scholarly journals Productive Human Immunodeficiency Virus Type 1 Infection in Peripheral Blood Predominantly Takes Place in CD4/CD8 Double-Negative T Lymphocytes

2007 ◽  
Vol 81 (18) ◽  
pp. 9693-9706 ◽  
Author(s):  
Philipp Kaiser ◽  
Beda Joos ◽  
Barbara Niederöst ◽  
Rainer Weber ◽  
Huldrych F. Günthard ◽  
...  
Keyword(s):  
T Cells ◽  
T Lymphocytes ◽  
Peripheral Blood ◽  
Productive Infection ◽  
Viral Transcription ◽  
Cell Type ◽  
Immunodeficiency Virus ◽  
Infected Cells ◽  
Hiv 1

ABSTRACT Human immunodeficiency virus type 1 (HIV-1) transcription is subject to substantial fluctuation during the viral life cycle. Due to the low frequencies of HIV-1-infected cells, and because latently and productively infected cells collocate in vivo, little quantitative knowledge has been attained about the range of in vivo HIV-1 transcription in peripheral blood mononuclear cells (PBMC). By combining cell sorting, terminal dilution of intact cells, and highly sensitive, patient-specific PCR assays, we divided PBMC obtained from HIV-1-infected patients according to their degree of viral transcription activity and their cellular phenotype. Regardless of a patient's treatment status, the bulk of infected cells exhibited a CD4+ phenotype but transcribed HIV-1 provirus at low levels, presumably insufficient for virion production. Furthermore, the expression of activation markers on the surface of these CD4+ T lymphocytes showed little or no association with enhancement of viral transcription. In contrast, HIV-infected T lymphocytes of a CD4−/CD8− phenotype, occurring exclusively in untreated patients, exhibited elevated viral transcription rates. This cell type harbored a substantial proportion of all HIV RNA+ cells and intracellular viral RNAs and the majority of cell-associated virus particles. In conjunction with the observation that the HIV quasispecies in CD4+ and CD4−/CD8− T cells were phylogenetically closely related, these findings provide evidence that CD4 expression is downmodulated during the transition to productive infection in vivo. The abundance of viral RNA in CD4−/CD8− T cells from viremic patients and the almost complete absence of viral DNA and RNA in this cell type during antiretroviral treatment identify HIV+ CD4−/CD8 T cells as the major cell type harboring productive infection in peripheral blood.

scholarly journals Disseminated human immunodeficiency virus 1 (HIV-1) infection in SCID-hu mice after peripheral inoculation with HIV-1.

1994 ◽  
Vol 179 (2) ◽  
pp. 513-522 ◽  
Author(s):  
T R Kollmann ◽  
M Pettoello-Mantovani ◽  
X Zhuang ◽  
A Kim ◽  
M Hachamovitch ◽  
...  
Keyword(s):  
Human Immunodeficiency Virus ◽  
T Cells ◽  
Lymph Nodes ◽  
Peripheral Blood ◽  
Interleukin 2 ◽  
Human T Cells ◽  
Immunodeficiency Virus ◽  
Hiv 1 ◽  
Human Immunodeficiency Virus 1

A small animal model that could be infected with human immunodeficiency virus 1 (HIV-1) after peripheral inoculation would greatly facilitate the study of the pathophysiology of acute HIV-1 infection. The utility of SCID mice implanted with human fetal thymus and liver (SCID-hu mice) for studying peripheral HIV-1 infection in vivo has been hampered by the requirement for direct intraimplant injection of HIV-1 and the continued restriction of the resultant HIV-1 infection to the human thymus and liver (hu-thy/liv) implant. This may have been due to the very low numbers of human T cells present in the SCID-hu mouse peripheral lymphoid compartment. Since the degree of the peripheral reconstitution of SCID-hu mice with human T cells may be a function of the hu-thy/liv implant size, we increased the quantity of hu-thy/liv tissue implanted under the renal capsule and implanted hu-thy/liv tissue under the capsules of both kidneys. This resulted in SCID-hu mice in which significant numbers of human T cells were detected in the peripheral blood, spleens, and lymph nodes. After intraimplant injection of HIV-1 into these modified SCID-hu mice, significant HIV-1 infection was detected by quantitative coculture not only in the hu-thy/liv implant, but also in the spleen and peripheral blood. This indicated that HIV-1 infection can spread from the thymus to the peripheral lymphoid compartment. More importantly, a similar degree of infection of the hu-thy/liv implant and peripheral lymphoid compartment occurred after peripheral intraperitoneal inoculation with HIV-1. Active viral replication was indicated by the detection of HIV-1 gag DNA, HIV-1 gag RNA, and spliced tat/rev RNA in the hu-thy/liv implants, peripheral blood mononuclear cells (PBMC), spleens, and lymph nodes of these HIV-1-infected SCID-hu mice. As a first step in using our modified SCID-hu mouse model to investigate the pathophysiological consequences of HIV-1 infection, the effect of HIV-1 infection on the expression of human cytokines shown to enhance HIV-1 replication was examined. Significantly more of the HIV-1-infected SCID-hu mice expressed mRNA for human tumor necrosis factors alpha and beta, and interleukin 2 in their spleens, lymph nodes, and PBMC than did uninfected SCID-hu mice. This suggested that HIV-1 infection in vivo can stimulate the expression of cytokine mRNA by human T cells.(ABSTRACT TRUNCATED AT 400 WORDS)

scholarly journals Human Immunodeficiency Virus Type 1 Protease Cleaves Procaspase 8 In Vivo

2007 ◽  
Vol 81 (13) ◽  
pp. 6947-6956 ◽  
Author(s):  
Zilin Nie ◽  
Gary D. Bren ◽  
Stacey R. Vlahakis ◽  
Alicia Algeciras Schimnich ◽  
Jason M. Brenchley ◽  
...  
Keyword(s):  
Human Immunodeficiency Virus ◽  
T Cells ◽  
Human Immunodeficiency Virus Type ◽  
Virus Type ◽  
Specific Product ◽  
Immunodeficiency Virus ◽  
Infected Cells ◽  
Hiv 1

ABSTRACT Human immunodeficiency virus type 1 (HIV-1) infection causes apoptosis of infected CD4 T cells as well as uninfected (bystander) CD4 and CD8 T cells. It remains unknown what signals cause infected cells to die. We demonstrate that HIV-1 protease specifically cleaves procaspase 8 to create a novel fragment termed casp8p41, which independently induces apoptosis. casp8p41 is specific to HIV-1 protease-induced death but not other caspase 8-dependent death stimuli. In HIV-1-infected patients, casp8p41 is detected only in CD4+ T cells, predominantly in the CD27+ memory subset, its presence increases with increasing viral load, and it colocalizes with both infected and apoptotic cells. These data indicate that casp8p41 independently induces apoptosis and is a specific product of HIV-1 protease which may contribute to death of HIV-1-infected cells.

scholarly journals HIV-1 Vpr- and Reverse Transcription-Induced Apoptosis in Resting Peripheral Blood CD4 T Cells and Protection by Common Gamma-Chain Cytokines

2015 ◽  
Vol 90 (2) ◽  
pp. 904-916 ◽  
Author(s):  
Benjamin Trinité ◽  
Chi N. Chan ◽  
Caroline S. Lee ◽  
David N. Levy
Keyword(s):  
T Cells ◽  
Cell Death ◽  
T Cell ◽  
Reverse Transcription ◽  
Peripheral Blood ◽  
Cd4 T Cells ◽  
Productive Infection ◽  
Hiv 1

ABSTRACTHIV-1 infection leads to the progressive depletion of the CD4 T cell compartment by various known and unknown mechanisms.In vivo, HIV-1 infects both activated and resting CD4 T cells, butin vitro, in the absence of any stimuli, resting CD4 T cells from peripheral blood are resistant to infection. This resistance is generally attributed to an intracellular environment that does not efficiently support processes such as reverse transcription (RT), resulting in abortive infection. Here, we show thatin vitroHIV-1 infection of resting CD4 T cells induces substantial cell death, leading to abortive infection.In vivo, however, various microenvironmental stimuli in lymphoid and mucosal tissues provide support for HIV-1 replication. For example, common gamma-chain cytokines (CGCC), such as interleukin-7 (IL-7), render resting CD4 T cells permissible to HIV-1 infection without inducing T cell activation. Here, we find that CGCC primarily allow productive infection by preventing HIV-1 triggering of apoptosis, as evidenced by early release of cytochromecand caspase 3/7 activation. Cell death is triggered both by products of reverse transcription and by virion-borne Vpr protein, and CGCC block both mechanisms. When HIV-1 RT efficiency was enhanced by SIVmac239 Vpx protein, cell death was still observed, indicating that the speed of reverse transcription and the efficiency of its completion contributed little to HIV-1-induced cell death in this system. These results show that a major restriction on HIV-1 infection in resting CD4 T cells resides in the capacity of these cells to survive the early steps of HIV-1 infection.IMPORTANCEA major consequence of HIV-1 infection is the destruction of CD4 T cells. Here, we show that delivery of virion-associated Vpr protein and the process of reverse transcription are each sufficient to trigger apoptosis of resting CD4 T cells isolated from peripheral blood. While these 2 mechanisms have been previously described in various cell types, we show for the first time their concerted effect in inducing resting CD4 T cell depletion. Importantly, we found that cytokines such as IL-7 and IL-4, which are particularly active in sites of HIV-1 replication, protect resting CD4 T cells from these cytopathic effects and, primarily through this protection, rather than through enhancement of specific replicative steps, they promote productive infection. This study provides important new insights for the understanding of the early steps of HIV-1 infection and T cell depletion.

scholarly journals Distinct Mechanisms Trigger Apoptosis in Human Immunodeficiency Virus Type 1-Infected and in Uninfected Bystander T Lymphocytes

1998 ◽  
Vol 72 (1) ◽  
pp. 660-670 ◽  
Author(s):  
Georges Herbein ◽  
Carine Van Lint ◽  
Jennie L. Lovett ◽  
Eric Verdin
Keyword(s):  
Human Immunodeficiency Virus ◽  
T Cells ◽  
T Lymphocytes ◽  
Human Immunodeficiency Virus Type ◽  
Virus Type ◽  
Peripheral Blood ◽  
Peripheral Blood Lymphocytes ◽  
Immunodeficiency Virus ◽  
Hiv 1

ABSTRACT Apoptosis is a main feature of AIDS pathogenesis and is thought to play a role in the progressive decrease of CD4+ T lymphocytes in infected individuals. To determine whether apoptosis occurs in infected and/or in uninfected peripheral blood T lymphocytes, we have used a recombinant human immunodeficiency virus type 1 (HIV-1) infectious clone expressing the green fluorescent protein (GFP). Using flow cytometry, we have determined the incidence of apoptosis by either terminal transferase dUTP nick end labeling or annexin-V assays in different cell subpopulations, i.e., in CD4+ or CD8+ T cells that were GFP positive or negative. After HIV-1 infection of purified peripheral blood lymphocytes, we observed that apoptosis occurred mostly in infected CD4+ peripheral blood lymphocytes. Remarkably, the presence of monocyte-derived macrophages in the culture increased dramatically the apoptosis of uninfected bystander T lymphocytes, while apoptosis in HIV-infected T lymphocytes was not changed. We therefore demonstrate that HIV-induced apoptosis results from at least two distinct mechanisms: (i) direct apoptosis in HIV-infected CD4+ T lymphocytes and (ii) indirect apoptosis in uninfected T cells mediated by antigen-presenting cells.

scholarly journals Cytopathic Killing of Peripheral Blood CD4+ T Lymphocytes by Human Immunodeficiency Virus Type 1 Appears Necrotic rather than Apoptotic and Does Not Require env

2002 ◽  
Vol 76 (10) ◽  
pp. 5082-5093 ◽  
Author(s):  
Michael J. Lenardo ◽  
Sara B. Angleman ◽  
Viengngeun Bounkeua ◽  
Joseph Dimas ◽  
Melody G. Duvall ◽  
...  
Keyword(s):  
Human Immunodeficiency Virus ◽  
T Cells ◽  
T Lymphocytes ◽  
Peripheral Blood ◽  
Fluorescent Protein ◽  
Jurkat Cells ◽  
Coding Region ◽  
Immunodeficiency Virus ◽  
Hiv 1

ABSTRACT An important unresolved issue of AIDS pathogenesis is the mechanism of human immunodeficiency virus (HIV)-induced CD4+ T-lymphocyte destruction. We show here that HIV type 1 (HIV-1) exerts a profound cytopathic effect upon peripheral blood CD4+ T lymphocytes that resembles necrosis rather than apoptosis. Necrotic cytopathology was found with both laboratory-adapted strains and primary isolates of HIV-1. We carefully investigated the role of env, which has been previously implicated in HIV cytopathicity. HIV-1 stocks with equivalent infectivity were prepared from constructs with either an intact or mutated env coding region and pseudotyped with the glycoprotein of vesicular stomatitis virus (VSV-G) so that the HIV envelope was not rate-limiting for infection. Infected Jurkat T cells died whether or not env was intact; however, the expression of env accelerated death significantly. The accelerated death was blocked by protease inhibitors, indicating that it was due to reinfection by newly produced virus in env+ cultures. Accordingly, we found no disparity in kinetics in CD4lo Jurkat cells. In highly infected peripheral blood T cells, profound necrosis occurred equivalently with both env+ and env− stocks of HIV-1. We also found that HIV-1 cytopathicity was undiminished by the absence of nef. However, viral stocks made by complementation or packaging of HIV-1 genomes with the natural protein-coding sequences replaced by the green fluorescent protein were highly infectious but not cytopathic. Thus, env can accelerate cell death chiefly as an entry function, but one or more viral functions other than env or nef is essential for necrosis of CD4+ T cells induced by HIV-1.

scholarly journals Peripheral Blood Cytotoxic γδ T Lymphocytes from Patients with Human Immunodeficiency Virus Type 1 Infection and AIDS Lyse Uninfected CD4+ T Cells, and Their Cytocidal Potential Correlates with Viral Load

2003 ◽  
Vol 77 (3) ◽  
pp. 1848-1855 ◽  
Author(s):  
Sardar T. A. K. Sindhu ◽  
Rasheed Ahmad ◽  
Richard Morisset ◽  
Ali Ahmad ◽  
José Menezes
Keyword(s):  
Human Immunodeficiency Virus ◽  
T Cells ◽  
T Cell ◽  
T Lymphocytes ◽  
Human Immunodeficiency Virus Type ◽  
Peripheral Blood ◽  
Cell Counts ◽  
Immunodeficiency Virus ◽  
Hiv 1

ABSTRACT Progression of human immunodeficiency virus type 1 (HIV-1) infection in humans is marked by declining CD4+-T-cell counts and increasing virus load (VL). Cytotoxic T lymphocytes (CTL) play an important role in the lysis of HIV-infected cells, especially during the early phase of asymptomatic infection. CTL responses in the later phase of disease progression may not be as effective since progressors with lower CD4+-T-cell counts have consistently higher VL despite having elevated CTL counts. We hypothesized that, apart from antiviral effects, some CTL might also contribute to AIDS pathogenesis by depleting CD4+ T cells and that this CTL activity may correlate with the VL in AIDS patients. Therefore, a cross-sectional study of 31 HIV-1-infected patients at various clinical stages was carried out. Purified CTL from these donors as well as HIV-seronegative controls were used as effectors against different human cell targets by using standard 51Cr release cytolytic assays. A direct correlation between VL and CTL-mediated, major histocompatibility complex (MHC)-unrestricted lysis of primary CD4+-T-cell, CEM.NKR, and K562 targets was observed. CD4+-T-cell counts and duration of infection also correlated with MHC-unrestricted cytolytic activity. Our data clearly show that γδ CTL are abnormally expanded in the peripheral blood of HIV-infected patients and that the Vδ1 subset of γδ T cells is the main effector population responsible for this type of cytolysis. The present data suggest that γδ CTL can contribute to the depletion of bystander CD4+ T cells in HIV-infected patients as a parallel mechanism to HIV-associated immunopathogenesis and hence expedite AIDS progression.

scholarly journals Highly Productive Infection with Pseudotyped Human Immunodeficiency Virus Type 1 (HIV-1) Indicates No Intracellular Restrictions to HIV-1 Replication in Primary Human Astrocytes

2001 ◽  
Vol 75 (17) ◽  
pp. 7925-7933 ◽  
Author(s):  
Mario Canki ◽  
Janice Ngee Foong Thai ◽  
Wei Chao ◽  
Anuja Ghorpade ◽  
Mary Jane Potash ◽  
...  
Keyword(s):  
Human Immunodeficiency Virus ◽  
Human Immunodeficiency Virus Type ◽  
Productive Infection ◽  
Human Astrocytes ◽  
Immunodeficiency Virus ◽  
Infected Cells ◽  
Virus Expression ◽  
Hiv 1

ABSTRACT Human astrocytes can be infected with human immunodeficiency virus type 1 (HIV-1) in vitro and in vivo, but, in contrast to T lymphocytes and macrophages, virus expression is inefficient. To investigate the HIV-1 life cycle in human fetal astrocytes, we infected cells with HIV-1 pseudotyped with envelope glycoproteins of either amphotropic murine leukemia virus or vesicular stomatitis virus. Infection by both pseudotypes was productive and long lasting and reached a peak of 68% infected cells and 1.7 μg of viral p24 per ml of culture supernatant 7 days after virus inoculation and then continued with gradually declining levels of virus expression through 7 weeks of follow-up. This contrasted with less than 0.1% HIV-1 antigen-positive cells and 400 pg of extracellular p24 per ml at the peak of astrocyte infection with native HIV-1. Cell viability and growth kinetics were similar in infected and control cells. Northern blot analysis revealed the presence of major HIV-1 RNA species of 9, 4, and 2 kb in astrocytes exposed to pseudotyped (but not wild-type) HIV-1 at 2, 14, and 28 days after infection. Consistent with productive infection, the 9- and 4-kb viral transcripts in astrocytes infected by pseudotyped HIV-1 were as abundant as the 2-kb mRNA during 4 weeks of follow-up, and both structural and regulatory viral proteins were detected in infected cells by immunoblotting or cell staining. The progeny virus released by these cells was infectious. These results indicate that the major barrier to HIV-1 infection of primary astrocytes is at virus entry and that astrocytes have no intrinsic intracellular restriction to efficient HIV-1 replication.

scholarly journals Notwithstanding Circumstantial Alibis, Cytotoxic T Cells Can Be Major Killers of HIV-1-Infected Cells

2016 ◽  
Vol 90 (16) ◽  
pp. 7066-7083 ◽  
Author(s):  
Saikrishna Gadhamsetty ◽  
Tim Coorens ◽  
Rob J. de Boer
Keyword(s):  
T Cells ◽  
Viral Replication ◽  
Cytotoxic T Cells ◽  
Chronic Phase ◽  
Replication Rate ◽  
Immunodeficiency Virus ◽  
Infected Cells ◽  
Eclipse Phase ◽  
Hiv 1

ABSTRACTSeveral experiments suggest that in the chronic phase of human immunodeficiency virus type 1 (HIV-1) infection, CD8+cytotoxic T lymphocytes (CTL) contribute very little to the death of productively infected cells. First, the expected life span of productively infected cells is fairly long, i.e., about 1 day. Second, this life span is hardly affected by the depletion of CD8+T cells. Third, the rate at which mutants escaping a CTL response take over the viral population tends to be slow. Our main result is that all these observations are perfectly compatible with killing rates that are much faster than one per day once we invoke the fact that infected cells proceed through an eclipse phase of about 1 day before they start producing virus. Assuming that the major protective effect of CTL is cytolytic, we demonstrate that mathematical models with an eclipse phase account for the data when the killing is fast and when it varies over the life cycle of infected cells. Considering the steady state corresponding to the chronic phase of the infection, we find that the rate of immune escape and the rate at which the viral load increases following CD8+T cell depletion should reflect the viral replication rate, ρ. A meta-analysis of previous data shows that viral replication rates during chronic infection vary between 0.5 ≤ ρ ≤ 1 day−1. Balancing such fast viral replication requires killing rates that are several times larger than ρ, implying that most productively infected cells would die by cytolytic effects.IMPORTANCEMost current data suggest that cytotoxic T cells (CTL) mediate their control of human immunodeficiency virus type 1 (HIV-1) infection by nonlytic mechanisms; i.e., the data suggest that CTL hardly kill. This interpretation of these data has been based upon the general mathematical model for HIV infection. Because this model ignores the eclipse phase between the infection of a target cell and the start of viral production by that cell, we reanalyze the same data sets with novel models that do account for the eclipse phase. We find that the data are perfectly consistent with lytic control by CTL and predict that most productively infected cells are killed by CTL. Because the killing rate should balance the viral replication rate, we estimate both parameters from a large set of published experiments in which CD8+T cells were depleted in simian immunodeficiency virus (SIV)-infected monkeys. This confirms that the killing rate can be much faster than is currently appreciated.

scholarly journals Preferential and persistent impact of acute HIV-1 infection on CD4+ iNKT cells in colonic mucosa

2021 ◽  
Vol 118 (46) ◽  
pp. e2104721118
Author(s):  
Dominic Paquin-Proulx ◽  
Kerri G. Lal ◽  
Yuwadee Phuang-Ngern ◽  
Matthew Creegan ◽  
Andrey Tokarev ◽  
...  
Keyword(s):  
T Cells ◽  
Peripheral Blood ◽  
Colonic Mucosa ◽  
Inkt Cells ◽  
Elevated Expression ◽  
Acute Hiv ◽  
The Impact ◽  
Hiv 1

Acute HIV-1 infection (AHI) results in the widespread depletion of CD4+ T cells in peripheral blood and gut mucosal tissue. However, the impact on the predominantly CD4+ immunoregulatory invariant natural killer T (iNKT) cells during AHI remains unknown. Here, iNKT cells from peripheral blood and colonic mucosa were investigated during treated and untreated AHI. iNKT cells in blood were activated and rapidly depleted in untreated AHI. At the time of peak HIV-1 viral load, these cells showed the elevated expression of cell death–associated transcripts compared to preinfection. Residual peripheral iNKT cells suffered a diminished responsiveness to in vitro stimulation early into chronic infection. Additionally, HIV-1 DNA, as well as spliced and unspliced viral RNA, were detected in iNKT cells isolated from blood, indicating the active infection of these cells in vivo. The loss of iNKT cells occurred from Fiebig stage III in the colonic mucosa, and these cells were not restored to normal levels after initiation of ART during AHI. CD4+ iNKT cells were depleted faster and more profoundly than conventional CD4+ T cells, and the preferential infection of CD4+ iNKT cells over conventional CD4+ T cells was confirmed by in vitro infection experiments. In vitro data also provided evidence of latent infection in iNKT cells. Strikingly, preinfection levels of peripheral blood CD4+ iNKT cells correlated directly with the peak HIV-1 load. These findings support a model in which iNKT cells are early targets for HIV-1 infection, driving their rapid loss from circulation and colonic mucosa.

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