In the past, the development of more effective, safe, convenient, broadly applicable, and easy to manufacture vaccines for allergen-specific immunotherapy (AIT) has been limited by the poor quality ...of natural allergen extracts. Progress made in the field of molecular allergen characterization has now made it possible to produce defined vaccines for AIT and eventually for preventive allergy vaccination based on recombinant DNA technology and synthetic peptide chemistry. Here we review the characteristics of recombinant and synthetic allergy vaccines that have reached clinical evaluation and discuss how molecular vaccine approaches can make AIT more safe and effective and thus more convenient. Furthermore, we discuss how new technologies can facilitate the reproducible manufacturing of vaccines of pharmaceutical grade for inhalant, food, and venom allergens. Allergy vaccines in clinical trials based on recombinant allergens, recombinant allergen derivatives, and synthetic peptides allow us to target selectively different immune mechanisms, and certain of those show features that might make them applicable not only for therapeutic but also for prophylactic vaccination.
Background Grass pollen is one of the most important sources of respiratory allergies worldwide. Objective This study describes the development of a grass pollen allergy vaccine based on recombinant ...hypoallergenic derivatives of the major timothy grass pollen allergens Phl p 1, Phl p 2, Phl p 5, and Phl p 6 by using a peptide-carrier approach. Methods Fusion proteins consisting of nonallergenic peptides from the 4 major timothy grass pollen allergens and the PreS protein from hepatitis B virus as a carrier were expressed in Escherichia coli and purified by means of chromatography. Recombinant PreS fusion proteins were tested for allergenic activity and T-cell activation by means of IgE serology, basophil activation testing, T-cell proliferation assays, and xMAP Luminex technology in patients with grass pollen allergy. Rabbits were immunized with PreS fusion proteins to characterize their immunogenicity. Results Ten hypoallergenic PreS fusion proteins were constructed, expressed, and purified. According to immunogenicity and induction of allergen-specific blocking IgG antibodies, 4 hypoallergenic fusion proteins (BM321, BM322, BM325, and BM326) representing Phl p 1, Phl p 2, Phl p 5, and Phl p 6 were included as components in the vaccine termed BM32. BM321, BM322, BM325, and BM326 showed almost completely abolished allergenic activity and induced significantly reduced T-cell proliferation and release of proinflammatory cytokines in patients' PBMCs compared with grass pollen allergens. On immunization, they induced allergen-specific IgG antibodies, which inhibited patients' IgE binding to all 4 major allergens of grass pollen, as well as allergen-induced basophil activation. Conclusion A recombinant hypoallergenic grass pollen allergy vaccine (BM32) consisting of 4 recombinant PreS-fused grass pollen allergen peptides was developed for safe immunotherapy of grass pollen allergy.
Recombinant allergens for immunotherapy Valenta, Rudolf, MD; Niederberger, Verena, MD
Journal of allergy and clinical immunology,
04/2007, Letnik:
119, Številka:
4
Journal Article
Recenzirano
Recombinant allergens can be produced as defined molecules in consistent quality and unlimited amounts according to the corresponding DNA template. Furthermore, they can be modified to reduce their ...allergenic activity and to foster certain advantageous immunologic properties. Recombinant allergens equaling the natural allergens are available for diagnostic and therapeutic purposes, and modified versions have been developed with the aim to to reduce IgE-mediated side effects during immunotherapy. First injection immunotherapy trials conducted with recombinant vaccines for birch pollen and grass pollen allergy show that recombinant allergen–based immunotherapy has vaccination characteristics and is clinically effective. The obtained results hold promise that recombinant allergen–based immunotherapy will improve current immunotherapy practice and may open possibilities for new treatment strategies and possibly even for prophylactic vaccination.
Background
Cigarette smoking is a major risk factor for head and neck squamous cell carcinoma. Still, the effect of cigarette smoke on the molecular level is unclear. The aim of the present study was ...to investigate the early effects of cigarette smoke on carcinogenesis of head and neck squamous cell carcinoma.
Methods
Human oral keratinocytes were exposed for 1 week to standardized cigarette smoke extract, and subsequently RT‐quantitative PCR array was performed. Protein expression of dysregulated genes was determined by immunohistochemistry in tissue samples of oral squamous cell carcinoma, oral leukoplakia, and tonsil mucosa.
Results
RT‐PCR revealed upregulation of ITGA‐2 and MMP‐1, whereas TEK receptor tyrosine kinase was downregulated in human oral keratinocytes. ITGA‐2 and MMP‐1 were significantly overexpressed in tissue samples of oral squamous cell carcinoma in comparison to normal mucosa (P <.01 in all experiments).
Conclusion
Upregulation of ITGA‐2 and MMP‐1 induced by cigarette smoke contributes significantly to oral carcinogenesis.
From allergen genes to allergy vaccines Valenta, Rudolf; Ferreira, Fatima; Focke-Tejkl, Margarete ...
Annual review of immunology,
01/2010, Letnik:
28
Journal Article
Recenzirano
IgE-mediated allergy is a hypersensitivity disease affecting more than 25% of the population. The structures of the most common allergens have been revealed through molecular cloning technology in ...the past two decades. On the basis of this knowledge of the sequences and three-dimensional structures of culprit allergens, investigators can now analyze the immune recognition of allergens and the mechanisms of allergic inflammation in allergic patients. Allergy vaccines have been constructed that are able to selectively target the aberrant immune responses in allergic patients via different pathways of the immune system. Here we review various types of allergy vaccines that have been developed based on allergen structures, results from their clinical application in allergic patients, and future strategies for allergen-specific immunotherapy and allergy prophylaxis.
Background Increasing evidence suggests that the low-affinity receptor for IgE, CD23, plays an important role in controlling the activity of allergen-specific T cells through IgE-facilitated allergen ...presentation. Objective We sought to determine the number of CD23 molecules on immune cells in allergic patients and to investigate whether the number of CD23 molecules on antigen-presenting cells is associated with IgE levels and influences allergen uptake and allergen-specific T-cell activation. Methods Numbers of CD23 molecules on immune cells of allergic patients were quantified by using flow cytometry with QuantiBRITE beads and compared with total and allergen-specific IgE levels, as well as with allergen-induced immediate skin reactivity. Allergen uptake and allergen-specific T-cell activation in relation to CD23 surface density were determined by using flow cytometry in combination with confocal microscopy and T cells transfected with the T-cell receptor specific for the birch pollen allergen Bet v 1, respectively. Defined IgE-allergen immune complexes were formed with human monoclonal allergen-specific IgE and Bet v 1. Results In allergic patients the vast majority of CD23 molecules were expressed on naive IgD+ B cells. The density of CD23 molecules on B cells but not the number of CD23+ cells correlated with total IgE levels ( R S = 0.53, P = .03) and allergen-induced skin reactions ( R S = 0.63, P = .008). Uptake of allergen-IgE complexes into B cells and activation of allergen-specific T cells depended on IgE binding to CD23 and were associated with CD23 surface density. Addition of monoclonal IgE to cultured PBMCs significantly ( P = .04) increased CD23 expression on B cells. Conclusion CD23 surface density on B cells of allergic patients is correlated with allergen-specific IgE levels and determines allergen uptake and subsequent activation of T cells.
...it is known that SIT also induces a rise in allergen-specific IgE.9 No relevant alterations in Bet v 1-specific IgG antibodies were observed for placebo-treated patients (Fig 1, C and D).
Background The low-affinity receptor for IgE, FcεRII (CD23), contributes to allergic inflammation through allergen presentation to T cells, regulation of IgE responses, and enhancement of ...transepithelial allergen migration. Objective We sought to investigate the interaction between CD23, chimeric monoclonal human IgE, and the corresponding birch pollen allergen Bet v 1 at a molecular level. Methods We expressed 4 CD23 variants. One variant comprised the full extracellular portion of CD23, including the stalk and head domain; 1 variant was identical with the first, except for an amino acid exchange in the stalk region abolishing the N-linked glycosylation site; and 2 variants represented the head domain, 1 complete and 1 truncated. The 4 CD23 variants were purified as monomeric and structurally folded proteins, as demonstrated by gel filtration and circular dichroism. By using a human IgE mAb, the corresponding allergen Bet v 1, and a panel of antibodies specific for peptides spanning the CD23 surface, both binding and inhibition assays and negative stain electron microscopy were performed. Results A hitherto unknown IgE-binding site was mapped on the stalk region of CD23, and the non–N-glycosylated monomeric version of CD23 was superior in IgE binding compared with glycosylated CD23. Furthermore, we demonstrated that a therapeutic anti-IgE antibody, omalizumab, which inhibits IgE binding to FcεRI, also inhibited IgE binding to CD23. Conclusion Our results provide a new model for the CD23-IgE interaction. We show that the stalk region of CD23 is crucially involved in IgE binding and that the interaction can be blocked by the therapeutic anti-IgE antibody omalizumab.
To address the question of whether and how frequently adult allergic patients and nonallergic subjects have IgE sensitizations to new allergen molecules, we performed a retrospective analysis of ...serum samples using an allergen microarray that contained 85 different purified allergen molecules (ISAC; Phadia, Uppsala, Sweden).2 The 85 allergens on the chip represented 50 allergen families with experimentally confirmed cross-reactivity (see Fig E1 in this article's Online Repository at www.jacionline.org).
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