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Papers by David Volsky

Scientific Reports, Jul 1, 2019

The widespread use of combination antiretroviral therapy (cART) has resulted in significantly red... more The widespread use of combination antiretroviral therapy (cART) has resulted in significantly reduced deaths from HIV-1 associated complications and opportunistic infections. However, it is estimated that up to 50% of HIV-1 infected individuals still develop HIV-1 associated neurocognitive disorders (HAND). With no treatment currently available for patients, there is a critical need to identify therapeutic approaches that can treat this disorder. Evidence suggests that targeting Peroxisome Proliferator-Activated Receptor-gamma (PPARγ) can be anti-inflammatory in neurological disorders. Here we show that treatment with ppARγ agonists (rosiglitazone or pioglitazone) in primary cultures of mouse glial cells reversed EcoHIV-induced inflammatory genes (TNFα, IL-1β, CCL2, CCL3, CXCL10) and indicator of oxidative stress (iNOS). Furthermore, in vivo, mice administered with EcoHIV through intracranial injection resulted in upregulation of inflammatory genes (TNFα, IL-1β, IFNγ, CCL2, CCL3, CXCL10) and oxidative stress marker (iNOS) in the brain which was reversed through intraperitoneal administration of ppARγ agonists (rosiglitazone or pioglitazone). Finally, we demonstrated that treatment with these compounds in vivo reduced EcoHIV p24 protein burden in the brain. Our results suggest that treatment with ppARγ agonists are anti-inflammatory and antiviral in an in vivo model of EcoHIV infection. These drugs hold promise as potential candidates for HAND treatment in the future. HIV-1 infection has been a prominent target for investigation and treatment, and many successful advances over the last two decades have greatly improved patient outcomes for those infected with the virus. The development and widespread use of combination antiretroviral therapy (cART) has resulted in significantly reduced deaths from HIV-1 associated complications and opportunistic infections 1,2 . However, despite the overall reduction of its incidence and severity, it is estimated that up to 50% of HIV-1 infected individuals still develop HIV-1 associated neurocognitive disorders (HAND) . These can manifest as memory, motor, and/or behavioural deficits, at varying severities, which can affect quality of daily life and mortality rates in these patients , yet the mechanisms contributing to HAND remain poorly understood. As a result, there is a lack of effective treatment for the condition, with patients relying on cART as the primary method of delaying or preventing the onset of cognitive impairment. This has proven to be insufficient in addressing the problem as several antiretroviral drugs (ARVs) exhibit poor blood-brain-barrier (BBB) permeability 7 or have been linked with neurotoxicity (e.g. efavirenz) 8 . Sub-therapeutic concentrations of ARVs in the brain can result in low level virus replication, allowing the development of an HIV-1 sanctuary in the brain 7 . Thus, there is a need to identify other therapeutic approaches that can be effective for the prevention and treatment of HIV-associated brain inflammation and neurocognitive disorders. HIV-1 can enter the brain very early on in the course of infection, and once in the central nervous system (CNS), primarly targets mononuclear phagocytes (e.g. perivascular macrophages and brain resident microglial cells) and to a lesser degree astrocytes 9 . Macrophages chronically infected with HIV-1 are resistant to viral apoptosis and resistant to post-infection cART, suggesting that this cell type can survive infection and serve as an HIV-1 reservoir . Upon infection, microglia, macrophages and astrocytes become activated and secrete

Frontiers in Immunology, Oct 7, 2022

Thirty-eight million people worldwide are living with HIV, PWH, a major public health problem. An... more Thirty-eight million people worldwide are living with HIV, PWH, a major public health problem. Antiretroviral therapy (ART) revolutionized HIV treatment and significantly increased the lifespan of PWH. However, approximately 15-50% of PWH develop HIV associated neurocognitive disorders (HIV-NCI), a spectrum of cognitive deficits, that negatively impact quality of life. Many PWH also have opioid use disorder (OUD), and studies in animal models of HIV infection as well as in PWH suggest that OUD can contribute to HIV-NCI. The synthetic opioid agonist, buprenorphine, treats OUD but its effects on HIV-NCI are unclear. We reported that human mature inflammatory monocytes express the opioid receptors MOR and KOR, and that buprenorphine reduces important steps in monocyte transmigration. Monocytes also serve as HIV reservoirs despite effective ART, enter the brain, and contribute to HIV brain disease. Using EcoHIV infected mice, an established model of HIV infection and HIV-NCI, we previously showed that pretreatment of mice prior to EcoHIV infection reduces mouse monocyte entry into the brain and prevents NCI. Here we show that buprenorphine treatment of EcoHIV infected mice with already established chronic NCI completely reverses the disease. Disease reversal was associated with a significant reduction in brain inflammatory monocytes and reversal of dendritic injury in the cortex and hippocampus. These results suggest that HIV-NCI persistence may require a continuing influx of inflammatory monocytes into the brain. Thus, we recommend buprenorphine as a potential therapy for mitigation of HIV brain disease in PWH with or without OUD.

It is known for years that cells are endowed with a periplasmic structure, the plasma membrane, w... more It is known for years that cells are endowed with a periplasmic structure, the plasma membrane, which served both as an insulating surface and as a medium of communication between the external and internal cell world. Due to its intrinsic structural properties and to specific mechanisms, the cell membrane gives selective admittance to particular agents while excluding many others. These properties although important for controlling the cellular milieu, have limited on the other hand, the access to the intra-cellular apparatus of probes and therapeutic agents. This restricted, in the past, the scope of studies of genetic and membrane engineering as well as chemical therapy.

The development of AIDS has been observed in the setting of a medical practice which provided car... more The development of AIDS has been observed in the setting of a medical practice which provided care to homosexual men in Greenwich Village area of New York since 1978. There was thus a unique opportunity to not only observe the clinical and laboratory manifestations of AIDS but also to achieve some appreciation of the setting in which the disease developed. AIDS and associated conditions developed in patients about whom prior information,particularly with respect to sexually transmitted diseases,had already been obtained. Systematic laboratory studies including assays for LAVantibodies were performed on ?0 asymptomatic homosexual men, 1^0 men with lymphadenopathy, 2^ men with -opportunistic infections, and 14 with Kaposi's sarcoma alone,For comparison with a low incidence area for AIDS 90 homosexual men in apparent good health in Omaha Nebraska, were also studied. In many instances isolation of LAVfrom lymphocytes of study participants was also undertaken'. In general, the ti...

Journal of Virology, 1991

Two molecularly cloned coisolates of human immunodeficiency virus type 1 (HIV-1) have been found ... more Two molecularly cloned coisolates of human immunodeficiency virus type 1 (HIV-1) have been found to exhibit different phenotypes of viral expression, either rapid and cytopathic (N1T-A virus) or delayed and noncytopathic (N1T-E virus [X. Ma, K. Sakai, F. Sinangil, E. Golub, and D. J. Volsky, Virology 176:184-194, 1990]). To identify the viral genetic elements responsible for these phenotypes, we prepared reciprocal recombinants in different regions of N1T-A and N1T-E viral genomes. Infectivity experiments with the recombinant viruses revealed that the rapid/cytopathic (N1T-A-like) phenotype assorted cleanly with the V1f-coding region and Vif expression. The smallest HIV-1 DNA region that conferred the complete phenotypic switch was a 284-bp NdeI-StuI fragment within the vif open reading frame. Nucleotide sequence analysis revealed a 35-bp deletion starting at nucleotide 218 in the N1T-E vif gene. A 23-kDa Vif protein was detected by immunoblotting using Vif-specific antiserum in ext...

Blood, 1996

Human erythrocytes bearing electroinserted full-length CD4 (RBC-CD4) can bind and fuse with a lab... more Human erythrocytes bearing electroinserted full-length CD4 (RBC-CD4) can bind and fuse with a laboratory strain of human immunodeficiency virus type 1 (HIV-1) or with T cells infected by HIV-1. Here we show that RBC-CD4 neutralize primary HIV-1 strains in an assay of cocultivation of peripheral blood mononuclear cells (PBMC) from HIV-1- infected persons with uninfected PBMC. RBC-CD4 inhibited viral p24 core antigen accumulation in these cocultures up to 10,000-fold compared with RBC alone. Viral p24 accumulation was inhibited equally well when measured in culture supernatants or in call extracts. The inhibition was dose-dependent and long-lived. Two types of recombinant CD4 tested in parallel were largely ineffective. The neutralization of primary HIV- 1 by RBC-CD4 in vitro was demonstrated in PBMC cultures from 21 of a total of 23 patients tested at two independent sites. RBC-CD4 may offer a route to blocking HIV-1 infection in vivo.

Modern pathology : an official journal of the United States and Canadian Academy of Pathology, Inc, 1990

Epstein-Barr virus has been implicated in the pathogenesis of primary brain lymphoma in patients ... more Epstein-Barr virus has been implicated in the pathogenesis of primary brain lymphoma in patients with congenital or acquired immunodeficiency states. To examine its role in central nervous system (CNS) lymphoma in the immunocompetent host, Epstein-Barr virologic studies were performed in six consecutive cases seen at our institutions. Virus DNA sequences were detected in only one of three tumor specimens studied by Southern blot hybridization. Serologic studies from the entire cohort disclosed past virus infection; however, antibody reactivity to virus-specific antigens in cerebrospinal fluid was limited to the patient harboring genome-positive tumor. Immunologic studies revealed hyperimmunoglobulin-E (range, 720 to 1040 micrograms/ml) in each of four patients tested. Our findings suggest that Epstein-Barr virus is an infrequent pathogen in nonimmunosuppressed patients with primary CNS lymphoma. Abnormalities in isotype-specific regulation of IgE production are common in such patien...

Thymus, 1984

Normal human thymic epithelial cells cannot be infected and transformed by Epstein-Barr virus (EB... more Normal human thymic epithelial cells cannot be infected and transformed by Epstein-Barr virus (EBV). Measurements using fluorescein-labelled EBV and cytofluorograph revealed that the cells do not have receptors for the virus. Following transplantation of functional EBV receptors onto epithelial cell membranes, however, the cells were infected with EBV and expressed EBV-determined nuclear antigen (EBNA). No EBV associated antigens characteristic of the lytic cycle of the virus were detected. This method of in vitro infection by transforming viruses such as EBV may provide ways of deriving functioning thymic epithelial cell lines.

Cancer detection and prevention, 1988

In the present investigation we have determined the effects of the differentiation-inducing chemi... more In the present investigation we have determined the effects of the differentiation-inducing chemicals dimethyl sulfoxide (DMSO) and sodium butyrate on the growth and tumorigenicity of a highly malignant/metastatic cell line (RAW117-H10) and its less tumorigenic parental lymphoma cell line (RAW117-P). Both of these agents at doses shown to be nontoxic slowed the growth of these cells in suspension culture and significantly lengthened the doubling time while reducing colony formation in the agar tumor stem cell assay. Corresponding to these observations, the in vivo tumorigenicity of the highly malignant RAW117-H10 line was reduced by both chemicals but particularly by butyrate treatment. In addition, both agents increased the expression of some glycoproteins and the glycolipid asialo GM1. There was also a corresponding increase in the NK susceptibility of the normally NK resistant RAW117-H10 cells. To determine if the decreased malignancy of the highly malignant cells following treat...

Virology, 1987

Infection of human helper T lymphocytes with the human immunodeficiency virus (HIV) results in a ... more Infection of human helper T lymphocytes with the human immunodeficiency virus (HIV) results in a rapid induction of cytopathic effects and cell lysis. We isolated a variant of the human T-lymphoblastoid cell line, CEM, that is fully susceptible to HIV infection but resistant to virally induced cytopathic effects. Exposure of the cells, designated CR-10, to HIV resulted in the expression of viral antigens in 100% of cells within 6-9 days. Virus-infected cells remained fully viable and could be cultivated under standard culture conditions for a desired period of time. Parental CEM cells died within 9-12 days after HIV infection. Proviral DNA could be detected in the HIV-infected CR-10 cells by Southern blot and molecular hybridization 4-5 days after infection; the relative amount of proviral DNA reached maximum at Days 6-10 and remained stable during an 8-month follow-up period. Virus production by HIV-infected CR-10 cells was documented by electron microscopy and detection of reverse transcriptase activity in cell culture supernatants. HIV-infected CR-10 cells exhibited a down modulation of the OKT-3, OKT-4, OKT-4A, OKT-8, and OKT-11 T-cell surface markers, but not of the OKT-9 (transferrin receptor). One of the HIV persistently infected CR-10 cell clones has been kept in continuous culture for over 8 months. During this period, the cells remained fully viable, 100% positive for HIV antigens, and negative for most of the T-cell surface markers tested and continued to produce biologically active HIV. The CR-10 and HIV-infected CR-10 cell lines will be useful in studies on the biology of HIV and in the isolation and large-scale propagation of this virus.

Virology, 1990

Recently described noncytopathic human immunodeficiency viruses type-l (HIV-l) form a new categot... more Recently described noncytopathic human immunodeficiency viruses type-l (HIV-l) form a new categoty within the HIV-l family due to their unique biological properties and predominant occurrence in symptom-free individuals. To study the mechanism of noncytopathic HIV-1 infection, we compared the infectivity and life cycles of two closely related HIV-1 clones with noncytopathic (NlT-E) or cytopathic (NlT-A) properties. NlT-E virus exhibited slow kinetics of infection in T cells and monocytes. Slow infection was not due to defective virus entry, because NlT-E and NIT-A exhibited equally efficient virus-cell fusion activity and nucleocapsid internalization. Kinetic studies of Nl T-E genome expression revealed low levels of viral RNA, structural proteins, and Tat protein during the first 7 days after virus entry. In contrast, cells infected with the same dose of cytopathic NlT-A virus began to express high levels of genomic RNA, structural proteins, and Tat protein within 48 hr of infection; the expression peaked on Day 5, followed by complete cell lysis. No delay in NIT-E replication, as compared to NlT-A, was observed after transfection of cloned NlT-E proviral DNA. NlT-E virus had intact Tat, Rev, and fusion functions and replicated well in chronically infected cells. These results suggest that delayed processing or expression of HIV-l genome during the early phase of the virus replicative cycle is an important determinant in noncytopathic infection.

Proceedings of the National Academy of Sciences, 1984

Purified EBV DNA and cloned DNA fragments were trapped in Sendai virus (SV) envelopes during enve... more Purified EBV DNA and cloned DNA fragments were trapped in Sendai virus (SV) envelopes during envelope reconstitution. The DNA-loaded reconstituted envelopes (RSVE/DNA) served as gene-transfer vehicles using the capability of RSVE to fuse with normal and tumor cells. The efficiency of RSVE-mediated EBV DNA transfer into lymphoid tumor cells and fresh human lymphocytes was 5-10% of the enveloped 3H-labeled EcoRI fragment B of EBV DNA. Purified intracellular EBV (B95-8 strain) DNA induced EBV nuclear antigen (EBNA) in 0.2-1% of human lymphocytes, transiently stimulated cellular DNA synthesis, but did not fully transform cells. Cloned Sal I F1 fragment [approximately equal to 9 kilobase pairs (kbp)] and a smaller BamHI K (5.2 kbp) fragment from the same region of B95-8 EBV DNA induced EBNA in 2-4% of human lymphocytes but did not stimulate DNA synthesis nor transform cells. Cloned BamHI D1 fragment (approximately equal to 9 kbp) from AG-876 virus DNA, or a combination of cloned BamHI X ...

Leukemia Research, 1983

The development of acute non-lymphocytic leukemia is preceded by a set of symptoms described as t... more The development of acute non-lymphocytic leukemia is preceded by a set of symptoms described as the preleukemia syndrome. Six patients who fulfilled the criteria for this prelenkemia syndrome have been evaluated for abnormalities in the lymphocyte population. The NK cell activity was reduced, the immunoregulatory cell populations were numerically abnormal, and the B cell subpopulation was deficient in EBV receptors. Thus, in addition to the abnormalities in the myeloid populations, there are serious defects in the lymphoid systems of preleukemic patients.

Leukemia Research, 1985

Ahstract--Epstein-Barr virus (EBV) can induce a broad spectrum of hematological diseases, especia... more Ahstract--Epstein-Barr virus (EBV) can induce a broad spectrum of hematological diseases, especially in immune deficient patients. We assayed for receptor for EBV (EBVR) using fluoresceinated viral particles on 44 human hematopoietic cell lines derived from patients with T, B, and non-T, non-B acute lymphocytic leukemia (ALL), non-lymphoid leukemia, Burkitt lymphoma, myeloma and several unique lines we and others have recently developed. All 31 EBV nuclearassociated antigen (EBNA) negative cell lines were of neoplastic origin. Seven of 13 EBNApositive cell lines were of normal cell origin. Four of 25 non-B (surface immunoglobulin negative) EBNA-negative neoplastic cell lines were EBVR-positive. Three of six EBNA-negative B-cell (surface immunoglobulin positive) lines were EBVR-positive. Nine of 13 EBNA-positive Burkitt and non-Burkitt cell lines strongly expressed EBVR. Four EBNA-positive Burkitt lymphoma cell lines exhibited EBVR only to a limited degree. Studies of the cell lines for EBVR, complement receptors (CR) and surface immunoglobulin (Slg) revealed that presence of Slg does not obligate the presence of EBVR. Functional EBVR accompanied Slg among EBNA-negative cell lines. Slgnegative cell lines can possess EBVR. Fourteen of 16 EBVR-positive lines were also positive for CR. The EBVR assay is a useful tool for assessing the potential role of EBV in the induction of hematopoietic disorders.

Journal of Immunological Methods, 1997

Herpesvirus saimiri HVS can infect and immortalize human T lymphocytes of both CD4-and CD8-positi... more Herpesvirus saimiri HVS can infect and immortalize human T lymphocytes of both CD4-and CD8-positive phenotypes. Ž . We have previously shown that infection of peripheral blood lymphocytes PBL from AIDS patients with HVS predominantly yielded immortalized CD8-positive T cell clones. Here we show that CD4-positive T cells from AIDS patients can be efficiently immortalized by HVS if patient PBL are enriched for CD4-positive T cell subpopulation prior to HVS infection. Such cells can be cloned and maintained in culture for prolonged times, and they exhibit activated T cell phenotype of Th1 class and are susceptible to HIV-1 infection. Several immortalized T cell clones obtained from one out of three AIDS patients tested here were HIV-1 positive and produced infectious virus. This approach permits efficient generation of multiple CD4-positive T cell clones from AIDS patients for functional and virological studies. q 1997 Elsevier Science B.V.

Bioscience Reports, 1984

Sendal virus envelopes (SVE) were isolated from Sendal virus particles by Triton X-100 solubiliza... more Sendal virus envelopes (SVE) were isolated from Sendal virus particles by Triton X-100 solubilization and ultracentrifugation. The envelopes were reconstituted in the presence of the fluorescent dye calcein by gradual removal of the detergent with Bio-beads SM-2. The internal volume of reconstituted Sendal virus envelopes (RSVE) was determined by quenching the fluorescence of calcein with cobalt (II) ions. The internal volume of RSVE was found to be proportional to the initial SVE protein concentration in the recon-stitution mixture, reaching about 18% of the total volume with 5.6 mg of SVE protein per ml. When radiolabelled cloned Epstein-Barr virus DNA fragment was included in the reconstitution mixture, the proportion of DNA associated with the vesicles much exceeded the trapping volume, indicating adsorption of DNA to the internal surface of RSVE. These deter-minations will allow optimization of the use of RSVE as gene-transfer vehicles.

Biochemical and Biophysical Research Communications, 1997

HIV-1 Vif has two conserved cysteine residues in positions 114 and 133, both of which were found ... more HIV-1 Vif has two conserved cysteine residues in positions 114 and 133, both of which were found to be essential for HIV-1 infection and for Vif function in transcomplementation assays (X-Y. Ma, P. Sova, W. Chao, and D. J. Volsky, 1994, J. Virol. 68: 1714-1720). We evaluated here the redox status and disulfide bond formation of Vif cysteines inside cells or in virions and tested the role of Vif cysteines in Vif distribution in cells and in virions. Immunoblot analysis of Vif in wild type virus-infected cells and virions under different redox conditions revealed that the cysteine residues are readily accessible to chemical interaction but they do not form intramolecular disulfide bonds either inside cells or in virions, nor do they form covalent bonds with other proteins in either compartment. Cysteine mutants of Vif resembled wildtype Vif in their intracellular and virion distribution, indicating that Vif cysteines do not affect intracellular Vif transport and packaging into virions. We conclude that the cysteines in Vif do not form sulfhydryl bonds either intracellularly or in virions and may contribute to Vif activity rather than structure.

AIDS, 2007

We previously described chimeric HIV-1, EcoHIV, which can infect mouse cells in culture and cause... more 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. We used chimeric virus EcoHIV/NDK constructed on the backbone of subtype D NDK. EcoHIV/NDK expression in mice was characterized 5-10 days after infection by testing viral DNA, RNA, and protein burdens in spleen and macrophages by real-time PCR (QPCR), RT-PCR, and p24 ELISA. For antiviral evaluation, groups of 5-7 mice were pretreated with 2&amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;#39;,3&amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;#39;-dideoxycytidine (ddC), abacavir, or vehicle; mice were then infected with EcoHIV/NDK, treatment maintained for additional 48 h, and tested for viral DNA and RNA burdens in spleens and macrophages by QPCR. EcoHIV/NDK infected mice reproducibly showed viral burdens of up to 1.4 x 10 viral DNA copies and 200 pg p24 per 10 spleen cells and expressed spliced Vif RNA and mature p24 in macrophages 5-10 days after infection. Treatment of mice with 60 or 300 mg ddC/kg/day blocked EcoHIV/NDK infection in a dose-dependent manner with significantly lower viral DNA and RNA burdens at both drug doses (P &amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;lt; 0.001) in the spleens of infected mice. Abacavir tested at 100 mg/kg/day caused 96% inhibition of viral DNA synthesis in spleen and it almost completely abolished viral spliced RNA synthesis in spleens and macrophages. The system of chimeric HIV-1 infection of mice permits rapid, statistically powerful, and inexpensive evaluation of antiretroviral drugs in vivo.

Scientific Reports, Apr 21, 2023

HIV enters the brain within days of infection causing neurocognitive impairment (NCI) in up to ha... more 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. EcoHIV enters mouse brain within 5 days of infection, but NCI develops gradually with established cognitive disease starting 25 days after infection. CCL2 knockout mice infected by intraperitoneal injection of virus failed to develop brain infection and NCI. However, when EcoHIV was directly injected into the brain, CCL2 knockout mice developed NCI. Knockout of CCL2 or its principal receptor, CCR2, slightly reduced macrophage infection in culture. Treatment of mice prior to and during EcoHIV infection with the CCL2 transcriptional inhibitor, bindarit, prevented brain infection and NCI and reduced macrophage infection. In contrast, bindarit treatment of mice 4 weeks after infection affected neither brain virus burden nor NCI. Based on these findings we propose that HIV enters the brain mainly through infected monocytes but that resident brain cells are sufficient to maintain NCI. These findings suggest that NCI therapy must act within the brain. Combination antiretroviral therapy (CART) in people living with HIV (PLWH) suppresses HIV replication, prevents immunodeficiency, and extends lifetimes of people on CART. Nevertheless, other chronic ailments caused by HIV continue 1,2 . Among these, the predominantly mild HIV-associated neurocognitive disorders (HAND) occur in roughly half of CART compliant patients impairing day-to-day activities and reducing the quality of life 3 . With aging, PLWH are facing the fact that HAND tends to worsen with age 4 . To control or eliminate HAND, we must understand its viral and cellular bases. In this effort, we have employed infection of conventional mice by EcoHIV, a chimeric HIV which encodes the ecotropic murine leukemia virus (MLV) envelope protein gp80 in place of gp120 thereby switching viral tropism from human to rodent 5 . EcoHIV largely reproduces HIV cell and tissue tropism, and systemic EcoHIV infection of conventional mice resembles chronic suppressed HIV infection in PLWH. However, EcoHIV infection does not induce immunodeficiency, possibly because the virus does not encode gp120 5 . We and others have shown that EcoHIV, like HIV, replicates primarily in CD4 + T lymphocytes, macrophages, and the brain; the virus establishes a lifelong chronic infection; and it induces several diseases seen in CART compliant PLWH, including neurocognitive impairment (NCI) and depression-like defects in all infected animals . EcoHIV persistence in conventional mice correlates, as in PLWH, with low levels of latent/inducible provirus in CD4 + T lymphocytes and expressed virus in macrophages 15 . CD4 + T cells are the only cell type infected in spleen 5 while thymocytes, the main cellular targets for MLV in mice, are not susceptible to EcoHIV infection in vivo 15 . Intracranial injection of EcoHIV into mice revealed that the virus mainly infects macrophage/microglial cells and not neurons in the brain 7,9 , a result reproduced using RNAscope in EcoHIV infected rats 11 . The control of EcoHIV replication in mice was attributed to both innate and HIV specific CD8 + T cell immune responses . Other research suggests that EcoHIV, like HIV, can infect neuronal progenitor cells 18 and pericytes 19 in the central nervous system.

Journal of Virology, 1990

Two human immunodeficiency virus type 1 (HIV-1) variants derived from a single parental isolate w... more Two human immunodeficiency virus type 1 (HIV-1) variants derived from a single parental isolate were found to differ substantially in their ability to replicate in CD4-positive cells. Using transient chloramphenicol acetyltransferase expression assays, we show that the long terminal repeat (LTR) of the better-replicating virus has significantly higher capacity than that of the companion virus to direct gene expression in T cells. Sequence data and site-specific mutagenesis experiments demonstrate that the higher LTR activity of the better-replicating HIV-1 is due to a combined effect of two mutations: (i) a point mutation in position -94 (relative to the transcriptional start site), which is located between the two subunits of the HIV-1 enhancer, and (ii) a duplication of 24 base pairs in positions -128 to -151, which was not previously known to be involved in any regulatory function. The presence of these mutations increases the basal level of the LTR-driven gene expression and doe...