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Human Herpesvirus 6 Infection of CD4 + T‐Cell Subsets
Author(s) -
Otani Naruhito,
Okuno Toshiomi
Publication year - 2007
Publication title -
microbiology and immunology
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.664
H-Index - 70
eISSN - 1348-0421
pISSN - 0385-5600
DOI - 10.1111/j.1348-0421.2007.tb03996.x
Subject(s) - biology , il 2 receptor , virology , immune system , virus , t cell , cytokine , interleukin 21 , viral replication , infectivity , cellular immunity , immunology
The immune system includes CD4 + regulatory T (T reg ) cells that play a role in self‐tolerance and demonstrate functional variations that govern immune responses. HHV‐6 is an important immunosuppressive virus that completely replicates in vivo and in vitro in only CD4 + T cells. However, there have been no reports of the specific T‐cell subpopulation that permits the replication of this virus. Here, we evaluated the infectivity of HHV‐6 to specific T‐cell populations such as CD4 + CD25 high , which includes the majority of Treg cells, and CD4 + CD25 – . These cells were isolated from peripheral blood and then expanded. The expanded cell fractions were then infected with the HHV‐6 variant B strain, and the spreads of infected cells were evaluated by immunofluorescence. Viral growth was also quantified by real‐time PCR. The effects of virus infection on cytokine production from these T‐cell subsets were examined using ELISA. Our results revealed that both these fractions permitted complete HHV‐6 replication. Virus infection enhanced the production of both Th1‐ and Th2‐type cytokines from CD4 + CD25 – T cells; however, only Th2‐type cytokine release was augmented from viral‐infected CD4 + CD25 high T cells. Further, while virus‐infected CD4 + CD25 high T cells shift their antiviral immunity toward Th2 dominance by producing IL‐10, the role of virus‐infected CD4 + CD25 – T cells remains obscure.