Merkel polyomavirus-specific T cells fluctuate with merkel cell carcinoma burden and express therapeutically targetable PD-1 and Tim-3 exhaustion markers.

ABSTRACT:

Purpose

The persistent expression of Merkel cell polyomavirus (MCPyV) oncoproteins in Merkel cell carcinoma (MCC) provides a unique opportunity to characterize immune evasion mechanisms in human cancer. We isolated MCPyV-specific T cells and determined their frequency and functional status.

Experimental design

Multiparameter flow cytometry panels and HLA/peptide tetramers were used to identify and characterize T cells from tumors (n = 7) and blood (n = 18) of patients with MCC and control subjects (n = 10). PD-1 ligand (PD-L1) and CD8 expression within tumors were determined using mRNA profiling (n = 35) and immunohistochemistry (n = 13).

Results

MCPyV-specific CD8 T cells were detected directly ex vivo from the blood samples of 7 out of 11 (64%) patients with MCPyV-p

SUBMITTER: Afanasiev OK 

PROVIDER: S-EPMC3790865 | biostudies-literature | 2013 Oct

REPOSITORIES: biostudies-literature