scholarly journals Combination of CD8β Depletion and Interleukin-15 Superagonist N-803 Induces Virus Reactivation in Simian-Human Immunodeficiency Virus-Infected, Long-Term ART-Treated Rhesus Macaques

2020 ◽  
Vol 94 (19) ◽  
Author(s):  
Julia B. McBrien ◽  
Andrew K. H. Wong ◽  
Erick White ◽  
Diane G. Carnathan ◽  
John H. Lee ◽  
...  
Keyword(s):  
Human Immunodeficiency Virus ◽  
T Cells ◽  
Rhesus Macaques ◽  
Plasma Viremia ◽  
Virus Reactivation ◽  
Hiv Cure ◽  
Immunodeficiency Virus ◽  
Shock And Kill ◽  
Interleukin 15

ABSTRACT The “shock and kill” strategy predicates that virus reactivation in latently infected cells is required to eliminate the human immunodeficiency virus (HIV) reservoir. In a recent study, we showed robust and persistent induction of plasma viremia in antiretroviral therapy (ART)-treated simian immunodeficiency virus-infected rhesus macaques (RMs) undergoing CD8α depletion and treated with the interleukin-15 (IL-15) superagonist N-803 (J. B. McBrien et al., Nature 578:154–159, 2020, https://doi.org/10.1038/s41586-020-1946-0). Of note, in that study we used an antibody targeting CD8α, thereby depleting NK cells, NKT cells, and γδ T cells, in addition to CD8+ T cells. In the current proof-of-concept study, we tested whether virus reactivation can be induced by administration of N-803 to simian-human chimeric immunodeficiency virus-infected, ART-treated RMs that are selectively depleted of CD8+ T cells via the CD8β-targeting antibody CD8b255R1. CD8β depletion was performed in five SHIVSF162P3-infected RMs treated with ART for 12 months and with plasma viremia consistently below 3 copies/ml. All animals received four weekly doses of N-803 starting at the time of CD8b255R1 administration. The induction of detectable plasma viremia was observed in three out of five RMs, with the level of virus reactivation seemingly correlated with the frequency of CD8+ T cells following CD8β depletion as well as the level of virus reactivation observed when the same animals underwent CD8α depletion and N-803 administration after 24 weeks of ART. These data indicate that CD8β depletion and N-803 administration can induce virus reactivation in SHIVSF162P3-infected RMs despite suboptimal depletion of CD8+ T cells and profound ART-induced suppression of virus replication, confirming a critical role for these cells in suppressing virus production and/or reactivation in vivo under ART. IMPORTANCE The “shock and kill” HIV cure strategy attempts to reverse and eliminate the latent viral infection that prevents eradication of the virus. Latency-reversing agents tested in clinical trials to date have failed to affect the HIV viral reservoir. IL-15 superagonist N-803, currently involved in a clinical trial for HIV cure, was recently shown by our laboratory to induce robust and persistent induction of plasma viremia during ART in three in vivo animal models of HIV infection. These results suggest a substantial role for CD8+ lymphocytes in suppressing the latency reversal effect of N-803 by promoting the maintenance of viral latency. In this study, we tested whether the use of a CD8β-targeting antibody, which would specifically deplete CD8+ T cells, would yield similar levels of virus reactivation. We observed the induction of plasma viremia, which correlated with the efficacy of the CD8 depletion strategy.

scholarly journals Generation of the Pathogenic R5-Tropic Simian/Human Immunodeficiency Virus SHIVAD8 by Serial Passaging in Rhesus Macaques

2010 ◽  
Vol 84 (9) ◽  
pp. 4769-4781 ◽  
Author(s):  
Yoshiaki Nishimura ◽  
Masashi Shingai ◽  
Ronald Willey ◽  
Reza Sadjadpour ◽  
Wendy R. Lee ◽  
...  
Keyword(s):  
Human Immunodeficiency Virus ◽  
T Cells ◽  
T Lymphocytes ◽  
Opportunistic Infections ◽  
Rhesus Macaques ◽  
Pneumocystis Carinii ◽  
Campylobacter Coli ◽  
Plasma Viremia ◽  
Cell Responses ◽  
Immunodeficiency Virus

ABSTRACT A new pathogenic R5-tropic simian/human immunodeficiency virus (SHIV) was generated following serial passaging in rhesus macaques. All 13 animals inoculated with SHIVAD8 passaged lineages experienced marked depletions of CD4+ T cells. Ten of these infected monkeys became normal progressors (NPs) and had gradual losses of both memory and naïve CD4+ T lymphocytes, generated antiviral CD4+ and CD8+ T cell responses, and sustained chronic immune activation while maintaining variable levels of plasma viremia (102 to 105 RNA copies/ml for up to 3 years postinfection [p.i.]). To date, five NPs developed AIDS associated with opportunistic infections caused by Pneumocystis carinii, Mycobacterium avium, and Campylobacter coli that required euthanasia between weeks 100 and 199 p.i. Three other NPs have experienced marked depletions of circulating CD4+ T lymphocytes (92 to 154 cells/μl) following 1 to 2 years of infection. When tested for coreceptor usage, the viruses isolated from four NPs at the time of their euthanasia remained R5 tropic. Three of the 13 SHIVAD8-inoculated macaques experienced a rapid-progressor syndrome characterized by sustained plasma viremia of >1 × 107 RNA copies/ml and rapid irreversible loss of memory CD4+ T cells that required euthanasia between weeks 19 and 23 postinfection. The sustained viremia, associated depletion of CD4+ T lymphocytes, and induction of AIDS make the SHIVAD8 lineage of viruses a potentially valuable reagent for vaccine studies.

scholarly journals Potent activity of 2'-beta-fluoro-2',3'-dideoxyadenosine against human immunodeficiency virus type 1 infection in hu-PBL-SCID mice.

1996 ◽  
Vol 40 (10) ◽  
pp. 2369-2374 ◽  
Author(s):  
K Ruxrungtham ◽  
E Boone ◽  
H Ford ◽  
J S Driscoll ◽  
R T Davey ◽  
...  
Keyword(s):  
Human Immunodeficiency Virus ◽  
T Cells ◽  
Hiv Infection ◽  
Infection Rate ◽  
Cd4 T Cells ◽  
Scid Mice ◽  
Immunodeficiency Virus ◽  
Anti Hiv

A new antiretroviral agent, 2'-beta-fluoro-2',3'-dideoxyadenosine (FddA), is an acid-stable compound whose triphosphate form is a potent reverse transcriptase inhibitor with in vitro anti-human immunodeficiency virus (HIV) activity and a favorable pharmacokinetic profile. Severe combined immunodeficiency (SCID) mice reconstituted with human peripheral blood leukocytes (hu-PBL-SCID mice) provide a useful small-animal model for HIV research. In the present study we utilized this experimental system for the in vivo evaluation of the anti-HIV activity of this new compound when administered prior to infection. Initial studies revealed that, following a challenge with 50 100% tissue culture infective doses of HIV type 1 lymphadenopathy-associated virus, 39 of 42 (93%) control mice developed HIV infection, as evidenced by positive coculture or positive PCR. Administration of zidovudine decreased the infection rate to 5 of 16 (31%), while administration of FddA decreased the infection rate to 0 of 44 (0%). In follow-up controlled studies, the anti-HIV activity of FddA was confirmed, with 18 of 20 control mice showing evidence of HIV infection, compared with 4 of 20 FddA-treated mice. In addition to having direct anti-HIV effects, FddA was found to have a protective effect on human CD4+ T cells in the face of HIV infection. Mice treated with FddA were found to have a significantly higher percentage of CD4+ T cells than controls (10.3% +/- 3.4% versus 0.27% +/- 0.21%; P = 0.01). Thus, FddA, with its potent anti-HIV activity in vivo, high oral bioavailability, long intracellular half-life, and ability to preserve CD4+ cells in the presence of HIV, appears to be a promising agent for clinical investigation.

scholarly journals CD4-Negative Cells Bind Human Immunodeficiency Virus Type 1 and Efficiently Transfer Virus to T Cells

2000 ◽  
Vol 74 (18) ◽  
pp. 8550-8557 ◽  
Author(s):  
Gene G. Olinger ◽  
Mohammed Saifuddin ◽  
Gregory T. Spear
Keyword(s):  
Human Immunodeficiency Virus ◽  
T Cells ◽  
Mononuclear Cells ◽  
Cell Types ◽  
Virus Binding ◽  
Peripheral Blood Mononuclear ◽  
Human Immunodeficiency Virus Strain ◽  
Immunodeficiency Virus

ABSTRACT The ability of human immunodeficiency virus strain MN (HIVMN), a T-cell line-adapted strain of HIV, and X4 and R5 primary isolates to bind to various cell types was investigated. In general, HIVMN bound to cells at higher levels than did the primary isolates. Virus bound to both CD4-positive (CD4+) and CD4-negative (CD4−) cells, including neutrophils, Raji cells, tonsil mononuclear cells, erythrocytes, platelets, and peripheral blood mononuclear cells (PBMC), although virus bound at significantly higher levels to PBMC. However, there was no difference in the amount of HIV that bound to CD4-enriched or CD4-depleted PBMC. Virus bound to CD4− cells was up to 17 times more infectious for T cells in cocultures than was the same amount of cell-free virus. Virus bound to nucleated cells was significantly more infectious than virus bound to erythrocytes or platelets. The enhanced infection of T cells by virus bound to CD4− cells was not due to stimulatory signals provided by CD4− cells or infection of CD4− cells. However, anti-CD18 antibody substantially reduced the enhanced virus replication in T cells, suggesting that virus that bound to the surface of CD4−cells is efficiently passed to CD4+ T cells during cell-cell adhesion. These studies show that HIV binds at relatively high levels to CD4− cells and, once bound, is highly infectious for T cells. This suggests that virus binding to the surface of CD4− cells is an important route for infection of T cells in vivo.

scholarly journals Simian Immunodeficiency Virus SIVagm Efficiently Utilizes Non-CCR5 Entry Pathways in African Green Monkey Lymphocytes: Potential Role for GPR15 and CXCR6 as Viral Coreceptors

2015 ◽  
Vol 90 (5) ◽  
pp. 2316-2331 ◽  
Author(s):  
Nadeene E. Riddick ◽  
Fan Wu ◽  
Kenta Matsuda ◽  
Sonya Whitted ◽  
Ilnour Ourmanov ◽  
...  
Keyword(s):  
T Cells ◽  
Mononuclear Cells ◽  
Rhesus Macaques ◽  
Target Cells ◽  
Peripheral Blood Mononuclear ◽  
Immunodeficiency Virus ◽  
Sooty Mangabeys ◽  
Natural Hosts

ABSTRACTAfrican green monkeys (AGM) are natural hosts of simian immunodeficiency virus (SIV), and infection in these animals is generally nonpathogenic, whereas infection of nonnatural hosts, such as rhesus macaques (RM), is commonly pathogenic. CCR5 has been described as the primary entry coreceptor for SIVin vivo, while human-derived CXCR6 and GPR15 also appear to be usedin vitro. However, sooty mangabeys that are genetically deficient in CCR5 due to an out-of-frame deletion are infectible with SIVsmm, indicating that SIVsmm can use alternative coreceptorsin vivo. In this study, we examined the CCR5 dependence of SIV strains derived from vervet AGM (SIVagmVer) and the ability of AGM-derived GPR15 and CXCR6 to serve as potential entry coreceptors. We found that SIVagmVer replicated efficiently in AGM and RM peripheral blood mononuclear cells (PBMC) in the presence of the CCR5 antagonist maraviroc, despite the fact that maraviroc was capable of blocking the CCR5-tropic strains SIVmac239, SIVsmE543-3, and simian-human immunodeficiency virus SHIV-AD8 in RM PBMC. We also found that AGM CXCR6 and AGM GPR15, to a lesser extent, supported entry of pseudotype viruses bearing SIVagm envelopes, including SIVagm transmitted/founder envelopes. Lastly, we found that CCR5, GPR15, and CXCR6 mRNAs were detected in AGM and RM memory CD4+T cells. These results suggest that GPR15 and CXCR6 are expressed on AGM CD4+T cells and are potential alternative coreceptors for SIVagm usein vivo. These data suggest that the use of non-CCR5 entry pathways may be a common feature of SIV replication in natural host species, with the potential to contribute to nonpathogenicity in these animals.IMPORTANCEAfrican green monkeys (AGM) are natural hosts of SIV, and infection in these animals generally does not cause AIDS, whereas SIV-infected rhesus macaques (RM) typically develop AIDS. Although it has been reported that SIV generally uses CD4 and CCR5 to enter target cellsin vivo, other molecules, such as GPR15 and CXCR6, also function as SIV coreceptorsin vitro. In this study, we investigated whether SIV from vervet AGM can use non-CCR5 entry pathways, as has been observed in sooty mangabeys. We found that SIVagmVer efficiently replicated in AGM and RM peripheral blood mononuclear cells in the presence of the CCR5 antagonist maraviroc, suggesting that non-CCR5 entry pathways can support SIVagm entry. We found that AGM-derived GPR15 and CXCR6 support SIVagmVer entryin vitroand may serve as entry coreceptors for SIVagmin vivo, since their mRNAs were detected in AGM memory CD4+T cells, the preferred target cells of SIV.

scholarly journals With Minimal Systemic T-Cell Expansion, CD8+ T Cells Mediate Protection of Rhesus Macaques Immunized with Attenuated Simian-Human Immunodeficiency Virus SHIV89.6 from Vaginal Challenge with Simian Immunodeficiency Virus

2008 ◽  
Vol 82 (22) ◽  
pp. 11181-11196 ◽  
Author(s):  
Meritxell Genescà ◽  
Pamela J. Skinner ◽  
Jung Joo Hong ◽  
Jun Li ◽  
Ding Lu ◽  
...  
Keyword(s):  
Human Immunodeficiency Virus ◽  
T Cells ◽  
T Cell ◽  
Simian Immunodeficiency Virus ◽  
Rhesus Macaques ◽  
T Cell Response ◽  
Lymphoid Tissues ◽  
Vaginal Mucosa ◽  
Challenge Virus ◽  
Immunodeficiency Virus

ABSTRACT The presence, at the time of challenge, of antiviral effector T cells in the vaginal mucosa of female rhesus macaques immunized with live-attenuated simian-human immunodeficiency virus 89.6 (SHIV89.6) is associated with consistent and reproducible protection from pathogenic simian immunodeficiency virus (SIV) vaginal challenge (18). Here, we definitively demonstrate the protective role of the SIV-specific CD8+ T-cell response in SHIV-immunized monkeys by CD8+ lymphocyte depletion, an intervention that abrogated SHIV-mediated control of challenge virus replication and largely eliminated the SIV-specific T-cell responses in blood, lymph nodes, and genital mucosa. While in the T-cell-intact SHIV-immunized animals, polyfunctional and degranulating SIV-specific CD8+ T cells were present in the genital tract and lymphoid tissues from the day of challenge until day 14 postchallenge, strikingly, expansion of SIV-specific CD8+ T cells in the immunized monkeys was minimal and limited to the vagina. Thus, protection from uncontrolled SIV replication in animals immunized with attenuated SHIV89.6 is primarily mediated by CD8+ T cells that do not undergo dramatic systemic expansion after SIV challenge. These findings demonstrate that despite, and perhaps because of, minimal systemic expansion of T cells at the time of challenge, a stable population of effector-cytotoxic CD8+ T cells can provide significant protection from vaginal SIV challenge.

scholarly journals Physiological Levels of Virion-Associated Human Immunodeficiency Virus Type 1 Envelope Induce Coreceptor-Dependent Calcium Flux

2006 ◽  
Vol 81 (4) ◽  
pp. 1773-1785 ◽  
Author(s):  
Marta Melar ◽  
David E. Ott ◽  
Thomas J. Hope
Keyword(s):  
Human Immunodeficiency Virus ◽  
T Cells ◽  
Chemokine Receptors ◽  
Calcium Flux ◽  
Target Cells ◽  
Immunodeficiency Virus ◽  
Hiv Entry ◽  
The One ◽  
Signaling Activation

ABSTRACT Human immunodeficiency virus (HIV) entry into target cells requires the engagement of receptor and coreceptor by envelope glycoprotein (Env). Coreceptors CCR5 and CXCR4 are chemokine receptors that generate signals manifested as calcium fluxes in response to binding of the appropriate ligand. It has previously been shown that engagement of the coreceptors by HIV Env can also generate Ca2+ fluxing. Since the sensitivity and therefore the physiological consequence of signaling activation in target cells is not well understood, we addressed it by using a microscopy-based approach to measure Ca2+ levels in individual CD4+ T cells in response to low Env concentrations. Monomeric Env subunit gp120 and virion-bound Env were able to activate a signaling cascade that is qualitatively different from the one induced by chemokines. Env-mediated Ca2+ fluxing was coreceptor mediated, coreceptor specific, and CD4 dependent. Comparison of the observed virion-mediated Ca2+ fluxing with the exact number of viral particles revealed that the viral threshold necessary for coreceptor activation of signaling in CD4+ T cells was quite low, as few as two virions. These results indicate that the physiological levels of virion binding can activate signaling in CD4+ T cells in vivo and therefore might contribute to HIV-induced pathogenesis.

Detection and characterization of apoptotic peripheral blood lymphocytes in human immunodeficiency virus infection and cancer chemotherapy by a novel flow immunocytometric method

Blood ◽  
1994 ◽  
Vol 83 (5) ◽  
pp. 1268-1277 ◽  
Author(s):  
M Carbonari ◽  
M Cibati ◽  
M Cherchi ◽  
D Sbarigia ◽  
AM Pesce ◽  
...  
Keyword(s):  
Human Immunodeficiency Virus ◽  
T Cells ◽  
Hiv Infection ◽  
Peripheral Blood ◽  
Peripheral Blood Leukocytes ◽  
Blood Leukocytes ◽  
Cell Counts ◽  
Immunodeficiency Virus

We have developed a quantitative and sensitive flow cytometric method for the detection of human apoptotic lymphocytes that, unlike previously described assays, allows their identification in mixed populations of peripheral blood leukocytes as well as their immunophenotyping. Apoptotic lymphocytes are identified on the basis of peculiar light scatter changes, reflecting their smaller size and their modified nucleus/cytoplasm organization, and of the decreased expression of surface CD45 molecules. Based on these criteria, apoptotic lymphocytes generated by exposure to ionizing radiation can be easily distinguished from viable cells and from necrotic lymphocytes generated by treatment with antibody and complement. Using this assay, we reappraised the phenomenon of the in vitro apoptosis of lymphocytes from patients with human immunodeficiency virus (HIV) infection. Lymphocytes from HIV patients, unlike those from normal HIV-negative subjects, undergo apoptosis upon simple in vitro culture. We found that the percentages of lymphocytes undergoing apoptosis were significantly higher in patients with low CD4 cell counts (< 400/microL) than in patients at earlier stages (> 400 CD4 cells/microL). However, phenotypic analysis disclosed that apoptotic lymphocytes generated in these cultures were mostly CD8+ T cells and CD19+ B cells. Thus, in contrast to what has been previously suggested, the phenomenon of in vitro lymphocyte apoptosis might not be pathogenetically related to the depletion of CD4+ T cells in acquired immunodeficiency syndrome. Nevertheless, it might represent an useful marker of disease progression. Our assay allows the analysis of unfractionated peripheral blood leukocytes and thus the identification of apoptotic lymphocytes circulating in vivo. Apoptotic lymphocytes could indeed be detected in the circulation of a patient with cancer shortly after high-dose cytotoxic chemotherapy. By contrast, no apoptotic lymphocytes could be detected in vivo in patients with early or advanced HIV infection.

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 Effects of in Vivo Cd8+ T Cell Depletion on Virus Replication in Rhesus Macaques Immunized with a Live, Attenuated Simian Immunodeficiency Virus Vaccine

1999 ◽  
Vol 191 (11) ◽  
pp. 1921-1932 ◽  
Author(s):  
Karin J. Metzner ◽  
Xia Jin ◽  
Fred V. Lee ◽  
Agegnehu Gettie ◽  
Daniel E. Bauer ◽  
...  
Keyword(s):  
T Cells ◽  
T Cell ◽  
Simian Immunodeficiency Virus ◽  
Cd8 T Cells ◽  
Rhesus Macaques ◽  
Cd8 T Cell ◽  
T Cell Depletion ◽  
Challenge Virus ◽  
Immunodeficiency Virus

The role of CD8+ T lymphocytes in controlling replication of live, attenuated simian immunodeficiency virus (SIV) was investigated as part of a vaccine study to examine the correlates of protection in the SIV/rhesus macaque model. Rhesus macaques immunized for &gt;2 yr with nef-deleted SIV (SIVmac239Δnef) and protected from challenge with pathogenic SIVmac251 were treated with anti-CD8 antibody (OKT8F) to deplete CD8+ T cells in vivo. The effects of CD8 depletion on viral load were measured using a novel quantitative assay based on real-time polymerase chain reaction using molecular beacons. This assay allows simultaneous detection of both the vaccine strain and the challenge virus in the same sample, enabling direct quantification of changes in each viral population. Our results show that CD8+ T cells were depleted within 1 h after administration of OKT8F, and were reduced by as much as 99% in the peripheral blood. CD8+ T cell depletion was associated with a 1–2 log increase in SIVmac239Δnef plasma viremia. Control of SIVmac239Δnef replication was temporally associated with the recovery of CD8+ T cells between days 8 and 10. The challenge virus, SIVmac251, was not detectable in either the plasma or lymph nodes after depletion of CD8+ T cells. Overall, our results indicate that CD8+ T cells play an important role in controlling replication of live, attenuated SIV in vivo.

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