Single-cell RNA-sequencing reveals predictive features of response to pembrolizumab in Sézary syndrome

Autor: Tianying Su, George E. Duran, Alexa C. Kwang, Nirasha Ramchurren, Steven P. Fling, Youn H. Kim, Michael S. Khodadoust
Jazyk: angličtina
Rok vydání: 2022
Předmět:
Zdroj: OncoImmunology, Vol 11, Iss 1 (2022)
Druh dokumentu: article
ISSN: 2162402X
2162-402X
DOI: 10.1080/2162402X.2022.2115197
Popis: The PD-1 inhibitor pembrolizumab is effective in treating Sézary syndrome, a leukemic variant of cutaneous T-cell lymphoma. Our purpose was to investigate the effects of pembrolizumab on healthy and malignant T cells in Sézary syndrome and to discover characteristics that predict pembrolizumab response. Samples were analyzed before and after 3 weeks of pembrolizumab treatment using single-cell RNA-sequencing of 118,961 peripheral blood T cells isolated from six Sézary syndrome patients. T-cell receptor clonotyping, bulk RNA-seq signatures, and whole-exome data were integrated to classify malignant T-cells and their underlying subclonal heterogeneity. We found that responses to pembrolizumab were associated with lower KIR3DL2 expression within Sézary T cells. Pembrolizumab modulated Sézary cell gene expression of T-cell activation associated genes. The CD8 effector populations included clonally expanded populations with a strong cytotoxic profile. Expansions of CD8 terminal effector and CD8 effector memory T-cell populations were observed in responding patients after treatment. We observed intrapatient Sézary cell heterogeneity including subclonal segregation of a coding mutation and copy number variation. Our study reveals differential effects of pembrolizumab in both malignant and healthy T cells. These data support further study of KIR3DL2 expression and CD8 immune populations as predictive biomarkers of pembrolizumab response in Sézary syndrome.
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