FIGURE 1.

Immunohistochemical and schematic depiction of the choline biology of the pneumococcal surface. Immunogold labeling of pneumococci with (A) TEPC-15 antibody recognizing free choline and (B) antiautolysin antibody. These two images contrast free (A) versus CBP-bound (B) choline. (C) Schematic view of the capsule (blue), cell wall (green), and membrane (red). The teichoic and lipoteichoic acids are indicated as dark blue lines bearing choline (circles). A proportion of these are capped by choline-binding proteins. Courtesy of K.G. Murti, St. Jude Electron Microscopy Core Facility.