The SCID-hu mouse: a small animal model for HIV infection and pathogenesis.

The SCID-hu mouse is a heterochimeric small animal model designed to support hematopoietic differentiation and function in vivo. Multiple organs of the human hematolymphoid system have been successfully engrafted into the immunodeficient C.B-17 scid scid mouse, including fetal liver, thymus, lymph node, and skin. Co-implantation of human fetal liver and human fetal thymus results in long-term, multilineage human hematopoiesis in vivo. Mature human lymphocytes within the SCID-hu mouse are phenotypically and functionally normal. HIV infection of the SCID-hu mouse reflects a tropism similar to that found in humans: only human organs with CD4+ cells are infected. Viral replication can thereafter be monitored with assays that are safe, reproducible, and quantitative. Given this small animal model, it is now possible to study systematically the infective process of HIV and to address questions about the efficacy of novel antiviral compounds or vaccines in vivo.