Plant derived toxins (ricin, abrin)

Ricin and abrin are potent plant-derived lethal toxins that halt protein synthesis in cells. Pulmonary or systemic exposure to these toxins induces ARDS (acute respiratory stress syndrome) and multi-organ failure, respectively, leading inevitably to death. To date, there is no approved medical countermeasure for post-exposure therapy. 

Wide-range studies demonstrate that highly-efficient protection levels may be reached by post-exposure administration of potent anti-toxin antibody preparations together with selected drugs to ricin- and abrin- intoxicated animals.

Profiling of toxin-cell interactions in diverse tissues, measurement of alterations over time in cell populations following intoxication and in-depth analyses of pathological markers, enabled scientists at the IIBR to identify specific immunomodulatory compounds for treatment. When these judiciously chosen drugs were incorporated in treatment regimes in conjunction with anti-toxin neutralizing antibody administration, unprecedented high protection rates were achieved at clinically-relevant time-points in selected ricin-intoxicated animal models.

​Figure 1: Scientists at the IIBR developed a wide-range series of methodologies to decipher toxin-induced cellular and molecular pathogenic pathways. Confocal microscopy immunohistochemical analyses demonstrates the elimination of specific lung cell populations following pulmonary exposure of mice to ricin. 
Figure 2: Kaplan-Meier survival curves of mice that were intranasally exposed to a lethal dose of ricin. Intoxicated mice were either not treated or treated 24 hours post-exposure with anti-ricin antibodies or with antibodies and drugs, as indicated.​