title: Epstein-Barr virus infection and clinical outcome in breast cancer patients correlate with immune cell TNF-α/IFN-γ response.
abstract: BACKGROUND
  For nearly two decades now, various studies have reported detecting the Epstein-Barr virus (EBV) in breast cancer (BC) cases. Yet the results are unconvincing, and their interpretation has remained a matter of debate. We have now presented prospective data on the effect of EBV infection combined with survival in patients enrolled in a prospective study.
  
  
  METHODS
  We assessed 85 BC patients over an 87-month follow-up period to determine whether EBV infection, evaluated by qPCR in both peripheral blood mononuclear cells (PBMCs) and tumor biopsies, interacted with host cell components that modulate the evolution parameters of BC. We also examined the EBV replicating form by the titration of serum anti-ZEBRA antibodies. Immunological studies were performed on a series of 35 patients randomly selected from the second half of the survey, involving IFN-γ and TNF-α intracellular immunostaining tests performed via flow cytometry analysis in peripheral NK and T cells, in parallel with EBV signature. The effect of the EBV load in the blood or tumor tissue on patient survival was analyzed using univariate and multivariate analyses, combined with an analysis of covariance.
  
  
  RESULTS
  Our study represents the first ever report of the impact of EBV on the clinical outcome of BC patients, regardless of tumor histology or treatment regimen. No correlation was found between: (i) EBV detection in tumor or PBMCs and tumor characteristics; (ii) EBV and other prognostic factors. Notably, patients exhibiting anti-ZEBRA antibodies at high titers experienced poorer overall survival (p = 0.002). Those who recovered from their disease were found to have a measurable EBV DNA load, together with a high frequency of IFN-γ and TNF-α producing PBMCs (p = 0.04), which indicates the existence of a Th1-type polarized immune response in both the tumor and its surrounding tissue.
  
  
  CONCLUSIONS
  The replicative form of EBV, as investigated using anti-ZEBRA titers, correlated with poorer outcomes, whereas the latent form of the virus that was measured and quantified using the EBV tumor DNA conferred a survival advantage to BC patients, which could occur through the activation of non-specific anti-tumoral immune responses.
authors.forename: Gina
authors.initials: G
authors.lastname: Marrão
authors.forename: Mohammed
authors.initials: M
authors.lastname: Habib
authors.forename: Artur
authors.initials: A
authors.lastname: Paiva
authors.forename: Dominique
authors.initials: D
authors.lastname: Bicout
authors.forename: Catherine
authors.initials: C
authors.lastname: Fallecker
authors.forename: Sofia
authors.initials: S
authors.lastname: Franco
authors.forename: Samira
authors.initials: S
authors.lastname: Fafi-Kremer
authors.forename: Teresa
authors.initials: T
authors.lastname: Simões da Silva
authors.forename: Patrice
authors.initials: P
authors.lastname: Morand
authors.forename: Carlos
authors.initials: C
authors.lastname: Freire de Oliveira
authors.affiliation: Université de Grenoble-Alpes, Unit for Virus Host-Cell Interactions, UMI 3265 UJF-CNRS-EMBL, CIBB, 71 Avenue des Martyrs, F-38042 Grenoble, Cedex 9, France. drouet@embl.fr.
authors.forename: Emmanuel
authors.initials: E
authors.lastname: Drouet
mesh_terms: D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D001943:Breast Neoplasms / Q000276:immunology / Q000401:mortality / Q000821:virology*; D020031:Epstein-Barr Virus Infections / Q000276:immunology* / Q000401:mortality / Q000821:virology; D005260:Female; D004854:Herpesvirus 4, Human / Q000235:genetics*; D006801:Humans; D007371:Interferon-gamma / Q000378:metabolism*; D007694:Killer Cells, Natural / Q000276:immunology / Q000821:virology; D008875:Middle Aged; D016019:Survival Analysis; D013601:T-Lymphocytes / Q000276:immunology / Q000821:virology; D014409:Tumor Necrosis Factor-alpha / Q000378:metabolism*
chemical_list: D014409:Tumor Necrosis Factor-alpha; D007371:Interferon-gamma