Quantitative analysis of melanoma-induced cytokine-mediated immunosuppression in melanoma sentinel nodes.
OBJECTIVE
Melanoma sentinel nodes (SN) show evidence of immunosuppression prior to tumor metastasis. Interleukin (IL)-10 and IFN-gamma can induce dendritic cells (DC) that express immunosuppressive enzyme indoleamine 2,3-dioxygenase (IDO). The goals of this study are to evaluate the role of melanoma in SN immunosuppression and to assess reversibility of SN immunosuppression by a cytokine therapy.


METHODS
Fifty-seven clinical stage I/II melanoma patients underwent wide local excision and sentinel lymphadenectomy (WLE/SL), with removal of non-SN. In 21 patients, nodal RNA was analyzed by quantitative real-time PCR for expression levels of IL-2, IL-10, IL-12, IFN-gamma, and IDO genes. Among the remaining 36 patients, 15 received peritumoral injection of recombinant human granulocyte macrophage colony-stimulating factor (rhGM-CSF) 2 to 5 days prior to WLE/SL. Lymph nodes (LN) from these 36 patients were assessed for T-cell area, DC area, and DC density.


RESULTS
Of 21 patients whose nodal RNA was analyzed, 13 had residual melanoma at the primary site or a tumor-positive SN. In these patients, expression levels of IL-10 (P = 0.05), IFN-gamma (P < 0.05), and IDO (P = 0.06) were dramatically higher in SNs than non-SNs. This difference was not evident in the 8 patients without residual melanoma or SN metastasis. Of the 36 patients whose LNs were examined for histologic features, the 15 patients who received rhGM-CSF had significantly higher SN values of T-cell area, DC area, and DC density than those who did not receive rhGM-CSF.


CONCLUSIONS
Our data provide molecular evidence of cytokine-mediated SN immunosuppression that is associated with presence of melanoma. Furthermore, SN immunosuppression can potentially be reversed by a cytokine therapy.
Lee
Jonathan H
JH
John Wayne Cancer Institute, Santa Monica, California 90404, USA.
Torisu-Itakara
Hitoe
H
Cochran
Alistair J
AJ
Kadison
Alan
A
Huynh
Young
Y
Morton
Donald L
DL
Essner
Richard
R
D000328:Adult; D000368:Aged; D016207:Cytokines / Q000378:metabolism*; D003713:Dendritic Cells / Q000378:metabolism; D005260:Female; D005786:Gene Expression Regulation; D016178:Granulocyte-Macrophage Colony-Stimulating Factor / Q000494:pharmacology; D006801:Humans; D007166:Immunosuppressive Agents / Q000494:pharmacology*; D050503:Indoleamine-Pyrrole 2,3,-Dioxygenase; D007371:Interferon-gamma / Q000096:biosynthesis / Q000378:metabolism; D016753:Interleukin-10 / Q000378:metabolism; D018664:Interleukin-12 / Q000096:biosynthesis; D007376:Interleukin-2 / Q000096:biosynthesis; D008198:Lymph Nodes / Q000378:metabolism; D008297:Male; D008545:Melanoma / Q000378:metabolism*; D008875:Middle Aged; D009362:Neoplasm Metastasis; D010865:Pilot Projects; D012313:RNA / Q000378:metabolism; D011994:Recombinant Proteins / Q000737:chemistry / Q000494:pharmacology; D020133:Reverse Transcriptase Polymerase Chain Reaction; D021701:Sentinel Lymph Node Biopsy / Q000379:methods*; D013601:T-Lymphocytes / Q000378:metabolism; D013997:Time Factors; D014366:Tryptophan Oxygenase / Q000096:biosynthesis
D016207:Cytokines; D007166:Immunosuppressive Agents; D050503:Indoleamine-Pyrrole 2,3,-Dioxygenase; D007376:Interleukin-2; D011994:Recombinant Proteins; D016753:Interleukin-10; D018664:Interleukin-12; D012313:RNA; D007371:Interferon-gamma; D016178:Granulocyte-Macrophage Colony-Stimulating Factor; D014366:Tryptophan Oxygenase