We investigated the role of various immune components in the pathogenesis of immune-mediated experimental herpetic uveitis. Inbred III/J strain of rabbits were sensitized with an intravitreal injection of 10-3PFU of type 1 herpes simplex virus (HSV), and sensitized cervical lymph node (LN) cells were obtained on postinfection day 12. Intravitreal injection to the normal III/J rabbit eye of HSV antigen with either sensitized LN cells or anti-HSV serum failed to induce uveitis, whereas intravitreal injection of HSV-antigen with both sensitized LN cells and anti-HSV serum produced severe uveitis within six hours. The combination of sensitized LN cells, HSV-antigen and normal rabbit serum, or that of normal LN cells, HSV antigen and anti-HSV serum, did not induce uveitis. Further studies using B lymphocyte and T lymphocyte fractions from sensitized LN showed that only the combination of sensitized T lymphocytes, HSV antigen and anti-HSV serum regularly produced uveitis following intravitreal injection. These results indicate that the interaction of HSV antigen, sensitized T lymphocytes and anti-HSV antibody may play a role in the pathogenesis of immune-mediated herpetic uveitis.