Molecular characterization of the microenvironment in CLL-like monoclonal B cell lymphocytosis and early-stage chronic lymphocytic leukemia

The analysis of the microenvironment in CLL-like monoclonal B cell lymphocytosis (MBL) and early-stage chronic lymphocytic leukemia (CLL) is relevant for understanding the natural history of CLL. To this end, a total of 58 MBL, 54 early-stage CLL and 31 healthy subjects were extensively characterize...

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Bibliographic Details
Author: Blanco Ares, Gonzalo
Format: doctoral thesis
Status:Published version
Publication Date:2017
Country:España
Institution:CBUC, CESCA
Repository:TDR. Tesis Doctorales en Red
OAI Identifier:oai:www.tdx.cat:10803/664506
Online Access:http://hdl.handle.net/10803/664506
Access Level:Open access
Keyword:Chronic lymphocytic leukemia (CLLl)
CLL-like monoclonal B cell lymphocytosis (MBL)
Tumor microenvironment (TME)
Inflammatory response
Leucemia linfàtica crónica (LLC)
Linfocitosis B monoclonal (LBM) de tipo LLC
Microambiente tumoral
Respuesta inflamatoria
577
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Summary:The analysis of the microenvironment in CLL-like monoclonal B cell lymphocytosis (MBL) and early-stage chronic lymphocytic leukemia (CLL) is relevant for understanding the natural history of CLL. To this end, a total of 58 MBL, 54 early-stage CLL and 31 healthy subjects were extensively characterized by various immunological and molecular methods. Purified CD4+ and CD8+ mononuclear cells from peripheral blood were subjected to gene expression studies and T cell receptor (TR) repertoire analysis, whereas cytokine immunoassays were performed in serum samples. Gene expression studies in CD4+ cells revealed increased cytotoxic and inflammatory pathways, which were higher in MBL than in early-stage CLL. Gene dysregulation was not remarkable in CD8+ cells. Increased serum levels of cytokines such as IL8, IFNγ and TNFα were also observed in MBL, while early-stage CLL generally displayed lower cytokine levels, especially amongst cases bearing somatically hypermutated IGHV genes. TR analysis demonstrated oligoclonality in both entities with persisting T cell clones over time and increasing clonality within CD4+ T cells concurrently with the expansion of neoplastic B cells. Besides, identical T cell clonotypes were identified in different MBL/CLL cases. All these findings implicate inflammatory processes and antigenic elements in the immune background of CLL, whose effects are significantly altered during progression from MBL to CLL.