Characterization of the chicken orthologues of mammalian CD154 and CD40

In mammals CD 154 (CD40 ligand, TNFSF5) and its cognate receptor CD40 (TNFRSF5) are essential for the generation of an adaptive immune response. To date very few members of either the TNF or TNF receptor superfamily have been identified in the chicken, and none of those that have share a high degree of homology with CD40 or CD 154. An EST derived from an activated chicken spleen cDNA library was identified as having a high homology to mammalian CD 154 sequences. A full-length cDNA containing this EST sequence was cloned, and used to generate a soluble form of the encoded protein. This soluble protein was to identify cells that expressed the receptor for this protein, and to clone a cDNA encoding this receptor. The protein was demonstrated to bind to chicken B cells and macrophages. The receptor to this putative chicken CD 154 protein shared a high degree of sequence homology to mammalian CD40 sequences. The sequence data alone was insufficient to identify these two proteins as orthologues of mammahan CD 154 and CCD40. The fusion protein was shown to have biological activity similar to its mammalian counterpart in three different bioassays, suggesting that these two proteins are functional and structural homologues of mammalian CD 154 and CD40.EThOS - Electronic Theses Online ServiceGBUnited Kingdo