Recombinant Mouse Anti-Staphylococcal enterotoxin B (SEB) Antibody (20B1)

Inhibition of T-cell proliferation by SEB-specific mAbs 20B1, 14G8, and 6D3, individually at concentration of 5 μg or in different combinations of 2.5 μg each followed by SEB (25 nM). Proliferation was measured by ViaLight HS cell proliferation kit after 96 h.

Dutta, K., Varshney, A. K., Franklin, M. C., Goger, M., Wang, X., & Fries, B. C. (2015). Mechanisms mediating enhanced neutralization efficacy of staphylococcal enterotoxin B by combinations of monoclonal antibodies. Journal of Biological Chemistry, 290(11), 6715-6730.

Protection against SEBILS was tested in BALB/c mice (n = 10 per group) that were injected intraperitoneally with 20 μg of SEB and treated with mAb alone or in combination. Analysis of survival data was performed using Mantel-Cox Test. Mice treated with combination of mAbs 6D3 (500 μg) and 14G8 (500 μg) or 20B1 (50 μg) and 14G8 (50 μg) significantly survived, although monotherapy with the individual mAb was either nonprotective (mAb 14G8 at 500 μg dose and mAb 20B1 at 50 μg dose) or partially protective (mAb 6D3 at 500 μg dose).

Dutta, K., Varshney, A. K., Franklin, M. C., Goger, M., Wang, X., & Fries, B. C. (2015). Mechanisms mediating enhanced neutralization efficacy of staphylococcal enterotoxin B by combinations of monoclonal antibodies. Journal of Biological Chemistry, 290(11), 6715-6730.

A and B, mice (n = 5) were treated with mAb 20B1, mAb 14G8, and mAb 6D3 alone or in combination (500 μg) and challenged with SEB. ELISAs were performed to measure the SEB levels from sera at 6 h after SEB challenge. SEB level was higher in blood at 6 h in mice treated with mAb alone or in combination of mAb 14G8 and mAb 6D3. Higher SEB clearance was observed from sera of mice treated with combination of mAb 20B1 and mAb 14G8 group.

Dutta, K., Varshney, A. K., Franklin, M. C., Goger, M., Wang, X., & Fries, B. C. (2015). Mechanisms mediating enhanced neutralization efficacy of staphylococcal enterotoxin B by combinations of monoclonal antibodies. Journal of Biological Chemistry, 290(11), 6715-6730.

C and D, SEB internalization with mAbs 20B1, 14G8, and 6D3 alone or in combination by primary peritoneal macrophage was performed in FcR (FcRγ−/−/RIIB−/−) knockout mice and compared with WT C57/BL6 mice. E and F, SEB internalization with mAb 20B1, mAb 14G8, or mAb 6D3 alone or in combination by purified human neutrophils. The y axis shows residual SEB concentration from the supernatant.

Dutta, K., Varshney, A. K., Franklin, M. C., Goger, M., Wang, X., & Fries, B. C. (2015). Mechanisms mediating enhanced neutralization efficacy of staphylococcal enterotoxin B by combinations of monoclonal antibodies. Journal of Biological Chemistry, 290(11), 6715-6730.

A, sequence alignment of selected SEB residues to SEC1–3 and SSA. The 17 SEB residues involved in the binding with 20B1 are colored green. B, ELISA showing comparable binding of mAb 20B1 to SEB and SEC-1. mAb 20B1 failed to bind SEC 2–3 and SSA toxins. The experiment was performed in duplicate. Each point represents the mean value of duplicates, and bars represent the standard error derived from measurements in the same experiment. C, BALB/c mice (n = 10 per group) were treated with mAb 20B1 (500 μg) or PBS intraperitoneally (intraperitoneal) and challenged with 5 μg of SEB or SEC-1 and sensitized with 75 μg of LPS (intraperitoneal) 3 h post-toxin injection. Mice treated with mAb 20B1 showed 100% survival compared with PBS treatment.

Dutta, K., Varshney, A. K., Franklin, M. C., Goger, M., Wang, X., & Fries, B. C. (2015). Mechanisms mediating enhanced neutralization efficacy of staphylococcal enterotoxin B by combinations of monoclonal antibodies. Journal of Biological Chemistry, 290(11), 6715-6730.