Designing a T-cell epitope-based vaccine using in silico approaches against the Sal k 1 allergen of Salsola kali plant.

Allergens originated from Salsola kali (Russian thistle) pollen grains are one of the most important sources of aeroallergens causing pollinosis in desert and semi-desert regions. T-cell epitope-based vaccines (TEV) are more effective among different therapeutic approaches developed to alleviate allergic diseases. The physicochemical properties, and B as well as T cell epitopes of Sal k 1 (a major allergen of S. kali) were predicted using immunoinformatic tools. A TEV was constructed using the linkers EAAAK, GPGPG and the most suitable CD4+ T cell epitopes. RS04 adjuvant was added as a TLR4 agonist to the amino (N) and carboxyl (C) terminus of the TEV protein. The secondary and tertiary structures, solubility, allergenicity, toxicity, stability, physicochemical properties, docking with immune receptors, BLASTp against the human and microbiota proteomes, and in silico cloning of the designed TEV were assessed using immunoinformatic analyses. Two CD4+ T cell epitopes of Sal k1 that had high affinity with different alleles of MHC-II were selected and used in the TEV. The molecular docking of the TEV with HLADRB1, and TLR4 showed TEV strong interactions and stable binding pose to these receptors. Moreover, the codon optimized TEV sequence was cloned between NcoI and XhoI restriction sites of pET-28a(+) expression plasmid. The designed TEV can be used as a promising candidate in allergen-specific immunotherapy against S. kali. Nonetheless, effectiveness of this vaccine should be validated through immunological bioassays.

Immunochemical Characterization of Salix alba (S. alba) Pollen Allergens and Evaluation of the Cross-Reactivity Pattern with Common Allergenic Pollen Grains.

BACKGROUND: Pollens, particularly tree and plant pollens, are one of the major causes of allergic respiratory diseases worldwide. Allergy to pollens of different species of Salix trees has been reported in various regions of the world. The most common type of Salix tree in Iran is white willow (Salix alba). OBJECTIVES: This study aimed to identify and determine the immunochemical characteristics of allergenic proteins in S. alba tree pollen extract using SDS-PAGE and IgE- immunoblotting methods. Moreover, the cross-reaction pattern of the specific IgE antibody of S. alba tree pollen proteins with pollen allergens of common allergenic trees, i.e., Populus nigra (P. nigra), Cupressus sempervirens (C. sempervirens), Pinus brutia (P. brutia) and Platanus orientalis (P. orientalis) in the region was investigated. METHODS: The reaction of allergenic proteins in S. alba pollen extract with specific IgE antibodies in patients' sera was investigated using SDS-PAGE and IgE-immunoblotting methods. The cross-reaction of specific IgE antibodies of the proteins present in S. alba pollen extract with pollen allergens of common allergenic trees in the region was investigated using ELISA and immunoblotting inhibition methods. In silico methods such as phylogenetic tree drawing and alignment of amino acid sequences were used to examine the evolutionary relationship and homology structure of common allergenic proteins (Panallergens) responsible for cross reactions. RESULTS: More than 11 protein bands binding to specific IgE antibodies in patients' sera with a molecular weight between 13 and 95 kDa were identified in the S. alba tree pollen extract. ELISA and immunoblotting inhibition results showed that P. nigra extract could inhibit the binding of IgE antibodies to S. alba pollen extract proteins to a greater extent than C. sempervirens, P. brutia, and P. orientalis tree extracts. In silico methods investigated the results of ELISA and immunoblotting inhibition methods. Moreover, a high structural homology and evolutionary relationship were observed between S. alba and P. nigra tree pollen panallergens. CONCLUSION: In this study, it was found that more than 80 % of the sensitive patients who were examined had specific IgE antibodies reacting with the approximately a 15 kDa-protein present in the S. alba pollen extract. Furthermore, the specific IgE-binding proteins found in the pollens of S. alba and P. nigra trees had relative structural homology, and it is likely that if recombinant forms are produced, they can be used for diagnostic and therapeutic purposes for both of the trees.

Anti-allergic effects of vitamin E in allergic diseases: An updated review.

Allergic diseases are caused by the immune system's response to innocent antigens called allergens. Recent decades have seen a significant increase in the prevalence of allergic diseases worldwide, which has imposed various socio-economic effects in different countries. Various factors, including genetic factors, industrialization, improved hygiene, and climate change contribute to the development of allergic diseases in many parts of the world. Moreover, changes in lifestyle and diet habits play pivotal roles in the prevalence of allergic diseases. Dietary changes caused by decreased intake of antioxidants such as vitamin E lead to the generation of oxidative stress, which is central to the development of allergic diseases. It has been reported in many articles that oxidative stress diverts immune responses to the cells associated with the pathogenesis of allergic diseases. The aim of this short review was to summarize current knowledge about the anti-allergic properties of vitamin E.