Abstract: Objective: To explore the potential of autologous dendritic cells (DCs) pulsed with caner/testis antigen NY-ESO-1 peptides in inducing specific cytotoxic T lymphocyte (CTLs) response and antineoplastic immune function of specific CTLs. Methods: Fifteen patients with Ⅱ to Ⅲ stage positive HLA-A0201⁺ and NY-ESO-1⁺ were enrolled in the Cancer Hospital Chinese Academy of Medical Sciences on the basis of preclinical experiments from November 2014 to October 2015, and their peripheral blood mononuclear cells (PBMCs) and peripheral blood lymphocytes (PBLs) were isolated. The PBMCs were induced into DCs and pulsed with NY-ESO-1 peptide. The phenotypes of DCs were stained with antibodies against HLA-DR⁺CD11c⁺,CD80⁺,CD83⁺ and CD86⁺, and subsequently analyzed by multichannel flow cytometry (FCM). The killing effects of CTLs pulsed with HLA-A0201-binding peptide NY-ESO-1 and the potential of autologous DCs pulsed with NY-ESO-1 peptides in inducing specific cytotoxic T lymphocytes (CTLs) responses were determined. The patients were administered two infusions of auto-logous CTLs for 1 time every two weeks. The total infusion was with 2 times. The immunological responses and clinical responses were examined in 1 week after the final administration. Results: The immunophenotype of DCs pulsed with NY-ESO-1 peptide was analyzed, HLA-DR⁺CD11c⁺ cells (93.6%±1.2%), CD80⁺ cells (87.3%±3.6%), CD83⁺ cells (82.8%±2.5%) and CD86⁺ cells (93.4%±6.4%). PBLs isolated from patients primed by DCs pulsed with NY-ESO-1 peptide proliferated continuously and the proliferation index (PI) of the PBLs were analyzed. There was significant difference between the DCs loaded with polypeptides and those unloaded, though it could promote the proliferation of PBLs, but the PI was significantly lower than that of the DCs loaded with NY-ESO-1 peptide (P<0.05). The average percentage of special CTLs primed by DCs pulsed with NY-ESO-1 peptides was significantly higher than that in the control group (5.2%±1.2% vs. 0.4%±0.1%). CTLs induced by NY-ESO-1 pulsed DCs exerted a stronger killing effect on T2 cell line pulsed with NY-ESO-1 peptide than that in the control group at the ratio of E (effect) to T (target) as 30︰1, P<0.05. The cytokine levels in the patients’sera such as IFN-γ, IL-2 and IL-12 were increased after treatments [(132.9±10.2) μg/L vs. (46.4±3.1) μg/L; (101.3±6.4) μg/L vs. (26.7±1.2) μg/L; (51.3±2.6) μg/L vs. (26.4±1.1) μg/L; all P<0.05], and the percentages of antigen-specific CD8⁺IFN-γ⁺ increased in these patients (P<0.01). Conclusion:Auto-DCs pulsed with NY-ESO-1 peptides can induce the proliferation of allogenic CTLs, which elicit specific immune responses ex vivo or in vivo, and boost anticancer immunity markedly.

Key words: T-lymphocytes, cytotoxic, Immunity, Antigens, Peptides, Immunotherapy, Dendritic cell, NY-ESO-1 peptide