[Allogeneic dendritic cell vaccine pulsed with heat shocked tumor cell lysate can enhance antitumor immunity].
OBJECTIVE
To explore whether the allogeneic dendritic cells-pulsed with heat shock protein (HSP)-70-rich tumor cell lysate can enhance the antitumor immunity.


METHODS
Mouse Lewis lung cancer cells were dipped into water of the temperature of 43 degrees C for 1 h so as to undergo heat shock. C57BLK(b)) to elicit increased hsp70 expression, The LLCs were lysed by freeze thawing and the supernatant was collected (LhTCL). Dendritic cells (DCs) were isolated from allogeneic inbred mice (615Kk or BALB/CKd) bone marrow (Bm-DCs), and were pulsed with the LhTCL that underwent heart shock. The phenotypes of the Bm-DCs were analyzed by flow cytometry (FCM). The level of IL-12 was detected by ELISA. The Bm-Dcs of Balb/c mice that were pulsed by LhTCL or not, were injected into the foot pads of C57BL mice as vaccine, 3 d later the lymph nodes in the drainage area of popliteal fossa were taken out to make single cell suspension to undergo immunohistochemistry. Inducible hsp70 in LhTCL was assayed by Western Blotting. The ability of taking up LhTCL by immature DC was evaluated by phagocytosis experiment in vitro and the uptake of CFSE labeled allogeneic DC by recipient DC was evaluated by tracing experiment in vivo. The supernatant cytokine release was determined by sandwich ELISA. Double stained DC was confirmed by FCM and confocal microscopy. Cytotoxic activity was assessed by LDH release assay. The immuno-effect of vaccine was valued by immunoprophylaxis in LLC transplanted model and therapy experiment of LLC-bearing mice of early stage.


RESULTS
43 degrees C heating significantly increased the expression of inducible hsp70 in the LLCs. The allogeneic immature DC s showed full ability to uptake LhTCL and enhanced the expression of CD86 molecules on DC surface and IL-12 secretion, showing that they promoted the maturation of DCs. Subcutaneous injection of allogeneic DC/LhTCL promoted the uptake of allogeneic DC by recipient DC. The spleen cells from the C57BL mice immunized with allogeneic DC/LhTCL vaccine specifically killed the viable LLCs, and secreted Th-1 related cytokine (i.e. high level of INF-gamma and low level of IL-4/IL-10). The experiment of immunoprophylaxis of LLC transplant and therapy of LLC-bearing C57BL mice both confirmed that immunization with allogeneic DC/LhTCL prevented or delayed the growth of LLCs, which elicited higher immunological effect than that with syngeneic DCs/HLTCL.


CONCLUSIONS
Immunization with vaccine of allogeneic DC pulsed with heat shocked hsp70-rich tumor cell lysate is able to enhance antitumor immunity.
You
Jian
J
Department of Thoracic Surgery, Tianjin Medical University Cancer Hospital & Institute, Tianjin 300060, China.
Wang
Chang-li
CL
Hao
Xi-shan
XS
D019264:Adoptive Transfer / Q000379:methods*; D000818:Animals; D015153:Blotting, Western; D019496:Cancer Vaccines / Q000235:genetics / Q000276:immunology / Q000627:therapeutic use*; D018827:Carcinoma, Lewis Lung / Q000378:metabolism / Q000473:pathology / Q000628:therapy*; D045744:Cell Line, Tumor; D003713:Dendritic Cells / Q000276:immunology* / Q000637:transplantation; D004797:Enzyme-Linked Immunosorbent Assay; D005260:Female; D005434:Flow Cytometry; D050883:HSC70 Heat-Shock Proteins / Q000378:metabolism; D006358:Hot Temperature; D007150:Immunohistochemistry; D018664:Interleukin-12 / Q000378:metabolism; D051379:Mice; D008810:Mice, Inbred C57BL; D016019:Survival Analysis
D019496:Cancer Vaccines; D050883:HSC70 Heat-Shock Proteins; D018664:Interleukin-12