Organotypic cultures of human fetal central nervous system (CNS) tissue will be used to test the hypothesis that human immunodeficiency virus (HIV) can infect neural tissue during gestation. Such an infection might account for the neurologic dysfunction seen in some children with congenital HIV- seropositivity, acquired immunodeficiency syndrome (AIDS), or AIDS-related complex (ARC). The experimental strategies will focus on fetal CNS tissue obtained from elective pregnancy terminations of HIV-seronegative females, to which HIV will be added, and from females who are HIV-seropositive or have ARC or AIDS. The ability of HIV to induce pathology in organotypic CNS cultures will be assessed by microscopy and immunocytochemistry in conjunction with nucleic acid and protein biochemistry. Specifically, the ability of HIV to infect different neural cell types and its location within cells will be determined by electron microscopy for viral particles and immunoelectron microscopic staining for HIV-specific proteins. Since HIV is a retrovirus and its genome, or parts thereof, may be incorporated into host cell DNA, Southern Blot analysis and in situ nucleic acid hybridization will be used to examine this point. A component of HIV-induced neuropathology may involve alterations in normal cell-type specific proteins, therefore, Western Blot analyses will be used to examine possible changes in protein synthesis and post-translational modifications of differentiation markers. To determine alterations in metabolism, additional studies will focus on enzyme kinetics in infected tissue. Similar experiments using abortus cultures from HIV-infected females may define the kinetics of transplacental fetal infection and the resultant neuropathology. These experiments will enhance the understanding of the mechanisms by which HIV infection may interfere with normal CNS tissue development. In addition to determining: (1) if HIV can infect neural cells; (2) which cells are infected; and, (3) what perturbations of cell structure and function may result from infection. Those environments may define HIV receptors other than the T4 molecule. Such insights may permit the design of improved preventative or therapeutic protocols for combatting HIV infection.
