[IL-15 enhance the therapeutic effects of whole cell vaccine in mouse CT26 colon carcinoma model].
OBJECTIVE
To determine the enhancement effects of IL-15 to the tumor whole cell vaccine in tumor immunotherapy.


METHODS
CT26 colon carcinoma model was established with BALB/c mice. Thirty two mice with CT26 colon carcinoma were divided randomly into four groups, which were subcutaneously injected at several spots with PBS (200 microL), CT26 whole cell vaccine (2 x 10(6) cells in 200 microL PBS), mIL-15 (20 microg, encapsulated with liposome in 200 microL 5% glucose solution) and CT26 whole cell vaccine (2 x 10(6) cells in 100 microL PBS) plus mIL-15 (20 microg, encapsulated with liposome in 100 microL 5% glucose solution) respectively every three days for six doses, the plasmid was injected beside the vaccine injecting spots. The size of tumors was measured every four days. All mice were sacrificed 30 days after tumor implantation. The pathologic observation and apoptotic analysis of tumors were preceded.


RESULTS
CT26 whole cell vaccine combined with mIL-15 inhibited tumor growth by 45% compared with that of control group, the differences between CT26 + mIL-15 group and the other three groups were significant (P < 0. 05). The HE staining showed that the necrosis areas in tumors of the CT26 + mIL-15 group were larger than those of other three groups. The apoptotic index of tumors from the CT26 + mIL-15 group was (46.7 +/- 7.2)%, higher than that of the other three groups obviously (P < 0.05).


CONCLUSIONS
IL-15 could enhance the therapeutic effects of CT26 whole cell vaccine in tumor immunotherapy.
Zhao
Yu-Wei
YW
Key Laboratory of Biotherapy, West China Hospital, Sichuan University, Chengdu 610041, China.
Li
Zhi-Mian
ZM
Zhao
Cheng-Jian
CJ
Zhang
Ling
L
Jin
Lu
L
Wang
Xiao-Fei
XF
Yang
Han-Shuo
HS
D000818:Animals; D019496:Cancer Vaccines / Q000276:immunology / Q000627:therapeutic use*; D003110:Colonic Neoplasms / Q000276:immunology* / Q000473:pathology / Q000628:therapy*; D004357:Drug Synergism; D007167:Immunotherapy / Q000379:methods; D019409:Interleukin-15 / Q000627:therapeutic use*; D051379:Mice; D008807:Mice, Inbred BALB C; D009368:Neoplasm Transplantation; D011897:Random Allocation
D019496:Cancer Vaccines; D019409:Interleukin-15