Th17 cells, a recently discovered subset of T helper cells that secrete IL-17A, can affect the inflammation process autoimmune and cancer diseases development. The purpose of this study was to evaluate the role of Th17 cells and IL17A in biology of CLL. The study group included 294 untreated CLL patients in different clinical stages. Here, we show that higher Th17 and IL-17A values were associated with less advanced clinical stage of CLL. Th17 cells’ percentages in PB were lower in patients who died due to CLL during follow-up due to CLL (as compared to surviving patients) and in patients responding to first-line therapy with fludarabine-based regimens (as compared to non-responders). IL-17A inversely correlated with the time from CLL diagnosis to the start of therapy and was lower in patients who required treatment during follow-up. Th-17 and IL-17A values were lower in patients with adverse prognostic factors (17p and 11q deletion, CD38 and ZAP-70 expression). CLL patients with detectable IL-17A mRNA in T cells were in Rai Stage 0 and negative for both ZAP-70 and CD38 expression. Th17 percentages positively correlated with iNKT and adversely with Treg cells. The results of this study suggest that Th17 may play a beneficial role in CLL immunity.

The aim of this study was to investigate the expression of miR-17∼92 cluster members in chronic lymphocytic leukemia (CLL) patients. Six microRNAs (miRNAs)—miR-17, miR-18a, miR-19a, miR-19b-1, miR-20a, and miR-92a-1—very poorly characterized in CLL patients, were chosen for the study to consider their possible role as cancer biomarkers. It is currently unclear to which extent miR-17~92 expression is related to other routinely measured CLL markers, and whether the findings can be of any clinical significance. To achieve this goal, we report the expression levels of these miRNAs detected by RT-qPCR in purified CD19+ B lymphocytes of 107 CLL patients and correlate them with existing clinical data. The study provides new evidence regarding the heterogeneity of miR-17~92 cluster members’ expression in CLL patients. Higher miR-17-5p expression was associated with unfavorable prognostic factors (i.e., 17p and 11q deletions, CD38 and ZAP-70 expression). On the other hand, miR-19a, miR-20a, and miR-92a-1 negatively correlated with these adverse factors. The presence of del(13q) as a sole aberration was associated with a significantly lower miR-17-5p as well as higher miR-19a-3p and miR-92a-1-5p expression compared to patients carrying unfavorable genetic aberrations. Particularly, miR-20a could be considered an independent favorable prognostic factor. In a multivariate analysis, high miR-20a expression remained an independent marker predicting long TTT (time to treatment) for CLL patients.

Malignant B cells in chronic lymphocytic leukemia serve an essential role in the whole immune response, so their interactions with other immune cells are more complex than observed in solid tumors. The latest study results indicate that the immune dysregulation in chronic lymphocytic leukemia (CLL) also affects a small population of invariant natural killer T cells (iNKT). Using peripheral blood iNKT cells obtained from patients with CLL, the objective of the present study was to assess the intracellular expression of typical cytokines involved in the Th1 (IFN‑γ) and Th2 (IL‑4) response pathways following stimulation with the iNKT‑specific ligand α‑galactosylceramide. iNKT cells from patients with CLL exhibited upregulated IL‑4 and IFN‑γ expression in comparison to those from HVs. No significant association between the ability of iNKT cells to produce IL‑4 or IFN‑γ and the expression of CD1d on leukemic B lymphocytes or monocytes was identified. However, the function of iNKT cells was compromised in patients with CLL by a strong Th2 bias (high IL‑4 and low IFN‑γ expression). The ratio of iNKT+IFN‑γ+:iNKT+IL‑4+ was significantly decreased in the CLL group when compared with HVs, and this decreased further as the disease progressed. This change may result in the promotion of leukemic B lymphocyte survival. Therefore, in the pathogenesis of CLL, Th2 bias may delay the antitumor response that relies on stimulation of the Th1 immune response.

Monocytes are one of the least studied immune cells with a potentially important role in the pathogenesis of chronic lymphocytic leukemia (CLL). Nevertheless, data regarding the role of subpopulations of monocytes in the CLL microenvironment are still limited. For the very first time, this study presents an assessment of monocyte subsets divided according to SLAN and CD16 expression in CLL patients. The study involved 70 freshly diagnosed CLL patients and 35 healthy donors. Using flow cytometry, monocyte subpopulations were assessed among PBMCs. CD14⁺ monocytes can be divided into: “classical” (CD14⁺CD16⁻SLAN⁻), “intermediate” (CD14⁺CD16⁺SLAN⁻) and “non-classical” (CD14^dimCD16⁺SLAN⁺). In our study, we noted an increased percentage of non-classical monocytes with intracellular expression of TNF and IL-12. On the other hand, among the intermediate monocytes, a significantly higher percentage of cells synthesizing anti-inflammatory IL-10 was detected. The percentage of CD14^dimCD16⁺SLAN⁺ monocytes producing TNF and IL-12 decreased with the stage of CLL and inversely correlated with the expression of the prognostic factors ZAP-70 and CD38. Moreover, the percentage of CD14^dimCD16⁺SLAN⁺ monocytes producing TNF and IL-12 was lower in CLL patients requiring treatment. This may indicate the beneficial effect of non-classical monocytes on the anti-tumor response.

Cell plasticity, defined as the ability to undergo phenotypical transformation in a reversible manner, is a physiological process that also exerts important roles in disease progression. Two forms of cellular plasticity are epithelial–mesenchymal transition (EMT) and its inverse process, mesenchymal–epithelial transition (MET). These processes have been correlated to the poor outcome of different types of neoplasias as well as drug resistance development. Since EMT/MET are transitional processes, we generated and validated a reporter cell line. Specifically, a far-red fluorescent protein was knocked-in in-frame with the mesenchymal gene marker VIMENTIN (VIM) in H2170 lung cancer cells. The vimentin reporter cells (VRCs) are a reliable model for studying EMT and MET showing cellular plasticity upon a series of stimulations. These cells are a robust platform to dissect the molecular mechanisms of these processes, and for drug discovery in vitro and in vivo in the future.