Manipulating the tumor microenvironment ex vivo for enhanced expansion of tumor-infiltrating lymphocytes for adoptive cell therapy

Clin Cancer Res. 2015 Feb 1;21(3):611-21. doi: 10.1158/1078-0432.CCR-14-1934. Epub 2014 Dec 3.


Purpose: Cultured tumor fragments from melanoma metastases have been used for years as a source of tumor-infiltrating lymphocytes (TIL) for adoptive cell therapy (ACT). The expansion of tumor-reactive CD8(+) T cells with interleukin-2 (IL2) in these early cultures is critical in generating clinically active TIL infusion products, with a population of activated 4-1BB CD8(+) T cells recently found to constitute the majority of tumor-specific T cells.

Experimental design: We used an agonistic anti-4-1BB antibody added during the initial tumor fragment cultures to provide in situ 4-1BB costimulation.

Results: We found that addition of an agonistic anti-4-1BB antibody could activate 4-1BB signaling within early cultured tumor fragments and accelerated the rate of memory CD8(+) TIL outgrowth that were highly enriched for melanoma antigen specificity. This was associated with NFκB activation and the induction of T-cell survival and memory genes, as well as enhanced IL2 responsiveness, in the CD8(+) T cells in the fragments and emerging from the fragments. Early provision of 4-1BB costimulation also affected the dendritic cells (DC) by activating NFκB in DC and promoting their maturation inside the tumor fragments. Blocking HLA class I prevented the enhanced outgrowth of CD8(+) T cells with anti-4-1BB, suggesting that an ongoing HLA class I-mediated antigen presentation in early tumor fragment cultures plays a role in mediating tumor-specific CD8(+) TIL outgrowth.

Conclusions: Our results highlight a previously unrecognized concept in TIL ACT that the tumor microenvironment can be dynamically regulated in the initial tumor fragment cultures to regulate the types of T cells expanded and their functional characteristics.

Publication types

  • Research Support, N.I.H., Extramural
  • Research Support, Non-U.S. Gov't

MeSH terms

  • Active Transport, Cell Nucleus / drug effects
  • Antibodies, Monoclonal / pharmacology
  • Dendritic Cells / drug effects
  • Dendritic Cells / immunology
  • Humans
  • Immunophenotyping
  • Immunotherapy, Adoptive* / methods
  • Lymphocytes, Tumor-Infiltrating / drug effects
  • Lymphocytes, Tumor-Infiltrating / immunology*
  • Lymphocytes, Tumor-Infiltrating / metabolism
  • Melanoma / immunology
  • Melanoma / pathology
  • Melanoma / therapy
  • NF-kappa B / metabolism
  • Neoplasms / genetics
  • Neoplasms / immunology*
  • Neoplasms / metabolism
  • Neoplasms / pathology
  • Neoplasms / therapy*
  • Phenotype
  • Signal Transduction / drug effects
  • Tumor Microenvironment / genetics
  • Tumor Microenvironment / immunology*
  • Tumor Necrosis Factor Receptor Superfamily, Member 9 / agonists
  • Tumor Necrosis Factor Receptor Superfamily, Member 9 / genetics
  • Tumor Necrosis Factor Receptor Superfamily, Member 9 / metabolism


  • Antibodies, Monoclonal
  • NF-kappa B
  • Tumor Necrosis Factor Receptor Superfamily, Member 9