Abstract
R095
Problem: Dendritic cells (DCs) are the key antigen-presenting cells (APC) for inducing an antigen-specific immune response. Generating DCs from head and neck squamous cell cancer (HNSCC) patients may be a very important initial step in manipulating the patient's immune system to fight their cancer. In this study we test our ability to generate functional DCs from advanced-stage HNSCC patients' peripheral blood mononuclear cells (PBMC) or lymph node mononuclear cells (LNMC).
Methods: Mononuclear cells were stimulated for 10 days in vitro with soluble IL-4 (90hg/mL)/GM-CSF (100U/mL), then soluble TNFa (20 hg/mL) for 48 hours. Flow cytometry was performed to measure the population of cells, which were CD1a+, CD14-, CD15-, CD80+, CD83+, CD86+, HLA-DR++, and CD4+. DCs were then pulsed with Flu-peptide at increasing concentrations (25, 50, and 100 mg/mL) and used to stimulate Flu-specific T cells from HLA-A2+ individuals. Expansion of Flu-specific T cells was measured by re-exposing T cells to Flu-peptide for 24 hours and measuring intra-cellular expression of IFNg. Experiments were also performed in parallel with normal HLA-A2 donors PBMC.
Results: Mononuclear cells from HNSCC patients were able to generate a population of cells expressing CD1a+, CD14-, CD15-, CD80+, CD83+, CD86+, HLA-DR++, and CD4+, consistent with DCs. DCs were effective at stimulating Flu-specific T cells from HLA-A2 positive individuals and increased the percentage of T cells (CD4/CD8) expressing intracellular IFNg after re-exposure to Flu-peptide.
Conclusion: DCs could be generated from HNSCC patients' mononuclear cells. Functionality of these DCs to induce a Flu-specific immune response was demonstrated by increased intra-cellular expression of IFNg in CD4 and CD8 cell populations after re-priming.
Significance: DCs may be useful in generating an antigen-specific anti-cancer immune response in HNSCC patients.
Support: None reported.