title: Characterization of the class I-restricted gp100 melanoma peptide-stimulated primary immune response in tumor-free vaccine-draining lymph nodes and peripheral blood.
abstract: OBJECTIVE
  The aim of this study was to characterize the primary gp100(209-2M)-specific T-cell response in vaccine-draining, metastases-free lymph nodes and peripheral blood of peptide-vaccinated stage I to III melanoma patients.
  
  
  METHODS
  After two or three gp100(209-2M) vaccinations, sentinel lymph nodes that drained both the primary tumor and adjacent vaccine sites were excised concomitant with wide excision of the tumor. Comparative 7-color flow cytometry phenotype analysis was done on gp100 tetramer-positive CD8(+) T cells from sentinel lymph nodes, closely proximate time-related peripheral blood mononuclear cells (PBMC) collected 2 to 4 weeks after sentinel lymph node excision, and on PBMC collected 6 months later after 7 or 11 more immunizations. Lymph node and peripheral blood T cells were tested for proliferative response, functional avidity, and tumor cell-induced CD107 mobilization.
  
  
  RESULTS
  The frequencies of gp100-specific CD8(+) T cells from time-related PBMC and sentinel lymph nodes were comparable and were similar to those reported for virus-specific memory T cells. Their respective in vitro proliferation responses were also equivalent but statistically higher than proliferation responses of peripheral blood T cells collected after completion of the entire vaccine regimen. By contrast, functional avidity and CD107 responses were significantly higher in circulating T cells. Sentinel lymph node-derived, gp100-specific CD8(+) T cells predominantly expressed central and effector memory phenotype signatures, whereas there were higher frequencies of effector T cells in the peripheral blood.
  
  
  CONCLUSIONS
  Priming immunization with gp100(209-2M) without coadministration of CD4(+) helper T cell-restricted antigens induced the effective expansion of peptide-specific central and effector memory CD8(+) T cells with high proliferation potential in vaccine-draining lymph nodes of stage I to III melanoma patients. Lymph node memory T cells gave rise to circulating gp100-specific effector T cells exhibiting increased functional maturation.
authors.affiliation: Robert W Franz Cancer Research Center, Earle A Chiles Research Institute, Providence Portland Medical Center, Portland, Oregon 97213, USA. Edwin.Walker@providence.org
authors.forename: Edwin B
authors.initials: EB
authors.lastname: Walker
authors.forename: William
authors.initials: W
authors.lastname: Miller
authors.forename: Daniel
authors.initials: D
authors.lastname: Haley
authors.forename: Kevin
authors.initials: K
authors.lastname: Floyd
authors.forename: Brendan
authors.initials: B
authors.lastname: Curti
authors.forename: Walter J
authors.initials: WJ
authors.lastname: Urba