Costimulatory molecule expression on human uveal melanoma cells: functional analysis of CD40 and B7-H1.
Costimulatory molecules play important roles in regulating T cell function in tumor immunity. In this study, we investigated costimulatory molecule expression on human uveal melanoma cells (a primary culture, and OCM-1, OMM-1 and 92-1 cell lines) and assessed the functional roles of selected costimulatory molecules. Uveal melanoma cells were incubated in the presence or absence of IFN-γ and expression of costimulatory molecules on the cells was measured by flow cytometry. The costimulatory effect of B7-H1-expressing uveal melanoma cells on cytokine production by purified T cells was studied in uveal melanoma/T cell co-culture experiments using a blocking anti-B7-H1 monoclonal antibody (mAb). The functional role of CD40-mediated interactions in modifying immune responses to uveal melanoma cells was assessed in vitro using recombinant human CD40 ligand (rhCD40L). MHC class I and B7-H1 were consistently detected and further upregulated by IFN-γ stimulation in all human uveal melanoma cell cultures. CD40 was consistently detected and further upregulated by IFN-γ stimulation in primary culture, OCM-1, and OMM-1 but not 92-1. IL-2 production from purified CD3(+) T cells co-stimulated with IFN-γ-treated uveal melanoma cells was significantly enhanced by the addition of anti-B7-H1 mAb. Treatment of primary culture, OCM-1, or OMM-1 with rhCD40L induced or enhanced secretion of chemokines IL-8, MCP-1, IP-10 and RANTES. These results suggest that the expression of B7-H1 on IFN-γ-treated uveal melanoma cells contributes to suppression of T cells by decreasing IL-2 production. In contrast, CD40 expressed on uveal melanoma cells plays an important role in augmenting anti-tumor immunity by stimulating chemokine production. The dual effects of CD40 and B7-H1 may contribute to positive or negative regulation of anti-tumor immune responses to human uveal melanoma.
Department of Ophthalmology, Tokyo Medical University, 6-7-1 Nishishinjuku, Shinjuku-ku, Tokyo 160-0023, Japan.
Juan
J
Ma
Yoshihiko
Y
Usui
Takeshi
T
Kezuka
Yoko
Y
Okunuki
Lina
L
Zhang
Xiaoming
X
An
Atsushi
A
Mizota
Hiroshi
H
Goto
D060890:B7-H1 Antigen / Q000378:metabolism*; D019013:CD40 Antigens / Q000378:metabolism*; D016207:Cytokines / Q000378:metabolism; D005434:Flow Cytometry; D019084:Fluorescent Antibody Technique, Indirect; D006801:Humans; D007371:Interferon-gamma / Q000494:pharmacology; D008545:Melanoma / Q000378:metabolism*; D013601:T-Lymphocytes / Q000276:immunology; D014407:Tumor Cells, Cultured / Q000187:drug effects; D015854:Up-Regulation; D014604:Uveal Neoplasms / Q000378:metabolism*
D060890:B7-H1 Antigen; D019013:CD40 Antigens; D016207:Cytokines; D007371:Interferon-gamma