Antitumor effects induced by b7-1 gene modified EL-4 lymphoma cooperated with IL-2in vivo andin vitro

Abstract

Costimulation plays very important role in T cells activation and tumor immunity. B7-1 is alone of the major costimulatory molecules both in human and rodents. Previous work indicated that B7-1 gene transfected EL-4 lymphoma can induce antitumor immunityin vivo. This paper showed that inoculation of EL-4B7-1⁺ plus IL-2 could elicit an antitumor effectsin vivo andin vitro. Immunization with EL-4B7-1⁺ tumor cells or EL-4B7-1⁺ tumor cells plus IL-2 could significantly prolong the survival time of the EL-4 tumor-bearing mice and also delay the occurrence of the tumor nodein vivo. A strong proliferation response and CTL activity as well as the increased IL-2 and TNF production of the splenocyte from the immunized mice with EL-4B7-1⁺ or EL-4B7-1⁺ plus IL-2 were seen in thein vitro TLMC system. These finding indicated that the costimulatory molecule is necessary for inducing an effective antitumor immunity and IL-2 optimal production.