title: Efficient identification of mutated cancer antigens recognized by T cells associated with durable tumor regressions.
abstract: OBJECTIVE
  Cancer immunotherapy with adoptive transfer of tumor-infiltrating lymphocytes (TIL) represents an effective treatment for patients with metastatic melanoma, with the objective regressions in up to 72% of patients in three clinical trials. However, the antigen targets recognized by these effective TILs remain largely unclear.
  
  
  METHODS
  Melanoma patients 2359 and 2591 both experienced durable complete regressions of metastases ongoing beyond five years following adoptive TIL transfer. Two conventional screening approaches were carried out to identify the antigens recognized by these clinically effective TILs. In addition, a novel approach was developed in this study to identify mutated T-cell antigens by screening a tandem minigene library, which comprised nonsynonymous mutation sequences identified by whole-exome sequencing of autologous tumors.
  
  
  RESULTS
  Screening of an autologous melanoma cDNA library using a conventional approach led to the identification of previously undescribed nonmutated targets recognized by TIL 2359 or TIL 2591. In contrast, screening of tandem minigene libraries encoding tumor-specific mutations resulted in the identification of mutated kinesin family member 2C (KIF2C) antigen as a target of TIL 2359, and mutated DNA polymerase alpha subunit B (POLA2) antigen as a target of TIL 2591. Both KIF2C and POLA2 have been found to play important roles in cell proliferation.
  
  
  CONCLUSIONS
  These findings suggest that the minigene screening approach can facilitate the antigen repertoire analysis of tumor reactive T cells, and lead to the development of new adoptive cell therapies with purified T cells that recognize candidate-mutated antigens derived from genes essential for the carcinogenesis.
authors.affiliation: Authors' Affiliations: Surgery Branch, National Cancer Institute, NIH, Bethesda, Maryland; and Yong-Chen.Lu@nih.gov Paul_Robbins@nih.gov.
authors.forename: Yong-Chen
authors.initials: YC
authors.lastname: Lu
authors.affiliation: Authors' Affiliations: Surgery Branch, National Cancer Institute, NIH, Bethesda, Maryland; and.
authors.forename: Xin
authors.initials: X
authors.lastname: Yao
authors.affiliation: Authors' Affiliations: Surgery Branch, National Cancer Institute, NIH, Bethesda, Maryland; and.
authors.forename: Jessica S
authors.initials: JS
authors.lastname: Crystal
authors.affiliation: Authors' Affiliations: Surgery Branch, National Cancer Institute, NIH, Bethesda, Maryland; and.
authors.forename: Yong F
authors.initials: YF
authors.lastname: Li
authors.affiliation: Authors' Affiliations: Surgery Branch, National Cancer Institute, NIH, Bethesda, Maryland; and.
authors.forename: Mona
authors.initials: M
authors.lastname: El-Gamil
authors.affiliation: Authors' Affiliations: Surgery Branch, National Cancer Institute, NIH, Bethesda, Maryland; and.
authors.forename: Colin
authors.initials: C
authors.lastname: Gross
authors.affiliation: Authors' Affiliations: Surgery Branch, National Cancer Institute, NIH, Bethesda, Maryland; and.
authors.forename: Lindy
authors.initials: L
authors.lastname: Davis
authors.affiliation: Authors' Affiliations: Surgery Branch, National Cancer Institute, NIH, Bethesda, Maryland; and.
authors.forename: Mark E
authors.initials: ME
authors.lastname: Dudley
authors.affiliation: Authors' Affiliations: Surgery Branch, National Cancer Institute, NIH, Bethesda, Maryland; and.
authors.forename: James C
authors.initials: JC
authors.lastname: Yang
authors.affiliation: Department of Molecular Cell Biology, Weizmann Institute of Science, Rehovot, Israel.
authors.forename: Yardena
authors.initials: Y
authors.lastname: Samuels
authors.affiliation: Authors' Affiliations: Surgery Branch, National Cancer Institute, NIH, Bethesda, Maryland; and.
authors.forename: Steven A
authors.initials: SA
authors.lastname: Rosenberg
authors.affiliation: Authors' Affiliations: Surgery Branch, National Cancer Institute, NIH, Bethesda, Maryland; and Yong-Chen.Lu@nih.gov Paul_Robbins@nih.gov.
authors.forename: Paul F
authors.initials: PF
authors.lastname: Robbins
mesh_terms: D000483:Alleles; D000595:Amino Acid Sequence; D000818:Animals; D000951:Antigens, Neoplasm / Q000737:chemistry / Q000235:genetics* / Q000276:immunology*; D001324:Autoantigens / Q000276:immunology; D002460:Cell Line; D018450:Disease Progression; D018604:Epitope Mapping; D018984:Epitopes, T-Lymphocyte / Q000737:chemistry / Q000276:immunology / Q000378:metabolism; D015723:Gene Library; D006649:Histocompatibility Antigens / Q000235:genetics / Q000276:immunology; D006801:Humans; D016246:Lymphocytes, Tumor-Infiltrating / Q000276:immunology / Q000378:metabolism; D009154:Mutation; D009369:Neoplasms / Q000235:genetics* / Q000276:immunology* / Q000473:pathology; D010455:Peptides / Q000737:chemistry / Q000276:immunology; D011485:Protein Binding / Q000276:immunology; D013601:T-Lymphocytes / Q000276:immunology* / Q000378:metabolism*
chemical_list: D000951:Antigens, Neoplasm; D001324:Autoantigens; D018984:Epitopes, T-Lymphocyte; D006649:Histocompatibility Antigens; D010455:Peptides