Human herpesvirus 7 (HHV-7) is endemic in the adult human population. Although HHV-7 preferentially infects activated CD4(+) T lymphocytes, the consequence of T-cell infection for viral pathogenesis and immunity are still largely unknown. HHV-7 infection induces apoptosis mostly in uninfected bystander cells but not in productively infected CD4(+) T cells. To dissect the underlying molecular events, the role of death-inducing ligands belonging to the tumor necrosis factor (TNF) cytokine superfamily was investigated. HHV-7 selectively up-regulated the expression of TNF-related apoptosis-inducing ligand (TRAIL), but not that of CD95 ligand or TNF-alpha in lymphoblastoid (SupT1) or primary activated CD4(+) T cells. Moreover, in a cell-to-cell-contact assay, HHV-7-infected CD4(+) T lymphocytes were cytotoxic for bystander uninfected CD4(+) T cells through the TRAIL pathway. By contrast, HHV-7 infection caused a marked decrease of surface TRAIL-R1, but not of TRAIL-R2, CD95, TNF-R1, or TNF-R2. Of note, the down-regulation of TRAIL-R1 selectively occurred in cells coexpressing HHV-7 antigens that became resistant to TRAIL-mediated cytotoxicity. These findings suggest that the TRAIL-mediated induction of T-cell death may represent an important immune evasion mechanism of HHV-7, helping the virus to persist in the host organism throughout its lifetime.
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Data di pubblicazione: | 2001 | |
Titolo: | Human herpesvirus 7 induces the functional up-regulation of tumor necrosis factor-related apoptosis-inducing ligand (TRAIL) coupled to TRAIL-R1 down-modulation in CD4+ T cells | |
Autori: | Secchiero, Paola; Mirandola, Prisco; Zella, D; Celeghini, Claudio; Gonelli, Arianna; Vitale, M; Capitani, Silvano; Zauli, Giorgio | |
Rivista: | BLOOD | |
Keywords: | Human herpesvirus 7, tumor necrosis factor–related apoptosis-inducing ligand, CD41 T cells | |
Abstract in inglese: | Human herpesvirus 7 (HHV-7) is endemic in the adult human population. Although HHV-7 preferentially infects activated CD4(+) T lymphocytes, the consequence of T-cell infection for viral pathogenesis and immunity are still largely unknown. HHV-7 infection induces apoptosis mostly in uninfected bystander cells but not in productively infected CD4(+) T cells. To dissect the underlying molecular events, the role of death-inducing ligands belonging to the tumor necrosis factor (TNF) cytokine superfamily was investigated. HHV-7 selectively up-regulated the expression of TNF-related apoptosis-inducing ligand (TRAIL), but not that of CD95 ligand or TNF-alpha in lymphoblastoid (SupT1) or primary activated CD4(+) T cells. Moreover, in a cell-to-cell-contact assay, HHV-7-infected CD4(+) T lymphocytes were cytotoxic for bystander uninfected CD4(+) T cells through the TRAIL pathway. By contrast, HHV-7 infection caused a marked decrease of surface TRAIL-R1, but not of TRAIL-R2, CD95, TNF-R1, or TNF-R2. Of note, the down-regulation of TRAIL-R1 selectively occurred in cells coexpressing HHV-7 antigens that became resistant to TRAIL-mediated cytotoxicity. These findings suggest that the TRAIL-mediated induction of T-cell death may represent an important immune evasion mechanism of HHV-7, helping the virus to persist in the host organism throughout its lifetime. | |
Digital Object Identifier (DOI): | 10.1182/blood.V98.8.2474 | |
Handle: | http://hdl.handle.net/11392/470697 | |
Appare nelle tipologie: | 03.1 Articolo su rivista |