CD4-CD8-T cells contribute to the persistence of viral hepatitis by striking a delicate balance in immune modulation

► DN T cells remarkably increased in mice with MHV-3 induced chronic viral hepatitis. ► Adoptive transfer of DN T cells increased the survival rate of MHV-3 infected mice. ► DN T cells had enhanced production of IFN-γand IL-2 facilitating virus clearance. ► DN T cells could specifically kill CD8+ T cells via the Fas/FasL dependent pathway. ► DN T cells may lead to viral persistence in MHV-3 induced hepatitis.