Efficient ex vivo induction of T cells with potent anti-tumor activity by protein antigen encapsulated in nanoparticles

Publication Type:

Journal Article


Cancer immunology, immunotherapy , Volume 62, pp. 1161-1173 (2013)


1432-0851 (Electronic)03

DOI Name (links to online publication)



Protein antigen (Ag)-based immunotherapies have the advantage to induce T cells with a potentially broad repertoire of specificities. However, soluble protein Ag is generally poorly cross-presented in MHC class I molecules and not efficient in inducing robust cytotoxic CD8+ T cell responses. In the present study, we have applied poly(lactic-co-glycolic acid) (PLGA) nanoparticles (NP) which strongly improve protein Ag presentation by dendritic cells (DC) in the absence of additional Toll-like receptor ligands or targeting devices. Protein Ag-loaded DC were used as antigen presenting cells to stimulate T cells in vitro and subsequently analyzed in vivo for their anti-tumor effect via adoptive transfer, a treatment strategy widely studied in clinical trials as a therapy against various malignancies. In a direct comparison with soluble protein Ag, we show that DC presentation of protein encapsulated in plain PLGA-NP results in efficient activation of CD4+ and CD8+ T cells as reflected by high numbers of activated CD69+ and CD25+, interferon (IFN)-gamma and interleukin (IL)-2-producing T cells. Adoptive transfer of PLGA-NP-activated CD8+ T cells in tumor-bearing mice displayed good in vivo expansion capacity, potent Ag-specific cytotoxicity and IFN-gamma cytokine production, resulting in curing mice with established tumors. We conclude that delivery of protein Ag through encapsulation in plain PLGA-NP is a very efficient and simple procedure to stimulate potent anti-tumor T cells.