Abstract
Human herpesvirus-6 (HHV-6) infection normally persists for the lifetime of the host and may reactivate with immunosuppression. The mechanism behind HHV-6 latent infection is still not fully understood. In this study, we observed that decreased proliferation of CD4+ T cells and PBMCs but not CD8 + T cells from HHV-6-infected individuals was stimulated with HHV-6-infected cell lysates. Moreover, HHV-6-stimulated CD4+ T cells from HHV-6-infected individuals have suppressive activity on naive CD4 + T and CD8+ T cells from HHV-6-uninfected individuals. However, no increased proportion of CD4+ CD25+ Treg cells from HHV-6-infected individuals contributed to the suppressive activity of the HHV-6-stimulated CD4+ T cells from HHV-6-infected individuals. Transwell experiments, ELISA and anti-IL-10 antibody blocking experiment demonstrated that IL-10 may be the suppressive cytokine required for suppressive activity of CD4+ T cells from HHV-6-infected individuals. Results of intracellular interleukin (IL)-10 and IL-4 further implicated the HHV-6-specific IL-10-producing CD4+ T cells in the suppressive activity of CD4+ T cells from HHV-6-infected individuals. Results of intracellular interferon (IFN)-γ demonstrated a decreased frequency of HHV-6-specific IFN-γ-producing CD4+ T, but not CD8+ T cells in HHV-6-infected individuals, indicating that it was the CD4 + Th1 responses in HHV-6-infected individuals that were selectively impaired. Our findings indicated that HHV-6-specific IL-10-producing CD4 + T cells from HHV-6-infected individuals possess T regulatory type 1 cell activity: immunosuppression, high levels of IL-10 production, with a few cells expressing IFN-γ, but none expressing IL-4. These cells may play an important role in latent HHV-6 infection.
Original language | English |
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Pages (from-to) | 787-803 |
Number of pages | 17 |
Journal | Microbiology and Immunology |
Volume | 50 |
Issue number | 10 |
DOIs | |
State | Published - 2006 |
Keywords
- Cell response
- Human herpesvirus-6
- Interleukin-10
- T regulatory type 1 cell