PET imaging follows distribution of PA-BaL-⁶⁴Cu after oral viral challenge.

Four animals were orally challenged with PA-GFP-BaL-⁶⁴Cu. Two animals were sacrificed two hours post challenge and another two four hours post challenge, and the oral cavity and entire GI tract removed in one piece. The tissues were cut into pieces, frozen, cryosectioned, and prepared for fluorescent microscopy. A,B) Representative PET images of neonates after oral viral challenge with PA-GFP-BaL-⁶⁴Cu. Scale in Standard Uptake Value (SUV) (A) Whole body PET images at two and four hours post-oral challenge. B) PET image overlayed on photograph of 25 individual tissue blocks from oral mucosa and GI tract four hours post-challenge. C) Representative fluorescent microscopy image showing individual HIV virions (red puncta indicated by arrows) penetrating the tongue of an animal that received PA-BaL-⁶⁴Cu at two hours post-challenge. Green–pre-activation, Red–post-activation (virion), Blue–Hoechst. White arrow indicates virion shown in inset; grey arrows indicate other virions in the micrograph.