Pseudomonas aeruginosa injection enhanced antitumor cytotoxicity of cytokine-induced killer cells derived from cord blood.

Cord blood (CB) is becoming an extensive source of cytokine-induced killer cells. It had been used in several clinical settings and proven to be efficacious and safe. Therefore, we investigated the possibility of combining CIK cells derived from cord blood (CB-CIK) and Pseudomonas aeruginosa injection (PA-MSHA) in order to enhance the cytotoxicity of CB-CIK cells against tumors. Compared with the CB-CIK cells, the PA-MSHA-treated CB-CIK cells demonstrated with increased proliferation rates, higher expression of activated cell surface marker CD28 and lower expression of inhibited cell surface markers PD-1 and CTLA-4. Furthermore, PA-MSHA-treated CB-CIK cells exhibited more effectively for secreting pro-inflammatory cytokine such as IFN-γ and expressing high levels of TLR2, TLR4 and TLR6. The expression of CD107a was higher in the CD3(+)CD56(+) subset of PA-MSHA-treated CB-CIK cells. Our results indicate that the PA-MSHA-treated CB-CIK cells exhibited a more potent in cytotoxic activity against tumor cells. Thus, PA-MSHA enhanced the antitumor ability of CB-CIK cells.