Identification of Barramundi (Lates calcarifer) DC-SCRIPT, a Specific Molecular Marker for Dendritic Cells in Fish

摘要: Antigen presentation is a critical step bridging innate immune recognition and specific memory. In mammals, the process orchestrated by dendritic cells (DCs) in lymphatic system, which initiate clonal proliferation of antigen-specific lymphocytes. However, fish lack classical system there are currently no cellular markers for DCs fish, thus antigen-presentation poorly understood. Recently, antigen-presenting similar structure function to mammalian were identified various including rainbow trout (Oncorhynchus mykiss) zebrafish (Danio rerio). The present study aimed identify potential molecular marker therefore targeted DC-SCRIPT, well-conserved zinc finger protein that preferentially expressed all sub-types human DCs. Putative obtained culture maturation spleen pronephros-derived monocytes. DC-SCRIPT was barramundi homology using RACE PCR genome walking. Specific expression detected Stellaris mRNA FISH, combination with MHCII when exposed bacterial derived peptidoglycan, suggesting presence L. calcarifer. Moreover, morphological identification achieved light microscopy cytospins prepared from these cultures. cultured morphologically Migration assays determined have ability move towards pathogens pathogen associated patterns, preference peptidoglycans over lipopolysaccharides. also strongly phagocytic, engulfing bacteria rapidly breaking them down. Barramundi induced significant responder populations T-lymphocytes, supporting their role as antigen presenting cells. head kidney higher 6 24 h following intraperitoneal challenge peptidoglycan lipopolysaccharide declined after 3 days relative PBS-injected controls. Relative lower at post but increased again 7 days. As constitutively nuclear receptor, independent activation, this may indicate initial migration immature injection site, followed return presentation. be valuable tool investigation facilitate optimisation vaccines adjuvants aquaculture.