Broad antiviral activity in tissues of crustaceans

Innate antiviral substances occur in vertebrates and may function as host d efenses. Virus infections are common among invertebrates, but little is kno wn about the ability of invertebrates to control viral infections. Pre-exis ting antiviral substances may be particularly important. since invertebrate s lack the antiviral defense conferred by specific immunity. Tn our study, we found that tissue extracts of blue crab (Callinectes sapidus), shrimp (P enaeus setiferus), and crayfish (Procambarus clarkii) contained antiviral a ctivities that inhibit a variety of DNA and RNA viruses, i.e. Sindbis virus (SB), vaccinia virus (VAC), vesicular stomatitis virus (VS), mengo virus ( MENGO), banzi virus (BANZI) and poliomyelitis (POLIO). The concentration of inhibitory activity was relatively high, ranging from 102 to 216 U/g tissu e For Sindbis virus, using the various tissue extracts. The other viruses w ere somewhat less sensitive to the inhibitor. The main antiviral activity i n the inhibitor preparation from blue crab resided in an approximately 440 kDa Fraction. It was inactivated significantly by lipid extraction, but not by proteinase K or glycosidases. The antiviral mechanism of the inhibitor from the blue crab was inhibition of virus attachment to eukaryotic cells, as evidenced by inhibitory activity at 4 degreesC. These studies are among the first to show the existence of broadly active antiviral activities in a quatic crustaceans. These antiviral substances may function as innate host defenses in these species that lack specific antibody immunity and, therefo re, merit further study. (C) 2000 Published by Elsevier Science B.V.