Retrovirus-mediated gene transfer of B7-1 and MHC class II converts a poorly immunogenic neuroblastoma into a highly immunogenic one.
The T cell co-stimulatory molecule B7-1 was transduced into a poorly immunogenic murine neuroblastoma cell line (Neuro-2a, N-2a) alone or in combination with MHC class II genes to test the ability of these genes to stimulate antitumor immunity. N-2a cells transduced with B7-1 exhibited reduced tumorigenicity, whereas N-2a cells overexpressing both MHC class II (syngeneic, I-Ak) and B7-1 totally abrogated tumorigenicity. Rejection of I-Ak/B7-1 cells was dependent on both CD4+ and CD8+ T cells. The ability of both vaccines to induce protection against parental N-2a was temporally dependent on the time of secondary N-2a challenge. To investigate the immunity generated by N-2a/B7-1 and N-2a/I-Ak/B7-1 vaccines, we tested the ability of these modified cells to stimulate in vitro the proliferation of syngeneic splenocytes from naive mice. A significant increase in splenocyte proliferation was observed with N-2a/I-Ak/B7-1 cells compared to N-2a cells. We also determined that vaccination with N-2a/I-Ak/B7-1 cells was able to generate cytotoxic T cell responses to unmodified N-2a cells. The introduction of B7-1 and I-Ak into N-2a was able to convert a poorly immunogenic tumor to a highly immunogenic one; however, mice bearing large established unmodified tumors had little response to vaccination with N-2a/I-Ak/B7-1 cells. Our results emphasize the importance of tumor immunogenicity in the treatment of established tumors with MHC class II/B7-1 tumor cell vaccines.
Heuer
J G
JG
Herman B Wells Center for Pediatric Research, Department of Pediatrics, Indiana University School of Medicine, Indianapolis, 46202, USA.
Tucker-McClung
C
C
Gonin
R
R
Hock
R A
RA
D000818:Animals; D018122:B7-1 Antigen / Q000235:genetics* / Q000276:immunology*; D015496:CD4-Positive T-Lymphocytes / Q000276:immunology; D018414:CD8-Positive T-Lymphocytes / Q000276:immunology; D002478:Cells, Cultured; D003602:Cytotoxicity, Immunologic; D005822:Genetic Vectors; D000949:Histocompatibility Antigens Class II / Q000235:genetics* / Q000276:immunology*; D008213:Lymphocyte Activation; D051379:Mice; D009447:Neuroblastoma / Q000235:genetics* / Q000276:immunology*; D011995:Recombination, Genetic; D012190:Retroviridae / Q000235:genetics; D013601:T-Lymphocytes / Q000276:immunology; D013602:T-Lymphocytes, Cytotoxic / Q000276:immunology
D018122:B7-1 Antigen; D000949:Histocompatibility Antigens Class II