Advantages of a human immunodeficiency virus type 1 (HIV-1) persistently infected HeLa T4+ cell line for HIV-1 indirect immunofluorescence serology.

Topotecan (TPT), a known inhibitor of topoisomerase I, has previously been shown to inhibit the replication of several viruses. The mechanism of inhibition was proposed to be the inhibition of topoisomerase I. We report that TPT decreased replication of human immunodeficiency virus type 1 (HIV-1) in CPT-K5, a cell line with a topoisomerase I mutation. TPT inhibited production of HIV-1 RNA and p24 in CPT-K5 and wild-type cells equally effectively. The antiviral effects of TPT were observed not only in the topoisomerase-mutated CPT-K5 line but also in peripheral blood mononuclear cells (PBMC) acutely infected with clinical isolates and in OM10.1 cells latently infected with HIV and activated by tumor necrosis factor alpha. Little toxicity from TPT was noted in HIV-1-infected PBMC and in CPT-K5 and OM10.1 cells as measured by cell growth and proliferation assays. These observations suggest that TPT targets factors in virus replication other than cellular topoisomerase I and inhibits cytokine-mediated activation in latently infected cells by means other than cytotoxicity. These results suggest a potential for TPT and for other camptothecins in anti-HIV therapy alone and in combination with other antiretroviral drugs.

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Evidence that Ecotropic Murine Leukemia Virus Contamination in TZM-bl Cells Does Not Affect the Outcome of Neutralizing Antibody Assays with Human Immunodeficiency Virus Type 1

Journal of Virology ◽

10.1128/jvi.00709-09 ◽

2009 ◽

Vol 83 (16) ◽

pp. 8289-8292 ◽

Cited By ~ 169

Author(s):

Emily J. Platt ◽

Miroslawa Bilska ◽

Susan L. Kozak ◽

David Kabat ◽

David C. Montefiori

Keyword(s):

Human Immunodeficiency Virus ◽

Cell Line ◽

Human Immunodeficiency Virus Type ◽

Virus Type ◽

Murine Leukemia Virus ◽

Leukemia Virus ◽

Immunodeficiency Virus ◽

Hiv 1 ◽

Murine Leukemia

ABSTRACT The TZM-bl cell line that is commonly used to assess neutralizing antibodies against human immunodeficiency virus type 1 (HIV-1) was recently reported to be contaminated with an ecotropic murine leukemia virus (MLV) (Y. Takeuchi, M. O. McClure, and M. Pizzato, J. Virol. 82:12585-12588, 2008), raising questions about the validity of results obtained with this cell line. Here we confirm this observation and show that HIV-1 neutralization assays performed with a variety of serologic reagents in a similar cell line that does not harbor MLV yield results that are equivalent to those obtained in TZM-bl cells. We conclude that MLV contamination has no measurable effect on HIV-1 neutralization when TZM-bl cells are used as targets for infection.

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The budding of defective human immunodeficiency virus type 1 (HIV-1) particles from cell clones persistently infected with HIV-1

Archives of Virology ◽

10.1007/bf01310507 ◽

1990 ◽

Vol 111 (1-2) ◽

pp. 87-101 ◽

Cited By ~ 28

Author(s):

T. Goto ◽

K. Ikuta ◽

J. J. Zhang ◽

C. Morita ◽

K. Sano ◽

...

Keyword(s):

Human Immunodeficiency Virus ◽

Human Immunodeficiency Virus Type ◽

Virus Type ◽

Persistently Infected ◽

Cell Clones ◽

Immunodeficiency Virus ◽

Hiv 1

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Human immunodeficiency virus type 1 neutralization is determined by epitope exposure on the gp120 oligomer.

Journal of Experimental Medicine ◽

10.1084/jem.182.1.185 ◽

1995 ◽

Vol 182 (1) ◽

pp. 185-196 ◽

Cited By ~ 267

Author(s):

Q J Sattentau ◽

J P Moore

Keyword(s):

Human Immunodeficiency Virus ◽

Cell Line ◽

Human Immunodeficiency Virus Type ◽

Virus Type ◽

Virus Neutralization ◽

V3 Loop ◽

Immunodeficiency Virus ◽

Monomeric Gp120 ◽

Hiv 1

The major target of the neutralizing antibody response to infection by the human immunodeficiency virus type 1 (HIV-1) is the outer envelope glycoprotein, gp120. The spectrum of HIV-1 neutralization specificity is currently represented by monoclonal antibodies (mAbs) that can be divided broadly into five groups. We have studied the binding of these mAbs to functional oligomeric and soluble monomeric gp120 derived from the molecular clone of a cell line-adapted isolate of HIV-1, and compared these binding properties with virus neutralization. Binding of all mAbs except those reactive with the V3 loop was much weaker to oligomeric than to monomeric gp120. This reduction in binding to oligomeric gp120 was determined mostly by a slower relative rate of association, although the dissociation rate also had some influence on relative variation in mAb affinity. Virus neutralization correlated broadly with mAb binding to the oligomeric rather than to the monomeric form of gp120, and neutralization potency was related to the estimated association rate. Thus, with the exception of the hypervariable V3 loop, regions of HIV-1 gp120 with the potential to induce a neutralization response are likely to be poorly presented for antibody recognition on the surface of cell line-adapted virions.

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Induction of Neutralizing Antibodies to T-Cell Line-Adapted and Primary Human Immunodeficiency Virus Type 1 Isolates with a Prime-Boost Vaccine Regimen in Chimpanzees

Journal of Virology ◽

10.1128/jvi.72.2.1052-1059.1998 ◽

1998 ◽

Vol 72 (2) ◽

pp. 1052-1059 ◽

Cited By ~ 56

Author(s):

Susan Zolla-Pazner ◽

Michael Lubeck ◽

Serena Xu ◽

Sherri Burda ◽

Robert J. Natuk ◽

...

Keyword(s):

Human Immunodeficiency Virus ◽

T Cell ◽

Cell Line ◽

Human Immunodeficiency Virus Type ◽

Virus Type ◽

Neutralizing Antibodies ◽

High Dose ◽

Immunodeficiency Virus ◽

Hiv 1

ABSTRACT Five chimpanzees were immunized by administration of one or more intranasal priming doses of one to three recombinant adenoviruses containing a gp160 insert from human immunodeficiency virus type 1 (HIV-1) MN (HIV-1MN) followed by one or more boosts of recombinant HIV-1SF2 gp120 delivered intramuscularly with MF59 adjuvant. This regimen resulted in humoral immune responses in three of five animals. Humoral responses included immunochemically active anti-HIV-1 antibodies (Abs) directed to recombinant gp120 and neutralizing Abs reactive with T-cell-line-adapted HIV-1MNand HIV-1SF2. In addition, neutralizing activity was detected to the two homologous primary isolates and to two of three heterologous primary isolates which, like the immunizing strains, can use CXCR4 as a coreceptor for infection. The three animals with detectable neutralizing Abs and a fourth exhibiting the best cytotoxic T-lymphocyte response were protected from a low-dose intravenous challenge with a cell-free HIV-1SF2 primary isolate administered 4 weeks after the last boost. Animals were rested for 46 weeks and then rechallenged, without a boost, with an eightfold-higher challenge dose of HIV-1SF2. The three animals with persistent neutralizing Abs were again protected. These data show that a strong, long-lived protective Ab response can be induced with a prime-boost regimen in chimpanzees. The data suggest that in chimpanzees, the presence of neutralizing Abs correlates with protection for animals challenged intravenously with a high dose of a homologous strain of HIV-1, and they demonstrate for the first time the induction of neutralizing Abs to homologous and heterologous primary isolates.

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Study of the V3 Loop as a Target Epitope for Antibodies Involved in the Neutralization of Primary Isolates versus T-Cell-Line-Adapted Strains of Human Immunodeficiency Virus Type 1

Journal of Virology ◽

10.1128/jvi.72.12.9855-9864.1998 ◽

1998 ◽

Vol 72 (12) ◽

pp. 9855-9864 ◽

Cited By ~ 55

Author(s):

Catherine Spenlehauer ◽

Sentob Saragosti ◽

Hervé J. A. Fleury ◽

André Kirn ◽

Anne-Marie Aubertin ◽

...

Keyword(s):

Human Immunodeficiency Virus ◽

T Cell ◽

Cell Line ◽

Human Immunodeficiency Virus Type ◽

Virus Type ◽

V3 Loop ◽

Immunodeficiency Virus ◽

Target Epitope ◽

Hiv 1

ABSTRACT Previous studies characterized the third variable (V3) loop of the envelope gp120 as the principal neutralizing determinant for laboratory T-cell-line-adapted (TCLA) strains of human immunodeficiency virus type 1 (HIV-1). However, primary viruses isolated from infected individuals are more refractory to neutralization than TCLA strains, suggesting that qualitatively different neutralizing antibodies may be involved. In this study, we investigated whether the V3 loop constitutes a linear target epitope for antibodies neutralizing primary isolates. By using peptides representative of the V3 regions of various primary isolates, an early, relatively specific and persistent antibody response was detected in sera from HIV-infected patients. To assess the relationship between these antibodies and neutralization, the same peptides were used in competition and depletion experiments. Addition of homologous V3 peptides led to a competitive inhibition in the neutralization of the TCLA strain HIVMN/MT-4 but had no effect on the neutralization of the autologous primary isolate. Similarly, the removal of antibodies that bind to linear V3 epitopes resulted in a loss of HIVMN/MT-4 neutralization, whereas no decrease in the autologous neutralization was measured. The different roles of V3-specific antibodies according to the virus considered were thereby brought to light. This confirmed the involvement of V3 antibodies in the neutralization of a TCLA strain but emphasized a more pronounced contribution of either conformational epitopes or epitopes outside the V3 loop as targets for antibodies neutralizing primary HIV-1 isolates. This result underlines the need to focus on new vaccinal immunogens with epitopes able to induce broadly reactive and efficient antibodies that neutralize a wide range of primary HIV-1 isolates.

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Replication of a macrophage-tropic strain of human immunodeficiency virus type 1 (HIV-1) in a hybrid cell line, CEMx174, suggests that cellular accessory molecules are required for HIV-1 entry.

Journal of Virology ◽

10.1128/jvi.67.11.6707-6715.1993 ◽

1993 ◽

Vol 67 (11) ◽

pp. 6707-6715 ◽

Cited By ~ 13

Author(s):

K A Stefano ◽

R Collman ◽

D Kolson ◽

J Hoxie ◽

N Nathanson ◽

...

Keyword(s):

Human Immunodeficiency Virus ◽

Cell Line ◽

Human Immunodeficiency Virus Type ◽

Virus Type ◽

Hybrid Cell ◽

Hybrid Cell Line ◽

Immunodeficiency Virus ◽

Accessory Molecules ◽

Hiv 1

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OX40 Stimulation by gp34/OX40 Ligand Enhances Productive Human Immunodeficiency Virus Type 1 Infection

Journal of Virology ◽

10.1128/jvi.75.15.6748-6757.2001 ◽

2001 ◽

Vol 75 (15) ◽

pp. 6748-6757 ◽

Cited By ~ 24

Author(s):

Yoshiaki Takahashi ◽

Yuetsu Tanaka ◽

Atsuya Yamashita ◽

Yoshio Koyanagi ◽

Masataka Nakamura ◽

...

Keyword(s):

Human Immunodeficiency Virus ◽

T Cells ◽

T Cell ◽

Cell Line ◽

Human Immunodeficiency Virus Type ◽

Virus Type ◽

Cell Leukemia Virus Type ◽

Immunodeficiency Virus ◽

Hiv 1

ABSTRACT OX40 is a member of the tumor necrosis factor (TNF) receptor superfamily and known to be an important costimulatory molecule expressed on activated T cells. To investigate the role of costimulation of OX40 in human immunodeficiency virus type 1 (HIV-1) infection by its natural ligand, gp34, the OX40-transfected ACH-2 cell line, ACH-2/OX40, chronically infected with HIV-1, was cocultured with paraformaldehyde (PFA)-fixed gp34-transfected mouse cell line, SV-T2/gp34. The results showed that HIV-1 production was strongly induced. This was followed by apparent apoptosis, and both processes were specifically inhibited by the gp34-specific neutralizing monoclonal antibody 5A8. Endogenous TNF alpha (TNF-α) and TNF-β production were not involved in the enhanced HIV-1 production. Furthermore, enhanced HIV-1 transcription in gp34-stimulated ACH-2/OX40 cells was dependent on the κB site of the HIV-1 long terminal repeat, and the OX40-gp34 interaction activated NF-κB consisting of p50 and p65 subunits. When primary activated CD4+ T cells acutely infected with HIV-1NL4-3 (CXCR4-using T-cell-line-tropic) were cocultured with PFA-fixed gp34+ human T-cell leukemia virus type 1-bearing MT-2 cells or SV-T2/gp34 cells, HIV-1 production was also markedly enhanced. The enhancement was again significantly inhibited by 5A8. The present study first shows that OX40-gp34 interaction stimulates HIV-1 expression and suggests that OX40 triggering by gp34 may play an important role in enhancing HIV-1 production in both acutely and latently infected CD4+ T cells in vivo.

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