Sialylated Fetuin-A as a candidate predictive biomarker for successful grass pollen allergen immunotherapy.

Background: Eligibility to immunotherapy is based on the determination of IgE reactivity to a specific allergen by means of skin prick or in vitro testing. Biomarkers predicting the likelihood of clinical improvement during immunotherapy would significantly improve patient selection.

Methods: Proteins were differentially assessed by using 2-dimensional differential gel electrophoresis and label-free mass spectrometry in pretreatment sera obtained from clinical responders and nonresponders within a cohort of 82 patients with grass pollen allergy receiving sublingual immunotherapy or placebo.

New insights into ragweed pollen allergens.

Pollen allergens from short ragweed (Ambrosia artemisiifolia) cause severe respiratory allergies in North America and Europe. To date, ten short ragweed pollen allergens belonging to eight protein families, including the recently discovered novel major allergen Amb a 11, have been recorded in the International Union of Immunological Societies (IUIS) allergen database. With evidence that other components may further contribute to short ragweed pollen allergenicity, a better understanding of the allergen repertoire is a requisite for the design of proper diagnostic tools and efficient immunotherapies.

Identification of the cysteine protease Amb a 11 as a novel major allergen from short ragweed.

Background: Allergy to pollen from short ragweed (Ambrosia artemisiifolia) is a serious and expanding health problem in the United States and in Europe.

Objective: We sought to investigate the presence of undescribed allergens in ragweed pollen.

Methods: Ragweed pollen proteins were submitted to high-resolution gel electrophoresis and tested for IgE reactivity by using sera from 92 American or European donors with ragweed allergy.

Glycoproteins are species-specific markers and major IgE reactants in grass pollens.

Grass pollen allergic patients are concomitantly exposed and sensitized to pollens from multiple Pooideae (i.e. common grass) species.

Recombinant fusion proteins assembling Der p 1 and Der p 2 allergens from Dermatophagoides pteronyssinus.

Background: Fusion proteins assembling multiple allergens can be engineered by recombinant DNA technologies in order to produce tools for diagnostic and immunotherapeutic purposes. Herein, we developed and characterized chimeras assembling Der p 1 and Der p 2 allergens as potential candidate vaccines against house dust mite allergy.

Methods: Fusion proteins encompassing Der p 2 with either mature or proDer p 1 were expressed in Escherichia coli or Pichia pastoris.

Mass spectrometric investigation of molecular variability of grass pollen group 1 allergens.

Natural grass pollen allergens exhibit a wide variety of isoforms. Precise characterization of such microheterogeneity is essential to improve diagnosis and design appropriate immunotherapies. Moreover, standardization of allergen vaccine production is a prerequisite for product safety and efficiency.

High throughput screening of mixed-mode sorbents and optimisation using pre-packed lab-scale columns for the purification of the recombinant allergen rBet v 1a.

Mixed-mode chromatography was investigated for the purification of the recombinant allergen rBet v 1a expressed in Escherichia coli (E. coli) and used as an active principle for specific immunotherapy (SIT) treatment against birch pollen allergy. The screening of micro-volumes of three mixed-mode sorbents established that rBet v 1a could be captured without any pre-treatment of the crude feedstock on HEA or PPA HyperCel sorbents equilibrated in "physiological-like" conditions.

Oral dendritic cells mediate antigen-specific tolerance by stimulating TH1 and regulatory CD4+ T cells.

Background: A detailed characterization of oral antigen-presenting cells is critical to improve second-generation sublingual allergy vaccines.

Objective: To characterize oral dendritic cells (DCs) within lingual and buccal tissues from BALB/c mice with respect to their surface phenotype, distribution, and capacity to polarize CD4(+) T-cell responses.

Methods: In situ analysis of oral DCs was performed by immunohistology.

A synthetic triacylated pseudo-dipeptide molecule promotes Th1/TReg immune responses and enhances tolerance induction via the sublingual route.

In this study, we tested two triacylated pseudo-dipeptidic molecules, OM-197-MP-AC and OM-294-BA-MP as candidate adjuvants for allergy vaccines. Both molecules induce human dendritic cell (h-DC) maturation and polarize naïve T cells toward the Th1 type with IFNgamma production. Only OM-294-BA-MP induces IL10 gene expression both in monocyte-derived DCs and CD4+ naïve T cells.

Production and proteomic characterization of pharmaceutical-grade Dermatophagoides pteronyssinus and Dermatophagoides farinae extracts for allergy vaccines.

Background: House dust mites (HDM) such as Dermatophagoides pteronyssinus and Dermatophagoides farinae represent a major cause of type 1 allergies worldwide. Hence large quantities of well-characterized HDM extracts are needed to prepare pharmaceutical-grade allergy vaccines. To this aim, the present study was undertaken to define optimal conditions for large-scale cultures.

Characterization of wild-type recombinant Bet v 1a as a candidate vaccine against birch pollen allergy.

Background: We describe the production in Escherichia coli as a recombinant protein of clinical grade wild-type Bet v 1a (rBet v 1a), to be used as a candidate vaccine against birch pollen allergy.

Methods: This recombinant protein was purified by hydrophobic interaction and ion exchange chromatography and characterized by SDS-PAGE, immunoprint and circular dichroism in parallel with natural Bet v 1 (nBet v 1) purified from a birch pollen extract. We also compared rBet v 1 and nBet v 1 for their capacity to induce histamine release from basophils and to stimulate T lymphocyte proliferation.