Previous studies have shown that vaccination with antigen peptide linked with 4-1BBL enhances dendritic cell activation and antigen uptake and promotes CD8+ T cell effector/memory responses. Similarly, the administration of both 4-1BBL and a HPV-specific E7 peptide or survivin protein eliminates E7-expressing TC-1 cervical cancer or survivin-expressing 3LL lung cancers in vivo. Zhang et al. reported that vaccination with natural 4-1BBL, is more efficient and less toxic side effects in inducing colorectal cancer regression in mice, as compared with treatment with anti-4-1BB agonist antibodies. In addition, a previous study has found that vaccination with a recombinant Salmonella-based 4-1BBL vaccine efficiently enhances T cell immunity in rats.
Ye J, Li L, Zhang Y, Zhang X, Ren D, Chen W. 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. Journal of Biomedical Science. 2013;20(1):8.