Ricin is a member of the ribosome-inactivating protein (RIP) family of plant and bacterial toxins. In this study we used a high-throughput, cell-based assay to screen more than 118,000 compounds from diverse chemical libraries for molecules that reduced ricin-induced cell death. We describe three compounds, PW66, PW69, and PW72 that at micromolar concentrations significantly delayed ricin-induc...

The ribosome-inhibiting toxin ricin binds exposed β1→4 linked galactosyls on multiple glycolipids and glycoproteins on the cell surface of most eukaryotic cells. After endocytosis, internal cell trafficking is promiscuous, with only a small proportion of ricin proceeding down a productive (cytotoxic) trafficking route to the endoplasmic reticulum (ER). Here, the catalytic ricin A chain traverse...

Potent T-cell subset-directed immunotoxins (ITs) were generated by conjugating the anti-CD4 monoclonal antibody (MoAb) G17-2 and the anti-CD8 MoAb G10.1 to the ribosome-inhibitory protein, ricin. The cell-type-specific cytotoxicities of the generated ITs were evaluated at the clonal level using human alloreactive T-cell clones. The kinetics of anti-CD4 ricin-induced inactivation of protein synt...

Background: Jatropha curcas,commonly known as “Saboo Dum,” is the most common plant poisoning in Thailand. Saboo Dum seeds are used as raw material for biodiesel fuel manufacture, especially in Royal Thai Military units. The seed contains a toxin called curcin which can cause hepatotoxicity in humans. Case Presentation: We reported twenty-eight private soldiers who were brought to the emergency...

The battlefield risk from toxic industrial chemicals, materials, or threat agents is aerosol exposure. In most cases, this is not the natural route of exposure, so we must rely on animal models to predict disease course in humans. Deposition patterns for small (1μm) and large (8μm) particles were easily predicted, but effect on disease course for Ricinus communis (ricin) was unknown. Ricin smal...

Autofagi merupakan proses adaptasi yang dilakukan sebagai pertahanan dalam respon seluler, seperti kekurangan nutrisi atau stress metabolik lain. Mekanisme autofagi diregulasi oleh protein dinamakan Autophagy-Related Genes (ATG). juga telah banyak dikaitkan dengan berbagai penyakit pada manusia, misalnya kanker degeneratif lainnya. Ricin toksik berasal dari biji jarak Ricinus communis L. dan di...

PURPOSE Ricin-mAb35 is an immunotoxin targeted against skeletal muscle. Previously, we have shown that injection of ricin-mAb35 into rabbit extraocular muscle results in long-term muscle loss, and we have proposed this as a potential treatment for strabismus. In this study, we assessed the effects of ricin-mAb35 injection on extraocular muscle force generation. METHODS Ricin-mAb35, 0.2 microg...

BACKGROUND Mechanisms of antibody-mediated neutralization are of much interest. For plant and bacterial A-B toxins, A chain mediates toxicity and B chain binds target cells. It is generally accepted and taught that antibody (Ab) neutralizes by preventing toxin binding to cells. Yet for some toxins, ricin included, anti-A chain Abs afford greater protection than anti-B. The mechanism(s) whereby ...

PURPOSE To examine force generation and duration of effect of botulinum toxin pretreatment, followed by injection of ricin-mAb35 in extraocular muscle. METHODS In normal adult rabbits, one superior rectus muscle was injected with either 5 units botulinum toxin or 1/50 maximally tolerated dose for rats (rMTD) of ricin-mAb35. Additional rabbits were first injected with 5 units botulinum toxin, ...

In vitro translation systems were prepared with supernatant factors from wheat germ and 80S ribosomes from wheat germ, barley embryos, watermelon cotyledons, pea cotyledons, and castor bean endosperm. Ricin A-chain, which strongly inhibits protein synthesis by mammalian ribosomes, inhibited all of the plant ribosomal systems by 50% when present at 25-45 mug/ml- approximately 23,000 times the co...