| Abstract: | Using a new device which increases the sensitivity of detection of specific immune lysis of target cells by labeling them with [35S]-methionine, the in vitro cell-mediated cytotoxic response of spleen lymphocytes and peripheral blood lymphocytes from chickens vaccinated with herpesvirus of turkey (HVT), O1 strain, against MSB-1 line cells was clearly demonstrated. The cytotoxic activity was clearly inhibited by pretreatment of effector lymphocytes with anti-T lymphocyte serum and complement. The activity was greater using T cells purified from spleen lymphocytes and peripheral blood lymphocytes than with the unfractionated cells, indicating that T lymphocytes play the main role in effector activity. Using sera from HVG-vaccinated chickens, no significant cytotoxic effects were detected in the complement-dependent antibody cytotoxicity test against MSB-1 cells. These results suggest that cellular immunity against the surface antigen of Marek's disease (MD) lymphoma cells is mainly related to the preventive mechanism against MD incidence by HVT vaccination. |
