Polyomavirus BK-Specific Cellular Immune Response to VP1 and Large T-Antigen in Kidney Transplant Recipients

Abstract

Polyomavirus BK (BKV) is the primary cause of polyomavirus-associated nephropathy (PVAN) in kid-

Characterization of Immunodominant BK Polyomavirus 9mer Epitope T Cell Responses

“…Because of the low BKPyV‐specific T cell frequency in PBMCs, an in vitro expansion protocol was adopted 35, and PBMCs were stimulated using BKPyV EVGR 15mP or LPP. IFN‐γ ELISpot assays were performed before and after expansion using 15mP, LPP, 9mP and 9msP for single‐epitope cross‐identification.…”

“…Cells were restimulated after expansion, as reported 35, using 15mP or a pool of 73 predicted 9mer peptides (9mP). The 9mer peptides were also resuspended in different subpools according to a checkerboard matrix approach, from A to H and from 1 to 9 (called 9msA–H and 9ms1–9).…”

“…T cell responses to the LVGR‐encoded capsid viral protein VP1 were generally more pronounced than those to EVGR‐encoded viral proteins 30, 35, 49. Interferon γ (IFN‐γ) responses were largely derived from CD4 + T cells and, to a lesser extent, from CD8 + T cells 30, 35, 51, 52, 53. Because most of these studies used overlapping 15mer peptide pools (15mP), the contribution of individual CD8 + T cell–restricted epitopes to these responses is largely undefined.…”

“…We and others investigated cellular immune responses to overlapping peptide pools encoded in the early viral gene region (EVGR) or the late viral gene region (LVGR) of the BKPyV DNA genome 30, 35, 36, 49, 50. T cell responses to the LVGR‐encoded capsid viral protein VP1 were generally more pronounced than those to EVGR‐encoded viral proteins 30, 35, 49.…”

Polyomavirus JC-targeted T-cell therapy for progressive multiple leukoencephalopathy in a hematopoietic cell transplantation recipient

“…21 Briefly, 2 Â 10 6 donor PBMCs were pulsed with 15-mer peptide pools, spanning the entire JCV-VP1 and large T (LT) proteins (5 ng/mL concentration of each mix; Eurogentec, Seraing Belgium) 22 in 1 ml volume of X-VIVO 20 medium containing 10% autologous or human AB serum. On day þ 12, cultured cells were recovered, counted and re-plated at 2 Â 10 5 per well in 24-well plates, pre-incubated overnight with 1 Â 10 6 autologous irradiated stimulator PBMC, pulsed with 50 ng/mL JCV-VP1 and LT peptide mixes.…”