We found that the frequency of CD4 + T-cells within livers of coinfected individuals was reduced compared to HCV monoinfection. Surprisingly, HAART did not appear to reconstitute the CD4 + T-cell population within liver. Despite this defect of CD4 + T-cell help, comparable frequencies of HCV-specific-CD8 + T-cells were found in co-infected livers. HAART-treated biopsies showed further reduced frequencies of HCV-specific responses. These data support previous findings that show HAART induces CD4 + T-cell recovery but not any restoration of HCV-specific Tcell responses peripherally [30] . Further investigation is needed to clarify the role of CD4 + T-cell help in affecting the frequencies of HCV-specific CD8 + T-cells in HCV/HIV-1 co-infection. HAART was also associated with a reduction in frequencies of HIV-specific T-cell responses within liver, indicating that removing the HIV antigenic load may also reduce the opportunity for such cells to accumulate within hepatic tissue.