However, the induction of novel env

However, the induction of novel env183-specific CD8+ T-cell responses by therapeutic vaccines should additionally be considered. So far, different therapeutic vaccines are already used in several clinical trials with limited effect on chronic HBV infection (64–67). In sum, the heterogeneity of HBV-specific CD8+ T cells suggest that HBV cure can probably not be achieved by only one single approach. Therefore, a combination of different immunotherapeutic interventions might be necessary to induce viral elimination or at least T cell-based control in chronic HBV infection.ConclusionExhausted T cells consist of functionally diverse T-cell subpopulations that co-exist during chronic HBV infection. These findings revealed that HBV-specific CD8+ T cells specific for different HBV proteins harbor distinct phenotypical and more importantly functional features in chronically HBV-infected patients. This knowledge allows specializing future immunotherapeutic approaches to target the specific T-cell subpopulation and its molecular pathway that is suitable for the desired kind of immunomodulation. However, the current state of immunotherapeutic treatments suggests that the task of controlling chronic HBV infection is quite difficult. Further characterization of the recently discovered HBV-specific CD8+ T-cell subpopulations are needed to uncover new molecular pathways that could be additionally targeted by immunotherapeutic interventions.