Localization of T17 antibody labeling in amastigotes.

Abstract

(A) Epifluorescent microscopy of an amastigote (72 h post metacyclic infection) within a PEM labeled with T17 antibody along with antibodies recognizing parasite histones and DNA stain Hoechst 33342. Scale bar, 2 μm. (B) Electron micrograph of an L. major amastigote within a PEM following immuno-gold labeling with T17 antibody. Scale bar, 0.5 μm. Arrowhead indicates concentration of T17 immuno-labeling at the distal tip of the amastigote flagellum. (C) T17 immuno-labeling around the perimeter of the parasite flagellum. Scale bar, 0.5 μm. (D) T17 immuno-labeling is concentrated at the phagolysosome-parasite flagellum contact site, with some signal on the host cell-side of the phagolysosome. Scale bar, 0.5 μm. (E) Confocal micrograph of PEM 3 d after L. major or mock infection. Samples were stained with T17, antibodies reactive to Leishmania histones, and a DNA stain. Zoomed in images of the boxed regions are shown to the right. Scale bar, 10 μm. (F) ImmunoEM labeling with T17 of vesicular structures in L. major-infected PEM. Images from three different cells shown. Arrows indicate membranous structures containing the parasite antigen recognized by T17 within the PEM cytoplasm. Scale bar, 0.5 μm. Abbreviations: p, parasite posterior; n, nucleus; k, kinetoplast; pf, parasite flagellum.</p