title: The observation of immunosuppressor(s) derived from cultured tumor cells and its partial neutralization with OK-432.
abstract: Malignant tumors such as brain tumors have been reported to be associated with immunosuppression caused by certain tumor-secreted cytokines. The reversion of tumor-derived immunosuppression has not been described. The use of OK-432, an immunomodulatory agent prepared from Su-strain of Streptococcus pyogenes A3, to activate peripheral blood mononuclear cells from a patient with glioblastoma multiforme has demonstrated a sharp rise in proliferative response. This proliferative response was compromised in the presence of living and irradiated autogeneic cancer cells. The conditioned media from cultured cells of glioblastoma multiforme, astrocytoma, and cholangiocarcinoma were tested for immunosuppressive ability. We found that conditioned media from 3 of 4 cases of glioblastoma, all 3 cases of astrocytoma, and 1 case of cholangiocarcinoma exhibited immunosuppressive activity toward the proliferative response of allogeneic peripheral blood mononuclear cells to phytohemagglutinin. This is the first report that cholangiocarcinoma produces soluble immunosuppressor(s). Our finding suggested that soluble substance(s) as well as direct cell-cell contact between tumor cells and mononuclear cells play roles in the observed tumor-derived immunosuppression.
authors.affiliation: Department of Pharmacology, Faculty of Medicine Siriraj Hospital, Mahidol University, Bangkok, Thailand.
authors.forename: A
authors.initials: A
authors.lastname: Wongkajornsilp
authors.forename: R A
authors.initials: RA
authors.lastname: Luankosolchai
authors.forename: S
authors.initials: S
authors.lastname: Huabprasert
authors.forename: V
authors.initials: V
authors.lastname: Chanyavanich
authors.forename: N
authors.initials: N
authors.lastname: Tisavipat
authors.forename: P
authors.initials: P
authors.lastname: Watanapa
mesh_terms: D000276:Adjuvants, Immunologic; D000970:Antineoplastic Agents / Q000627:therapeutic use*; D001254:Astrocytoma / Q000188:drug therapy* / Q000276:immunology; D002455:Cell Division; D018281:Cholangiocarcinoma / Q000188:drug therapy* / Q000276:immunology; D003124:Colorimetry; D017077:Culture Media, Conditioned; D006801:Humans; D007963:Leukocytes, Mononuclear / Q000276:immunology*; D010844:Picibanil / Q000627:therapeutic use*; D014407:Tumor Cells, Cultured
chemical_list: D000276:Adjuvants, Immunologic; D000970:Antineoplastic Agents; D017077:Culture Media, Conditioned; D010844:Picibanil