λ-Carrageenan improves the antitumor effect of dendritic cellbased vaccine

// Jinyao Li 1, 2, 3 , Adila Aipire 2 , Jinyu Li 2 , Hongge Zhu 1 , Yanping Wang 4 , Wenjia Guo 1 , Xiaoqin Li 1 , Jia Yang 1 , Chunling Liu 1 1 Affiliated Tumor Hospital of Xinjiang Medical University, Urumqi 830011, China 2 College of Life Science and Technology, Xinjiang University, Urumqi 830046, China 3 XinJiang DingJu Biotech CO., LTD, Urumqi 830000, China 4 Bayin Guoleng Vocational and Technical College, Korla 841000, China Correspondence to: Jinyao Li, email: ljyxju@qq.com Jinyu Li, email: lijinyu234@163.com Chunling Liu, email: liudeyouxiang66@sina.com Keywords: λ-carrageenan, TLR4, dendritic cell-based vaccine, cancer immunotherapy, cellular responses Received: November 10, 2016     Accepted: January 24, 2017     Published: February 22, 2017 ABSTRACT In this study, we investigated the effect of λ-carrageenan on the maturation and function of dendritic cells (DCs) and its adjuvant effect on DC-based vaccine. We found that λ-carrageenan dose-dependently decreased the endocytosis of DCs, promoted DC maturation and increased cytokine production through TLR4 mediated signaling pathway. λ-carrageenan treatment also enhanced the ability of DCs in the stimulating allogenic splenocyte proliferation. In TC-1 tumor mouse model, HPV peptides pulsed λ-carrageenan-DC (HPV-CGN-DC) significantly inhibited tumor growth compared with control group. The frequencies of CD4 + and CD8 + T cells in spleens of tumor mice and their activation status were significantly increased in HPV-CGN-DC group, but the frequencies of natural regulatory T cells and CD11b + Gr-1 + cells were significantly decreased. Further, HPV-CGN-DC induced strong CD8 + T cell responses, which are negatively correlated with tumor volumes. The results suggested that λ-carrageenan promoted DC maturation through TLR4 signaling pathway and could be used as the adjuvant in DC-based vaccines.