Bovine Holo-Beta-Lactoglobulin Cross-Protects Against Pollen Allergies in an Innate Manner in BALB/c Mice: Potential Model for the Farm Effect.

The lipocalin beta-lactoglobulin (BLG) is a major protein compound in cow's milk, and we detected it in cattle stable dust. BLG may be a novel player in the farm protective effect against atopic sensitization and hayfever. In previous studies, we demonstrated that only the ligand-filled holo-form of BLG prevented sensitization to itself. Here, we investigated whether holo-BLG could, in an innate manner, also protect against allergic sensitization to unrelated birch pollen allergens using a murine model. BALB/c mice were nasally pretreated four times in biweekly intervals with holo-BLG containing quercetin-iron complexes as ligands, with empty apo-BLG, or were sham-treated. Subsequently, mice were intraperitoneally sensitized two times with apo-BLG or with the unrelated birch pollen allergen apo-Bet v 1, adjuvanted with aluminum hydroxide. After subsequent systemic challenge with BLG or Bet v 1, body temperature drop was monitored by anaphylaxis imaging. Specific antibodies in serum and cytokines of BLG- and Bet v 1-stimulated splenocytes were analyzed by ELISA. Additionally, human peripheral blood mononuclear cells of pollen allergic subjects were stimulated with apo- versus holo-BLG before assessment by FACS. Prophylactic treatment with the holo-BLG resulted in protection against allergic sensitization and clinical reactivity also to Bet v 1 in an unspecific manner. Pretreatment with holo-BLG resulted in significantly lower BLG-as well as Bet v 1-specific antibodies and impaired antigen-presentation with significantly lower numbers of CD11c+MHCII+ cells expressing CD86. Pretreatment with holo-BLG also reduced the release of Th2-associated cytokines from Splenocytes in BLG-sensitized mice. Similarly, in vitro stimulation of PBMCs from birch pollen allergic subjects with holo-BLG resulted in a relative decrease of CD3+CD4+ and CD4+CRTh2 cells, but not of CD4+CD25+CD127- Treg cells, compared to apo-BLG stimulation. In conclusion, prophylactic treatment with holo-BLG protected against allergy in an antigen-specific and -unspecific manner by decreasing antigen presentation, specific antibody production and abrogating a Th2-response. Holo-BLG therefore promotes immune resilience against pollen allergens in an innate manner and may thereby contribute to the farm protective effect against atopic sensitization.

Bombyx batryticatus Protein-Rich Extract Induces Maturation of Dendritic Cells and Th1 Polarization: A Potential Immunological Adjuvant for Cancer Vaccine.

Bombyx batryticatus, a protein-rich edible insect, is widely used as a traditional medicine in China. Several pharmacological studies have reported the anticancer activity of B. batryticatus extracts; however, the capacity of B. batryticatus extracts as immune potentiators for increasing the efficacy of cancer immunotherapy is still unverified. In the present study, we investigated the immunomodulatory role of B. batryticatus protein-rich extract (BBPE) in bone marrow-derived dendritic cells (BMDCs) and DC vaccine-immunized mice. BBPE-treated BMDCs displayed characteristics of mature immune status, including high expression of surface molecules (CD80, CD86, major histocompatibility complex (MHC)-I, and MHC-II), increased production of proinflammatory cytokines (tumor necrosis factor-α and interleukin-12p70), enhanced antigen-presenting ability, and reduced endocytosis. BBPE-treated BMDCs promoted naive CD4+ and CD8+ T-cell proliferation and activation. Furthermore, BBPE/ovalbumin (OVA)-pulsed DC-immunized mice showed a stronger OVA-specific multifunctional T-cell response in CD4+ and CD8+ T cells and a stronger Th1 antibody response than mice receiving differently treated DCs, which showed the enhanced protective effect against tumor growth in E.G7 tumor-bearing mice. Our data demonstrate that BBPE can be a novel immune potentiator for a DC-based vaccine in anticancer therapy.

The biology and functional importance of MAIT cells.

In recent years, a population of unconventional T cells called 'mucosal-associated invariant T cells' (MAIT cells) has captured the attention of immunologists and clinicians due to their abundance in humans, their involvement in a broad range of infectious and non-infectious diseases and their unusual specificity for microbial riboflavin-derivative antigens presented by the major histocompatibility complex (MHC) class I-like protein MR1. MAIT cells use a limited T cell antigen receptor (TCR) repertoire with public antigen specificities that are conserved across species. They can be activated by TCR-dependent and TCR-independent mechanisms and exhibit rapid, innate-like effector responses. Here we review evidence showing that MAIT cells are a key component of the immune system and discuss their basic biology, development, role in disease and immunotherapeutic potential.

Identifying Antigens Recognized by Cytolytic T Lymphocytes on Tumors.

Identification of antigenic peptides recognized by cytolytic T lymphocytes (CTL) is a prerequisite for the development of targeted cancer immunotherapy approaches. This chapter provides a global approach for the identification of peptides recognized by CTL. It implies the identification of the HLA molecule presenting the peptide as well as the design and screening of a cDNA library derived from the tumor cells. Methods used for the identification of spliced peptides on tumors are also described.

Peptide Vaccine Formulation Controls the Duration of Antigen Presentation and Magnitude of Tumor-Specific CD8+ T Cell Response.

Despite remarkable progresses in vaccinology, therapeutic cancer vaccines have not achieved their full potential. We previously showed that an excessively long duration of Ag presentation critically reduced the quantity and quality of vaccination-induced T cell responses and subsequent antitumor efficacy. In this study, using a murine model and tumor cell lines, we studied l-tyrosine amino acid-based microparticles as a peptide vaccine adjuvant with a short-term Ag depot function for the induction of tumor-specific T cells. l-Tyrosine microparticles did not induce dendritic cell maturation, and their adjuvant activity was not mediated by inflammasome activation. Instead, prolonged Ag presentation in vivo translated into increased numbers and antitumor activity of vaccination-induced CD8+ T cells. Indeed, prolonging Ag presentation by repeated injection of peptide in saline resulted in an increase in T cell numbers similar to that observed after vaccination with peptide/l-tyrosine microparticles. Our results show that the duration of Ag presentation is critical for optimal induction of antitumor T cells, and can be manipulated through vaccine formulation.

Unconventional Peptide Presentation by Major Histocompatibility Complex (MHC) Class I Allele HLA-A*02:01: BREAKING CONFINEMENT.

Peptide antigen presentation by major histocompatibility complex (MHC) class I proteins initiates CD8+ T cell-mediated immunity against pathogens and cancers. MHC I molecules typically bind peptides with 9 amino acids in length with both ends tucked inside the major A and F binding pockets. It has been known for a while that longer peptides can also bind by either bulging out of the groove in the middle of the peptide or by binding in a zigzag fashion inside the groove. In a recent study, we identified an alternative binding conformation of naturally occurring peptides from Toxoplasma gondii bound by HLA-A*02:01. These peptides were extended at the C terminus (PΩ) and contained charged amino acids not more than 3 residues after the anchor amino acid at PΩ, which enabled them to open the F pocket and expose their C-terminal extension into the solvent. Here, we show that the mechanism of F pocket opening is dictated by the charge of the first charged amino acid found within the extension. Although positively charged amino acids result in the Tyr-84 swing, amino acids that are negatively charged induce a not previously described Lys-146 lift. Furthermore, we demonstrate that the peptides with alternative binding modes have properties that fit very poorly to the conventional MHC class I pathway and suggest they are presented via alternative means, potentially including cross-presentation via the MHC class II pathway.

Calreticulin acts as an adjuvant to promote dendritic cell maturation and enhances antigen-specific cytotoxic T lymphocyte responses against non-small cell lung cancer cells.

Dendritic cell (DC)-based immunotherapy has promising for treatment of non-small cell lung cancer (NSCLC). Melanoma-associated antigen 3 (MAGE-A3) is a tumor-specific antigen and expressed in approximately 35-40% of NSCLC tissues. Calreticulin (CALR) is a protein chaperone and can enhance DC maturation and antigen presentation. In this study, we evaluated the adjuvant activity of CALR in human DC maturation and their capacity to induce MAGE-A3-specific CD8+ cytotoxic T lymphocyte (CTL) responses to NSCLC in vitro. Infection with recombinant Ad-CALR and/or Ad-MAGE-A3, but not with control Ads, induced CALR and/or MAGE-A3 expression in DCs. Infection with Ad-CALR significantly increased the percentages of CD80+, CD83+, CD86+ and HLA-DR+ DCs and IL-12 secretion, but reduced IL-10 production in DCs. Co-culture of autologous lymphocytes with DC-Ad-CALR or DC-Ad-CM significantly increased the numbers of induced CD8+ CTLs. The percentages of IFNγ-secreting CTLs responding to SK-LU-1 and NCI-H522 NSCLC, but not to non-tumor NL-20 cells in Ad-C-CTL, Ad-M-CTL and Ad-CM-CTL were significantly higher than that of DC-CTL and Ad-null-CTL. Ad-C-CTL, Ad-M-CTL and Ad-CM-CTL, but not control DC-CTL and Ad-null-CTL, induced higher frequency of MAGE-A3+HLA-A2+ NCI-H-522 cell apoptosis, but did not affect the survival of MAGE-A3+HLA-A2- SK-LU-1 and non-tumor NL20 cells in vitro. Treatment with anti-HLA-I antibody, but not with anti-HLA-II, dramatically diminished the cytotoxicity of Ad-CM-CTLs against NCI-H522 cells. Our data indicated that CALR acted as an adjuvant to promote DC maturation, which induced CTL development and enhanced MAGE-A3-specific CTL cytotoxicity against NSCLC.

Immune adjuvant effect of Juzentaihoto, a Japanese traditional herbal medicine, on tumor vaccine therapy in a mouse model.

Japanese traditional herbal medicine (Kampo) have been used to improve the general physical condition after surgery and to mitigate the side effects of radiation and chemotherapy in tumor patients. Juzentaihoto (JTT) consists of ten medical herbs, and is also called Shi-Quan-Da-Bu-Tang in Chinese herbal medicine. Among Kampo medicines, JTT has especially gained attention as a biological response modifier. Currently, clinical trials of various tumor vaccine therapies are being performed world-wide. However, tumor antigens that are inoculated as vaccines do not have high immunogenicity; thus, it is difficult to obtain an effective therapeutic effect. Thus, it is necessary to develop a tumor vaccine adjuvant that is more potent and very safe. In the present study, we examined the efficacy of JTT as an oral adjuvant when given together with tumor vaccines. As a result, JTT enhanced the phagocytic ability of OVA antigen and the presentation ability of OVA antigen in dendritic cells in vitro. Furthermore, tumor growth was markedly decreased, and the survival period was significantly prolonged in mice inoculated with mouse lymphoma, which is expressed with tumor model antigen. In conclusion, these findings suggest that JTT can be used with tumor vaccines as an immune adjuvant.

The role of tomatine adjuvant in antigen delivery for cross- presentation.

The aim of this study was to investigate the use of tomatine adjuvant to deliver soluble antigen for crosspresentation by bone marrow-derived dendritic cells (BMDCs). BMDCs were incubated with tomatine adjuvantovalbumin (OVA) complex and analyzed for antigen uptake by flow cytometry. Adjuvant-induced cell death was examined in situ by terminal deoxynucleotidyl transferase dUTP nick end labelling (TUNEL) assay. To elucidate the effect of antigen internalization on tomatine adjuvant-mediated antigen presentation, BMDCs were treated with several endocytosis inhibitors, and antigen presentation was analyzed by B3Z activity assay. Our data indicated that tomatine adjuvant enhanced antigen internalization by antigen presenting cells (APCs) and induced significant cell death and leukocyte infiltration at the injection sites. In vitro tomatine adjuvant treatment of BMDCs activated Ova/K(b) restricted B3Z T cell hybridomas, whereas this activation was impaired by pretreatment with brefeldin A, cytochalasin B, wortmannin, or ZnCl2. Our results demonstrated the role of tomatine adjuvant in antigen delivery to antigen presenting cells (APCs) and suggested the involvement of phagocytosis and PI3K signaling during the delivery of soluble antigens in the context of MHC class I.

Ginseng Berry Extract Promotes Maturation of Mouse Dendritic Cells.

Ginseng extract has been shown to possess certain anti-virus, anti-tumor and immune-activating effects. However, the immunostimulatory effect of ginseng berry extract (GB) has been less well characterized. In this study, we investigated the effect of GB on the activation of mouse dendritic cells (DCs) in vitro and in vivo. GB treatment induced up-regulation of co-stimulatory molecules in bone marrow-derived DCs (BMDCs). Interestingly, GB induced a higher degree of co-stimulatory molecule up-regulation than ginseng root extract (GR) at the same concentrations. Moreover, in vivo administration of GB promoted up-regulation of CD86, MHC class I and MHC class II and production of IL-6, IL-12 and TNF-α in spleen DCs. GB also promoted the generation of Th1 and Tc1 cells. Furthermore, Toll like receptor 4 (TLR4) and myeloid differentiation primary response 88 (MyD88) signaling pathway were essential for DC activation induced by GB. In addition, GB strongly prompted the proliferation of ovalbumin (OVA)-specific CD4 and CD8 T cells. Finally, GB induced DC activation in tumor-bearing mice and the combination of OVA and GB treatment inhibited B16-OVA tumor cell growth in C57BL/6 mice. These results demonstrate that GB is a novel tumor therapeutic vaccine adjuvant by promoting DC and T cell activation.

Immunoregulatory T cell epitope peptides: the new frontier in allergy therapy.

Allergen immunotherapy (AIT) has been practised since 1911 and remains the only therapy proven to modify the natural history of allergic diseases. Although efficacious in carefully selected individuals, the currently licensed whole allergen extracts retain the risk of IgE-mediated adverse events, including anaphylaxis and occasionally death. This together with the need for prolonged treatment regimens results in poor patient adherence. The central role of the T cell in orchestrating the immune response to allergen informs the choice of T cell targeted therapies for down-regulation of aberrant allergic responses. Carefully mapped short synthetic peptides that contain the dominant T cell epitopes of major allergens and bind to a diverse array of HLA class II alleles, can be delivered intradermally into non-inflamed skin to induce sustained clinical and immunological tolerance. The short peptides from allergenic proteins are unable to cross-link IgE and possess minimal inflammatory potential. Systematic progress has been made from in vitro human models of allergen T cell epitope-based peptide anergy in the early 1990s, through proof-of-concept murine allergy models and early human trials with longer peptides, to the current randomized, double-blind, placebo-controlled clinical trials with the potential new class of synthetic short immune-regulatory T cell epitope peptide therapies. Sustained efficacy with few adverse events is being reported for cat, house dust mite and grass pollen allergy after only a short course of treatment. Underlying immunological mechanisms remain to be fully delineated but anergy, deletion, immune deviation and Treg induction all seem contributory to successful outcomes, with changes in IgG4 apparently less important compared to conventional AIT. T cell epitope peptide therapy is promising a safe and effective new class of specific treatment for allergy, enabling wider application even for more severe allergic diseases.

Immune evasion in cancer: Mechanistic basis and therapeutic strategies.

Cancer immune evasion is a major stumbling block in designing effective anticancer therapeutic strategies. Although considerable progress has been made in understanding how cancers evade destructive immunity, measures to counteract tumor escape have not kept pace. There are a number of factors that contribute to tumor persistence despite having a normal host immune system. Immune editing is one of the key aspects why tumors evade surveillance causing the tumors to lie dormant in patients for years through "equilibrium" and "senescence" before re-emerging. In addition, tumors exploit several immunological processes such as targeting the regulatory T cell function or their secretions, antigen presentation, modifying the production of immune suppressive mediators, tolerance and immune deviation. Besides these, tumor heterogeneity and metastasis also play a critical role in tumor growth. A number of potential targets like promoting Th1, NK cell, γδ T cell responses, inhibiting Treg functionality, induction of IL-12, use of drugs including phytochemicals have been designed to counter tumor progression with much success. Some natural agents and phytochemicals merit further study. For example, use of certain key polysaccharide components from mushrooms and plants have shown to possess therapeutic impact on tumor-imposed genetic instability, anti-growth signaling, replicative immortality, dysregulated metabolism etc. In this review, we will discuss the advances made toward understanding the basis of cancer immune evasion and summarize the efficacy of various therapeutic measures and targets that have been developed or are being investigated to enhance tumor rejection.

Immunological comparison of allergen immunotherapy tablet treatment and subcutaneous immunotherapy against grass allergy.

BACKGROUND: IgE-mediated allergic rhinitis to grass pollen can successfully be treated with either allergen immunotherapy tablets (SLIT tablet) or SQ-standardized subcutaneous immunotherapy (SCIT). The efficacy of these two treatment modalities for grass allergy is comparable, but the immunological mechanisms may differ. ClinicalTrials.gov ID: NCT01889875. OBJECTIVES: To compare the immunological changes induced by SQ-standardized SCIT and SLIT tablet. METHODS: We randomized 40 individuals with grass pollen rhinitis into groups receiving SCIT, SLIT tablet, or neither and followed them for 15 months with regular serum measurements of specific IgE, IgG4, IgE-blocking factor, facilitated antigen presentation (FAP), and basophil activation test (BAT). Nasal challenges were used to assess changes in nasal sensitivity. RESULTS: After 15 months of treatment IgG4, IgE-blocking factor, FAP, and BAT values differed significantly in both SCIT and SLIT-tablet treatment groups when compared to the control group. Both SCIT and SLIT-tablet groups were significantly different from the control group after 1­3 months of treatment. In general, the changes induced by SCIT reached twice that of SLIT tablet, with the exception of specific IgE where SLIT tablet induced initial threefold increase compared with SCIT. A slight but significant increase in IgE and BAT after season was seen only in the control group. Significant differences between SCIT and SLIT tablet were observed early, but the differences diminished with the length of treatment, especially for FAP inhibition. CONCLUSIONS: Both SCIT and SLIT tablet induce significant changes in specific antibodies (IgE and IgG4) and competition assays (IgE-blocking factor, FAP, and BAT). Overall, SCIT induced larger (two- to threefold) changes than SLIT tablet, with the exception of FAP, where SLIT tablet showed a gradual increase ending at the same level as SCIT. Maximal change was generally reached after 3 months' treatment.

Enhanced endoplasmic reticulum entry of tumor antigen is crucial for cross-presentation induced by dendritic cell-targeted vaccination.

Efficient cross-presentation of protein Ags to CTLs by dendritic cells (DCs) is essential for the success of prophylactic and therapeutic vaccines. In this study, we report a previously underappreciated pathway involving Ag entry into the endoplasmic reticulum (ER) critically needed for T cell cross-priming induced by a DC-targeted vaccine. Directing the clinically relevant, melanoma Ag gp100 to mouse-derived DCs by molecular adjuvant and chaperone Grp170 substantially facilitates Ag access to the ER. Grp170 also strengthens the interaction of internalized protein Ag with molecular components involved in ER-associated protein dislocation and/or degradation, which culminates in cytosolic translocation for proteasome-dependent degradation and processing. Targeted disruption of protein retrotranslocation causes exclusive ER retention of tumor Ag in mouse bone marrow-derived DCs and splenic CD8(+) DCs. This results in the blockade of Ag ubiquitination and processing, which abrogates the priming of Ag-specific CD8(+) T cells in vitro and in vivo. Therefore, the improved ER entry of tumor Ag serves as a molecular basis for the superior cross-presenting capacity of Grp170-based vaccine platform. The ER access and retrotranslocation represents a distinct pathway that operates within DCs for cross-presentation and is required for the activation of Ag-specific CTLs by certain vaccines. These results also reinforce the importance of the ER-associated protein quality control machinery and the mode of the Ag delivery in regulating DC-elicited immune outcomes.

A glucose-6-phosphate isomerase peptide induces T and B cell-dependent chronic arthritis in C57BL/10 mice: arthritis without reactive oxygen species and complement.

Immunization with human glucose-6-phosphate isomerase (hG6PI) protein or with several of its peptides induces arthritis in DBA/1 mice. We investigated G6PI peptide-induced arthritis in C57BL/10 mice and the effect of oxidative burst on disease. To study the arthritogenicity of G6PI peptides and its immune dependency, we used genetically modified and congenic mice on the C57BL/10 background and in vitro T- and B-cell assays. hG6PI(325-339) peptide induced arthritis in C57BL/10 mice. The disease was associated with major histocompatibility complex class II and was dependent on T cells, B cells, and complement C5. Th1 and Th17 cells primed with the hG6PI(325-339) peptide cross-reacted with the murine G6PI protein. The severity of the disease increased in mice carrying a mutation in Ncf1 (Ncf1*/*), which abolishes the NADPH oxidase 2 complex oxidative burst. Ncf1*/* mice developed arthritis also on immunization with the mouse G6PI325-339 peptide and in the absence of C5. The antibody responses to the G6PI protein and peptides were minimal in both Ncf1*/* and wild-type mice. Herein is described G6PI peptide as the first peptide to induce arthritis in C57BL/10 mice. The differences between the wild-type and Ncf1*/* mice suggest that an alternative complement-independent arthritogenic pathway could be operative in the absence of oxidative burst.

A nonallergenic birch pollen allergy vaccine consisting of hepatitis PreS-fused Bet v 1 peptides focuses blocking IgG toward IgE epitopes and shifts immune responses to a tolerogenic and Th1 phenotype.

Allergen-specific immunotherapy is the only allergen-specific and disease-modifying treatment for allergy. The construction and characterization of a vaccine for birch pollen allergy is reported. Two nonallergenic peptides, PA and PB, derived from the IgE-reactive areas of the major birch pollen allergen Bet v 1 were fused to the hepatitis B surface protein, PreS, in four recombinant fusion proteins containing different numbers and combinations of the peptides. Fusion proteins expressed in Escherichia coli and purified to homogeneity showed a lack of IgE reactivity and allergenic activity when tested with sera and basophils from patients allergic to birch pollen. Compared to Bet v 1 allergen, peptides PA and PB showed reduced T cell activation in PBMCs from allergic patients, whereas PreS fusion proteins induced less IL-5 and more IL-10 and IFN-γ. Immunization of rabbits with the fusion proteins, in particular with a PreS fusion protein 2PAPB-PreS, containing two copies of each peptide, induced high levels of IgG Abs against the major IgE-reactive site on Bet v 1 and related allergens. These IgG Abs inhibited allergic patients' IgE binding to Bet v 1 better than did IgG induced by immunization with complete Bet v 1. Furthermore, 2PAPB-PreS-induced IgG inhibited Bet v 1-induced basophil activation in allergic patients and CD23-facilitated allergen presentation. Our study exemplifies novel beneficial features for a PreS carrier-based peptide vaccine for birch pollen, which, in addition to the established reduction in allergenic activity, include the enhanced focusing of blocking Ab responses toward IgE epitopes, immunomodulatory activity, and reduction of CD23-facilitated allergen presentation.

Association of HLA-DR1 with the allergic response to the major mugwort pollen allergen: molecular background.

BACKGROUND: Mugwort pollen allergens represent the main cause of pollinosis in late summer. The major allergen, Art v 1, contains only one single immunodominant, solely HLA-DR-restricted T cell epitope (Art v 125-36). The frequency of HLA-DRB1*01 is highly increased in mugwort-allergic individuals and HLA-DR1 serves as restriction element for Art v 125-36. However, Art v 125-36 also binds to HLA-DR4 with high affinity and DR1-restricted Art v 125-36 -specific T cell receptors can be activated by HLA-DR4 molecules. To understand the predominance of HLA-DR1 in mugwort allergy in spite of the degeneracy in HLA/peptide-binding and TCR-recognition, we investigated the molecular background of Art v 125-36 /MHC/TCR interactions in the context of HLA-DR1 compared to -DR4. RESULTS: The majority of Art v 125-36 -specific T cell lines and clones from HLA-DR1 carrying, mugwort pollen-allergic donors reacted to synthetic and naturally processed Art v 1-peptides when presented by HLA-DR1 or HLA-DR4 expressing antigen presenting cells. However, at limiting peptide concentrations DR1 was more effective in T cell stimulation. In addition, the minimal epitope for 50% of Art v 125-36 -specific T cells was shorter for DR1 than for DR4. In vitro binding assays of Art v 125-36 mutant peptides to isolated DR1- and DR4-molecules indicated similar binding capacities and use of the same register. In silico simulation of Art v 125-36 binding to HLA-DR1 and -DR4 suggested similar binding of the central part of the peptide to either molecule, but a higher flexibility of the N- and C-terminal amino acids and detachment at the C-terminus in HLA-DR1. CONCLUSIONS: The predominance of HLA-DR1 in the response to Art v 125-36 may be explained by subtle conformation changes of the peptide bound to DR1 compared to DR4. Computer simulation supported our experimental data by demonstrating differences in peptide mobility within the HLA-DR complex that may influence TCR-binding. We suggest that the minor differences observed in vitro may be more relevant in the microenvironment in vivo, so that only presentation by HLA-DR1, but not -DR4 permits successful T cell activation.

The neuroendocrine-immune connection regulates chronic inflammatory disease in allergy.

Allergy is an instructive model to study neuroendocrine-immune interaction in chronic inflammation, a key research task taken on by a relatively new scientific field: psychoneuroimmunology (PNI). Itch, as the prime symptom of many chronic inflammatory diseases but especially of allergic inflammation, hints at the prominent role of neurogenic inflammation in the course of the disease. Environmental factors ranging from allergens to perceived stress can trigger the release of neuropeptides from peripheral nerve endings that than activate mast cells and induce an exaggerated alarm response in peripheral organs such as the skin. Beyond this innate immune response, neuroendocrine-immune interaction regulates specific immune balance. Depending on intensity and timing of neuroendocrine activation, especially neuropeptides and neurotrophins either enhance or suppress tissue regeneration and inflammation, the conditions of which will be discussed in detail here. Allergic inflammation thus serves to understand the clinical and therapeutic implications of neuroendocrine-immune interaction in chronic inflammatory disease and its implications for future treatment strategies.

Nitration of the pollen allergen bet v 1.0101 enhances the presentation of bet v 1-derived peptides by HLA-DR on human dendritic cells.

Nitration of pollen derived allergens can occur by NO(2) and ozone in polluted air and it has already been shown that nitrated major birch (Betula verrucosa) pollen allergen Bet v 1.0101 (Bet v 1) exhibits an increased potency to trigger an immune response. However, the mechanisms by which nitration might contribute to the induction of allergy are still unknown. In this study, we assessed the effect of chemically induced nitration of Bet v 1 on the generation of HLA-DR associated peptides. Human dendritic cells were loaded with unmodified Bet v 1 or nitrated Bet v 1, and the naturally processed HLA-DR associated peptides were subsequently identified by liquid chromatography-mass spectrometry. Nitration of Bet v 1 resulted in enhanced presentation of allergen-derived HLA-DR-associated peptides. Both the copy number of Bet v 1 derived peptides as well as the number of nested clusters was increased. Our study shows that nitration of Bet v 1 alters antigen processing and presentation via HLA-DR, by enhancing both the quality and the quantity of the Bet v 1-specific peptide repertoire. These findings indicate that air pollution can contribute to allergic diseases and might also shed light on the analogous events concerning the nitration of self-proteins.