Development of a novel transgenic mouse/SCID-hu mouse system to characterize the in vivo behavior of reservoirs of human immunodeficiency virus type 1-infected cells.

To develop a system in which transgenic and knockout technologies are used to study the in vivo behavior of human immunodeficiency virus type 1 (HIV-1) reservoirs, 2 different mouse models were combined: transgenic mice carrying full-length provirus encoding the monocyte-tropic HIV-1(JR-CSF) isolate (JR-CSF mice) and severe combined immunodeficient mice implanted with human fetal thymus and liver tissues (thy/liv-SCID-hu mice). Extensive HIV-1 infection of human thymic implants occurred after injection of JR-CSF mouse leukocytes into thy/liv-SCID-hu mice, indicating that these cells provide an in vivo source of replication-competent HIV-1. In vivo persistence of transferred JR-CSF mouse leukocytes carrying replication-competent HIV-1 in thy/liv-SCID-hu mice was indicated by the emergence of HIV-1 infection in mice that had no detectable HIV-1 infection until after highly active antiretroviral therapy. Thus, thy/liv-SCID-hu mice populated with JR-CSF mouse leukocytes, a persistent cellular reservoir harboring replication-competent HIV-1, present a new in vivo system for characterizing reservoirs of HIV-1 and evaluating therapeutic strategies designed to eliminate them.