Database of 2329 Experimentally Validated Allergens

About AllerBase

AllerBase is a comprehensive knowledgebase of allergens and allergen related features. It comprises of vast collection of experimentally validated allergens from various sources like plants, animals, fungi etc. These include WHO/IUIS Allergen Nomenclature Sub-committee recognized allergens as well as other proteins reported as allergens in published literature. The allergen data archived in AllerBase has been compiled and curated by integration from existing bioinformatics and immunological resources as well as by extensive search and curation from the published literature.

One of the important features of AllerBase is a unique representation of each allergen, in which data for nine informative allergen attributes is provided. These attributes are core data on allergens/allergenicity, experimental validation reporting assays/methods employed for allergenicity characterization, IgE epitope, IgE cross-reactivity, IgE antibody as well as sequence and structure cross-references.

Core Allergen Data:

The criterion for inclusion of an allergen in AllerBase is availability of experimental validation of its allergenic activity. Each allergen is provided with basic information such as AllerBase Id, Allergen name, Source organism, Taxonomic level, Biological role/function and Mode of exposure. The data on isoallergens/variants of allergens, if present, is represented appropriately in the database. Each allergen is also provided with cross-references to primary sequence and structure databases like GenBank, GenPept, UniProtKB and PDB (Protein Data Bank) along with allergen databases such as IUIS-Allergen, Allergome and AllFam.

Experimental Validation of Allergenicity:

Each allergen archived in AllerBase has been provided with the experimental evidence of its allergenic activity. AllerBase documents the experimental validation data by enlisting the assays/tests employed for immunological characterization of each allergen. These assays/tests are grouped into four categories, the details of which are given on here.

IgE-binding Epitope:

An IgE-binding epitope of an allergen is responsible for recognition of allergen by IgE antibodies. AllerBase archives comprehensive data on experimentally validated non-overlapping IgE-binding epitopes from allergens. Each epitope is provided with detailed annotation that includes epitope sequence, sequence position, epitope type (Sequential/Linear or Discontinuous/Conformational), antibody/sera used in the study, assay used to characterize the epitope. Additional information that represents epitope nature (Major/Minor/Immunodominant) or antibody affinity (Strong/Moderate/Weakly binding) is also provided where available. This information is curated from the relevant references and it is retained as provided by the authors in respective publications.. Cross-references to important immunological databases like Immune Epitope Database (IEDB), International ImMunoGeneTics (IMGT) database and Antigen-Antibody Interactions Database (AgAbDb) are also provided, where applicable.

IgE Antibody:

IgE antibodies are the special class of antibodies that are responsible for development of an allergic reaction. The IgE antibody data archived in AllerBase comprise of nucleotide and protein sequences of different regions of immunoglobulin E (IgE) including light and heavy chains as well as single chain antibody fragments. These antibodies are generated in response to allergic sensitization or allergic disease like atopic dermatitis. Number of these antibodies are specific for an individual allergen while others are produced in response to a broad category of allergen/s such as Food allergens. Each antibody is provided with basic description which includes antibody/chain, source, clone/isolate along with cross-links to IMGT/LIGM-DB and GenPept databases. The allergen associated information like the broad allergen category, specific allergen name, materials used for sensitization, allergic disease and patient/population in which the antibody has been raised and studied is also documented.

IgE Cross-reactivity:

Cross-reactivity is a phenomenon in which an antibody is capable of reacting with two or more antigens. Cross-reactivity among allergens is specifically mediated by high affinity IgE antibodies. AllerBase enlists experimentally verified IgE-mediated cross-reactivity for each allergen. Each IgE cross-reactivity relation among allergens is provided with a reference to the respective experimental study. Representation of cross-reactive allergens is characterized by bidirectional search utility in which cross-reactivity relations among allergens can be easily visualized.

Completeness Index is a novel and informative feature of AllerBase in which each allergen is represented by using a Binary Notation that summarizes the available data for the particular allergen.
AllerBase is also equipped with utilities for visualization of allergen 3D structures and IgE epitopes as well as for sequence analysis of allergens.