Morphological study of washed platelets incubated with HIV particles.

(A) Internalization of HIV particles in endosomelike structures. In the early stage of internalization, HIV particles are found in some characteristic small vacuoles as endosomelike structures tightly surrounding 1 or 2 particles (vi), and located close to the plasma membrane (pm). a indicates α-granules. Original magnification, × 36 800; inset original magnification, × 55 200. (B) (C) HIV particles (vi) are further retrieved in the OCS. These platelets show morphological activation signs: spherical shape, bristled surface with pseudopods (arrows), dilated OCS. mi indicates mitochondria. Original magnification, × 41 850.