Roles of T Cells and Related Immunological Molecules in the Enhancement of Cancer CD Suicide Gene Therapy by Lymphotactin / 中国肿瘤生物治疗杂志

ABSTRACT

We previously showed that adenvirus-mediated lymphotactin (Ltn) gene transfer in vivo could improve the an-titumor efficacy of cytosine deaminase (CD) gene therapy significantly. In the precent study, we investigated the im-munological mechanisms involved in the enhanced antitumor efficacy. Upregulation of CD80 and CD54 on murine CT26 colon carcinoma cells was observed after combined transfection with adenovirus encoding CD (AdCD) and adenovirus encoding murine Ltn ( AdLtn) followed by administration of 5-PC in vitro. IL-2 and IFN-? level secreted by splenocytes increased significantly after the combination therapy. In vivo depletion analysis showed that both CD4~+ and CD8~+ T cells participated in the antitumor effect of the host with CD8~+ T cells being the main T cell subset responsible for the enhanced antitumor immune response. These data suggested that increased irnmunogenicity and efficient induction of antitumor immunity of the host might contribute to the enhanced antitumor effects of the combined Ltn and CD suicide therapy.