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Title: Assessment of sequence homology and cross-reactivity

Journal Article · · Toxicology and Applied Pharmacology
 [1]
  1. Department of Immunopathology, Sanquin Research at CLB, Plesmanlaan 125, 1066 CX Amsterdam (Netherlands) and Landsteiner Laboratory, Academic Medical Centre, 1066 CX Amsterdam (Netherlands)

Three aspects of allergenicity assessment and are discussed: IgE immunogenicity, IgE cross-reactivity and T cell cross-reactivity, all with emphasis on in-silico predictability: from amino acid sequence via 3D structure to allergenicity.(1)IgE immunogenicity depends to an overwhelming degree on factors other than the protein itself: the context and history of the protein by the time it reaches the immune system. Without specification of these two factors very few foreign proteins can be claimed to be absolutely non-allergenic. Any antigen may be allergenic, particularly if it avoids activation of TH2-suppressive mechanisms (CD8 cells, TH1 cells, other regulatory T cells and regulatory cytokines). (2)IgE cross-reactivity can be much more reliably assessed by a combination of in-silico homology searches and in vitro IgE antibody assays. The in-silico homology search is unlikely to miss potential cross-reactivity with sequenced allergens. So far, no biologically relevant cross-reactivity at the antibody level has been demonstrated between proteins without easily-demonstrable homology. (3)T cell cross-reactivity is much more difficult to predict compared to B cell cross-reactivity, and its effects are more diverse. Yet, pre-existing cross-reactive T cell activity is likely to influence the outcome not only of the immune response, but also of the effector phase of the allergic reaction.

OSTI ID:
20721902
Journal Information:
Toxicology and Applied Pharmacology, Vol. 207, Issue 2,suppl.1; Conference: ICT X 2004: 10. international congress of toxicology: Living in a safe chemical world, Tampere (Finland), 11-15 Jul 2004; Other Information: DOI: 10.1016/j.taap.2005.01.021; PII: S0041-008X(05)00225-5; Copyright (c) 2005 Elsevier Science B.V., Amsterdam, The Netherlands, All rights reserved; Country of input: International Atomic Energy Agency (IAEA); ISSN 0041-008X
Country of Publication:
United States
Language:
English