Anti-tumor vaccine adjuvant effects of IL-2 liposomes in mice immunized against MCA-102 sarcoma.
MCA-102, a murine sarcoma previously reported to be non-immunogenic in C57/BL6 murine tumor models was used in a tumor vaccine preparation which included liposome encapsulated IL-2 as an adjuvant. C57/BL6 mice were immunized in the right hind footpad with irradiated MCA-102 murine sarcoma cells on days 0, 7, and 21 with or without IL-2 liposome adjuvant at 25,000 IL-2 units/injection. Mice were challenged with live tumor in the right flank on day 35. Survival of mice given IL-2 liposomes with irradiated MCA-102 cells was significantly prolonged over mice given tumor antigen with saline, and non-immunized mice. In addition, mice which received the IL-2 liposome adjuvant also had prolonged survival over those mice immunized with the additional control adjuvants of free IL-2 or dimyristoyl phosphatidyl choline (DMPC) lipid in the form of empty liposomes. IL-2 liposome plus tumor antigen also yielded a significant local protective response against live MCA-102 tumor challenge. When live tumor was injected into the site of previous immunizations on day 21 after two immunizations, the IL-2 liposome adjuvant group showed significantly delayed local growth of tumor compared to animals immunized without adjuvant, or with the adjuvants of empty liposomes or free IL-2. Finally, immunized mice were challenged with irradiated tumor cells and saline intradermally in the ears and delayed type hypersensitivity (DTH), an indicator of helper T cell response, was measured.(ABSTRACT TRUNCATED AT 250 WORDS)
Sencer
S F
SF
Department of Pediatrics, University of Minnesota, Minneapolis 55455.
Rich
M L
ML
Katsanis
E
E
Ochoa
A C
AC
Anderson
P M
PM
D000276:Adjuvants, Immunologic / Q000008:administration & dosage*; D000818:Animals; D005260:Female; D006968:Hypersensitivity, Delayed; D007114:Immunization; D007376:Interleukin-2 / Q000008:administration & dosage*; D008081:Liposomes; D051379:Mice; D008810:Mice, Inbred C57BL; D012513:Sarcoma, Experimental / Q000517:prevention & control*
D000276:Adjuvants, Immunologic; D007376:Interleukin-2; D008081:Liposomes