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

Abstract

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.

Lentiviral Vectors Encoding Human Immunodeficiency Virus Type 1 (HIV-1)-Specific T-Cell Receptor Genes Efficiently Convert Peripheral Blood CD8 T Lymphocytes into Cytotoxic T Lymphocytes with Potent In Vitro and In Vivo HIV-1-Specific Inhibitory Activity

“…Mice. The specific-pathogen-free male SCID mice (8 to 12 weeks old) used in this study were housed and maintained as described previously (62). All animal studies were approved by the Institutional Animal Care and Use Committee and were consistent with the guidelines for the care and use of laboratory animals.…”

“…The intrasplenically injected HIV-1-infected human PBMCs persist in the mouse for at least 2 weeks and are readily detectible by flow cytometry and coculture. After 1 week, the mice were sacrificed and the number of HIV-1-infected human PBMCs in the spleen was measured by limiting dilution coculture as described previously (62). Briefly, fivefold dilutions of splenocytes isolated from the injected mouse spleens that ranged from 1 ϫ 10 6 cells to 3.2 ϫ 10 2 cells per well were cultured in quadruplicate at 37°C in 24-well culture plates with PHA-activated donor mononuclear cells (1.0 ϫ 10 6 /well) in 2 ml of complete RPMI medium with added IL-2 (32 U/ml).…”

Human Immunodeficiency Virus Type 1 Infection Increases the In Vivo Capacity of Peripheral Monocytes To Cross the Blood-Brain Barrier into the Brain and the In Vivo Sensitivity of the Blood-Brain Barrier to Disruption by Lipopolysaccharide

“…Although this model has been very useful for studying some aspects of BBB function, it does not fully recapitulate the in vivo function of the BBB. As an in vivo model to investigate whether HIV-1-infection alters the capacity of monocytes to cross the intact BBB and whether HIV-1 infection increases the sensitivity of the BBB to disruption by systemic LPS, we used our well-characterized system consisting of JR-CSF mice, which are transgenic for an infectious HIV-1 provirus (13,46,64).…”

“…Our JR-CSF transgenic mouse line circumvents the block of HIV-1 entry into mouse cells by carrying as a transgene a full-length infectious HIV-1 provirus derived from the primary R5-tropic clinical isolate HIV-1 JR-CSF , and these mice display plasma viremia at levels comparable to that observed in HIV-1-infected patients (46,64). Furthermore, infectious HIV-1 is produced by monocytes and microglia from the JR-CSF mice, and LPS-stimulated JR-CSF mouse monocytes and microglia produce higher levels of MCP-1 than monocytes and microglia from LPS-stimulated control mice (65).…”

Inhibition of In Vivo HIV Infection in Humanized Mice by Gene Therapy of Human Hematopoietic Stem Cells with a Lentiviral Vector Encoding a Broadly Neutralizing Anti-HIV Antibody

“…The pathogen-free, non-obese-diabetic/severe combined immunodeficient mouse line harboring a complete null mutation of the common cytokine receptor ␥ chain (NOD/SCID/␥ c null mice; 8 to 12 weeks old) used in this study were a kind gift of Leonard Shultz (Jackson Laboratory, Bar Harbor, ME) (10) and were housed and maintained as described previously (32). All animal studies were approved by the Einstein Institutional Animal Care and Use Committee and were consistent with the guidelines for the care and use of laboratory animals.…”