EcoHIV Infection of Primary Murine Brain Cell Cultures to Model HIV Replication and Neuropathogenesis.

Background: EcoHIV is a chimeric HIV that replicates in mice in CD4+ T cells, macrophages, and microglia (but not in neurons), causing lasting neurocognitive impairment resembling neurocognitive disease in people living with HIV. The present study was designed to develop EcoHIV-susceptible primary mouse brain cultures to investigate the indirect effects of HIV infection on neuronal integrity.

Results: We used two EcoHIV clones encoding EGFP and mouse bone marrow-derived macrophages (BMM), mixed mouse brain cells, or enriched mouse glial cells from two wild-type mouse strains to test EcoHIV replication efficiency, the identity of productively infected cells, and neuronal apoptosis and integrity.

Innate immune responses reverse HIV cognitive disease in mice: Profile by RNAseq in the brain.

Antiretroviral therapy controls immunodeficiency in people with HIV but many develop mild neurocognitive disorder. Here we investigated HIV brain disease by infecting mice with the chimeric HIV, EcoHIV, and probing changes in brain gene expression during infection and reversal with polyinosinic-polycytidylic acid (poly I:C). EcoHIV-infected C57BL/6 mice were treated with poly I:C and monitored by assay of learning in radial arm water maze, RNAseq of striatum, and QPCR of virus burden and brain transcripts.

Protocol for optimizing production and quality control of infective EcoHIV virions.

EcoHIV is a model of HIV infection that recapitulates aspects of HIV-1 pathology in mice. However, there are limited published protocols to guide EcoHIV virion production. Here, we present a protocol for producing infective EcoHIV virions and essential quality controls.

CCL2 is required for initiation but not persistence of HIV infection mediated neurocognitive disease in mice.

HIV enters the brain within days of infection causing neurocognitive impairment (NCI) in up to half of infected people despite suppressive antiretroviral therapy. The virus is believed to enter the brain in infected monocytes through chemotaxis to the major monocyte chemokine, CCL2, but the roles of CCL2 in established NCI are not fully defined. We addressed this question during infection of conventional and CCL2 knockout mice with EcoHIV in which NCI can be verified in behavioral tests.

Prevention and treatment of HIV infection and cognitive disease in mice by innate immune responses.

HIV associated neurocognitive impairment afflicts roughly half of infected individuals on antiretroviral therapy. This disease currently has no treatment. We have previously shown that type I interferon is induced by and partially controls infection and neuropathogenesis in mice infected by chimeric HIV, EcoHIV.

Intranasal insulin therapy reverses hippocampal dendritic injury and cognitive impairment in a model of HIV-associated neurocognitive disorders in EcoHIV-infected mice.

Objective: Almost half of HIV-positive people on antiretroviral therapy have demonstrable mild neurocognitive impairment (HIV-NCI), even when virologically suppressed. Intranasal insulin therapy improves cognition in Alzheimer's disease and diabetes. Here we tested intranasal insulin therapy in a model of HIV-NCI in EcoHIV-infected conventional mice.

EcoHIV infection of mice establishes latent viral reservoirs in T cells and active viral reservoirs in macrophages that are sufficient for induction of neurocognitive impairment.

Suppression of HIV replication by antiretroviral therapy (ART) or host immunity can prevent AIDS but not other HIV-associated conditions including neurocognitive impairment (HIV-NCI). Pathogenesis in HIV-suppressed individuals has been attributed to reservoirs of latent-inducible virus in resting CD4+ T cells. Macrophages are persistently infected with HIV but their role as HIV reservoirs in vivo has not been fully explored.

HIV induces expression of complement component C3 in astrocytes by NF-κB-dependent activation of interleukin-6 synthesis.

Background: Abnormal activation of the complement system contributes to some central nervous system diseases but the role of complement in HIV-associated neurocognitive disorder (HAND) is unclear.

Methods: We used real-time PCR and immunohistochemistry to detect complement expression in postmortem brain tissue from HAND patients and controls. To further investigate the basis for viral induction of gene expression in the brain, we studied the effect of HIV on C3 expression by astrocytes, innate immune effector cells, and targets of HIV.

Chronic, highly productive HIV infection in monocytes during supportive culture.

Peripheral blood monocytes of HIV-infected individuals carry virus, constituting one potential reservoir. However, most studies of infection in tissue culture find monocytes refractory to HIV replication, suggesting that culture conditions limit the relative susceptibility of this target cell. We employed a tissue culture system optimized for maintenance of human monocytes without differentiation and compared HIV infection efficiency of monocytes and fully differentiated monocyte derived macrophages (MDM).

Enhanced human immunodeficiency virus Type 1 expression and neuropathogenesis in knockout mice lacking Type I interferon responses.

The roles of Type I interferon (IFN) in human immunodeficiency virus Type 1 (HIV-1) neuropathogenesis are poorly understood; both protective and deleterious effects of IFN signaling have been described. We used genetically modified mice deficient in the Type I IFN receptor (IFNRKO) to analyze the progress of HIV-1 brain infection and neuropathogenesis in the absence of IFN signaling. IFNRKO and wild-type (WT) mice on the 129xSv/Ev or C57BL/6 strain backgrounds were infected systemically with EcoHIV, a chimeric HIV-1 that productively infects mice.

Transmission of chimeric HIV by mating in conventional mice: prevention by pre-exposure antiretroviral therapy and reduced susceptibility during estrus.

Heterosexual transmission accounts for the majority of new human immunodeficiency virus (HIV) cases worldwide. The current approach to investigate HIV heterosexual transmission in animals involves application of virus stock to the vaginal surface, a method that does not reproduce the physiological conditions of vaginal intercourse that influence the rate of transmission. We have previously described efficient infection of conventional mice using EcoHIV/NL4-3 and EcoHIV/NDK, chimeric HIV molecular clones constructed to express all HIV structural and regulatory genes except envelope, which is replaced by a rodent-tropic envelope gene.

T cells induced by recombinant chimpanzee adenovirus alone and in prime-boost regimens decrease chimeric EcoHIV/NDK challenge virus load.

The popularity of nonreplicating adenoviruses of chimpanzee origin (ChAdVs) as vectors for subunit vaccines is on the rise. This is mainly for their excellent safety and impressive immunogenicity observed in human studies to date. Here, we recloned the chimpanzee adenovirus sero type 68 (ChAdV-68), also designated SAdV-25 and AdC68, genome and demonstrated its straightforward genetic manipulation facilitated by the use of bacterial artificial chromosome recombineering.

Mice chronically infected with chimeric HIV resist peripheral and brain superinfection: a model of protective immunity to HIV.

Infection by some viruses induces immunity to reinfection, providing a means to identify protective epitopes. To investigate resistance to reinfection in an animal model of HIV disease and its control, we employed infection of mice with chimeric HIV, EcoHIV. When immunocompetent mice were infected by intraperitoneal (IP) injection of EcoHIV, they resisted subsequent secondary infection by IP injection, consistent with a systemic antiviral immune response.

Significant effects of antiretroviral therapy on global gene expression in brain tissues of patients with HIV-1-associated neurocognitive disorders.

Antiretroviral therapy (ART) has reduced morbidity and mortality in HIV-1 infection; however HIV-1-associated neurocognitive disorders (HAND) persist despite treatment. The reasons for the limited efficacy of ART in the brain are unknown. Here we used functional genomics to determine ART effectiveness in the brain and to identify molecular signatures of HAND under ART.

A common path to innate immunity to HIV-1 induced by Toll-like receptor ligands in primary human macrophages.

Toll-like receptors (TLR) represent the best characterized receptor family transducing innate immune responses, the first line of defense against microbial invaders. This study was designed to investigate whether responses through TLR inhibit HIV-1 replication in its primary target cells. Primary human macrophages and lymphocytes from several different donors and HIV-1 infection in tissue culture were used exclusively in this work.

Protective efficacy of serially up-ranked subdominant CD8+ T cell epitopes against virus challenges.

Immunodominance in T cell responses to complex antigens like viruses is still incompletely understood. Some data indicate that the dominant responses to viruses are not necessarily the most protective, while other data imply that dominant responses are the most important. The issue is of considerable importance to the rational design of vaccines, particularly against variable escaping viruses like human immunodeficiency virus type 1 and hepatitis C virus.

Novel HIV-1 clade B candidate vaccines designed for HLA-B*5101(+) patients protected mice against chimaeric ecotropic HIV-1 challenge.

Novel candidate HIV-1 vaccines have been constructed, which are tailor-designed for HLA-B*5101(+) patients infected with HIV-1 clade B. These vaccines employ novel immunogen HIVB-B*5101 derived from consensus HIV-1 clade B Gag p17 and p24 regions coupled to two Pol-derived B*5101-restricted epitopes, which are together with a third B*5101 epitope in Gag dominant in HIV-1-infected long-term non-progressing patients. Both plasmid DNA and modified vaccinia virus Ankara (MVA) vectors supported high expression levels of the HIVB-B*5101 immunogen in cultured cells.

Vaccine-induced protection from infection of mice by chimeric human immunodeficiency virus type 1, EcoHIV/NL4-3.

EcoHIV/NL4-3 is a chimeric human immunodeficiency virus type 1 (HIV-1) that can productively infect mice. This study tests the utility of EcoHIV/NL4-3 infection to reveal protective immune responses to an HIV-1 vaccine. Immunocompetent mice were first immunized with VRC 4306 which encodes subtype B consensus sequences of gag, pol, and nef and then were infected by EcoHIV/NL4-3.

Host and virus strain dependence in activation of human macrophages by human immunodeficiency virus type 1.

Human immunodeficiency virus type 1 (HIV-1)-associated neuropathogenesis occurs in a large minority of infected people. Presently, there are neither viral nor cellular markers that predict the development of brain disease during HIV-1 infection. This study was conducted to determine whether there exist systematic differences among human cell donors and virus strains for the activation of macrophage gene expression by HIV-1 that may contribute to neuropathogenesis.

Human immunodeficiency virus type 1 efficiently binds to human fetal astrocytes and induces neuroinflammatory responses independent of infection.

Background: HIV-1 infects human astrocytes in vitro and in vivo but the frequency of infected cells is low and its biological significance is unknown. In studies in vitro, recombinant gp120 alone can induce profound effects on astrocyte biology, suggesting that HIV-1 interaction with astrocytes and its functional consequences extend beyond the limited levels of infection in these cells. Here we determined the relative efficiencies of HIV-1 binding and infection in human fetal astrocytes (HFA), mainly at the single cell level, using HIV-1 tagged with green fluorescence protein (GFP)-Vpr fusion proteins, termed HIV-GFP, to detect virus binding and HIV-1 expressing Rev and NefGFP fusion proteins to detect productive infection.

Testing antiretroviral drug efficacy in conventional mice infected with chimeric HIV-1.

Objective: We previously described chimeric HIV-1, EcoHIV, which can infect mouse cells in culture and cause spreading infection in conventional immunocompetant mice. We have now applied this system as a model for preclinical evaluation of anti-retroviral drugs.

Design And Methods: We used chimeric virus EcoHIV/NDK constructed on the backbone of subtype D NDK.