title: Tumor-specific CD8+ T cell reactivity in the sentinel lymph node of GM-CSF-treated stage I melanoma patients is associated with high myeloid dendritic cell content.
abstract: OBJECTIVE
  Impaired immune functions in the sentinel lymph node (SLN) may facilitate early metastatic events during melanoma development. Local potentiation of tumor-specific T cell reactivity may be a valuable adjuvant treatment option.
  
  
  METHODS
  We examined the effect of locally administered granulocyte/macrophage-colony stimulating factor (GM-CSF) on the frequency of tumor-specific CD8+ T cells in the SLN and blood of patients with stage I melanoma. Twelve patients were randomly assigned to preoperative local administration of either recombinant human GM-CSF or NaCl 0.9%. CD8+ T cells from SLN and peripheral blood were tested for reactivity in an IFNgamma ELISPOT assay against the full-length MART-1 antigen and a number of HLA-A1, HLA-A2, and HLA-A3-restricted epitopes derived from a range of melanoma-associated antigens.
  
  
  RESULTS
  Melanoma-specific CD8+ T cell response rates in the SLN were one of six for the control group and four of six for the GM-CSF-administered group. Only one patient had detectable tumor-specific CD8+ T cells in the blood, but at lower frequencies than in the SLN. All patients with detectable tumor-specific CD8+ T cells had a percentage of CD1a+ SLN-dendritic cells (DC) above the median (i.e., 0.33%). This association between above median CD1a+ SLN-DC frequencies and tumor antigen-specific CD8+ T cell reactivity was significant in a two-sided Fisher's exact test (P = 0.015).
  
  
  CONCLUSIONS
  Locally primed antitumor T cell responses in the SLN are detectable as early as stage I of melanoma development and may be enhanced by GM-CSF-induced increases in SLN-DC frequencies.
authors: Department of Surgical Oncology, Pathology, VU University Medical Center, Amsterdam, the Netherlands.
authors: Ronald J C L M
authors: RJ
authors: Vuylsteke
authors: Barbara G
authors: BG
authors: Molenkamp
authors: Paul A M
authors: PA
authors: van Leeuwen
authors: Sybren
authors: S
authors: Meijer
authors: Pepijn G J T B
authors: PG
authors: Wijnands
authors: John B A G
authors: JB
authors: Haanen
authors: Rik J
authors: RJ
authors: Scheper
authors: Tanja D
authors: TD
authors: de Gruijl