Expansion and Characterization of Human Melanoma Tumor-Infiltrating Lymphocytes (TILs)

PLoS One. 2010 Nov 10;5(11):e13940. doi: 10.1371/journal.pone.0013940.

Abstract

Background: Various immunotherapeutic strategies for cancer are aimed at augmenting the T cell response against tumor cells. Adoptive cell therapy (ACT), where T cells are manipulated ex vivo and subsequently re-infused in an autologous manner, has been performed using T cells from various sources. Some of the highest clinical response rates for metastatic melanoma have been reported in trials using tumor-infiltrating lymphocytes (TILs). These protocols still have room for improvement and furthermore are currently only performed at a limited number of institutions. The goal of this work was to develop TILs as a therapeutic product at our institution.

Principal findings: TILs from 40 melanoma tissue specimens were expanded and characterized. Under optimized culture conditions, 72% of specimens yielded rapidly proliferating TILs as defined as at least one culture reaching ≥3×10(7) TILs within 4 weeks. Flow cytometric analyses showed that cultures were predominantly CD3+ T cells, with highly variable CD4+:CD8+ T cell ratios. In total, 148 independent bulk TIL cultures were assayed for tumor reactivity. Thirty-four percent (50/148) exhibited tumor reactivity based on IFN-γ production and/or cytotoxic activity. Thirteen percent (19/148) showed specific cytotoxic activity but not IFN-γ production and only 1% (2/148) showed specific IFN-γ production but not cytotoxic activity. Further expansion of TILs using a 14-day "rapid expansion protocol" (REP) is required to induce a 500- to 2000-fold expansion of TILs in order to generate sufficient numbers of cells for current ACT protocols. Thirty-eight consecutive test REPs were performed with an average 1865-fold expansion (+/- 1034-fold) after 14 days.

Conclusions: TILs generally expanded efficiently and tumor reactivity could be detected in vitro. These preclinical data from melanoma TILs lay the groundwork for clinical trials of ACT.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Adult
  • Aged
  • Aged, 80 and over
  • Cell Line, Tumor
  • Cell Proliferation*
  • Cells, Cultured
  • Coculture Techniques
  • Cytotoxicity, Immunologic / immunology
  • Female
  • Flow Cytometry
  • Humans
  • Immunophenotyping
  • Immunotherapy, Adoptive / methods
  • Interferon-gamma / immunology
  • Interferon-gamma / metabolism
  • Lymphocytes, Tumor-Infiltrating / immunology
  • Lymphocytes, Tumor-Infiltrating / pathology*
  • Lymphocytes, Tumor-Infiltrating / transplantation
  • Male
  • Melanoma / immunology
  • Melanoma / pathology*
  • Melanoma / therapy
  • Middle Aged
  • Tumor Cells, Cultured

Substances

  • Interferon-gamma