Selective colorectal cancer cell lysates enhance the immune function of mature dendritic cells in vitro.

The aim of the present study was to determine the most effective antigen with which to mature dendritic cells (DCs). The immune function of DCs loaded with lysates from three different colorectal cancer cell lines was compared. DCs were induced using granulocyte macrophage colony‑stimulating factor, interleukin (IL)‑4 and tumor necrosis factor-α from the peripheral blood mononuclear cells of patients with colorectal cancer, and loaded with lysates from Colo320, SW480 and SW620 colorectal cancer cell lines, respectively. Autogenous T cells were co‑cultured with mature DCs. Surface markers and the secretory function of mature DCs and stimulated T cells were then analyzed. MTT assays were used to evaluate the killing capacity of autogenous cytotoxic T lymphocytes (CTLs). Compared with control, cluster of differentiation (CD)1a, CD83 and CD86, and human leukocyte antigen‑DR expression levels were significantly higher in DCs matured using cancer cell lysates. In addition, IL‑12 secretion levels were elevated. Autogenous T cells stimulated with DCs that were matured using cancer cell lysates showed a higher proliferation capacity, increased interferon-γ secretion levels and stronger cytotoxic abilities compared with control cells. Among the three cell lines, SW480 lysates were most effective at promoting DC and T cell function. The results showed that SW480 lysates are more efficient than Colo320 and SW620 lysates in inducing DC immune function and activating the antitumor function of autogenous T cells.