FIG 1.

Characterization of E. chaffeensis OMP-1-specific huMAbs. (A) Three of the E. chaffeensis-specific huMAbs (EHRL-2, -4, and-15) recognized the OMP-1 (∼28 kDa) in E. chaffeensis whole-cell lysate by Western immunoblotting. (B) huMAb recognition of overlapping peptides within the OMP-1 HVR1 by ELISA, demonstrating fine specificity of EHRL-4 and EHRL-15. (C) The E. chaffeensis OMP-1-specific huMAbs tested for inhibition of ehrlichial growth as determined by in vitro ehrlichial inhibition assay. THP-1 cells were incubated with antibodies and then inoculated with cell-free E. chaffeensis; infection status was determined on days 1, 2, and 3 by qPCR. Bar graphs represent means ± SEMs. *, P < 0.05.