Publication
Blockade of programmed cell death protein 1 (PD-1) in Sézary syndrome reduces Th2 phenotype of non-tumoral T lymphocytes but may enhance tumor proliferation
Journal Paper/Review - Mar 18, 2020
Saulite Ieva, Bobrowicz Malgorzata, Hoetzenecker Wolfram, Pascolo Steve, Scarisbrick Julia, Dummer Reinhard, Cozzio Antonio, Nägeli Mirjam, Anzengruber Florian, Varypataki Eleni, Dimitriou Florentia, Fassnacht Christina, Chang Yun-Tsan, Desislava Ignatova, Guenova Emmanuella
Units
PubMed
Doi
Citation
Type
Journal
Publication Date
Issn Print
Pages
Brief description/objective
Sézary syndrome (SS) is an aggressive leukemic variant of cutaneous T-cell lymphoma (L-CTCL) that arises from malignant clonally derived skin-homing CD4 T cells. Based on advancements in our understanding of the mechanisms underlying L-CTCL, boosting the suppressed immune response emerges as a promising strategy in SS management. Immune checkpoint inhibitory molecules have already demonstrated efficacy in a wide spectrum of malignancies. Currently, agents targeting the programmed death-1 (PD-1) axis are under evaluation in L-CTCL. Here we investigated the expression of PD-1 and its ligands, PD-L1 and PD-L2 in blood and skin from patients with L-CTCL. We demonstrate that PD-1 expression is markedly increased on tumor T cells compared to non-tumor CD4 T cells from SS patients and to CD4 cells from healthy individuals. In contrast, PD-L1 shows decreased expression on tumor T cells, while PD-L2 expression is low without significant differences between these groups. Functional PD-1 blockade resulted in reduced Th2 phenotype of non-tumor T lymphocytes, but enhanced the proliferation of tumor T cells from SS patients. Our study sheds some light on the PD-1 axis in both peripheral blood and skin compartments in SS patients, which may be relevant for the treatment of L-CTCL with immune checkpoint inhibitor.