Recognition of Non-self in Crustaceans

This paper reviews the current concepts of recognition of non-selfin crustaceans and relates these concepts to recognition inthe invertebrates in general. It focuses primarily on a decapodcrustacean, the blue crab(callinectes sapidus)and on resultsusing this animal as a model to study the clearance of virusesand xenogeneic proteins. Clearance studies indicate that bluecrabs possess a quasi-specific recognition system in the normalor "non-immunized"state. This system is capable of rapidly clearingforeign proteins and certain viruses from the circulation, andresults in concentration of such proteins into the gills andviruses into the hepatopancreas or gills. Although humoral factorswhich bind foreign proteins or neutralize viruses have beenisolated, transfusion exchange experiments involving depletionof circulating cells and/or humoral factors indicate that theblue crab does not require circulating hemocytes or humoralfactors for clearance of foreign proteins. These results suggestthat a population of fixed cells, possibly those in the gills,may be the critical component for recognition of foreign proteinsby normal crabs.