Pediatric organ transplant recipients are at highest risk of developing morbidity and mortality from EBV infection. There is broad consensus that T cell immunity is important in controlling viral replication and expansion of infected B cells. In this study, we simultaneously analyze virus-specific T cells’ phenotypes, functions, and epitope specificity using 37-parameter mass cytometry in the setting of pediatric organ transplant recipients, followed over the first two years post-transplant. We compared T cell responses to peptide pools derived from lytic and latent EBV antigens in both healthy EBV+ donors and pediatric transplant patients. The results suggest that healthy EBV+ donors can mount CD8+ T cell responses to both lytic and latent EBV antigens, with production of multiple cytokines. In contrast, pediatric patients have much weaker T cell responses, especially to lytic antigens. Based on current data, we hypothesize a polyfunctional T cell response to lytic antigens may preferentially protect against EBV viremia. We also use the SPADE algorithm for unsupervised clustering to compare the distribution of different T cell subsets in cytokine-producing cells. In addition, we analyze these T cells’ functional capacity for cytokine production by visualization in a heatmap. By employing highly multi-parameter mass cytometry and longitudinal sampling, we have created a more detailed picture of the T cell responses to EBV in the setting of pediatric transplant recipients.
- Copyright © 2013 by The American Association of Immunologists, Inc.