Published in:
01-11-2013 | Original Article
Expanded CD8+ T cells of murine and human CLL are driven into a senescent KLRG1+ effector memory phenotype
Authors:
Joachim Rudolf Göthert, Lewin Eisele, Ludger Klein-Hitpass, Stefanie Weber, Marie-Louise Zesewitz, Ludger Sellmann, Alexander Röth, Hanspeter Pircher, Ulrich Dührsen, Jan Dürig
Published in:
Cancer Immunology, Immunotherapy
|
Issue 11/2013
Login to get access
Abstract
Altered numbers and functions of T cells have previously been demonstrated in chronic lymphocytic leukemia (CLL) patients. However, dynamics and specific T-cell subset alterations have not been studied in great detail. Therefore, we studied CLL blood lymphocyte subsets of individual patients in a longitudinal manner. Dynamic expansions of blood CD4
+
and CD8
+
T-cell numbers were consistently associated with a progressively increasing CLL leukemic compartment. Interestingly, the T-cell subset expansion over time was more pronounced in CD38
+
CLL. Additionally, we performed gene expression profiling of CD3
+
T cells of CLL patients and normal donors. Using gene set enrichment analysis, we found significant enrichment of genes with higher expression in CLL T cells within CD8+ effector memory and terminal effector T-cell gene signatures. In agreement with these data, we observed a marked expansion of phenotypic CD8
+
effector memory T cells in CLL by flow cytometry. Moreover, we observed that increments of CD8
+
effector memory T cells in human CLL and also mouse CLL (Eμ-TCL1 model) were due to an expansion of the inhibitory killer cell lectin-like receptor G1 (KLRG1) expressing cellular subset. Furthermore, higher plasma levels of the natural KLRG1 ligand E-cadherin were detected in CLL patients compared to normal donor controls. The predominance of KLRG1+ expression within CD8+ T cells in conjunction with increased systemic soluble E-cadherin might significantly contribute to CLL immune dysfunction and might additionally represent an important component of the CLL microenvironment.