FIG. 4.

Immunohistochemical staining for HAM56, MAC387, LN3, and CD-3-12 of cerebellar brain sections from control and SIV-infected monkeys. The two groups of SIV-infected animals manifested different patterns of CNS pathology. Uninfected group A animals do not manifest any lesions (e.g., animal 298). Group B animals, with chronic nonprogressive infection, show small nodules of lymphocytes and macrophages (e.g., animal 291). Group C animals, with a rapid disease course, showed encephalitis (three monkeys; e.g., animal 321) or a less severe pathology (one monkey; animal 330). Magnification, ×100.