Th1 Bias in PBMC Induced by Large Scale Auto-CIK Infusion in Malignant Solid Tumor Patients in China

OBJECTIVE This article is to verify feasibility and validity of autologous cytokine-induced killer cell (Auto-CIK) treatment in solid malignancy patients.

METHODS Amplification, phenotypic characteristics, cytokine secretion, antitumor cytotoxicity and clinical response to Auto-CIK derived from 65 cases of solid tumor patients with different pathological types and clinical stages were compared with LAKs in a large-scale clinical trial.

RESULTS We found that seriousness of disease and metastatic status had no influence on effective components and antitumor immunological activity of Auto-CIK. Comparing cytotoxicity against various tumor cells with LAKs at various effector to target ratios, CIKs showed more effective cytotoxicity against NK sensitive or non-sensitive solid tumor cell lines at a low E/T ratio (6:1) which suggests indirectly that Auto-CIK had a longer effective time in vivo than LAKs. These results suggest that CIKs are more suitable for immunotherapy for those solid malignancy patients at high risk of relapse or recurrence.

CONCLUSIONS Our experimental data were consistent with the reported conclusion that the potent antitumor activity of Auto-CIK mainly rooted in the CD4^- part of CIKs, including CD3⁺CD56⁺ cells and CD8⁺ CTLs. The CD4⁺ part of CIKs seemed to have no direct tumor lytic activity. The results indicate that the special “Th1 bias” and enhanced cytotoxicity against K562 cells occurred in PBMCs after multicycles of Auto-CIK infusions suggesting the induction of a “Th1 shift” and rectification of “Th2 dominance” in PBMC after Auto-CIK treatments.