HIV virions distribute throughout and penetrate the mucosal epithelium of the entire GI tract four hours post-oral challenge.

Whole GI tracts were excised and imaged by PET at two- and four-hours following necropsy. PET images overlayed on photographs allow for visualization of radioactivity throughout the GI tract at two hours (A-B) and four hours (C-D) post challenge. White dotted lines depict where the GI tracts were dichotomized into upper (esophagus and stomach) and lower (small and large intestines) regions. Quantification of virions and viral penetration in the oral cavity, upper GI tract, and lower GI tract mucosa two and four hours after oral viral challenge. E) Total number of virions counted in images. Means of the virion count per group shown on stacked bars in white numbers. F) Frequency of total virions counted in each specific anatomic site; frequencies obtained by combining the virions in both animals at each time point, respectively. G) Quantification of the number of penetrating virions. Circle area represents the number of virions. H) Virion penetration depth in microns. Each virion depth was truncated to integer numbers for representation purposes. Circle area represents the number of virions with the same depth value. Blue: two hours, Red: four hours.