Novel approach for improved assessment of phenotypic and functional characteristics of BKV-specific T-cell immunity

Transplantation. 2011 Dec 15;92(11):1269-77. doi: 10.1097/TP.0b013e318234e0e5.


Background: BKV-associated nephropathy represents a serious complication of the posttransplant period in kidney transplant recipients. Monitoring BKV-specific immunity is of a special importance for estimation of clinical course in patients with BKV reactivation. Our recent data demonstrated that all five BKV antigens are immunogenic and elicit T-cell responses varying within patients. Therefore, all five BKV proteins should be evaluated for the assessment of BKV-specific immunity. However, analysis of five proteins performed separately is time- and cost-intensive and requires large amount of blood.

Methods: Using novel approach of a mixture of overlapping peptide pools encompassing all five BKV antigens (viral protein [VP] 1, VP2, VP3, large tumor antigen, and small tumor antigen) and multiparameter flow cytometry, we evaluate BKV-specific T cells in patients with a previous/present severe long-lasting or transient BKV reactivation. Patients without BKV reactivation were used as control.

Results: In this study, we show that using mixture of overlapping peptide pool results in the magnitude of CD4- and CD8-positive BKV-specific T-cell response, which is significantly higher compared with any frequencies detected by previously used single BKV antigen stimulation. Of interest, patients with a history of rapid BKV clearance had significantly higher frequency of multifunctional interferon gamma-γ/interleukin (IL)-2/tumor necrosis factor-α and IL-2/tumor necrosis factor-α CD4-positive T cells, suggesting protective potential of polyfunctional T cells. Furthermore, we did not find IL-17-producing BKV-specific memory T cells in patients recovered from BKV reactivation.

Conclusions: Here, we established a fast and sensitive approach allowing the most comprehensive assessment of the total BKV immunity performed to date and offer a new platform for further prospective studies.

Publication types

  • Comparative Study
  • Evaluation Study
  • Research Support, Non-U.S. Gov't

MeSH terms

  • Adult
  • Aged
  • BK Virus / immunology*
  • CD4-Positive T-Lymphocytes / immunology
  • CD4-Positive T-Lymphocytes / metabolism
  • CD4-Positive T-Lymphocytes / pathology
  • CD8-Positive T-Lymphocytes / immunology
  • CD8-Positive T-Lymphocytes / metabolism
  • CD8-Positive T-Lymphocytes / pathology
  • Female
  • Flow Cytometry / methods*
  • Humans
  • Interferon-gamma / metabolism
  • Interleukin-2 / metabolism
  • Kidney / immunology
  • Kidney / pathology
  • Kidney / virology
  • Kidney Diseases / immunology
  • Kidney Diseases / pathology
  • Kidney Diseases / virology*
  • Kidney Transplantation*
  • Male
  • Middle Aged
  • Phenotype*
  • Postoperative Complications*
  • Sensitivity and Specificity
  • T-Lymphocytes / immunology*
  • T-Lymphocytes / metabolism
  • T-Lymphocytes / pathology
  • Tumor Necrosis Factor-alpha / metabolism


  • Interleukin-2
  • Tumor Necrosis Factor-alpha
  • Interferon-gamma