Mouse Anti-Ricin Recombinant Antibody (clone mAb RAC18) (CAT#: PABL-692)

Figure 1 Neutralizing Ab delays internalization of ricin.

HeLa-DsRed cells were incubated with labeled ricin (green) for the indicated time in the presence or absence of RAC18 mAb and images obtained by confocal microscopy. The white bar indicates 10 mm.

Song, K., Mize, R. R., Marrero, L., Corti, M., Kirk, J. M., & Pincus, S. H. (2013). Antibody to ricin a chain hinders intracellular routing of toxin and protects cells even after toxin has been internalized. PLoS One, 8(4), e62417.

Figure 2 Ricin accumulates at the cell surface in the presence of neutralizing Ab.

The increase of cell surface ricin is confirmed, and quantified, by flow cytometry. Cells were incubated with the indicated Ab and ricin for 60 min either in the cold with sodium azide, or at 37u in tissue culture medium. The former studies passive binding at the cell surface, the latter also allows for internalization. 10,000 cells were analyzed. In either case RAC 18 results in approximately two-fold increase in cell-associated ricin.

Song, K., Mize, R. R., Marrero, L., Corti, M., Kirk, J. M., & Pincus, S. H. (2013). Antibody to ricin a chain hinders intracellular routing of toxin and protects cells even after toxin has been internalized. PLoS One, 8(4), e62417.

Figure 3 Neutralizing Ab delays internalization of ricin.

Neutralization of ricin cytotoxicity by mAbs is confirmed using MTS assays. H9 cells were premixed with Ab at 10 mg/ml, and then ricin was added to the indicated concentration. MTS dye reduction was measured 48 hr later. This is representative of .5 Ab neutralization assays, error bars indicate SEM.

Song, K., Mize, R. R., Marrero, L., Corti, M., Kirk, J. M., & Pincus, S. H. (2013). Antibody to ricin a chain hinders intracellular routing of toxin and protects cells even after toxin has been internalized. PLoS One, 8(4), e62417.

Figure 4 Neutralizing Ab delays internalization of ricin.

Affinity of Abs, and data obtained from internalization curves shown in panel C. Affinity was determined by Biacore analyses of mAbs captured via Fc and tested against soluble ricin. N is the number of cells imaged to obtain the data for analysis, and the p value (by F test) compares the internalization curve of each Ab to that of no Ab.

Song, K., Mize, R. R., Marrero, L., Corti, M., Kirk, J. M., & Pincus, S. H. (2013). Antibody to ricin a chain hinders intracellular routing of toxin and protects cells even after toxin has been internalized. PLoS One, 8(4), e62417.