltrate, a higher proportion of mucus-producing cells, and increased IL-4 and IL-5 levels in BAL were detected compared to control mice. These effects were more profound in females than males. Moreover, only females from stressed dams showed an increase in IgE levels. CONCLUSIONS: Increased litter susceptibility to develop allergic lung inflammation induced by maternal stress persists after puberty and is more potent in females than in male mice.

Development of a new generation of miniemulsion based on cottonseed oil with α-tocopherol and ZnO and evaluation of its adjuvant activity.

Background: Emulsions have been widely used as immunological adjuvants. But the use of materials derived from plants such as cottonseed oil, alpha-tocopherol, or minerals such as zinc, as well as their use at the nanometric scale has been little explored. In this study, we develop a new miniemulsion and evaluated its antioxidant and phagocytic capacity, as well as parameters related to immune response stimulation by cytokine expression and antibodies production in a mice model. Methods: Formulated CN (cottonseed oil miniemulsion) and CNZ (cottonseed oil miniemulsion whit zinc oxide nanoparticles) miniemulsions were characterized by scanning electronic microscopy SEM, DLS and FT-IR. In murine macrophages, splenocytes and thymocytes primary cultures safety and cytotoxicity were determined by MTT. In macrophages the antioxidant and phagocytic capacity was evaluated. In BALB/c mice, the stimulation of the immune system was determined by the expression of cytokines and the production of antibodies. Results: The CN and CNZ presented stability for 90 days. Immediately after preparation, the CN presented a higher particle size (543.1 nm) than CNZ (320 nm). FT-IR demonstrated the correct nanoparticle synthesis by the absence of sulfate groups. CN and CNZ (1.25 to 10 µL/mL) had no toxic effect on macrophages (p = 0.108), splenocytes (p = 0.413), and thymocytes (p = 0.923). All CN and CNZ doses tested induced nitric oxide and antioxidants production in dose dependent manner when compared with control. CN-ovalbumin and CNZ-ovalbumin treatments in femoral subcutaneous tissue area showed inflammation with higher leukocyte infiltration compared with FCA. The intraperitoneal administration with CN, CNZ, and FCA showed a higher total intraperitoneal cells recruitment (CD14+) after 24 h of inoculation than control (p = 0.0001). CN and CNZ increased the phagocyte capacity with respect to untreated macrophages in the Candida albicans-phagocytosis assay. The evaluation of residual CFU indicated that only CN significantly decreased (p = 0.004) this value at 3 h. By other side, only CN increased (p = 0.002) the nitric oxide production. CNZ stimulated a major INFγ secretion compared with FCA at day 7. A major IL-2 secretion was observed at days 7 and 14, stimulated with CN and CNZ. Both miniemulsions did not affect the antibody isotypes production (IgG1, IgG2a, IgG3, IgA and IgM) at days 7, 14, 28, and 42. CN induced a significant IgG production against OVA, but lesser than FCA. Conclusions: The two new miniemulsions with adjuvant and antioxidant capacity, were capable of generating leukocyte infiltration and increased cytokines and antibodies production.

Anti-asthmatic activity of standardized hydro-ethanolic and aqueous extracts of Stachytarpheta cayennensis (Rich.) Vahl in a murine model.

ETHNOPHARMACOLOGICAL RELEVANCE: Stachytarpheta cayennensis (Verbenaceae) has been used in Brazilian traditional medicine to treat asthma and other respiratory diseases. AIMS OF THE STUDY: To investigate the effects of different doses of standardized hydro-ethanolic (SCH) and aqueous (SCA) extracts of aerial parts of S. cayennensis using a murine ovalbumin (OVA)-induced asthma model. MATERIALS AND METHODS: The major constituents of the plant extracts were identified and standardized by ultra-performance liquid chromatography coupled with mass spectrometry. Balb/c mice were challenged with OVA solution and treated concomitantly by intraperitoneal injection of standardized SCH or SCA extracts at 50, 100, and 200 mg/kg concentrations. OVA-challenged control animals were treated with either dexamethasone (OVA-DEX) or saline solution (OVA-SAL). After challenge, we assessed in vivo bronchial hyperresponsiveness, airway inflammation (number of cells), peribronchial inflammation (histological analysis) and production of OVA-specific IgE and interleukin (IL)-4, IL-5, and IL-13 (ELISA). RESULTS: Acteoside, isoacteoside, and ipolamiide were the major constituents of SCH and SCA. The respective concentrations of acteoside in SCH and SCA were 78 and 98 µg/mL, while those of ipolamiide were 30 and 19 µg/mL. Treatment with 200 mg/kg of SCH or SCA decreased IL-4, IL-5, and IL-13 in lung homogenates. These reductions were accompanied by a lower influx of inflammatory cells (eosinophils, lymphocytes, and macrophages) to the airways and lungs. In addition to the anti-inflammatory effects, administration of SCA, but not SCH, ameliorated the parameters of bronchial hyperresponsiveness and decreased levels of circulating OVA-specific IgE. CONCLUSION: The results presented herein demonstrate for the first time the anti-asthmatic activity of S. cayennensis extracts in a murine model, thereby supporting the ethnopharmacological uses of the plant.

Kinetics of antigen cross-presentation assessed experimentally and by a model of the complete endomembrane system.

Dendritic cells (DCs) have a specialized endomembrane system capable of presenting exogenous antigens in the context of MHC class I (MHC-I) molecules. This process, named cross-presentation, is crucial to activate CD8+ T lymphocytes and initiate cytotoxic immune responses. In this report, we present an Agent-Based Model in combination with Ordinary Differential Equations with enough complexity to reproduce cross-presentation. The model embraces the secretory and endocytic pathways, in connection with the plasma membrane, the endoplasmic reticulum, and the cytosol. Key molecules required for cross-presentation were included as cargoes. In the simulations, the kinetics of MHC-I uptake and recycling, and cross-presentation accurately reproduced experimental values. The model proved to be a suitable tool to elaborate hypotheses and design experiments. In particular, the model predictions and the experimental results obtained indicate that the rate-limiting step in cross-presentation of soluble ovalbumin is MHC-I loading after proteasomal processing of the antigenic protein.