Group identifies HHV-6B-specific CD8+ T Cell response
A new study from the University of Munchen in Munich, Germany, has identified a subset of CD8+ T cells that specifically recognize HHV-6B and not HHV-6A. The group is led by Dr. Andreas Moosman, who presented preliminary findings at the 7th International Conference on HHV-6 & 7 in 2011. Their work demonstrates that a specific class of CD8+ T cells recognizes HLA-A2-restricted peptides from the viral structural proteins U54 and U11, and displays several antigen-specific antiviral effector functions. HHV-6B-infected primary CD4+ T cells are recognized by these CD8+ T cells in an HLA-restricted manner, and furthermore produce antiviral cytokines, which contribute to the effective killing of infected cells. HHV-6A infected cells, on the other hand, are not recognized by the CD8+ T cells.
Importantly, this finding suggests that future immunotherapies could be aimed at minimizing the affects of HHV-6B-associated disease through taking advantage of these newly characterized virus-specific CD8+ T cell responses. As recent studies (Tormo et al, others) have indicated that lymphopenia-associated deficiencies in T cells specific for either HHV-6 or CMV can lead to the reactivation of both viruses in immunosuppressed patients, the reconstitution of antigen-specific T cells specific for HHV-6B may also serve as an effective therapeutic strategy for limiting the affects of CMV or EBV in these patients as well.
For more information, read the abstract. You can also visit this summary to learn more about CD8+ T Cell immunotherapies currently in development for transplant patients.