Assessment of the pathway of apoptosis involving PAR-4, DAXX and ZIPK proteins in CLL patients and its relationship with the principal prognostic factors.

Par-4 (prostate apoptosis response-4) protein was originally found upregulated in prostate tumor cells undergoing apoptosis. Then it was further identified as a proapoptotic protein upregulated both in normal and leukemic lymphocytes. The aim of our study was to assess PAR-4 protein expression in the B cells of CLL patients and to examine its relationship with the expression of other proteins involved in the apoptosis process, such as DAXX, ZIPK and BCL-2. We found a positive relationship between PAR-4 and BCL-2 protein expression. Additionally, there was a positive correlation between PAR-4 and both DAXX and ZIPK protein expression. The results of our research were also analyzed in association with the principal CLL prognostic factors. There was a positive correlation between the expression of PAR-4 protein and the lactate dehydrogenase (LDH) serum concentration (p < 0.005). The expression of PAR-4 protein in B cells correlated positively with the percentage of CD38(+) cells (p < 0.05), as well as with CD38(+)/ZAP-70(+) cells (p < 0.05). Moreover, we found a close relationship between LPL protein expression or LPL/ADAM29 MFI ratio and PAR-4 protein expression. Our results confirm the significance of apoptosis deregulation in CLL, and suggest a possible relationship between PAR-4 expression and the clinical course of the disease. This however requires further investigation.

Evaluation of monocyte-derived dendritic cells, T regulatory and Th17 cells in chronic myeloid leukemia patients treated with tyrosine kinase inhibitors.

Immunotherapy with dendritic cells (DC) may constitute a new and advantageous option for patients with chronic myeloid leukemia (CML) who respond to therapy with tyrosine kinase inhibitors (TKI), but do not reach complete cytogenetic or molecular remission. In this study, we evaluated the immunophenotype of DC generated from monocytes (Mo-DC) of patients with CML and the influence of TKI therapy on the results of CML-DC generation. We also measured the percentages of T regulatory cells (Tregs) as well as Th17 cells in 19 untreated patients suffering from CML, and in 28 CML patients treated with TKI. We found that DC can be reliably generated from the peripheral blood CD14+ cells of untreated CML patients. But we observed a persistent expression of CD14 monocyte marker on DC from CML patients, together with lower percentages of Mo-DC with expression of CD1a (p = 0.002), CD80 (p = 0.0005), CD83 (p = 0.0004), and CD209 (p = 0.02) compared to healthy donors. There was an adverse correlation between WBC count and the percentage of Mo-DC with co-expression of CD80 and CD86 (R = -0.63; p = 0.03). In patients treated with TKI, we observed higher efficacy of DC generation in seven-day cultures, compared to untreated patients. Expression of CD209 on DC was higher in patients treated with TKI (0.02). The duration of TKI therapy correlated adversely with MFI for CD1a (R = -0.49; p = 0.006) and positively with MFI for CD83 (R = 0.63; p = 0.01). Percentages of CD4+CD25highFoxP3+ cells (p = 0.0002) and Th17 cells (p = 0.02) were significantly higher in untreated CML patients compared to healthy controls. There was a significant correlation between the percentage of Treg cells and the percentage of peripheral blood basophiles (R = 0.821; p = 0.02). There were no changes in Tregs or Th17 cell percentages in CML patients after six months of TKI therapy. However, the expression of intracellular IL-17 in Th17 cells correlated negatively with the time of TKI therapy in the whole group of treated patients (R = -0.516; p = 0.04). We noted a correlation between IL-6 serum level and peripheral blood WBC count (R = 0.492; p = 0.04). There was also an inverse correlation between the serum level of IL-6 and the duration of TKI therapy (R = -0.66; p = 0.03). Taken together, our data shows that mature DC can be generated from CML patients treated with TKI, and that the yield of Mo-DC is higher in patients treated with TKI than in patients with active disease. This should encourage further trials with DC immunotherapy in patients with cytogenetic response after TKI therapy. We also found increased frequencies of T regulatory and Th17 cells in CML patients, which might suggest their potential role in immunity against this disease. Further studies are needed to determine if manipulation of these cell populations might improve the results of DC immunotherapy.

CD3+/CD16+CD56+ cell numbers in peripheral blood are correlated with higher tumor burden in patients with diffuse large B-cell lymphoma.

Diffuse large B-cell lymphoma is the commonest histological type of malignant lymphoma, and remains incurable in many cases. Developing more efficient immunotherapy strategies will require better understanding of the disorders of immune responses in cancer patients. NKT (natural killer-like T) cells were originally described as a unique population of T cells with the co-expression of NK cell markers. Apart from their role in protecting against microbial pathogens and controlling autoimmune diseases, NKT cells have been recently revealed as one of the key players in the immune responses against tumors. The objective of this study was to evaluate the frequency of CD3(+)/CD16(+)CD56(+) cells in the peripheral blood of 28 diffuse large B-cell lymphoma (DLBCL) patients in correlation with clinical and laboratory parameters. Median percentages of CD3(+)/CD16(+)CD56(+) were significantly lower in patients with DLBCL compared to healthy donors (7.37% vs. 9.01%, p = 0.01; 4.60% vs. 5.81%, p = 0.03), although there were no differences in absolute counts. The frequency and the absolute numbers of CD3(+)/CD16(+)CD56(+) cells were lower in advanced clinical stages than in earlier ones. The median percentage of CD3(+)/CD16(+)CD56(+) cells in patients in Ann Arbor stages 1-2 was 5.55% vs. 3.15% in stages 3-4 (p = 0.02), with median absolute counts respectively 0.26 G/L vs. 0.41 G/L (p = = 0.02). The percentage and absolute numbers of CD3(+)/CD16(+)CD56(+) cells were significantly higher in DL -BCL patients without B-symptoms compared to the patients with B-symptoms, (5.51% vs. 2.46%, p = 0.04; 0.21 G/L vs. 0.44 G/L, p = 0.04). The percentage of CD3(+)/CD16(+)CD56(+) cells correlated adversely with serum lactate dehydrogenase (R= -445; p 〈 0.05) which might influence NKT count. These figures suggest a relationship between higher tumor burden and more aggressive disease and decreased NKT numbers. But it remains to be explained whether low NKT cell counts in the peripheral blood of patients with DLBCL are the result of their suppression by the tumor cells, or their migration to affected lymph nodes or organs.