Selected miRNA levels are associated with IKZF1 microdeletions in pediatric acute lymphoblastic leukemia.

The clinical outcome of children with high-risk relapsed B-cell precursor acute lymphoblastic leukemia (BCP-ALL) is poor. The present study assessed the utility and prognostic value of selected microRNA (miRNA/miR) in BCP-ALL. The changes in the expression levels of these miRNAs regarding known gene lesions affecting lymphoid development [early B-cell factor 1 (EBF1), ETS variant 6 (ETV6), IKAROS family zinc finger 1 (IKZF1), paired box 5 (PAX5), cyclin dependent kinase inhibitor (CDKN) 2A/CDKN2B, retinoblastoma 1 (RB1), pseudoautosomal region 1 (PAR1), B-cell translocation gene 1 protein (BTG1)] were analyzed. The following miRNAs were analyzed: miR-24, miR-31, miR-128, miR-542, and miR-708. The present study focused on patients with deletions of the IKAROS transcriptional factor gene IKZF1, which is currently considered to be an independent negative prognostic factor for ALL outcome. It was demonstrated that the expression level of miR-128 was significantly lower in patients with IKZF1 deletion compared with patients without IKZF1 deletion. Additionally, low expression of miR-542 was associated with CDKN2A/B and miR-31deletions, and low expression of miR-24 was associated with miR-31 deletion. Low expression of miR-31, miR-24, miR-708 and miR-128 was associated with PAX5 deletion, high expression of miR-24 and miR-542 was associated with PAR1 deletion and high expression of miR-708 was associated with ETV6 deletion. The expression of the selected miRNAs was not associated with deletions of BTG1, EBF1 and RB1. These data, by emphasizing the association of miRNAs expression level with microdeletions, may assist to elucidate ALL biology and contribute to future studies on the possible applications of the miRNA profile for diagnosis.

Surgery decreases number of cells secreting cytotoxic mediators and increases secretion of interleukin 10 in patients with lung cancer.

AIMS: The phenomenon of immunosuppression induced by surgery is widely described as the adverse impact of surgical interventions on leukocytes' populations and secretion of several cytokines. Best of our knowledge, we present the first report evaluating the effect of surgical treatment on the specific anti-cancer immune response against tumour antigens. METHODS: The study included 30 patients operated on for lung cancer. Specific secretion of IFN-γ, Granzyme B, perforines, IL-4, IL-5, IL-10, IL-17a was assessed by ELISPOT (Enzyme-Linked Immunosorbent Spot Assay). RESULTS: Number of cells secreting IFN-γ, Granzyme B and perforines under the influence of autologous tumour antigens or mitogens was significantly decreased on the first day after surgery. During the postoperative recovery we observed an increase in the number of cells secreting IFN-γ, but on the 7th day it still remained lower than before the operation. On the 28th postoperative day it reached a level which was not significantly higher than before the surgery. On the 1st and 7th postoperative day we discovered a significant increase in IL-10 secretion, in response to autologous tumour antigens. CONCLUSIONS: Our results suggest an immunosuppressive effect of surgery on the specific and nonspecific immune stimulation. This effect is particularly expressed in relation to Th1-type immunological response which is associated with direct elimination of cancer cells. Another unfavourable observation is elevated secretion of immunosuppressive IL-10 in response to cancer antigens. These phenomena are associated with shorter survival of the patients.

OS007. The apoptosis markers are altered in CD4(+)CD25(+)FOXP3(+) T regulatorylymphocytes in pre-eclampsia.

INTRODUCTION: Pre-eclampsia (PE) is a common obstetric syndrome affecting about 5-10% of pregnant women. The etiology and pathogenesis of this syndrome are not fully understood. There are many studies describing alterations in the innate and adaptive immune system which may have an influence on the onset of this disorder. It was suggested that the activation of cell-mediated immunity may play the key role in the etiology of pre-eclampsia. It was proposed that inappropriate activation of the immune system can lead to pre-eclampsia. OBJECTIVES: The aim of our study was to estimate the surface expressions of CD95(APO-1/Fas) antigen and the intracellular expressions of anti-apoptotic proteinBcl-2 and pro-apoptotic proteinBax in CD4(+)CD25(+)FoxP3(+) T regulatory lymphocytes (Tregs) as well as the percentage of CD8(+)CD28(+) T cytotoxic cells in peripheral blood of patients with pre-eclampsia in comparison with healthy pregnant women in the third trimester of physiological pregnancy. METHODS: Twenty-four women with pre-eclampsia and twenty normal third trimester pregnant women were included in the study. The lymphocytes were isolated from peripheral blood samples and labelled with monoclonal antibodies. The expressions of surface antigens and intracellular proteins were estimated using flow cytometry. RESULTS: The population of CD4(+)CD25(+)FoxP3(+) Treg cells was significantly lower in peripheral blood of patients with pre-eclampsia when compared to normal third trimester pregnant women. The percentages of CD4(+)CD25(+)FoxP3(+) Treg cells that express Bcl-2 protein were significantly lower in peripheral blood of patients with pre-eclampsia when compared to healthy pregnant women, whereas the percentages of CD4(+)CD25(+)FoxP3(+) Treg cells with the expressions of Bax protein did not differ in both groups. Moreover, the mean fluorescence intensity (MFI) of Bcl-2 protein in CD4(+)CD25(+)FoxP3(+) Treg cells was significantly lower and MFI of Bax protein significantly higher in pre-eclampsia when compared to the control group. The percentage of CD8(+)CD28(+) T cells did not differ in both studied groups but MFI of CD28 antigen on T CD8(+) cells was significantly higher in pre-eclampsia when compared to the control group. CONCLUSION: The obtained results suggest that the deficit of CD4(+)CD25(+)FoxP3(+) Treg lymphocytes which is observed in pre-eclampsia maybe associated with alterations in apoptosis markers.

Definition of a target for immunotherapy and results of the first Peptide vaccination study in chronic lymphocytic leukemia.

Results of bone marrow transplantation, as well as remission phenomena after viral infections, suggest that chronic lymphocytic leukemia (CLL) might be targeted effectively by T-cell-based immunotherapy. Antigen-targeted immunotherapies represent novel treatments for CLL patients. Earlier, we screened the mRNA expression of several tumor associated antigens (TAAs), observing the presence of RHAMM/CD168, fibromodulin, syntaxin, and NY-Ren60 in 55%-90% of CLL patients. RHAMM/CD168, fibromodulin, PRAME, and MPP11 were expressed in CLL patients but not in healthy volunteers. Quantitative reverse transcriptase polymerase chain reaction revealed higher RHAMM expression in high-risk CLL patients as well as in advanced stages of the disease. CLL cases with higher RHAMM expressions showed significantly shorter median treatment-free survivals. Among patients with mutated IgVH genes, an analysis of RHAMM expression enabled us to distinguish a subgroup of patients with a favorable prognosis. In lymph nodes, RHAMM staining correlated with a higher Ki-67 index and CD40L expression. Functionally, stimulation with CD40L enhanced RHAMM expression in CLL. Because of the exquisite tissue expression of RHAMM and its high expression frequency in CLL patients, we further characterized RHAMM-specific CD8+ T cells in these patients. CD8+ T cells primed with the RHAMM-derived epitope R3, which is restricted by human leukocyte antigen (HLA)A2, lysed RHAMM+ CLL cells. Therefore, we initiated a Phase I clinical trial of R3 peptide vaccination. Four patients exhibited reduced white blood cell counts during the vaccination process. In 5/6 patients, R3-specific CD8+ T cells were detected with the corresponding peptide/HLA-A2 tetrameric complex; these populations were verified functionally in 4/5 patients using ELISpot assays. In conclusion, RHAMM expression seems to be of prognostic value, and may reflect the proliferative capacity of CLL cells; it may therefore represent an interesting target for immunotherapy. Peptide vaccination in CLL patients was safe eliciting specific CD8+ T-cell responses against the tumor antigen RHAMM.

Enhanced phenotypic and functional maturation of monocyte-derived dendritic cells from patients with active Crohn's disease and ulcerative colitis.

Disturbed immunoregulation and an inappropriate immune response to gut microflora is assumed to be involved in the pathogenesis of inflammatory bowel disease (IBD). Physiologically dendritic cells (DCs) as the professional antigen presenting cells play a crucial role in the control of intestinal inflammation and immune tolerance. In order to evaluate their role in the IBD we analyzed the phenotypic and functional properties of monocyte-derived DCs (MoDCs) generated from UC and CD patients following stimulation with TNF-α, lipopolisaccharide E. coli or hydrocortisone. Thirty seven patients with moderate to severe inflammation (19 UC, 18 CD) were recruited to the study. Monocyte-derived dendritic cell immunophenotypes and their endocytic ability were analysed by flow cytometry and confocal microscopy, IL-6, IL-10, IL-12 and IL-23 secretion were investigated by ELISA. Both unstimulated and stimulated MoDCs generated from IBD patients had more mature phenotype and secreted elevated concentrations of proinflammatory cytokines as compared to a control group. The addition of LPS E. coli to culture media was associated with enhanced dendritic cell activation and maturation as compared to DCs stimulated only with TNF-α. This may suggest altered dendritic cell interactions with intestinal microflora in inflammatory bowel disease. Hydrocortisone decreases the numbers of mature dendritic cells and the proinflammatory cytokine concentrations in all cell culture types that may explain the efficacy of steroid therapy in inflammatory bowel disease.

Vaccination of B-CLL patients with autologous dendritic cells can change the frequency of leukemia antigen-specific CD8+ T cells as well as CD4+CD25+FoxP3+ regulatory T cells toward an antileukemia response.

Recently, we described that vaccination with allogeneic dendritic cells (DCs) pulsed with tumor cell lysate generated specific CD8+ T cell response in patients with B-cell chronic lymphocytic leukemia (B-CLL). In the present study, the potential of autologous DCs pulsed ex vivo with tumor cell lysates to stimulate antitumor immunity in patients with B-CLL in early stages was evaluated. Twelve patients at clinical stage 0-2 as per Rai were vaccinated intradermally up to eight times with a mean number of 7.4 x 10(6) DCs pulsed with B-CLL cell lysate. We observed a decrease of peripheral blood leukocytes and CD19+/CD5+ leukemic cells in five patients, three patients showed a stable disease and four patients progressed despite DC vaccination. A significant increase of specific cytotoxic CD8+ T lymphocytes against the leukemia-associated antigens RHAMM or fibromodulin was detected in four patients after DC vaccination. In patients with a clinical response, an increase of interleukin 12 (IL-12) serum levels and a decrease of the frequency of CD4+CD25(+)FOXP3+ T regulatory cells were observed. Taken together, the study demonstrated that vaccination with autologous DC in CLL patients is feasible and safe. Immunological and to some extend hematological responses could be noted, justifying further investigation on this immunotherapeutical approach.

Activated T lymphocytes in pre-eclampsia.

PROBLEM: The aim of our study was to investigate the activation markets of T CD3(+), T helper CD4(+) and T cytotoxic CD8(+) cells, as well as, the populations of T naïve CD4(+) CD45RA(+), T memory CD4(+) CD45RO(+) and T regulatory lymphocytes in PE and healthy pregnant women. METHOD OF STUDY: Twenty-five patients with PE and thirty healthy third trimester pregnant women were included in the study. Peripheral blood mononuclear cells were isolated from peripheral blood, stained with monoclonal antibodies and estimated using the flow cytometric method. RESULTS: The percentages of CD4(+)CD25(+), CD4(+)CD25(dim), CD3(+)HLA-DR(+), CD4(+)HLA-DR(+) and CD8(+)HLA-DR(+) cells did not differ between study groups. The population of T regulatory CD4(+)CD25(bright) lymphocytes was significantly lower in the group of patients with PE when compared with the controls (P < 0.01). The percentages of CD3(+)CD25(+) (P < 0.05), CD8(+)CD25(+) (P < 0.05), CD4(+)45RO(+) (P < 0.01) lymphocytes were significantly higher, while CD4(+)CD45RA(+) (P < 0.01) cells--significantly lower in peripheral blood of patients with PE when compared with the control group. CONCLUSION: The increased levels of T CD4(+)45RO(+) and T CD8(+) CD25(+) cells can suggest the activation of CD4(+) and CD8(+) T lymphocytes in pre-eclampsia. It seems possible that the activation of T lymphocytes is associated with the deficiency of T regulatory cells in PE.

Allogeneic dendritic cells pulsed with tumor lysates or apoptotic bodies as immunotherapy for patients with early-stage B-cell chronic lymphocytic leukemia.

Recently, immunotherapies with allogeneic dendritic cells (DCs) pulsed with tumor antigens to generate specific T-cell responses have been tested in clinical trials for patients with solid tumors. This is the first report on a clinical vaccination study with DCs for patients with B-cell chronic lymphocytic leukemia (B-CLL). The potential of allogeneic DCs pulsed ex vivo with tumor cell lysates or apoptotic bodies to stimulate antitumor immunity in patients with B-CLL in early stages was evaluated. Monocyte-derived DCs were obtained from unrelated healthy donors. Nine patients (clinical stage 0 and 1 according to Rai) were vaccinated five times with a mean number of 32 x 10(6) stimulated DCs administered intradermally once every 2-3 weeks. No signs of autoimmunity were detected, and only mild local skin reactions were noted. During the treatment period, we observed a decrease of peripheral blood leukocytes and CD19+/CD5+ leukemic cells. In one patient, a significant increase of specific cytotoxic T lymphocytes against RHAMM/CD168, a recently characterized leukemia-associated antigen, could be detected after DC vaccination. Taken together, the study demonstrated that DC vaccination in CLL patients is feasible and safe. Immunological and to some extent hematological responses could be noted, justifying further investigation on this immuno-therapeutical approach.

CD1c(+) immature myeloid dendritic cells are predominant in cord blood of healthy neonates.

It has been suggested lately that some types of antigen presenting cells-myeloid dendritic (DC-1) cells can differentiate the immune response towards Th1 type immunity, whereas lymphoid cells (DC-2) can stimulate Th2 type immunity. It has been observed that neonates are deficient in Th1 response. The purpose of our study was to estimate the proportions of immature myeloid (CD1c(+)) and lymphoid (BDCA-2(+), BDCA-4(+)) dendritic cells and the CD1c(+):BDCA-2(+) cell ratio in cord blood of healthy neonates in comparison with dendritic cells of healthy adults. Thirty healthy neonates born from normal pregnancies and 30 healthy adults were included in the study. The dendritic cells were isolated from cord and peripheral blood, stained with anti-CD1c, anti-BDCA-2, anti-BDCA-4, anti-CD123 and anti-CD19 monoclonal antibodies and estimated using flow cytometry. The percentage of CD1c(+) dendritic cells in cord blood of healthy newborns did not differ significantly when compared to those in peripheral blood of healthy adults. The percentages of cord blood BDCA-2(+) and BDCA-4(+) dendritic cells of neonates were significantly lower when compared to lymphoid dendritic cells in peripheral blood of adults. The CD1c(+):BDCA-2(+) ratio was significantly higher in cord blood of neonates in comparison with CD1c(+):BDCA-2(+) ratio in adult's blood. Myeloid and lymphoid dendritic cells may be involved in the immune regulation during fetal development. Immature myeloid dendritic cells are predominant in cord blood of healthy neonates. Immature lymphoid dendritic cells are not the major population of dendritic cells in cord blood.

Blood myeloid and lymphoid dendritic cells are stable during the menstrual cycle but deficient during mid-gestation.

The aim of this study was to estimate the populations of peripheral blood myeloid and lymphoid dendritic cells (CD1c(+), BDCA-2(+), BDCA-4(+)) and the CD1c(+):BDCA-2(+) ratio in phases of the ovarian cycle and in normal pregnant patients. 18 non-pregnant women and 17 normal pregnant women were included. Dendritic cells were isolated from peripheral blood, stained with monoclonal antibodies (mAbs) against blood dendritic cell antigens (anti-BDCA-1, BDCA-2, BDCA-4) and estimated using flow cytometry. CD1c(+), BDCA-2(+) and BDCA-4(+) dendritic cells were present in the follicular and luteal phases of the ovarian cycle and in all trimesters of normal pregnancy. The percentages of CD1c(+) dendritic cells did not differ between the follicular and luteal phases of the ovarian cycle. The percentage of BDCA-2(+) dendritic cells was lower in the luteal phase of the ovarian cycle compared with the follicular phase, but the differences were not statistically significant. The CD1c(+):BDCA-2(+) cell ratio was significantly lower in the luteal phase compared with the follicular phase of the ovarian cycle. The numbers of dendritic cells were significantly lower in the second trimester when compared with the first and third trimesters of normal pregnancy. Furthermore, in the second trimester, the CD1c(+):BDCA-2(+) ratio was higher than in the other trimesters of normal pregnancy. All populations of dendritic cells and the CD1c(+):BDCA-2(+) ratio did not differ in the first and third trimesters of physiological pregnancy. Our results suggest that myeloid and lymphoid dendritic cells are not affected by steroid hormones during the menstrual cycle. The deficiency of peripheral blood dendritic cells observed during the second trimester of normal pregnancy can be associated with their migration to the uterus during the second physiological invasion by cytotrophoblast.

Myeloid and lymphoid dendritic cells in normal pregnancy and pre-eclampsia.

The aim of our study was to estimate the populations of peripheral blood myeloid and lymphoid dendritic cells (CD1c+, BDCA-2+) and the CD1c+ : BDCA-2+ ratio in normal pregnant women and in patients with pre-eclampsia. Fifteen women in the first, second and third trimesters of normal pregnancy, and 25 patients with pre-eclampsia were included in the study. The dendritic cells were isolated from peripheral blood, stained with monoclonal antibodies against blood dendritic cell antigens (anti-CD1c, anti-BDCA-2) and estimated using the flow cytometric method. CD1c+ and BDCA-2+ dendritic cells were present in women during all trimesters of physiological pregnancy and in pre-eclamptic patients. It was observed that the numbers of dendritic cells were significantly lower in the second trimester when compared with the first and third trimesters of normal pregnancy. Furthermore, in the second trimester, CD1c+ : BDCA-2+ ratio was higher than in the other trimesters of physiological pregnancy. All populations of dendritic cells and CD1c+ : BDCA-2+ ratio did not differ in the first and third trimesters of normal pregnancy. The percentage of BDCA-2+ dendritic cells was significantly lower in pre-eclampsia in comparison with healthy women in the third trimester of physiological pregnancy, while CD1c+ : BDCA-2+ ratio was significantly higher in pre-eclamptic patients when compared with control groups. We concluded that dendritic cells may be involved in the immune regulation during physiological pregnancy. CD1c+ and BDCA-2+ cells can influence the Th2 phenomenon which is observed during physiological pregnancy. Furthermore, it seems possible that lower BDCA-2+ cells percentage and higher CD1c+ : BDCA-2+ ratio can be associated with increased Th1-type immunity in patients with pre-eclampsia.