The Role of B Regulatory Cells in the Immunological Escape of Tumor Cells in Hodgkin Lymphoma

Autor: M Rocco, G Villani, Valentina Giudice, Carmine Selleri, R Rosamilio, L Pezzullo, Bianca Serio, Idalucia Ferrara
Rok vydání: 2016
Předmět:
Zdroj: Blood. 128:1768-1768
ISSN: 1528-0020
0006-4971
DOI: 10.1182/blood.v128.22.1768.1768
Popis: Hodgkin and Reed-Sternberg (HRS) cells in classical Hodgkin Lymphoma (HL) are surrounded by a rich inflammatory infiltrate which aids in their survival and escape from cytotoxic CD8+ T cells (CTLs) and Natural Killer cells (NKs). Within HL environment, T regulatory cells (Tregs) directly suppress the activity of CTLs and NKs, enhancing the tolerance against HRS cells. B regulatory cells (Bregs) have been shown to support the differentiation of Tregs through IL-10 production; thus, we hypothesized that they could have a role in the pathophysiology of HL. We evaluated 30 classic HL patients (M/F: 18/12; median age, 31 years, range 15-62) and 5 healthy controls (HC) for circulating peripheral blood (PB) Bregs, Tregs, CTLs, NKs, and NKTs. Twenty-four of them were new-diagnosed patients (NwHL) and 6 received a previous diagnosis of HL but were in complete remission (CR) for more than 12 months (PvHL). NwHL patients were divided according to the International Prognostic Score (IPS) and the Ann-Arbor Staging System. All subjects were treated following the ABVD protocol (doxorubicin 25 mg/m2, bleomycin 10 U/m2, vinblastine 6 mg/m2, and dacarbazine 375 mg/m2). Flow cytometry was performed on heparinized PB samples with a 5-color Beckman Coulter Cytomics FC500 flow cytometer. Breg (CD19+CD24+), Treg (CD3+CD4+CD25+), CTL (CD3+CD8+), NK (CD3-CD56+), and NKT (CD3+CD56+) levels were measured simultaneously with the PET/CT evaluations, ie at diagnosis, at the end of the second ABVD administration, at the end of treatment, and at 6 and/or 12 months off-therapy. Moreover, Breg levels were compared to IPS and Ann-Arbor staging groups, and also were correlated to the erythrocyte sedimentation rate (ESR) and to the absolute lymphocyte count (ALC). We found decreased circulating Bregs in NwHL and PvHL patients compared to controls (0.39% vs 0.875% vs 1.813%, respectively, p Our preliminary data suggest involvement of Bregs in the escape and survival of HRS cells during active disease. Peripheral blood may mirror disease activity in lymphoid tissues. Thus, the decrease of circulating Bregs may be related to the recruitment of these cells to the tumor site; amplification of the Bregs/Tregs ratio may result in a greater Breg-dependent Treg activation with subsequent inhibition of CTL and NK function. Additionally, the normalization of Bregs and the Bregs/Tregs ratio after chemotherapy could be used to predict disease remission. While larger prospective studies are required to validate these results, we present intriguing evidence of the involvement of Bregs in the pathophysiology of HL. Disclosures No relevant conflicts of interest to declare.
Databáze: OpenAIRE
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