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According to the data obtained from in vivo and in vitro testing in Serbia, a significant number of patients have allergic symptoms caused by grass pollen. We examined the protein composition of grass pollens (Dactylis glomerata, Lolium perenne and Phleum pratense) and cross-reactivity in patients allergic to grass pollen from our region. The grass pollen allergen extract was characterized by SDS-PAGE, while cross-reactivity of single grass pollens was revealed by immunoblot analysis. A high degree of cross-reactivity was demonstrated for all three single pollens in the sera of allergic patients compared to the grass pollen extract mixture. Confirmation of the existence of cross-reactivity between different antigenic sources facilitates the use of monovalent vaccines, which are easier to standardize and at the same time prevent further sensitization of patients and reduces adverse reactions. [Projekat Ministarstva nauke Republike Srbije, br. 172049 i br. 172024]

Convenient source of lipases for science and industry is yeast Candida rugosa. Crude preparation of Candida rugosa lipase (CRL) consists of several extracellular lipases. Isoenzyme profile depends on the culture or fermentation conditions. All isoforms are coded by lip pseudogene family; they are monomers of 534 amino acids and molecular weight of about 60 kDa. They share the same catalytic mechanism and interfacial mode of activation. Isoenzymes differ in isoelectric points, post-translational modifications, substrate specificity and hydrophobicity. The presence of different lipase isoforms and other substances (i. e. inhibitors) in crude preparation leads to lack of their productivity in biocatalytic reactions. Purification of specific isoform improves its overall performance and stability. This paper provides an overview of different methods for purification of CRL isoenzymes up to date, their advantages and disadvantages. [Projekat Ministarstva nauke Republike Srbije, br. 172049, br. 046010, br. 451-03-00605/2012-16/51 and FP7 Reg Pot FCUB ERA, GA No 256716.]

Since its first appearance on the market kiwifruit has become very popular in the human diet due to its pleasant taste, low caloric value and high content of vitamin C. However, kiwifruit allergy has become a frequent cause of type I hypersensitivity in the western society. Molecular basis for kiwifruit allergy has been ascribed to up-to-now 11 identified IgE reactive molecules. They are proteins and glycoproteins with a molecular mass between 50 and 10 kDa. The major kiwifruit allergen is a cysteine protease denoted as Act d 1, which represents 50% of the soluble protein extract. Due to a difference in the abundance of protein components and biological activity, the quality of kiwifruit extracts intended for allergy diagnosis can vary in content and amount of IgE reactive molecules. In addition, the quality of allergen extracts for allergy diagnosis depends on the fruit ripening stage and storage conditions. In terms of clinical reactivity it has become evident that kiwifruit allergy is not a homogeneous disorder. Different patterns of IgE reactivity accompany several clinical subgroups that have been identified in different geographical regions. In the last decade an enormous progress has been made in isolation and characterization of kiwifruit allergens. This paper will give an overview of the structural features of kiwifruit allergens. [Projekat Ministarstva nauke Republike Srbije, br. 172049]

For the heterologous production of a banana glucanase in Escherichia coli, its gene (GenBank GQ268963) was cloned into a pGEX-4T expression vector as a fusion protein with glutathione-S-transferase (GST). BL21 cells transformed with the GST-Mus a 5 construct were employed for the protein production induced by 1 mM of isopropyl-â-D-tiogalactopyranoside (IPTG). Conditions for the protein expression were optimized by varying the temperature (25°C, 30°C, and 37°C) and duration of protein expression (3h, 6h and 12h). The level of protein production was analyzed by densitometry of sodium dodecyl sulfate - polyacrylamide gel (SDS-PAG) after electrophoretic resolution of respective cell lysates. The optimal protein expression for downstream processing was obtained after 12h of cell growth under 25°C upon addition of IPTG. Recombinant GST-Mus a 5 purified by glutathione affinity chromatography revealed a molecular mass of about 60 kDa. The IgE and IgG reactivity of rGST-Mus a 5 was confirmed by dot blot analysis with individual patient’s sera from subjects with banana allergy and polyclonal rabbit antibodies against banana extract, respectively. Purified recombinant glucanase is a potential candidate for banana allergy diagnosis.

Introduction. Ingestion is the principal route for food allergens to trigger allergic reaction in atopic persons. However, in some highly sensitive patients severe symptoms may develop upon skin contact and by inhalation. The clinical spectrum ranges from mild facial urticaria and angioedema to life-threatening anaphylactic reactions. Outline of Cases. We describe cases of severe anaphylactic reactions by skin contact, induced by kissing in five children with prior history of severe anaphylaxis caused by food ingestion. These cases were found to have the medical history of IgE mediated food allergy, a very high total and specific serum IgE level and very strong family history of allergy. Conclusion. The presence of tiny particles of food on the kisser's lips was sufficient to trigger an anaphylactic reaction in sensitized children with prior history of severe allergic reaction caused by ingestion of food. Allergic reaction provoked with food allergens by skin contact can be a risk factor for generalized reactions. Therefore, extreme care has to be taken in avoiding kissing allergic children after eating foods to which they are highly allergic. Considering that kissing can be a cause of severe danger for the food allergic patient, such persons should inform their partners about the risk factor for causing their food hypersensitivity.

Art v 1 is the major allergen of mugwort (Artemisia vulgaris) pollen, a significant cause of hay fever all over Europe. Specific immunotherapy is the only treatment modality for allergic disease. Application of modified allergens makes the treatment safer and more efficient. In this work, two out of three (citraconic anhydride, cis-aconitic anhydride, 2,3-dimethylmaleic anhydride) tested anhydrides were proven to be suitable for chemical modifications of allergens. Art v 1 was modified by cis-aconitylation and citraconylation in order to obtain derivatives of Art v 1 that may be suitable for further immunological testing. Acylation of Art v 1 gave derivatives (caaArt v 1 and citArt v 1) with about 80 % modified amino groups. The derivatives were in the monomeric form and had dramatically reduced pI values. Both derivatives were relatively stable at neutral pH values, while the acyl groups undergo hydrolysis under acidic conditions. Modification of allergens by cis-aconitylation and citraconylation could be a new tool for obtaining allergoids.

House dust mites (HDM) represent a major source of allergens, contributing to the increasing incidence of type I hypersensitivity disease worldwide. Over 30 different IgE-binding proteins from the HDM extract were detected. Although group 1 and 2 have been identified as major allergens, due to the safety and efficacy of allergy diagnosis and immunotherapy, there is a need to carefully evaluate the clinical relevance of other allergens present in the HDM extract. In regard to this, a high molecular mass allergen of about 68 kD was purified from the HDM extract using a combination of gel permeation chromatography and reversed-phase chromatography. The IgG and IgE reactivity of the purified protein were preserved during the purification process, as confirmed by Western blot analysis with polyclonal rabbit antibodies and dot blot analysis with a pool of sera from subjects with house dust mite allergy, respectively. In addition, the IgE reactivity was confirmed using ELISA testing with nine patient sera. The biological potency of the 68 kD allergen was confirmed by skin prick testing in five allergic subjects, suggesting that the high molecular mass allergen is a good candidate for component-resolved diagnosis of house dust mite allergy and eventual therapeutic treatment.

This paper aims to develop an amperometric, non-enzymatic sensor for detecting and quantifying UA as an alert signal induced by allergens with protease activity in human cell lines (HEK293 and HeLa). Uric acid (UA) has been classified as a damage-associated molecular pattern (DAMP) molecule that serves a physiological purpose inside the cell, while outside the cell it can be an indicator of cell damage. Cell damage or stress can be caused by different health problems or by environmental irritants, such as allergens. We can act and prevent the events that generate stress by determining the extent to which cells are under stress. Amperometric calibration measurements were performed with a carbon paste electrode modified with La(OH)3@MWCNT, at the potential of 0.3 V. The calibration curve was constructed in a linear operating range from 0.67 μM to 121 μM UA. The proposed sensor displayed good reproducibility with an RSD of 3.65% calculated for five subsequent measurements, and a low detection limit of 64.28 nM, determined using the 3 S/m method. Interference studies and the real sample analysis of allergen-treated cell lines proved that the proposed sensing platform possesses excellent sensitivity, reproducibility, and stability. Therefore, it can potentially be used to evaluate stress factors in medical research and clinical practice. [ABSTRACT FROM AUTHOR]