Product(s) used in this publication: PepMix™ Peptide Pools
BK virus infection remains an important cause of loss of allograft function afterkidneytransplantation. We sought to determine whether polyfunctionalTcells secreting multiple cytokines simultaneously, which have been shown to be associated with viral control, could be detected early after start of BKviremia, which would provide insight into the mechanism of successful antiviral control.
Peripheral blood mononuclear cells collected during episodes of BK viral replication were evaluated by multiparameter flow cytometry after stimulation by overlapping peptide pools of BK virus antigen to determine frequency of CD8+ and CD4+ Tcells expressing 1 or more cytokines simultaneously, as well as markers of T-cell activation, exhaustion, and maturation.
BK virus controllers, defined as those with episodes of BKviremia of 3 months or less, had an 11-fold increase in frequency of CD8+ polyfunctionalTcells expressing multiple cytokines, as compared with patients with prolonged episodes of BKviremia. Patients with only low level BKviremia expressed low frequencies of polyfunctionalTcells. PolyfunctionalTcells were predominantly of the effector memory maturation subtype and expressed the cytotoxicity marker CD107a.
Noninvasive techniques for immune assessment of peripheral blood can provide insight into the mechanism of control of BK virus replication and may allow for future patient risk stratification and customization of immune suppression at the onset of BKviremia.