Use this URL to cite or link to this record in EThOS: http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.594255
Title: Variable region-containing chitin binding proteins (VCBPs)in Ciona intestinalis
Author: Natale , Lenina
Awarding Body: Open University
Current Institution: Open University
Date of Award: 2012
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Abstract:
Variable region-containing chitin-binding proteins (VCBPs) were originally found and partially characterised in the cephalochordate Branchiostoma floridae. VCBPs consist of two immunoglobulin (IgV) domains and a chitin-binding domain; they exhibit a particularly high level of polymorphism, and are localized to the gut. These features suggested an immunological role for vesp molecules, which, because of the domain structure, have been assigned to the large variety of IgV domain containing innate immune-type receptors found in species that represent various metazoan phyla. Four VeBP genes, VeBP-A, -8, -C and -0, which did not exhibit hyperpolymorphism, were identified in the genome of the urochordate Ciona intestinalis. In situ hybridization (ISH) experiments localised VeBP expression in the stomach, intestine and granular amoebocytes of Ciona. Taking into account these results, my research project investigated if Ciona VCBPs are indeed immune-competent molecules. To address this issue, I performed immunohistochemical experiments with an anti-VCBP-C antibody, which confinned the expression pattern previously obtained by ISH. The same antibody, used in immunogold analysis of stomach sections of bacteria-fed animals, indicated that VCBP-C is secreted into the stomach lumen where it binds both Gram-positive and - negative bacteria. VCBP-C was then purified from stomach by affinity ,chromatography, and tested in in vitro functional assays. Chemotaxis and phagocytosis assays indicated that VCBP-C acts as a bacteria chemoattractant, and enhances bacteria phagocytosis by granular amoebocytes. The finding that an IgV-containing recombinant fragment of VCBP-C retained both functional activities of the native protein, pointed to the IgV domains as the main effectors of the immune-recognising activity of VCBP-C. Collectively, these data provide the first evidence that VCBPs act as secreted immune-type molecules and offer additional insight into the role of the IgV-containing innate immune-type receptors as an evolutionary link between conventional innate and adaptive immunity.
Supervisor: Not available Sponsor: Not available
Qualification Name: Thesis (Ph.D.) Qualification Level: Doctoral
EThOS ID: uk.bl.ethos.594255  DOI: Not available
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