In vivo modulation of Bacillus thuringiensis (commercial form) on Holothuria tubulosa immune defense mechanisms

Abstract

In invertebrates, cellular and humoral components are evolved to maintain their homeostais and integrity. Both these components respond to different non-self such as microorganisms, vertebrate erythrocytes and foreign proteins. The aim of this research was to study the possible modulating effects of Bacillus thuringiensis (Bt) in a commercial and vegetative form on the immune response of the echinoderm, sea cucumber Holothuria tubulosa. Bt is one of the most used biopesticides worldwide, covering the 90% of the organic market. Sicily is a region vocated to biological control and agricultural area are often closed to the coastal area. Investigate the effect of biopesticides on other non target organisms is important in a more exhaustive environmental risk assessment. Moreover correlative studies indicate that the immune surveillance is affected by both Bt forms in vivo challenge. In particularly we have evaluated the phagocitosys vs Saccharomyces cerevisiae, hemagglutination using rabbit erythrocytes and coelomocyte cytotoxic activity against rabbit erythrocytes and K562 tumor target cells. These results can contribute to improve the knowledge about the use of Bt like biological insecticidal on non target organisms.