THE HUMORAL AND CELLULAR IMMUNE-RESPONSE TO A LIPID ATTENUATED PORE-FORMING TOXIN FROM THE SEA-ANEMONE ACTINIA-EQUINA L

The immunogenicity of a pore-forming polypeptide, equinatoxin II, from the sea anemone Actinia equina was studied after attenuation of the t oxin's lethal and cytolytic activity by autologous polar lipids. In BA LB/c mice, the lipid-inactivated toxin was used to raise specific anti bodies and cellular immunity, resulting in in vivo protection. In vitr o, haemolytic activity could be diminished by both normal and immune s erum, the latter being more efficient. Purified specific IgG(1) and Ig C(2) did not or only poorly neutralized the haemolytic activity, there fore implying the marked role of serum lipoproteins in the toxin atten uation. In response at the cellular level, equinatoxin II activated sp ecific splenocytes. Increased concanavalin A stimulation of specific s plenocytes was observed in the absence of antigen.