Identification of a neutralization epitope on the envelope gp46 antigen of human T cell leukemia virus type I and induction of neutralizing antibody by peptide immunization.

Tanaka, Yuetsu; Zeng, Lee; Shiraki, Hiroshi; Shida, Hisatoshi; Tozawa, Hideki

doi:10.4049/jimmunol.147.1.354

Cited by 121 publications

(4 citation statements)

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“…To infect target cells with HTLV-1, all cells were plated in 6-well culture plates (1.5 × 10 5 cells per well), and viral stock solution was added to the wells (HTLV-1 p19 antigen = 10 or 20 ng equivalent of virus). In addition, the viral stock solution was preincubated with or without the HTLV-1 envelope-specific neutralizing monoclonal antibody ( 70 ), LAT-27 (10 or 20 µg/mL) for 1 hour at 37°C. To deplete extracellular matrix structures, the viral stock solution was filtrated through a 0.45 or 0.20 µm filter (Sartorius, Göttingen, Germany) before infection.…”

Section: Methodsmentioning

confidence: 99%

Establishment of a novel human T-cell leukemia virus type 1 infection model using cell-free virus

Nagata,

Tezuka,

Kuramitsu

et al. 2024

J Virol

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The primary mode of infection by human T-cell leukemia virus type 1 (HTLV-1) is cell-to-cell transmission during contact between infected cells and target cells. Cell-free HTLV-1 infections are known to be less efficient than infections with other retroviruses, and transmission of free HTLV-1 is considered not to occur in vivo . However, it has been demonstrated that cell-free HTLV-1 virions can infect primary lymphocytes and dendritic cells in vitro , and that virions embedded in biofilms on cell membranes can contribute to transmission. The establishment of an efficient cell-free HTLV-1 infection model would be a useful tool for analyzing the replication process of HTLV-1 and the clonal expansion of infected cells. We first succeeded in obtaining supernatants with high-titer cell-free HTLV-1 using a highly efficient virus-producing cell line. The HTLV-1 virions retained the structural characteristics of retroviruses. Using this cell-free infection model, we confirmed that a variety of cell lines and primary cultured cells can be infected with HTLV-1 and demonstrated that the provirus was randomly integrated into all chromosomes in the target cells. The provirus-integrated cell lines were HTLV-1-productive. Furthermore, we demonstrated for the first time that cell-free HTLV-1 is infectious in vivo using a humanized mouse model. These results indicate that this cell-free infection model recapitulates the HTLV-1 life cycle, including entry, reverse transcription, integration into the host genome, viral replication, and secondary infection. The new cell-free HTLV-1 infection model is promising as a practical resource for studying HTLV-1 infection. IMPORTANCE Co-culture of infected and target cells is frequently used for studying HTLV-1 infection. Although this method efficiently infects HTLV-1, the cell mixture is complex, and it is extremely difficult to distinguish donor infected cells from target cells. In contrast, cell-free HTLV-1 infection models allow for more strict experimental conditions. In this study, we established a novel and efficient cell-free HTLV-1 infection model. Using this model, we successfully evaluated the infectivity titers of cell-free HTLV-1 as proviral loads (copies per 100 cells) in various cell lines, primary cultured cells, and a humanized mouse model. Interestingly, the HTLV-1-associated viral biofilms played an important role in enhancing the infectivity of the cell-free infection model. This cell-free HTLV-1 infection model reproduces the replication cycle of HTLV-1 and provides a simple, powerful, and alternative tool for researching HTLV-1 infection.

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Section: Methodsmentioning

confidence: 99%

Establishment of a novel human T-cell leukemia virus type 1 infection model using cell-free virus

Nagata,

Tezuka,

Kuramitsu

et al. 2024

J Virol

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“…The plasmid pSV HTLV-1 env (kindly provided by Dr. R. Sutton, Baylor College of Medicine, Houston, TX, USA) and pCAGHTLV-1 env (obtained from Dr. K. Okuma, Kyushu University, Kukuoka, Japan) both express the HTLV-1 env gene under the SV40 and CMV promoter, respectively [ 33 , 34 ]. Anti-gp46 antibodies used in this study included the rat monoclonal antibody LAT-27 (kindly provided by Dr. Y. Tanaka, University of the Ryukyus, Okinawa, Japan) [ 35 ] and monoclonal antibodies SP2,3/4A (rabbit) and 0.5α (human) [ 36 , 37 ], both of which were provided by the NIH HIV Reagent Program and are known to be neutralizing.…”

Section: Methodsmentioning

confidence: 99%

Infection of the Ex Vivo Tonsil Model by HTLV-1 Envelope-Pseudotyped Viruses

et al. 2023

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Human T-cell leukemia virus type 1 (HTLV-1) is the causal agent of adult T-cell leukemia/lymphoma and HTLV-1-associated myelopathy/tropical spastic paraparesis. Its tropism is known to be broad in cultured cell lines, while in vivo data support a more selective transmission toward CD4+ T cells and the limited targeting of other hematopoietic cell types. An essential condition for HTLV-1 infection is cell-to-cell contact, to which both virological synapse and viral biofilm have been suggested to strongly contribute. As cell lines and animal models each present their own limitations in studying HTLV-1 replication, we have explored the use of an ex vivo model based on the secondary lymphoid tonsillar tissue. HIV-1 luciferase-expressing pseudotyped viruses bearing the HTLV-1 envelope protein at their surface were first shown to recapitulate the wide spectrum of infectivity of HTLV-1 toward various cell lines. Tonsil fragments were next exposed to pseudotyped viruses and shown to be reproducibly infected. Infection by HTLV-1 Env-pseudotyped viruses was blocked by different anti-gp46 antibodies, unlike infection by HIV-1 virions. The dose-dependent infection revealed a gradual increase in luciferase activity, which was again sensitive to anti-gp46 antibodies. Overall, these results suggest that the ex vivo tonsil model represents a reliable alternative for studying HTLV-1 replication and potentially viral latency, as well as early clonal formation.

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“…The 293T cells were then transfected with HTLV-1 Env and HTLV-1-or HIV-1-Gag-Venus vectors. The cell surface expression level of HTLV-1 Env in the Gag Venus-positive cell population was analyzed by flow cytometry using an anti-HTLV-1 gp46 mAb, LAT-27 (Figure 2A) [24]. We found that the expression of HTLV-1 Env increased in the presence of HTLV-1 or HIV-1 Gag.…”

Section: Inefficient Incorporation Of Htlv-1 Env Into Vlps Carrying H...mentioning

confidence: 96%

“…The 293T cells were transfected with the HTLV-1 Env expression plasmid (pcDNA-1E-RRE) and either pCRVI/HTLV-1/Gag-Venus or pCRVI/HIV-1/Gag-Venus, as described above. The cells were recovered 24 h post-transfection using a cell dissociation solution (Sigma-Aldrich), stained with the anti-gp46 rat mAb LAT-27 [24]. The cells were then further stained with APC-conjugated anti-rat IgG (Bioligands, San Diego, CA, USA) and fixed with 4% paraformaldehyde for 15 min.…”

Section: Flow Cytometrymentioning

confidence: 99%

Interaction of TSG101 with the PTAP Motif in Distinct Locations of Gag Determines the Incorporation of HTLV-1 Env into the Retroviral Virion

Maeda,

Monde,

Terasawa

et al. 2023

IJMS

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Human T-cell tropic virus type 1 (HTLV-1) is known to be mainly transmitted by cell-to-cell contact due to the lower infectivity of the cell-free virion. However, the reasons why cell-free HTLV-1 infection is poor remain unknown. In this study, we found that the retrovirus pseudotyped with HTLV-1 viral envelope glycoprotein (Env) was infectious when human immunodeficiency virus type 1 (HIV-1) was used to produce the virus. We found that the incorporation of HTLV-1 Env into virus-like particles (VLPs) was low when HTLV-1 Gag was used to produce VLPs, whereas VLPs produced using HIV-1 Gag efficiently incorporated HTLV-1 Env. The production of VLPs using Gag chimeras between HTLV-1 and HIV-1 Gag and deletion mutants of HIV-1 Gag showed that the p6 domain of HIV-1 Gag was responsible for the efficient incorporation of HTLV-1 Env into the VLPs. Further mutagenic analyses of the p6 domain of HIV-1 Gag revealed that the PTAP motif in the p6 domain of HIV-1 Gag facilitates the incorporation of HTLV-1 Env into VLPs. Since the PTAP motif is known to interact with tumor susceptibility gene 101 (TSG101) during the budding process, we evaluated the effect of TSG101 knockdown on the incorporation of HTLV-1 Env into VLPs. We found that TSG101 knockdown suppressed the incorporation of HTLV-1 Env into VLPs and decreased the infectivity of cell-free HIV-1 pseudotyped with HTLV-1 Env. Our results suggest that the interaction of TSG101 with the PTAP motif of the retroviral L domain is involved not only in the budding process but also in the efficient incorporation of HTLV-1 Env into the cell-free virus.

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Identification of a neutralization epitope on the envelope gp46 antigen of human T cell leukemia virus type I and induction of neutralizing antibody by peptide immunization.

Cited by 121 publications

References 0 publications

Establishment of a novel human T-cell leukemia virus type 1 infection model using cell-free virus

Establishment of a novel human T-cell leukemia virus type 1 infection model using cell-free virus

Infection of the Ex Vivo Tonsil Model by HTLV-1 Envelope-Pseudotyped Viruses

Interaction of TSG101 with the PTAP Motif in Distinct Locations of Gag Determines the Incorporation of HTLV-1 Env into the Retroviral Virion

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