Prognostic impact of NOTCH1, MYD88, and SF3B1 mutations in Polish patients with chronic lymphocytic leukemia

INTRODUCTION    Currently available prognostic factors determining the course of chronic lymphocytic leukemia (CLL) are not fully efficient, especially for newly diagnosed patients. Investigation of molecular changes may help clarify the reasons for the heterogeneity of the disease. Apart from already confirmed TP53 mutations, the novel candidates: NOTCH1, SF3B1, and MYD88 might represent clinically relevant biomarkers. OBJECTIVES    The aim of this study was to evaluate the mutational status of NOTCH1, MYD88, and SF3B1 and to compare the results with confirmed prognostic factors: ZAP‑70, CD38, and immunoglobulin heavy‑chain variable region (IGHV) mutation in CLL. The study assessed also prognostic significance in terms of the time to first treatment (TTFT) and subset analysis. PATIENTS AND METHODS The study was conducted on samples of 370 newly diagnosed patients with CLL. The analysis was performed using high‑resolution melting, Sanger sequencing, and polymerase chain reaction methods. RESULTS    Patients harboring the NOTCH1 mutation were significantly more often found among patients with an unmutated IGHV gene status and high expression of CD38 and ZAP‑70. The MYD88 mutation was equally distributed in patients with mutated and unmutated IGHV status (5 vs 7 patients). For MYD88 and SF3B1, there were no significant differences in the levels of CD38 and ZAP‑70 expression. The tendency for lower median TTFT was revealed in patients with mutated SF3B1 (P = 0.08). The analysis showed the presence of 14 different types of the subsets of IGHV in 50 of 345 patients (14.5%). The most frequent were subsets #1 and #2. CONCLUSIONS    The NOTCH1 and SF3B1 mutations accompany biological markers of unfavorable prognosis in patients with CLL. The mutations may contribute to the identification of patients with high‑risk CLL.

PD1/PD1L pathway, HLA-G and T regulatory cells as new markers of immunosuppression in cancers

The appropriate function of the immune system depends on the effective regulation of the immune response on multiple levels. The key element of an effective immune response to antigenic stimulation is maintaining a homeostasis between activation and inhibitory function of immunocompetent cells and molecules. In pathological conditions such as chronic infections, autoimmune diseases or cancer there are significant alterations, and prevalence of signals of one type over another. Main markers of these dysfunctions are altered expressions of molecules, such as programmed death-1 (PD-1), Human Leukocyte Antigen G (HLA-G), or changed percentages of T regulatory cells (Treg). These indicators of immune system dysfunction may contribute to disease progression, but also could represent good targets for treatment. Interestingly, in recent years there are many new, interesting reports which showed that the role of PD-1, HLA-G or Treg is ambiguous and not always their higher expression or frequency lead to the progression of disease. Recent studies have shown that Treg can suppress bacteria-driven inflammation which promotes carcinogenesis and thus protect the host from cancer development. Moreover, proliferation of hematological tumor cells expressing ILT-2 receptor can be inhibited by HLA-G, in contrast to solid tumors where HLA-G favors tumor escape. In this paper we present characteristics of expressions of PD-1 and its ligands, HLA-G, and frequency of Treg cells in a variety of physiological and pathological conditions associated with chronic infections, autoimmune diseases and cancer. The understanding of the complex interactions between the functional elements of immune system is essential for a detailed characteristics of the mechanisms leading to the development of diseases and identification of more effective targeted therapies.

Thalidomide regulation of NF-κB proteins limits Tregs activity in chronic lymphocytic leukemia

BACKGROUND

Thalidomide may represent a novel therapeutic strategy in the treatment of chronic lymphocytic leukemia (CLL). Since the activation of nuclear factor kappa B (NF-κB) causes not only malignant transformation and tumor progression, but also allows tumor cells to evade immune surveillance, NF-κB signaling components might constitute a potential target for future therapy in CLL.

OBJECTIVES

The current study is an attempt to characterize proteins regulated by thalidomide. Thalidomide's influence on NF-κB proteins and on regulatory T cells (Treg) in CLL was investigated.

MATERIAL AND METHODS

A total of 15 patients with CLL were treated with a combined thalidomide/fludarabine regimen. Peripheral blood mononuclear cells were separated by Ficoll density gradient centrifugation. To evaluate glucocorticoid induced tumour-necrosis-factor-receptor-related protein (GITR) expression in regulatory T cells, cells incubated with anti-CD3, ani-CD4 and anti-CD25 were permeabilized and then stained with anti-FOXP3 and analyzed using flow cytometry. Human TNF enzyme-linked immunosorbent assay (ELISA) was used to determine the tumor necrosis factor (TNF) levels in the serum. To evaluate NF-κB activity, chemiluminescent oligonucleotide-based ELISA was performed.

RESULTS

It was found that thalidomide regulates NF-κB activity differentially, and the activity of certain NF-κB components correlated with TNF levels and T regulatory cell (CD4 + CD25 high GITR + ).

CONCLUSIONS

These results might indicate that thalidomide not only regulates TNF but also directly interferes with NF-κB components.

Total expression of HLA-G and TLR-9 in chronic lymphocytic leukemia patients

Suppressed immune status facilitates immune escape mechanisms that allow chronic lymphocytic leukemia cells to proliferate and expand. The expression of HLA-G could effectively inhibit the immune response. In immune response inhibitory signals follow activation of immune system which might be occur during bacterial or viral infection in CLL patients. In the current study we characterized two components of immune system, inhibitory molecule HLA-G with its receptor - CD85j and Toll-like receptor 9. The material was obtained from 41 CLL patients and 41 HV with similar median age. In CLL patients expression of intracellular and surface HLA-G and soluble HLA-G levels were significantly higher than in HV. We found higher expression of CD85j compared to HV and the positive correlation between expression of HLA-G and CD85j. All the CLL cells expressed TLR-9, and the level of expression positively correlated with expression of HLA-G and CD85j. Patients with higher expression of intracellular expression of TLR-9 have significantly longer treatment-free survival than patients with low expression of TLR-9 (57 months vs. 8 months, respectively). Summarizing in CLL we characterized activatory and inhibitory components of immune system that might be connected functionally. Analysis of TLR-9 expression might have additional prognostic value for CLL patients.

Peptide vaccination induces profound changes in the immune system in patients with B-cell chronic lymphocytic leukemia

Although the immune status of chronic lymphocytic leukemia (CLL) patients is mostly characterized by immunosuppression, there is an accumulation of in vivo (graft-versus-leukemia effect) and in vitro (spontaneous remissions after infections) data that indicates that CLL might be effectively targeted by T-cell based immunotherapy. Recently, we characterized receptor for hyaluronic acid mediated motility (RHAMM) as a preferential target for immunotherapy of CLL. We also completed a RHAMM-derived peptide vaccination phase I/II clinical trial in CLL. Here, we present a detailed immunological analysis of six CLL patients vaccinated with HLA-A2 restricted RHAMM-derived epitope R3 (ILSLELMKL). Beside effective induction of R3-specific cytotoxic T-cells, peptide vaccination caused profound changes in different T-cell subsets as well as cytokines. We present longitudinal analyses of Th17, CD8(+)CD103(+), CD8(+)CD137(+) and IL-17 producing CD8(+) T cells (CD8(+)IL- -17(+)) as well as important cytokines involved in regulation of immune response such as TGF-β, IL-10, IL-2 and TNF throughout the peptide vaccination period.