STUDY OF MACROPHAGES FROM SPLEEN OF TILAPIA (Oreochromis sp.) TO EVALUATE IMMUNE MECHANISMS IN FISH

Increased understanding of fish antimicrobial host defences is an important step in aquaculture setting.Much of the information of macrophage biology comes from research in mammalian models, where distinct macrophage subsets have been noticed, including classically activated cells (M1) and alternatively activated cells (M2) which are associated with "kill" or "heal" response.In teleosts, the best characterized macrophage phenotype is that comparable to the M1 activation state, which act to induce inflammatory responses.Recent fish immunology research has focused on fish macrophage biology.In present research, the understanding of teleost macrophage morphology, study of phagocytosis, cell aggregation and functional heterogeneity has been addressed.Analysis from tilapia (Oreochromis sp.) splenic macrophages showed numerous macrophages as free or in aggregates (MAs).Formation of filopodia like extension, attachment of charcoal particles on cell surface, cell fusion, poorly organized cell aggregation was noticed.Numerous studies have shown an increase in number and size of macrophage aggregates (MAs), Melano-Macrophage Centres (MMCs) in fish collected at contaminated sites.These results can be used to study the role of macrophages against various immunomodulators.