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. Author manuscript; available in PMC: 2015 Jul 1.
Published in final edited form as: Mucosal Immunol. 2014 Jun 25;8(1):176–185. doi: 10.1038/mi.2014.55

Figure 8. Protection by reduced IgG antibody.

Figure 8

IgG was partially reduced to rIgG by incubation with DTT. (A) Whole IgG and rIgG fragments were separated by SDS-PAGE gel and detected by coomassie staining to determine the purity of rIgG under non-reducing conditions. Size markers in kilodaltons. Schematic of IgG reduction is shown, with dashed line indicating separation site and disulphide bonds represented by thin lines. (B) S. pneumoniae was incubated with whole IgG or rIgG and agglutination was visualized by Nomarski microscopy with 200× magnification, with 20micron scale bars. (C) Mice were immunized with equal amounts of whole IgG or rIgG, and challenged with 104 pneumococci (type 6A) 4 hours later. CFU/animal was determined 24 hours post immunization + SEM. n≥ 4 mice per group. * P<0.05. Dotted line indicates limit of detection (4 CFU). (D) Western blot analysis of nasal lavages from mice immunized 4 hrs prior detecting rabbit antibody with anti-rabbit IgG (F(ab’)2 specific) using alkaline phosphatase. Size marker in kilodaltons.