Reciprocal interactions between human T-lymphotropic virus type 1 and prostaglandins: implications for viral transmission

Abstract

Human T-lymphotropic virus type 1 (HTLV-1), the etiologic agent of adult T-cell leukemia/lymphoma, is transmitted through breast milk and seminal fluid, which are rich in prostaglandins (PGs). We demonstrate that PGE(2) upregulates the HTLV-1 long terminal repeat promoter through the protein kinase A pathway, induces replication of HTLV-1 in peripheral blood mononuclear cells (PBMC) derived from asymptomatic carriers, and enhances transmission of HTLV-1 to cord blood mononuclear cells (CBMC). Furthermore, HTLV-1 Tax transactivates a promoter for cyclooxygenase 2, a PG synthetase, and induces PGE(2) expression in PBMC or CBMC. Thus, HTLV-1 interacts with and benefits from PGs, constituents of its own vehicle for transmission.

FIG. 1

PGE₂ upregulates HTLV-1 LTR activity. (A) PGE₂ upregulates HTLV-1 LTR activity in a dose-dependent manner. A total of 40 million PBMC were transfected with 10 μg of pU3R-luc and were left unstimulated or were stimulated with the indicated amount of PGE₂, and luciferase activity of the transfected cell lysates was assayed 2 days posttransfection. Fold induction is the luciferase activity relative to that obtained without PGE₂ treatment. Results are means ± standard errors of the means from three independent experiments. (B and C) PKA activity is involved in PGE₂ induction of expression from the HTLV-1 LTR. A total of 40 million PBMC (B) or 20 million Jurkat cells (C) were transfected with 10 μg of pU3R-luc, and luciferase activity of the transfected cell lysates was assayed 2 days posttransfection. Where indicated, cells were treated with PGE₂ (100 nM) in the presence or absence of H7 (1 μM) or HA-1004 (1 μM) for 8 h before harvest. Fold induction is the luciferase activity relative to that obtained in the absence of the reagents. Results are means ± standard errors of the means from six independent experiments.

FIG. 1

PGE₂ upregulates HTLV-1 LTR activity. (A) PGE₂ upregulates HTLV-1 LTR activity in a dose-dependent manner. A total of 40 million PBMC were transfected with 10 μg of pU3R-luc and were left unstimulated or were stimulated with the indicated amount of PGE₂, and luciferase activity of the transfected cell lysates was assayed 2 days posttransfection. Fold induction is the luciferase activity relative to that obtained without PGE₂ treatment. Results are means ± standard errors of the means from three independent experiments. (B and C) PKA activity is involved in PGE₂ induction of expression from the HTLV-1 LTR. A total of 40 million PBMC (B) or 20 million Jurkat cells (C) were transfected with 10 μg of pU3R-luc, and luciferase activity of the transfected cell lysates was assayed 2 days posttransfection. Where indicated, cells were treated with PGE₂ (100 nM) in the presence or absence of H7 (1 μM) or HA-1004 (1 μM) for 8 h before harvest. Fold induction is the luciferase activity relative to that obtained in the absence of the reagents. Results are means ± standard errors of the means from six independent experiments.

FIG. 1

PGE₂ upregulates HTLV-1 LTR activity. (A) PGE₂ upregulates HTLV-1 LTR activity in a dose-dependent manner. A total of 40 million PBMC were transfected with 10 μg of pU3R-luc and were left unstimulated or were stimulated with the indicated amount of PGE₂, and luciferase activity of the transfected cell lysates was assayed 2 days posttransfection. Fold induction is the luciferase activity relative to that obtained without PGE₂ treatment. Results are means ± standard errors of the means from three independent experiments. (B and C) PKA activity is involved in PGE₂ induction of expression from the HTLV-1 LTR. A total of 40 million PBMC (B) or 20 million Jurkat cells (C) were transfected with 10 μg of pU3R-luc, and luciferase activity of the transfected cell lysates was assayed 2 days posttransfection. Where indicated, cells were treated with PGE₂ (100 nM) in the presence or absence of H7 (1 μM) or HA-1004 (1 μM) for 8 h before harvest. Fold induction is the luciferase activity relative to that obtained in the absence of the reagents. Results are means ± standard errors of the means from six independent experiments.

FIG. 2

HTLV-1 Tax transactivates the COX-2 promoter. Jurkat cells (A) or PBMC (B) were transfected with 10 or 40 μg of phPES(−1432/+59), respectively, along with 10 μg of pMT-2T or pMT-Tax, respectively. Where indicated, PBMC were stimulated with PMA (1 μM) plus ionomycin (1 μM) for 8 h. Fold induction is the luciferase activity relative to that obtained with phPES(−1432/+59) plus pMT-2T in the absence of PMA plus ionomycin. Results are means ± standard errors of the means from six independent experiments. (C) PBMC were transfected with 40 μg of phPES(−1432/+59) and treated with GST or GST-Tax (100 ng/ml) for 2 days. Results are means ± standard errors of the means from three independent experiments.

FIG. 2

HTLV-1 Tax transactivates the COX-2 promoter. Jurkat cells (A) or PBMC (B) were transfected with 10 or 40 μg of phPES(−1432/+59), respectively, along with 10 μg of pMT-2T or pMT-Tax, respectively. Where indicated, PBMC were stimulated with PMA (1 μM) plus ionomycin (1 μM) for 8 h. Fold induction is the luciferase activity relative to that obtained with phPES(−1432/+59) plus pMT-2T in the absence of PMA plus ionomycin. Results are means ± standard errors of the means from six independent experiments. (C) PBMC were transfected with 40 μg of phPES(−1432/+59) and treated with GST or GST-Tax (100 ng/ml) for 2 days. Results are means ± standard errors of the means from three independent experiments.

FIG. 2

HTLV-1 Tax transactivates the COX-2 promoter. Jurkat cells (A) or PBMC (B) were transfected with 10 or 40 μg of phPES(−1432/+59), respectively, along with 10 μg of pMT-2T or pMT-Tax, respectively. Where indicated, PBMC were stimulated with PMA (1 μM) plus ionomycin (1 μM) for 8 h. Fold induction is the luciferase activity relative to that obtained with phPES(−1432/+59) plus pMT-2T in the absence of PMA plus ionomycin. Results are means ± standard errors of the means from six independent experiments. (C) PBMC were transfected with 40 μg of phPES(−1432/+59) and treated with GST or GST-Tax (100 ng/ml) for 2 days. Results are means ± standard errors of the means from three independent experiments.

FIG. 3

Both the NF-κB and NF-IL6 sites are involved in Tax activation of the COX-2 promoter. (A) Jurkat cells were transfected with 10 μg of the luciferase reporter plasmid along with 10 μg of pMT-2T or pMT-Tax. Results are means ± standard errors of the means from four independent experiments. Fold induction by Tax of the respective luciferase reporter is shown to the right of the bars. (B) Jurkat cells were transfected with 10 μg of the luciferase reporter plasmid along with 10 μg of pMT-2T or pMT-Tax. Results are means ± standard errors of the means from six independent experiments. Fold induction by Tax of the respective luciferase reporter is shown to the right of the bars. (C) Jurkat cells were transfected with 10 μg of phPES(−1432/+59) and 10 μg of pMT-2T, pMT-p65, or pMT-Tax along with pMT-2T or pMT-IκB. Results are means ± standard errors of the means from four independent experiments.

FIG. 3

Both the NF-κB and NF-IL6 sites are involved in Tax activation of the COX-2 promoter. (A) Jurkat cells were transfected with 10 μg of the luciferase reporter plasmid along with 10 μg of pMT-2T or pMT-Tax. Results are means ± standard errors of the means from four independent experiments. Fold induction by Tax of the respective luciferase reporter is shown to the right of the bars. (B) Jurkat cells were transfected with 10 μg of the luciferase reporter plasmid along with 10 μg of pMT-2T or pMT-Tax. Results are means ± standard errors of the means from six independent experiments. Fold induction by Tax of the respective luciferase reporter is shown to the right of the bars. (C) Jurkat cells were transfected with 10 μg of phPES(−1432/+59) and 10 μg of pMT-2T, pMT-p65, or pMT-Tax along with pMT-2T or pMT-IκB. Results are means ± standard errors of the means from four independent experiments.

FIG. 3

Both the NF-κB and NF-IL6 sites are involved in Tax activation of the COX-2 promoter. (A) Jurkat cells were transfected with 10 μg of the luciferase reporter plasmid along with 10 μg of pMT-2T or pMT-Tax. Results are means ± standard errors of the means from four independent experiments. Fold induction by Tax of the respective luciferase reporter is shown to the right of the bars. (B) Jurkat cells were transfected with 10 μg of the luciferase reporter plasmid along with 10 μg of pMT-2T or pMT-Tax. Results are means ± standard errors of the means from six independent experiments. Fold induction by Tax of the respective luciferase reporter is shown to the right of the bars. (C) Jurkat cells were transfected with 10 μg of phPES(−1432/+59) and 10 μg of pMT-2T, pMT-p65, or pMT-Tax along with pMT-2T or pMT-IκB. Results are means ± standard errors of the means from four independent experiments.