Figure 6.

Absence of antibodies to the subdominant BamA ECL4 epitope in immune rabbit serum. (A) Immunoblot reactivities of sera (diluted 1:1,000) from rabbits hyperimmunized with PfTrx^BamA/ECL4 against graded nanogram amounts of TbpB-LCL^BamA/ECL4. (B) ELISA reactivity of rabbit PfTrx^BamA/ECL4 antisera or NMS with native S1, S2, and S3 peptides represented as AUC values. (C) Freshly extracted Tp were pre-incubated with 10% heat-inactivated NRS, five individual IRS, or sera from rabbits hyperimmunized with PfTrx^BamA/ECL4, PfTrx^Empty, TP0751, or Tpp17 followed by incubation with rabbit peritoneal macrophages for 4 h at an MOI 10:1. Phagocytic indices were determined as described in Materials and methods. Asterisks show significant differences with p-values of ≤0.05, ≤0.01, or ≤0.001. (D) Each representative confocal micrograph is a composite of 9–12 consecutive Z-stack planes with labeling of Tp, plasma membranes, and nuclei shown in green, red, and blue, respectively. (E) Immunoblot reactivity of individual IRS and NRS (diluted 1:250) against 200 ng of PfTrx^BamA/ECL4. ELISA reactivity (AUC values) of IRS against (F) PfTrx^BamA/ECL4 and (G) the S1, S2, and S3 peptides.