A complex family of diversified immunoglobulin domain-containing proteins (DICPs) includes inhibitory and activating forms and likely plays a role in zebrafish innate immunity (170.9)

• Published in: The Journal of immunology (1950) Vol. 186; no. 1_Supplement; pp. 170 - 170.9
• Main Authors: Yoder, Jeffrey, Haire, Robert, Turner, Poem, Mueller, M., O'Driscoll, Marci, Litman, Ronda, Cannon, John, Litman, Gary
• Format: Journal Article
• Language: English
• Published: 01.04.2011
• ISSN: 0022-1767; 1550-6606
• DOI: 10.4049/jimmunol.186.Supp.170.9

Abstract One of the first lines of defense against pathogens and disease is the recognition of foreign or altered antigens by innate immune receptors. A large number of these receptors fall into the large immunoglobulin (Ig) super family of proteins. We have identified a multi-gene family of 29 diversified immunoglobulin domain-containing proteins (DICPs) encoded on zebrafish chromosomes 3, 14 and 16. DICPs typically encode two extracellular Ig domains: an amino terminal variable (V) Ig domain and an additional Ig-like domain. Certain DICPs possess a single Ig domain. DICP variants include membrane bound and secreted forms. Putative inhibitory forms have been identified which possess cytoplasmic immunoreceptor tyrosine-based inhibition motifs (ITIMs). Putative activating forms have been identified which possess a positively charged residue within their transmembrane domain and are predicted to associate with adaptor proteins that possess cytoplasmic activation motifs (e.g. Dap12, Dap10 etc). Database searches reveal that the Ig domains of DICPs are unlike any other Ig domains encoded by the zebrafish genome and are more (albeit very weakly) similar to the V domains of mammalian immunoglobulin genes, than to any other zebrafish or mammalian sequence. DICP annotation, transcript variants, tissue-specific expression and efforts to identify DICP ligands will be discussed.