Anti-B. anthracis toxin Recombinant Antibody (24B1) (CAT#: MRO-092CT)

Figure 1 Neutralization of anthrax LT by human PA-specific monoclonal antibodies.

CHO-derived antibodies specific for PA were preincubated with fixed amounts of PA and LF prior to their addition to cultures of RAW 264.7 cells. Cell viability was determined approximately 16 h later, and the degree to which the added antibody blocked toxicity was determined. The domain specificity (PA₂₀, PA₆₃, or domain 4) is indicated for each clone.

Reason, D., Liberato, J., Sun, J., Keitel, W., & Zhou, J. (2009). Frequency and domain specificity of toxin-neutralizing paratopes in the human antibody response to anthrax vaccine adsorbed. Infection and immunity, 77(5), 2030-2035.

Figure 2 Domain-specific inhibition of antibody-mediated toxin neutralization by preincubation with PA or its amino-terminal fragment in a solid-phase ELISA.

Toxin-neutralizing antibodies were preincubated with a receptor-deficient mutant of PA (PArb−) or the amino-terminal 191 residues of PA expressed as a GFP fusion protein (PA₂₀-GFP) prior to their addition to the RAW267.4 cytotoxicity assay mixture. Open bars represent the degree of inhibition observed when antibodies were preincubated with PArb−. Filled bars represent inhibition by PA₂₀-GFP. Antibodies are grouped by their domain specificity.

Reason, D., Liberato, J., Sun, J., Keitel, W., & Zhou, J. (2009). Frequency and domain specificity of toxin-neutralizing paratopes in the human antibody response to anthrax vaccine adsorbed. Infection and immunity, 77(5), 2030-2035.

Figure 3 Relative toxin-neutralizing ability of PA₆₃- or PA₂₀-specific antibodies.

CHO-derived human antibodies specific for PA were titrated in the RAW 264.7 cytotoxicity assay and the amount required to bring about 50% cell death determined. The median value for each group is indicated by a horizontal line. PA₆₃- and PA₂₀-specific antibodies differed significantly in the concentration required to effect 50% neutralization of LT (P = 0.01 by the Mann-Whitney U test).

Reason, D., Liberato, J., Sun, J., Keitel, W., & Zhou, J. (2009). Frequency and domain specificity of toxin-neutralizing paratopes in the human antibody response to anthrax vaccine adsorbed. Infection and immunity, 77(5), 2030-2035.

Figure 4 Inhibition of Lethal Toxin neutralization.

PA₂₀-specific (47F12) and PA63-specific (24B1) neutralizing monoclonal antibodies were incubated with PA₂₀ or PArb- prior to their addition to the RAW cytotoxicity assay. The degree to which pre-incubation with the toxin components blocked the antibodies' ability to neutralize lethal toxin was calculated as a fraction of the neutralization achieved when antibody was pre-incubated with buffer alone.

Reason, D., Liberato, J., Sun, J., Camacho, J., & Zhou, J. (2011). Mechanism of Lethal Toxin Neutralization by a Human Monoclonal Antibody Specific for the PA20 Region of Bacillus anthracis Protective Antigen. Toxins, 3(8), 979-990.

Figure 5 Dot blot assay of representative CHO cell-derived IgG1 PA-specific human monoclonal antibodies.

PA83 and PA63 were purchased from List Biological Laboratories. D4-GFP and PA20-GFP were expressed and purified from E. coli as described in the materials and methods section. All antigens were spotted at 1 µg per spot using a 96 well manifold. Blots were cut into strips and probed with individual PA-specific monoclonal antibodies.

Reason, D. C., Ullal, A., Liberato, J., Sun, J., Keitel, W., & Zhou, J. (2008). Domain specificity of the human antibody response to Bacillus anthracis protective antigen. Vaccine, 26(32), 4041-4047.