title: CD20+ tumor-infiltrating lymphocytes have an atypical CD27- memory phenotype and together with CD8+ T cells promote favorable prognosis in ovarian cancer.
abstract: OBJECTIVE
  Tumor-infiltrating lymphocytes (TIL), in particular CD8(+) T cells and CD20(+) B cells, are strongly associated with survival in ovarian cancer and other carcinomas. Although CD8(+) TIL can mediate direct cytolytic activity against tumors, the role of CD20(+) TIL is poorly understood. Here, we investigate the possible contributions of CD20(+) TIL to humoral and cellular tumor immunity.
  
  
  METHODS
  Tumor and serum specimens were obtained from patients with high-grade serous ovarian cancer. CD8(+) and CD20(+) TIL were analyzed by immunohistochemistry and flow cytometry. Immunoglobulin molecules were evaluated by DNA sequencing. Serum autoantibody responses to the tumor antigens p53 and NY-ESO-1 were measured by ELISA.
  
  
  RESULTS
  The vast majority of CD20(+) TIL were antigen experienced, as evidenced by class-switching, somatic hypermutation, and oligoclonality, yet they failed to express the canonical memory marker CD27. CD20(+) TIL showed no correlation with serum autoantibodies to p53 or NY-ESO-1. Instead, they colocalized with activated CD8(+) TIL and expressed markers of antigen presentation, including MHC class I, MHC class II, CD40, CD80, and CD86. The presence of both CD20(+) and CD8(+) TIL correlated with increased patient survival compared with CD8(+) TIL alone.
  
  
  CONCLUSIONS
  In high-grade serous ovarian tumors, CD20(+) TIL have an antigen-experienced but atypical CD27(-) memory B-cell phenotype. They are uncoupled from serum autoantibodies, express markers of antigen-presenting cells, and colocalize with CD8(+) T cells. We propose that the association between CD20(+) TIL and patient survival may reflect a supportive role in cytolytic immune responses.
authors.affiliation: Trev and Joyce Deeley Research Centre, British Columbia Cancer Agency, Department of Biochemistry and Microbiology, University of Victoria, Victoria, British Columbia, Canada. jnielsen@bccancer.bc.ca
authors.forename: Julie S
authors.initials: JS
authors.lastname: Nielsen
authors.forename: Rob A
authors.initials: RA
authors.lastname: Sahota
authors.forename: Katy
authors.initials: K
authors.lastname: Milne
authors.forename: Sara E
authors.initials: SE
authors.lastname: Kost
authors.forename: Nancy J
authors.initials: NJ
authors.lastname: Nesslinger
authors.forename: Peter H
authors.initials: PH
authors.lastname: Watson
authors.forename: Brad H
authors.initials: BH
authors.lastname: Nelson
mesh_terms: D017951:Antigen Presentation; D018951:Antigens, CD20 / Q000032:analysis*; D000951:Antigens, Neoplasm / Q000276:immunology; D001323:Autoantibodies / Q000097:blood; D001402:B-Lymphocytes / Q000276:immunology*; D018122:B7-1 Antigen / Q000032:analysis; D051940:B7-2 Antigen / Q000032:analysis; D019013:CD40 Antigens / Q000032:analysis; D016827:CD8 Antigens / Q000032:analysis; D018414:CD8-Positive T-Lymphocytes / Q000276:immunology*; D003602:Cytotoxicity, Immunologic; D005260:Female; D015395:Histocompatibility Antigens Class I / Q000032:analysis; D000949:Histocompatibility Antigens Class II / Q000032:analysis; D006801:Humans; D007156:Immunologic Memory; D016246:Lymphocytes, Tumor-Infiltrating / Q000276:immunology*; D008565:Membrane Proteins / Q000276:immunology; D010051:Ovarian Neoplasms / Q000276:immunology*; D010641:Phenotype; D011379:Prognosis; D017422:Sequence Analysis, DNA; D018127:Tumor Necrosis Factor Receptor Superfamily, Member 7 / Q000032:analysis*; D016159:Tumor Suppressor Protein p53 / Q000276:immunology
chemical_list: D018951:Antigens, CD20; D000951:Antigens, Neoplasm; D001323:Autoantibodies; D018122:B7-1 Antigen; D051940:B7-2 Antigen; D019013:CD40 Antigens; D016827:CD8 Antigens; C104948:CTAG1B protein, human; D015395:Histocompatibility Antigens Class I; D000949:Histocompatibility Antigens Class II; D008565:Membrane Proteins; D018127:Tumor Necrosis Factor Receptor Superfamily, Member 7; D016159:Tumor Suppressor Protein p53