Recombinant salmonella-based 4-1BBL vaccine enhances T cell immunity and inhibits the development of colorectal cancer in rats: in vivo effects of vaccine containing 4-1BBL

Background: immunotherapy with vaccines is attractive for the treatment of cancer. this study is aimed at determining the effect of recombinant salmonella (sl3261)-based 4-1bb ligand (4-1bbl) vaccine on the development of colorectal cancers and the potential immune mechanisms in rats. results: in comparison with that in the pbs group,similar levels of 4-1bbl expression,the frequency of t cells,ifn-γ responses,and comparable numbers of tumors were detected in the sl3261 and sl3261c groups of rats. in contrast,significantly fewer numbers of tumors,increased levels of 4-1bbl expression in the spleens and colorectal tissues,higher frequency of peripheral blood and splenic cd3§ssup§ +§esup§cd25§ssup§+§esup§ t cells,and stronger splenic t cell ifn-γ responses were detected in the sl3261r group of rats. conclusion: our results indicated that vaccination with recombinant attenuated salmonella harboring the 4-1bbl gene efficiently enhanced t cell immunity and inhibited the development of carcinogen-induced colorectal cancers in rats. © 2013 ye et al.