Generation and use of monoclonal antibodies as leucocyte-markers to study the immune function in teleost fish (B219)

Abstract

Abstract Fish possess the first full immune system in the vertebrate evolution. To date, leucocyte abundance, distribution and function has attempted to elucidate how similar or different are the fish and mammalian immune system. Fish possess lymphocytes, monocyte-macrophages and granulocytes with main differences in the tissue origin, distribution and functioning. Lack of proper molecular markers, such as commercial specific antibodies, for fish leucocytes is still hampering the success in this field. Considering this, we immunized mice with gilthead seabream (Sparus aurata L.) leucocytes and generated monoclonal antibodies following standard protocols. We chose 3 clones (H4, D2 and C1) and characterised their specificity for seabream leucocytes by means of flow cytometry, immunocytochemistry, magnetic-activated cell sorting (MACS) and gene expression by RT-PCR. Functional studies with the isolated leucocyte populations were also conducted to ascertain their implication in phagocytosis, cell-mediated cytotoxicity or oxygen-free radical production. Generation of monoclonal antibodies is a promising field in order to get good markers for further characterisation of the fish immune system. Work partially funded by European (QLK2-CT-2002-00722), national (AGL2005-07454-C02-01) and regional (02958/PI/05) projects.