title: Immune-mediated tumor regression induced by CpG-containing oligodeoxynucleotides.
abstract: T-cell based immunotherapy is an attractive approach for the treatment of multiple tumor types including cervical carcinoma. Immunostimulating DNA containing unmethylated cytosine-guanine (CpG) motifs have been successfully used as adjuvants to enhance immune responses to vaccines designed to trigger antitumor T-cell responses. Using a murine model of cervical carcinoma, we report here that repeated administration of synthetic oligodeoxynucleotides bearing CpG motifs (CpG-ODNs) without the need of vaccination into animals bearing large, established tumors resulted in significant antitumor effects. Both tumor regressions and extended survival resulting from CpG-ODN therapy required the participation of CD8+ T cells. On the other hand, CD4+ T cells were not only not required, but also appeared to inhibit the therapeutic effect of CpG-ODN. Tumor regression correlated with increased infiltration of CD8+ T cells into the tumors and with enhanced expression of MHC class I and II antigens by the tumor cells. Together, these results indicate that CpG therapy could be promising as a single agent for the treatment of some tumors such as cervical carcinoma.
authors.affiliation: Department of Immunology, Mayo Clinic, Rochester, Minnesota 55905, USA.
authors.forename: Jonathan
authors.initials: J
authors.lastname: Baines
authors.forename: Esteban
authors.initials: E
authors.lastname: Celis
mesh_terms: D000818:Animals; D015496:CD4-Positive T-Lymphocytes / Q000378:metabolism; D018414:CD8-Positive T-Lymphocytes / Q000378:metabolism; D002277:Carcinoma / Q000235:genetics / Q000378:metabolism; D018899:CpG Islands; D019175:DNA Methylation; D004195:Disease Models, Animal; D005260:Female; D006801:Humans; D007150:Immunohistochemistry; D051379:Mice; D008810:Mice, Inbred C57BL; D018345:Mice, Knockout; D009841:Oligonucleotides / Q000235:genetics* / Q000494:pharmacology; D013997:Time Factors; D014162:Transfection; D002583:Uterine Cervical Neoplasms / Q000235:genetics / Q000378:metabolism
chemical_list: D009841:Oligonucleotides