Using the NOD/SCID Mice Model of Human Erythroleukemia for Evaluating the Cytotoxicity Activity of CB-CIK/NK Cells Stimulated by K562-DCs Fusion Vaccines.

CD3+CD56+ cytokine-induced killer (CIK) cells are prospective effectors for adoptive immunotherapy, CIK/NK cells incubated with K562-dendritic cells (DCs) fusion vaccines have more higher cytotoxicity activity. In this study, the efficacy and the safety of application of cord blood (CB) derived CIK/NK cells stimulated by K562-dendritic cells (DCs) fusion vaccines were evaluated in vivo by the NOD/SCID mice model of human erythroleukemia (K562 line, CD13+). DCs and CIK/NK cells were inducted by combination of cytokines from CB MNCs, DCs were fused with inactivated K562 tumor line by PEG (mw1500). 5 days before the harvest of CIK/NK cells, 1×10⁵ K562-DCs fusion vaccines were co-cultured with 1×10⁶ CB-CIK/NK cells to prepare for the K562-DCs fusion vaccines stimulated CIK/NK cells. NOD/SCID mice divided into six groups, eight in one group. Mice in A,B and C groups were inoculated with 1×10⁶ K562 cells by tail vein. 24 hours later, 1×10⁷ K562-DCs fusion vaccines stimulated CIK/NK cells and 1×10⁷ unstimulated CIK/NK cells were transfued into the mice of group A and B, respectively. Group D and E were K562-DCs fusion vaccines stimulated CIK/NK cells and no-stimulated CIK/NK cells control, transfued by 1×10⁷ stimulated CIK/NK cells and 1×10⁷ no-stimulated CIK/NK cells, respectively. Group F is a normal control that no any inoculation were taken. None of the NOD/SCID mice in group C that inoculated with 1×10⁶ K562 cells survived longer than 39 days, hepatosplenomegalic mass was seen in five mice. Death in group A and B were only one and two, respectively, at day 65 and day 56, 62. There was no tumour mass can be seen in group A and B, and the survial were more than 70 days. Both survival time of group A(69.38±1.77 days) and B(67.25±5.34 days) were longer than that of group C(30.38±4.57 days) significantly (P<0.01). The tumor marker (CD13) in periperal blood, live and lung of CIK/NK cells treated NOD/SCID mice (group A and B) significantly less than group C(P<0.01). There was no difference of CD56 positive in periperal blood of group A and B survival mice between that of the control (group D and E). These result indicated that K562-DCs fusion vaccines stimulating CB-CIK/NK cells have a potent anti-tumour activity in vivo and without any side-effect.