Mouse Model Of Sensitization Research Articles

Luteolin inhibits behavioral sensitization by blocking methamphetamine-induced MAPK pathway activation in the caudate putamen in mice.

GoalTo investigate the effect of luteolin on methamphetamine (MA)-induced behavioral sensitization and mitogen-activated protein kinase (MAPK) signal transduction pathway activation in mice.MethodsMice received a single dose of MA to induce hyperactivity or repeated intermittent intraperitoneal injections of MA to establish an MA-induced behavioral sensitization mouse model. The effect of luteolin on the development and expression of MA-induced hyperactivity and behavioral sensitization was examined. The expression and activity of ΔFosB and the levels of phosphorylated extracellular signal-regulated kinase 1/2 (pERK1/2), phosphorylated c-Jun N-terminal kinase (pJNK), and phosphorylated p38 mitogen-activated protein kinase (pp38) in the caudate putamen (CPu) were measured by western blot.ResultsLuteolin significantly decreased hyperactivity as well as the development and expression of MA-induced behavioral sensitization in mice. ΔFosB, pERK1/2, and pJNK levels in the CPu were higher in MA-treated mice than in control mice, whereas the pp38 level did not change. Injection of luteolin inhibited the MA-induced increase in ΔFosB, pERK1/2, and pJNK levels, but did not affect the pp38 level.ConclusionsLuteolin inhibits MA-induced hyperactivity and behavioral sensitization in mice through the ERK1/2/ΔFosB pathway. Furthermore, the JNK signaling pathway might be involved in MA-induced neurodegeneration in the CPu, and luteolin inhibits this process.

Epigenetic changes in obesity (383.6)

The aim of this study was to find epigenetic differences between obese sensitive and obese resistant phenotypes in an obesity sensitive mouse model. 88 C57BL/6J females were fed either a high‐fat diet (HF, 60% kilocalories from fat) or a control diet (CT, 10% kilocalories from fat) for 10 weeks. 15 CT mice, 15 mice from the low (obesity resistant ‐ HFR), and 15 high (obesity sensitive ‐ HFS) weight extremes, respectively, were selected based on the heterogeneous weight gain of the group exposed to HF. Promoter DNA methylation (liver) was assessed between the 3 groups using methylated CpG islands amplification combined with microarrays (MCAM). Following statistical analysis for microarrays and gene ontology (GO) ranking we found that the HFR group is epigenetically similar to the CT, with 8 hyper‐methylated and 73 hypo‐methylated genes. The HFS group had 7,721 differentially methylated genes compared to the CT, with the majority being hyper‐methylated. Also, we found higher methylation in the imprinted control region of the H19/Igf2 imprinted region, as determined by pyrosequencing, in the HFS group versus CT. In conclusion, the epigenomes of the obesity‐resistant and control mice are similar, while the epigenome of the obesity‐prone mice presents specific alterations. GO analysis revealed that such epigenetic alterations are grouped within functional classes related to key pathways involved in liver metabolism.Grant Funding Source: Nutrition Research Institute Research Funds

ROS-PIASγ cross talk channelizes ATM signaling from resistance to apoptosis during chemosensitization of resistant tumors

With the existing knowledge of ATM's role in therapeutic resistance, the present study aimed at identifying the molecular mechanisms that influence ATM to oscillate between chemoresistance and chemosensitivity. We observed that the redox status of tumors functions as a major determinant of ATM-dependent ‘resistance-to-apoptosis' molecular switch. At a low reactive oxygen species (ROS) condition during genotoxic insult, the ATM/sumoylated-IKKγ interaction induced NFκB activation that resisted JNK-mediated apoptosis, whereas increasing cellular ROS restored ATM/JNK apoptotic signaling. A search for the upstream missing link revealed that high ROS induces oxidation and ubiquitin-mediated degradation of PIASγ, thereby disrupting PIASγ-IKKγ cross talk, a pre-requisite for IKKγ sumoylation and subsequent NFκB activation. Interruption in the PIASγ-mediated resistance pathway channels ATM signaling toward ATM/JNK pro-death circuitry. These in vitro results also translated to sensitive and resistant tumor allograft mouse models in which low ROS-induced resistance was over-ruled in PIASγ knockout tumors, while its overexpression inhibited high ROS-dependent apoptotic cues. Cumulatively, our findings identified an unappreciated yet critical combinatorial function of cellular ROS and PIASγ in regulating ATM-mediated chemosensitization of resistant tumors. Thus, therapeutic strategies employing ROS upregulation to inhibit PIASγ during genotoxic therapy may, in future, help to eliminate the problems of NFκB-mediated tumor drug resistance.

Complement Activation and Liver Impairment in Trichloroethylene-Sensitized BALB/c Mice

Our recent studies have shown that trichloroethylene (TCE) was able to induce multisystem injuries in the form of occupational medicamentosa-like dermatitis, including skin, kidney, and liver damages. However, the role of complement activation in the immune-mediated liver injury is not known. This study examined the role of complement activation in the liver injury in a mouse model of TCE-induced sensitization. Treatment of female BALB/c mice with TCE under specific dosing protocols resulted in skin inflammation and sensitization. Skin edema and erythema occurred in TCE-sensitized groups. Trichloroethylene sensitization produced liver histopathological lesions, increased serum alanine aminotransferase, aspartate transaminase activities, and the relative liver weight. The concentrations of serum complement components C3a-desArg, C5a-desArg, and C5b-9 were significantly increased in 24-hour, 48-hour, and 72-hour sensitization-positive groups treated with TCE and peaked in the 72-hour sensitization-positive group. Depositions of C3a, C5a, and C5b-9 into the liver tissue were also revealed by immunohistochemistry. Immunofluorescence further verified high C5b-9 expression in 24-hour, 48-hour, and 72-hour sensitization-positive groups in response to TCE treatment. Reverse transcription-polymerase chain reaction detected C3 messenger RNA expression in the liver, and this was significantly increased in 24-hour and 48-hour sensitization-positive groups with a transient reduction at 72 hours. These results provide the first experimental evidence that complement activation may play a key role in the generation and progression of immune-mediated hepatic injury by exposure to TCE.

Probiotic VSL#3‐induced TGF‐β ameliorates food allergy inflammation in a mouse model of peanut sensitization through the induction of regulatory T cells in the gut mucosa

Among food allergies, peanut allergy is frequently associated with severe anaphylactic reactions. In the need for safe and effective therapeutic strategies, probiotics may be considered on the basis of their immunomodulatory properties. The aim of the present study was to investigate the immunological mediators involved in the effects of probiotic VSL#3 oral supplementation on Th2 inflammation and anaphylaxis in a mouse model of peanut allergy. VSL#3 supplementation to peanut-sensitized mice was effective in ameliorating anaphylaxis and Th2-mediated inflammation, by promoting regulatory responses in the jejunum mucosa and in the mesenteric lymph node, as evaluated by ELISA, real-time PCR, histologic, and immunohistochemical analysis. Probiotic-induced TGF-β mediates its protective effects through the induction of regulatory T cells expressing FOXP3 and/or latency-associated peptide, as proven by in vivo blockade of TGF-β in VSL#3-treated mice with a neutralizing monoclonal antibody one day before challenge. TGF-β, induced in the gut by VSL#3 supplementation, is capable of reducing the Th2 inflammation associated with food anaphylaxis in a mouse model of peanut sensitization. TGF-β acts through the induction/maintenance of regulatory T cells expressing FOXP3 and/or latency-associated peptide. Probiotics supplementation may represent an effective and safe strategy for treating food allergies in adult population.

Perinatal and Postweaning Exposure to Galactooligosaccharides/Inulin Prebiotics Induced Biomarkers Linked to Tolerance Mechanism in a Mouse Model of Strong Allergic Sensitization

Food allergies are increasing, and no treatment exists, thus enhancing interest in prebiotic strategies. This study aimed to analyze the preventive effects of prebiotic feeding during perinatal and postweaning periods in a mouse model of allergy by studying biomarkers related to tolerance (IgG2a, IgA, IFN-γ, TGF-β, and IL-10), to allergy (IgE, IgG1, IL-4, IL-17, symptoms), and to microbiota (propionate and MyD88). Balb/c mice, both dams and their pups, were fed a diet supplemented with (+Prb) or without (-Prb) GOS/inulin prebiotics. Mice were then sensitized with allergens. Regardless of diet, sensitized mice exhibited similar levels of IgE, IgG1, CD-23, IL-4, IL-17, and symptoms. However, in comparison to -Prb-sensitized mice, +Prb-sensitized mice displayed higher concentrations of total IgG2a (6669 ± 1788 vs 3696 ± 1326 fluorescence units, p < 0.005), specific IgA (285 ± 26 vs 156 ± 9 fluorescence units, p < 0.01), IFN-γ (3194 ± 424 vs 1853 ± 434 pg/mL, p < 0.01), IL-10 (777 ± 87 vs 95 ± 136 pg/mL, p < 0.005), TGF-β (4853 ± 1959 vs 243 ± 444 pg/mL, p < 0.01), MyD88 (0.033 ± 0.019 vs 0.009 ± 0.004 relative expression, p < 0.01), and propionate (4.15 ± 0.8 vs 2.9 ± 1.15 μmol, p < 0.05). In a mouse model of allergy, prebiotic exposure during perinatal and postweaning periods induced the highest expression of biomarkers related to tolerance without affecting biomarkers related to allergy.

Abstract 3794: The role of LMTK3 in breast cancer cell growth and invasion.

Abstract Abstract Title: The role of LMTK3 in breast cancer cell growth and invasion Background: We have identified Lemur tyrosine kinase-3 (LMTK3) as a novel regulator of estrogen receptor α (ERα) that is associated with disease free and overall survival and predicted response to endocrine therapies in breast cancer. In addition, inhibition of LMTK3 in tamoxifen (tam)-sensitive and tam-resistant xenograft mouse models led to tumor volume reduction. Moreover, a genome microarray analysis revealed various genes modulated by LMTK3 implicated in different canonical pathways. Herein we present evidence that further elucidates the mechanism of LMTK3 involvement in breast cancer growth and invasion. Methods: Stable over-expressed and depleted LMTK3 breast cancer cell lines were generated to study the effects of LMTK3 on proliferation and invasion. Various molecular and cellular biology techniques (including RT-PCR, immunofluorescence, immunoprecipitation and invasion assays) were carried out to elucidate the participation of LMTK3 in various signalling pathways. Stable isotope labelling by amino acids in cell culture (SILAC) was undertaken to identify and analyse novel LMTK3-regulated proteins. Results: Transwell and collagen 1 invasion assays results demonstrated that over-expression of LMTK3 in non-invasive MCF7 cells promote invasion while conversely knockdown of LMTK3 in MDA-MB-231 cells significantly inhibited invasion. Moreover, stable LMTK3 over-expressing cells form larger and looser acini structures compared to parental cells in 3D matrigel overlay assays. Wound healing assays demonstrated an increased motility of cells that over-express LMTK3 compared to LMTK3 knock-out cell lines. Cell adhesion assays revealed preferential binding of LMTK3 over-expressing cell lines to different ECM ligands. RT-qPCR analysis indicated up-regulation of an invasive gene signature (including MMPs, vimentin, and others) associated with LMTK3 over-expression. SILAC analysis identified various novel LMTK3-regulated proteins and phospho-proteins. In addition, modulation of LMTK3 affected the expression of specific members of the integrin family, as well as proteins involved in the focal adhesion complex. Co-immunoprecipitation and immunofluorescence experiments further helped us identify interacting partners of LMTK3 pertaining to the pathways conferring the observed pro-invasive phenotypic results. Finally, the involvement of LMTK3 in promoting tumorigenicity was confirmed in an in vivo xenograft mouse model. Conclusion: We show that LMTK3 is important for mediating breast cancer cell growth and invasion and propose a model of the mechanism of LMTK3 action in these processes. These data position LMTK3 in the map of well-known oncogenic signaling cascades. Citation Format: Yichen Xu, Aleksandra Filipovic, Hua Zhang, Lei Cheng Lit, Ylenia Lombardo, Justin Stebbing, Georgios Giamas. The role of LMTK3 in breast cancer cell growth and invasion. [abstract]. In: Proceedings of the 104th Annual Meeting of the American Association for Cancer Research; 2013 Apr 6-10; Washington, DC. Philadelphia (PA): AACR; Cancer Res 2013;73(8 Suppl):Abstract nr 3794. doi:10.1158/1538-7445.AM2013-3794

The major allergen of the Parietaria pollen contains an LPS‐binding region with immuno‐modulatory activity

The major allergens in Parietaria pollen, Par j 1 and Par j 2, have been identified as lipid transfer proteins. The family of the Par j 1 allergens is composed of two isoforms, which differ by the presence of a 37 amino acid peptide (Par37) exclusive to the Par j 1.0101 isoform. The goal of this study was to elucidate the biological properties of the Par37 peptide. In silico analysis, spectrofluorimetric experiments and in vitro cell culture assays were used to identify the biological properties of Par37. In addition, a mouse model of sensitization was used to study the influence of Par37 in the murine immune response. In silico analysis predicted that Par37 displays characteristics of a host defence peptide. Spectrofluorimetric analysis, real-time PCR and ELISA assays demonstrated that Par37 possesses an LPS-binding activity influencing cell signalling in vitro. In RAW264.7 cells, LPS-induced IL-6 and TNF-α transcription and translation were inhibited after preincubation with Par37. Consistent with these data, inhibition of IFN-γ secretion was observed in murine spleen cells and in human PBMC. Finally, mice immunized with the two Par j 1 isoforms differing in the presence or absence of the Par37 peptide showed different immunological behaviours in vivo. This study demonstrates that the Par j 1.0101 allergen displays LPS-binding activity due to the presence of a 37 amino acid COOH-terminal region and that this region is capable of influencing cytokine and antibody responses in vitro and in vivo.

Spleen tyrosine kinase inhibition attenuates airway hyperresponsiveness and pollution-induced enhanced airway response in a chronic mouse model of asthma

Asthma is a chronic inflammatory disease characterized by airways hyperresponsiveness (AHR), reversible airflow obstruction, airway remodeling, and episodic exacerbations caused by air pollutants, such as particulate matter (PM; PM <2.5 μm in diameter [PM(2.5)]) and ozone (O(3)). Spleen tyrosine kinase (Syk), an immunoregulatory kinase, has been implicated in the pathogenesis of asthma. We sought to evaluate the effect of Syk inhibition on AHR in a chronic mouse model of allergic airways inflammation and pollutant exposure. We used a 12-week chronic ovalbumin (OVA) sensitization and challenge mouse model of airways inflammation followed by exposure to PM(2.5) plus O(3). Respiratory mechanics and methacholine (MCh) responsiveness were assessed by using the flexiVent system. The Syk inhibitor NVP-QAB-205 was nebulized intratracheally by using a treatment-based protocol 15 minutes before assessment of MCh responsiveness. Syk expression increased significantly in the airway epithelia of OVA-sensitized and OVA-challenged (OVA/OVA) mice compared with OVA-sensitized but PBS-challenged (OVA/PBS) control mice. OVA/OVA mice exhibited AHR to MCh, which was attenuated by a single administration of NVP-QAB-205 (0.3 and 3 mg/kg). PM(2.5) plus O(3) significantly augmented AHR to MCh in the OVA/OVA mice, which was abrogated by NVP-QAB-205. Total inflammatory cell counts were significantly higher in the bronchoalveolar lavage fluid from OVA/OVA than OVA/PBS mice and were unaffected by PM(2.5) plus O(3) or NVP-QAB-205. NVP-QAB-205 reduced AHR and the enhanced response to PM(2.5) plus O(3) to normal levels in an established model of chronic allergic airways inflammation, suggesting that Syk inhibitors have promise as a therapy for asthma.

Lactoferrin restrains allergen-induced pleurisy in mice

ObjectivesThe aim of this study was to assess the utility of lactoferrin (LF), a natural immunomodulator, to restrain allergen-induced pleurisy in mice.Material and subjectsBALB/c female mice, 8- to 10-week old, weighing 24 g on average, were used.TreatmentMice were immunized intraperitoneally with 50 μg of ovalbumin (OVA) and the pleurisy was elicited 14 days later by intrapleural injection of 12.5 μg of OVA. LF was given 24 and 3 h before elicitation of the allergic reaction.MethodsThe cytokine levels in the pleural exudates were measured by immunoassays. The blood and pleural exudates smears were stained with Giemsa and May-Grünwald reagents and reviewed histologically. Lung sections were stained with eosin and hematoxylin for histological evaluation.ResultsLactoferrin significantly decreased manifestation of pleurisy induced by OVA in a sensitized mouse model. In particular, the percentages of eosinophils in blood and pleural exudates were strongly diminished. The histological analysis of lungs revealed that LF diminished the development of pathological lesions, such as pulmonary edema, diffuse alveolar hemorrhage and hemosiderosis, which were found in the lungs after injection of the eliciting dose of OVA. LF also decreased the level of IL-5 secreted into the pleural fluid.ConclusionsThis is a first demonstration that LF significantly decreases antigen-specific pleurisy in a sensitized mouse model.

Neurobehavioral assessment of mice following repeated postnatal exposure to chlorpyrifos-oxon

Chlorpyrifos (CPF), one of the most widely-used organophosphorus (OP) insecticides in agriculture, is degraded in the field to its oxon form, chlorpyrifos-oxon (CPO), which can represent a significant contaminant in exposures to adults and children. CPO is also responsible for the acetylcholinesterase (AChE) inhibition associated with CPF exposures; CPF is converted by liver CYP450 enzymes to CPO, which binds to and inhibits AChE and other serine active-site esterases, lipases and proteases. Young children represent a particularly susceptible population for exposure to CPF and CPO, in part because levels of the plasma enzyme, paraoxonase (PON1), which hydrolyzes CPO, are very low during early development. While a number of studies have demonstrated developmental neurotoxicity associated with CPF exposure, including effects at or below the threshold levels for AChE inhibition, it is unclear whether these effects were due directly to CPF or to its active metabolite, CPO. PON1 knockout (PON1−/−) mice, which lack PON1, represent a highly sensitive mouse model for toxicity associated with exposure to CPF or CPO. To examine the neurobehavioral consequences of CPO exposure during postnatal development, PON1−/− mice were exposed daily from PND 4 to PND 21 to CPO at 0.15, 0.18, or 0.25mg/kg/d. A neurobehavioral test battery did not reveal significant effects of CPO on early reflex development, motor coordination, pre-pulse inhibition of startle, startle amplitude, open field behavior, or learning and memory in the contextual fear conditioning, Morris water maze, or water radial-arm maze tests. However, body weight gain and startle latency were significantly affected by exposure to 0.25mg/kg/d CPO. Additionally, from PNDs 15–20 the mice exposed repeatedly to CPO at all three doses exhibited a dose-related transient hyperkinesis in the 20-min period following CPO administration, suggesting possible effects on catecholaminergic neurotransmission. Our previous study demonstrated wide-ranging effects of neonatal CPO exposure on gene expression in the brain and on brain AChE inhibition, and modulation of both of these effects by the PON1Q192R polymorphism. The current study indicates that the neurobehavioral consequences of these effects are more elusive, and suggests that alternative neurobehavioral tests might be warranted, such as tests of social interactions, age-dependent effects on learning and memory, or tests designed specifically to assess dopaminergic or noradrenergic function.

Characterization of a Par j 1/Par j 2 mutant hybrid with reduced allergenicity for immunotherapy of Parietaria allergy

Parietaria pollen is one of the major cause of pollinosis in the southern Europe. Specific immunotherapy is the only treatment able to modify the natural outcome of the disease restoring a normal immunity against allergens. We designed a recombinant molecule (PjEDloop1) comprised of genetic-engineered variants of the major allergens of the Parietaria pollen (Par j 2/Par j 1). Purity and chemical-physical properties of the derivative were analysed by RP-HPLC chromatography and Photon Correlation Spectroscopy. Immunological activity was evaluated by means of Western blotting, ELISA inhibition and PBMC proliferation assay in 10 Parietaria allergic patients. Basophil activation was studied in six subjects. The immunogenicity of the hybrid was studied looking at the immune responses induced in a mouse model of sensitization. The PjEDloop1 hybrid was produced as a purified recombinant protein with high stability in solution. Western blot, ELISA inhibition and basophil activation test showed that the PjEDloop1 displays a remarkable reduced IgE binding and anaphylactic activity. CD3 reactivity was conserved in all patients. Mice immunization with the rPjEDloop1 induced antibodies and T cell responses comparable to that obtained by the wild type allergens. Such antibodies shared the specificities to rPar j 1 and rPar j 2 with human IgE antibodies. Our results demonstrated that a mutant hybrid expressing genetically engineered forms of the major P. judaica allergens displayed reduced allergenicity and retained T cell reactivity for the induction of protective antibodies in vaccination approaches for the treatment of Parietaria pollinosis.

Vaccination Of Mice With Plasmid DNA Encoding Der p 2 And Blo t 5 Induced a CD4 T Cell Response To Allergen Proteins

T cells play a central role in the development of asthma. The ovalbumin sensitization and challenge mouse model is popularly used in the study of asthma. However, the physicochemical properties of allergens such as Dermatophagoides pteronyssinus, Blomia tropicalis and cockroach proteins that cause asthma in patients are markedly different from ovalbumin, and the response to exposure to these ‘asthma allergens’ may differ significantly from that generated to ovalbumin. The aim of our study is to characterize the CD4 T cell response to Der p 2 and Blo t 5 induced by intradermal plasmid DNA vaccination.

The 2S albumin allergens of Arachis hypogaea, Ara h 2 and Ara h 6, are the major elicitors of anaphylaxis and can effectively desensitize peanut‐allergic mice

Ara h 2 and Ara h 6, co-purified together in a 13-25kD fraction (Ara h 2/6; 20kD fraction) on gel filtration chromatography, account for the majority of effector activity in a crude peanut extract (CPE) when assayed with RBL SX-38 cells sensitized with IgE from human peanut allergic sera. To determine if Ara h 2/6 are the primary peanut allergens responsible for allergic reactions in vivo and to determine if Ara h 2/6 would be sufficient to prevent allergic reactions to a complete CPE. An oral sensitization mouse model of peanut allergy was used to assess the activity of Ara h 2/6 (20kD) and CPE without the 20kD fraction (CPE w/o 20kD) for allergic provocation challenge and immunotherapy. The activity of these preparations was also tested in an assay of histamine release from human basophils in whole blood. Compared with mice challenged with control CPE, mice challenged with CPE w/o 20kD experienced reduced symptoms (P<0.05) and a smaller decrease in body temperature (P<0.01). Results with the basophil histamine release assay corroborated these findings (P<0.01). The mouse model was also used to administer Ara h 2/6 (20kD) in an immunotherapy protocol, in which peanut-allergic mice treated with the 20kD fraction experienced significantly reduced symptoms, changes in body temperature, and mast cell protease (MMCP-1) release compared with placebo (P<0.01 for all parameters). Importantly, immunotherapy with the 20kD fraction was just as effective as treatment with CPE, whereas CPE w/o 20kD was significantly less effective for higher dose peanut challenges. Ara h 2/6 are the most potent peanut allergens in vivo and can be used to desensitize peanut-allergic mice. These results have potential implications for clinical research in the areas of diagnosis and immunotherapy for peanut allergy.

In vivo methods for testing allergenicity show that high hydrostatic pressure hydrolysates of β-lactoglobulin are immunologically inert

The major milk allergen β-lactoglobulin (β-LG) exhibits an enhanced susceptibility to proteolysis under high hydrostatic pressure and this may be an efficient method to produce hypoallergenic hydrolysates. The aim of this work was to evaluate the in vivo allergenicity of 3 β-LG hydrolysates produced under atmospheric pressure or high-pressure conditions. Hydrolysates were chosen based on previous experiments that showed that they provide a complete removal of intact β-LG but differed in vitro IgE-binding properties that could be traced to the peptide pattern. The ability to trigger systemic anaphylaxis was assessed using C3H/HeJ mice orally sensitized to β-LG. Outcome measures included symptom score, body temperature, serum mouse mast cell protease 1 (mMCP-1), and quantification of circulating basophils. Mast cell degranulation in vivo was assessed by passive cutaneous anaphylaxis. The 3 tested hydrolysates showed an abrogated allergenicity as revealed by the absence of anaphylactic symptoms and a decrease in body temperature. We demonstrated that the peptides present in the hydrolysates had lost their ability to cross-link 2 human IgE antibodies to induce mast cell degranulation, thus indicating that most of the peptides formed retain just one relevant IgE-binding epitope. The orally sensitized mouse model is a useful tool to address the in vivo allergenicity of novel milk formulas and demonstrates the safety of hydrolysates produced under high-pressure conditions.

Effect of the Velvet Antler of Formosan Sambar Deer (Cervus unicolor swinhoei) on the Prevention of an Allergic Airway Response in Mice.

Two mouse models were used to assay the antiallergic effects of the velvet antler (VA) of Formosan sambar deer (Cervus unicolor swinhoei) in this study. The results using the ovalbumin- (OVA-) sensitized mouse model showed that the levels of total IgE and OVA-specific IgE were reduced after VA powder was administrated for 4 weeks. In addition, the ex vivo results indicated that the secretion of T helper cell 1 (Th1), regulatory T (Treg), and Th17 cytokines by splenocytes was significantly increased (P < 0.05) when VA powder was administered to the mice. Furthermore, OVA-allergic asthma mice that have been orally administrated with VA powder showed a strong inhibition of Th2 cytokine and proinflammatory cytokine production in bronchoalveolar fluid compared to control mice. An increase in the regulatory T-cell population of splenocytes in the allergic asthma mice after oral administration of VA was also observed. All the features of the asthmatic phenotype, including airway inflammation and the development of airway hyperresponsiveness, were reduced by treatment with VA. These findings support the hypothesis that oral feeding of VA may be an effective way of alleviating asthmatic symptoms in humans.

Probiotic treatment induces intestinal regulatory dendritic and T cells, and counter-regulates Th2 responses and anaphylaxis in a mouse model of food allergy

The immunological mechanisms responsible for the anti-allergic effects of probiotic bacteria are still poorly defined. We tested the effect of a probiotic mixture (VSL#3) in in vitro, ex vivo and in vivo mouse systems. In vitro co-culture of naive bone marrow(BM)-derived DC (BM-DC) with VSL#3 induced the up-regulation of maturation marker and IL-10 and IL-12 production. Ex vivo analysis of mesenteric lymph node(MLN)-derived DC (MLN-DC) from naive mice receiving for three weeks VSL#3 by oral administration, indicated a different distribution and phenotype of DC within the MLN. In particular, VSL#3 treatment increased the frequency of plasmacytoid DC (pDC, B220+CD11clow), and upregulated the expression of maturation markers on conventional DC (cDC). Moreover, the frequency of IL-10-expressing cDC was increased. This finding was paralleled by the increase of CD4+CD25+ T cells and CD4+CD25- populations showing enhanced IL-10 production. Altogether, these results suggest that VSL#3 treatment can stimulate in the gut the activation of tolerogenic DC. Finally, we obtained in vivo preliminary data on therapeutic and preventive potential of VSL#3 in a mouse model of sensitization and anaphylaxis to peanut. Mice were orally sensitized and challenged with peanut extract to induce in vivo anaphylaxis. In the therapeutic experimental setting, animals received a three-weeks oral treatment with VSL#3 and were then re-challenged. In the preventive setting, oral probiotic treatment started one week before the beginning of the immunization schedule and continued until the challenge. In both approaches, VSL#3 was able to reduce anaphylaxis symptoms and IL-13 release in the jejunum of immunized mice upon post-treatment challenge. Furthermore, the therapeutic approach also induced allergen-specific IgA in the gut and TGF-β release. Then, the capacity of probiotics to induce protective immune responses linked to counter-regulation of Th2 responses might become an effective strategy in the treatment of type I allergy.

Chimeric Chikungunya Viruses Are Nonpathogenic in Highly Sensitive Mouse Models but Efficiently Induce a Protective Immune Response

Chikungunya virus (CHIKV) is an important pathogen causing outbreaks of highly debilitating and often chronic, arthralgic human disease. We have designed chimeric alphaviruses encoding CHIKV-specific structural proteins but no structural or nonstructural proteins capable of interfering with development of cellular antiviral response. These chimeras demonstrate a highly attenuated phenotype in both immunocompetent and immunocompromised (A129) mice. However, after a single vaccination, they induced protective immune response against subsequent CHIKV challenge, characterized by high titers of neutralizing antibodies. The rational design of alphavirus genomes provides a strong basis for the development of new recombinant alphaviruses with irreversible, highly attenuated, cell type-restricted phenotypes.

An adjuvant free mouse model of oral allergenic sensitization to rice seeds protein

BackgroundRice is commonly known as a staple crop consumed worldwide, though with several rice proteins being reported for allergic properties in clinical studies. Thus, there is a growing need for the development of an animal model to better understand the allergenicity of rice proteins and the immunological and pathophysiological mechanisms underlying the development of food allergy.MethodsGroups of BALB/c mice were sensitized daily with freshly homogenized rice flour (30 mg or 80 mg) without adjuvant by intragastric gavage. In addition, the mice were challenged with extracted rice flour proteins at several time points intragastrically. Hypersensitivity symptoms in mice were evaluated according to a scoring system. Vascular leakage, ELISA of rice protein-specific IgE, histopathology of small intestine, and passive cutaneous anaphylaxis were conducted on challenged mice.ResultsAn adjuvant free mouse model of rice allergy was established with sensitized mice showing increased scratching behaviors and increased vascular permeability. Rice protein-specific IgE was detected after eighteen days of sensitization and from the fifth challenge onwards. Inflammatory damage to the epithelium in the small intestine of mice was observed beyond one month of sensitization. Passive cutaneous anaphylaxis results confirmed the positive rice allergy in the mouse model.ConclusionsWe introduced a BALB/c mouse model of rice allergy with simple oral sensitization without the use of adjuvant. This model would serve as a useful tool for further analysis on the immunopathogenic mechanisms of the various rice allergens, for the evaluation of the hypersensitivity of rice or other cereal grains, and to serve as a platform for the development of immunotherapies against rice allergens.

Extract of Poncirus trifoliata fruit reduces elevated serum IgE concentrations in chemically induced allergic model mice

The fruit of trifoliate orange (Poncirus trifoliate) is widely used for treating allergies including allergenic dermatitis and inflammation in oriental medicine. Increased blood IgE concentration and histamine level following dermatitis, coughing and asthma are the most important clinical symptoms of allergic diseases. Decreases in the elevated serum IgE concentrations are essential in the treatment of allergy because increased IgE blood levels are initiated in allergenic immune disorders. This study was conducted to investigate the activities of an extract of trifoliate orange fruit using 100% methanol followed by extraction with boiling water on the regulation of blood IgE concentration in the U266B1 human myeloma cell line and a 1-chloro-2,4-dinitrobenzene (DNCB) sensitized mouse model. The results revealed that the extracts of trifoliate orange suppressed IgE production in U266B1 cells in a dose dependent manner with or without lipopolysaccharide (LPS) stimulation of the cells. In addition, chemically elevated blood IgE concentrations were dramatically decreased by oral administration, ventral injection, and topical application of the trifoliate orange extracts (TOE). The results indicated that the fraction of TOE should contain an important compound of the fruit of trifoliate orange, and TOE had the ability to reduce IgE concentrations in cultured cells and a chemically sensitized in vivo mouse model.