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Natural OX40L expressed on human T cell leukemia virus type-I-immortalized T cell lines interferes with infection of activated peripheral blood mononuclear cells by CCR5-utilizing human immunodeficiency virus.

Kasahara D, Takara A, Takahashi Y, Kodama A, Tanaka R, Ansari AA, Tanaka Y - Virol. J. (2013)

Bottom Line: Results of our studies showed that HTLV-1+ T cell lines bound exogenous OX40 but not OX40L, indicating that HTLV-1+ T cell lines express an active form of OX40L but an inactive form of OX40.Anti-OX40 non-blocking monoclonal antibody (mAb), but not blocking mAb, stained HTLV-1+ T cell lines, suggesting that the OX40 might be saturated with endogenous OX40L.Altogether, these results demonstrated that autologous T cell lines immortalized by HTLV-1 can be utilized as a conventional source of physiologically functional OX40L.

View Article: PubMed Central - HTML - PubMed

Affiliation: Department of Immunology, Graduate School of Medicine, University of the Ryukyus, Okinawa 903-0215, Japan. yuetsu@s4.dion.ne.jp.

ABSTRACT

Background: OX40 ligand (OX40L) co-stimulates and differentiates T cells via ligation of OX40 that is transiently induced on T cells upon activation, resulting in prolonged T cell survival and enhanced cytokine production by T cells. This view has led to the targeting of OX40 as a strategy to boost antigen specific T cells in the context of vaccination. In addition, the ligation of OX40 has also been shown to inhibit infection by CCR5-utilizing (R5) but not CXCR4-utilizing (X4) human immunodeficiency virus type-1 (HIV-1) via enhancement of production of CCR5-binding β-chemokines. It was reasoned that human T cell leukemia virus type-I (HTLV-1) immortalized T cell lines that express high levels of OX40L could serve as an unique source of physiologically functional OX40L. The fact that HTLV-1+ T cell lines simultaneously also express high levels of OX40 suggested a potential limitation.

Results: Results of our studies showed that HTLV-1+ T cell lines bound exogenous OX40 but not OX40L, indicating that HTLV-1+ T cell lines express an active form of OX40L but an inactive form of OX40. Anti-OX40 non-blocking monoclonal antibody (mAb), but not blocking mAb, stained HTLV-1+ T cell lines, suggesting that the OX40 might be saturated with endogenous OX40L. Functionality of the OX40L was confirmed by the fact that a paraformaldehyde (PFA)-fixed HTLV-1+ T cell lines inhibited the infection of autologous activated peripheral blood mononuclear cells (PBMCs) with R5 HIV-1 which was reversed by either anti-OX40L blocking mAb or a mixture of neutralizing mAbs against CCR5-binding β-chemokines.

Conclusions: Altogether, these results demonstrated that autologous T cell lines immortalized by HTLV-1 can be utilized as a conventional source of physiologically functional OX40L.

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Related in: MedlinePlus

HTLV-1+T cells are more potent in the inhibition of R5 HIV-1 infection than recombinant soluble OX40L. R5 HIV-1-infected PBMCs prepared as in Figure 5 were cultured in the presence or absence of a graded concentration of recombinant soluble OX40L or PFA-fixed autologous HTLV-1+ T cells. After 4 days, the levels of p24 produced in the culture supernatants were quantitated by ELISA. Data shown are representative of 2 independent experiments.
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Figure 6: HTLV-1+T cells are more potent in the inhibition of R5 HIV-1 infection than recombinant soluble OX40L. R5 HIV-1-infected PBMCs prepared as in Figure 5 were cultured in the presence or absence of a graded concentration of recombinant soluble OX40L or PFA-fixed autologous HTLV-1+ T cells. After 4 days, the levels of p24 produced in the culture supernatants were quantitated by ELISA. Data shown are representative of 2 independent experiments.

Mentions: Finally, we compared the potential of membrane bound OX40L of the fixed HTLV-1+ T cell lines with that of soluble rec-OX40L to inhibit R5 HIV-1 infection by the quantitation of p24 production in the culture supernatants. As shown in Figure 6, whereas the inhibitory effect of the rec-OX40L reached a plateau at levels > 1.25 μg/ml, the autologous HTLV-1+ T cell line could inhibit more effectively at even an HTLV-1+ T cell to PBMCs ratio as low as 0.3. The maximum inhibition reached with rec-OX40 was around 65% of the maximum inhibition reached with HTLV-1+ T cell line, with similar IC50. Altogether, these data demonstrate that indeed, the OX40L expressed by HTLV-1+ T cell lines is biologically active.


Natural OX40L expressed on human T cell leukemia virus type-I-immortalized T cell lines interferes with infection of activated peripheral blood mononuclear cells by CCR5-utilizing human immunodeficiency virus.

Kasahara D, Takara A, Takahashi Y, Kodama A, Tanaka R, Ansari AA, Tanaka Y - Virol. J. (2013)

HTLV-1+T cells are more potent in the inhibition of R5 HIV-1 infection than recombinant soluble OX40L. R5 HIV-1-infected PBMCs prepared as in Figure 5 were cultured in the presence or absence of a graded concentration of recombinant soluble OX40L or PFA-fixed autologous HTLV-1+ T cells. After 4 days, the levels of p24 produced in the culture supernatants were quantitated by ELISA. Data shown are representative of 2 independent experiments.
© Copyright Policy - open-access
Related In: Results  -  Collection

License
Show All Figures
getmorefigures.php?uid=PMC4225675&req=5

Figure 6: HTLV-1+T cells are more potent in the inhibition of R5 HIV-1 infection than recombinant soluble OX40L. R5 HIV-1-infected PBMCs prepared as in Figure 5 were cultured in the presence or absence of a graded concentration of recombinant soluble OX40L or PFA-fixed autologous HTLV-1+ T cells. After 4 days, the levels of p24 produced in the culture supernatants were quantitated by ELISA. Data shown are representative of 2 independent experiments.
Mentions: Finally, we compared the potential of membrane bound OX40L of the fixed HTLV-1+ T cell lines with that of soluble rec-OX40L to inhibit R5 HIV-1 infection by the quantitation of p24 production in the culture supernatants. As shown in Figure 6, whereas the inhibitory effect of the rec-OX40L reached a plateau at levels > 1.25 μg/ml, the autologous HTLV-1+ T cell line could inhibit more effectively at even an HTLV-1+ T cell to PBMCs ratio as low as 0.3. The maximum inhibition reached with rec-OX40 was around 65% of the maximum inhibition reached with HTLV-1+ T cell line, with similar IC50. Altogether, these data demonstrate that indeed, the OX40L expressed by HTLV-1+ T cell lines is biologically active.

Bottom Line: Results of our studies showed that HTLV-1+ T cell lines bound exogenous OX40 but not OX40L, indicating that HTLV-1+ T cell lines express an active form of OX40L but an inactive form of OX40.Anti-OX40 non-blocking monoclonal antibody (mAb), but not blocking mAb, stained HTLV-1+ T cell lines, suggesting that the OX40 might be saturated with endogenous OX40L.Altogether, these results demonstrated that autologous T cell lines immortalized by HTLV-1 can be utilized as a conventional source of physiologically functional OX40L.

View Article: PubMed Central - HTML - PubMed

Affiliation: Department of Immunology, Graduate School of Medicine, University of the Ryukyus, Okinawa 903-0215, Japan. yuetsu@s4.dion.ne.jp.

ABSTRACT

Background: OX40 ligand (OX40L) co-stimulates and differentiates T cells via ligation of OX40 that is transiently induced on T cells upon activation, resulting in prolonged T cell survival and enhanced cytokine production by T cells. This view has led to the targeting of OX40 as a strategy to boost antigen specific T cells in the context of vaccination. In addition, the ligation of OX40 has also been shown to inhibit infection by CCR5-utilizing (R5) but not CXCR4-utilizing (X4) human immunodeficiency virus type-1 (HIV-1) via enhancement of production of CCR5-binding β-chemokines. It was reasoned that human T cell leukemia virus type-I (HTLV-1) immortalized T cell lines that express high levels of OX40L could serve as an unique source of physiologically functional OX40L. The fact that HTLV-1+ T cell lines simultaneously also express high levels of OX40 suggested a potential limitation.

Results: Results of our studies showed that HTLV-1+ T cell lines bound exogenous OX40 but not OX40L, indicating that HTLV-1+ T cell lines express an active form of OX40L but an inactive form of OX40. Anti-OX40 non-blocking monoclonal antibody (mAb), but not blocking mAb, stained HTLV-1+ T cell lines, suggesting that the OX40 might be saturated with endogenous OX40L. Functionality of the OX40L was confirmed by the fact that a paraformaldehyde (PFA)-fixed HTLV-1+ T cell lines inhibited the infection of autologous activated peripheral blood mononuclear cells (PBMCs) with R5 HIV-1 which was reversed by either anti-OX40L blocking mAb or a mixture of neutralizing mAbs against CCR5-binding β-chemokines.

Conclusions: Altogether, these results demonstrated that autologous T cell lines immortalized by HTLV-1 can be utilized as a conventional source of physiologically functional OX40L.

Show MeSH
Related in: MedlinePlus