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Ibrutinib-based therapy represents a recent success in managing high-risk CLL patients with 17p/TP53 deletion. However, a subset of CLL patients are resistant to therapy. Deletion of lipoprotein lipase (LPL) has been postulated as a potential evasion mechanism to ibrutinib-based therapy. In this study, we assessed for LPL deletion by fluorescence in situ hybridization in 176 consecutive CLL patients with 17p/TP53 deletion. LPL deletion was detected in 35 (20%) of CLL patients. Patients with LPL deletion (del) showed a higher frequency of CD38 expression but have comparable frequencies of somatic hypermutation and ZAP-70 expression compared with patients with normal (nml) LPL. Gene mutation analysis showed that TP53 was mutated in 68% of LPL-del versus 91% of LPL-nml patients. The overall response to ibrutinib-based therapy was 57%, including 37% complete remission (CR) and 20% partial remission (PR) in patients with LPL-del versus 90% (56% CR and 34% PR) in patients with LPL-nml (p < 0.001). LPL-del patients also showed a poorer overall survival (OS) compared with patients with LPL-nml (median OS, 236 months versus undefined, p < 0.001). In summary, the data presented establish an association between LPL deletion, resistance to ibrutinib-based therapy, and poorer overall survival in TP53-deleted CLL patients. We suggest that LPL deletion might be utilized as a biomarker for risk stratification and to predict therapeutic response in this high-risk group of CLL patients.

The acquisition of complex karyotypes is related to the progression of chronic lymphocytic leukemia (CLL) and patients with this condition have a poor prognosis. Despite recent advances in the classification of prognosis in CLL patients, understanding of the molecular mechanisms that lead to genomic instability and progression of this disease remains inadequate. Interestingly, dysregulated expression of KDM4 members is involved in the progression of several cancer types and plays a role in the DNA damage response; however, the gene expression profile and the importance of KDM4 members in CLL are still unknown. Here, we assessed the gene expression profile of KDM4A, KDM4B, and KDM4C in 59 CLL samples and investigated whether these histone demethylases have any influence on the prognostic markers of this leukemia. KDM4A gene expression was higher in CLL patients as compared with control samples. In contrast, CLL samples showed decreased levels of the KDM4B transcript in relation to control cases, and no difference was detected in KDM4C expression. Furthermore, patients with positive expression of ZAP-70 had lower expression of KDM4B and KDM4C as compared with ZAP-70-negative patients. More importantly, patients with low expression of these histone demethylases had higher leukemic cell numbers and displayed adverse cytogenetic findings and the acquisition of a complex karyotype. The present data clearly show that the expression of KDM4 members is dysregulated in CLL and impact the prognosis of this leukemia. These findings are useful for a better understanding of the impact of epigenetics on CLL progression.

Background: Interleukin 2 (IL-2) influences the development and severity of pain due to its antinociceptive and immunomodulatory effects. Its production is influenced by the increased expression of c-Cbl (Casitas B-lineage lymphoma proto-oncogene) and Cbl-b E3 ubiquitin ligases. We evaluated the effects on IL-2-mediated changes in c-Cbl and Cbl-b expression in a rat model of chronic neuropathic pain., Methods: Peripheral neuropathy was induced in adult male Sprague-Dawley rats weighing 250-300 g by chronic spinal nerve ligation. Half of the spinal cord ipsilateral to the nerve injury was harvested at 1, 3, and 6 weeks, and the expression levels of IL-2, c-Cbl, Cbl-b, phospholipase C-γ1 (PLC-γ1), ZAP70, and protein kinase Cθ (PKCθ), as well as ubiquitin conjugation, were evaluated., Results: Total IL-2 mRNA levels were significantly decreased at 3 and 6 weeks after nerve injury compared to those in sham-operated rats. The mRNA levels of c-Cbl and Cbl-b, as well as the level of ubiquitin conjugation, were significantly increased at 3 and 6 weeks. In contrast, the levels of phosphorylated ZAP70 and PLC-γ1 were decreased at 3 and 6 weeks after spinal nerve ligation. Ubiquitination of PLC-γ1 and PKCθ was increased at 3 and 6 weeks., Conclusions: Our results suggest that ubiquitin and the E3 ubiquitin ligases c-Cbl and Cbl-b function as neuroimmune modulators in the subacute phase of neuropathic pain after nerve injury.

Chronic lymphocytic leukemia (CLL) cells are highly dependent on microenvironment, being the BCR pathway one key player in this crosstalk. Among proteins participating, ZAP-70 enhances response to microenvironmental stimuli. MicroRNA-21 (miR-21) is overexpressed in diverse neoplasias including CLL, where it has been associated to refractoriness to fludarabine and to shorter time to progression and survival. To further elucidate the role of ZAP-70 in the biology of CLL, we studied its involvement in miR-21 regulation. MiR-21 expression was higher in CLL cells with high ZAP-70. Ectopic expression of ZAP-70 induced transcription of miR-21 via MAPK and STAT3, which subsequently induced downregulation of tumor suppressors targeted by miR-21. The co-culture of primary CLL cells mimicking the microenvironment induced ZAP-70 and miR-21 expression, as well as downregulation of miR-21 targets. Interestingly, the increase in miR-21 after co-culture was significantly impaired by ibrutinib, indicating that the BCR signaling pathway is involved in its regulation. Finally, survival of CLL cells induced by the co-culture correlated with miR-21 upregulation. In conclusion, stimuli from the microenvironment regulate miR-21 and its targeted tumor suppressor genes via a signaling pathway involving ZAP-70, thus contributing to the cytoprotection offered by the microenvironment particularly observed in CLL cells expressing ZAP-70.

The SMAD proteins are responsible for transducing signals from activated transforming growth factor-beta. This is the first study assessing the expression of SMAD-1/8, SMAD-2/3, SMAD-4, and SMAD-7 in chronic lymphocytic leukemia cells with regard to their clinical significance and potential prognostic value. Overexpression of SMAD-1/8 was observed in 160 chronic lymphocytic leukemia patients compared to 42 healthy volunteers (p = 0.023) and was associated with a more progressive course of the disease (p = 0.016). Moreover, the high expression of SMAD-1/8 correlated with other, well-established prognostic factors, including clinical stage (p = 0.010) and lymphocyte doubling time (p = 0.021). The expression of SMAD-4 was lower in chronic lymphocytic leukemia patients compared with the control group (p = 0.003). Importantly, lower SMAD-4 levels correlated with longer progression-free survival (p = 0.009), progressive course of the disease (p = 0.002), advanced clinical stage (p = 0.0004), elevated beta-2-microglobulin and lactate dehydrogenase levels (p < 0.05), shorter lymphocyte doubling time (p = 0.009), and CD38 antigen expression (p = 0.039). In addition, lower SMAD-4 expression correlated with lower apoptotic index (p = 0.0007) and lower expression of receptors for vascular endothelial growth factors VEGFR-1 and VEGFR-2. A significant association was found between the low expression of inhibitory protein SMAD-7 and both zeta-chain-associated protein kinase 70-negative cells (p = 0.04) and lower apoptotic index (p = 0.004). No differences were observed in SMAD-2/3 expression. In conclusion, our results demonstrate a significant correlation between greater SMAD-1/8 and lower SMAD-4 expression in chronic lymphocytic leukemia cells, as well as more progressive outcome and poor prognosis. These data provide supporting evidence that the expression of SMAD proteins plays an important role in disease development and may be considered as a novel, biologic prognostic factor in this disease.

Objective: Chronic lymphocytic leukemia (CLL) is a disease that shows varying clinical progression, and expression of the protein tyrosine kinase ZAP70 has been described as a very valuable prognostic factor. Patients with ZAP70 positivity are characterized by worse clinical course and significantly shorter progression-free and overall survival. In this study, intracytoplasmic interferon gamma (IFN-γ) and interleukin-4 (IL-4) content of T, B, and CLL cells in CLL patients and their correlations with Rai staging and ZAP70 positivity were investigated., Materials and Methods: CLL patients newly diagnosed or in follow-up at the İstanbul University İstanbul Medical Faculty Hematology Department were included in this study. These patients were classified according to Rai staging and ZAP70 expression. IL-4, IFN-γ, and ZAP70 expressions in peripheral blood T, B, and CLL cells were measured by four-color flow cytometry., Results: There was a statistically significant correlation between advanced disease and ZAP70 positivity. IL-4-secreting T cells were significantly increased; however, IFN-γ secretion was significantly decreased in CLL patients compared to healthy individuals, whereas IL-4-secreting B cells were significantly diminished in contrast to T cells., Conclusion: These findings suggest damage in the cellular immunity and that IL-4 might lead to many complications and may be important in disease progression., Competing Interests: The authors of this paper have no conflicts of interest, including specific financial interests, relationships, and/or affiliations relevant to the subject matter or materials included.

Background & Objectives: The PAX5, a paired box transcription factor and B-cell activator protein (BSAP), activates B-cell commitment genes and represses non-B-cell lineage genes. About 14 transcript variants of PAX5 have been observed in human. Any alteration in its expression pattern leads to lymphogenesis or associated diseases and carcinogenesis in non-lymphoid tissues. Its mechanisms of function in pathophysiology of non-Hodgkin's lymphoma (NHL) are unclear. This study was intended to explore influence of PAX5 in cascade of NHL pathogenesis and diagnosis., Methods: Samples of 65 patients were evaluated by immunohistochemical staining for cellular localization of PAX5, CD19, CD3, cABL, p53, Ras and Raf and by TUNEL assay, RNA-isolation and reverse transcriptase (RT)-PCR, w0 estern blot analysis, and lactate dehydrogenase (LDH) specific staining., Results: B-cell type NHL patients were positive for PAX5, p53, Ras, CD19, Raf and CD3. All of them showed TUNEL-positive cells. The differential expression pattern of PAX5, CD19, p53, CD3, Zap700 , HIF 1α, Ras, Raf and MAPK (mitogen-activated protein kinase) at the levels of transcripts and proteins was observed. The LDH assay showed modulation of LDH4 and LDH5 isoforms in the lymph nodes of NHL patients., Interpretation & Conclusions: The histological observations suggested that the patients represent diverse cases of NHL like mature B-cell type, mature T-cell type and high grade diffuse B-cell type NHL. The findings indicate that patients with NHL may also be analyzed for status of PAX5, CD19 and ZAP70, and their transcriptional and post-translational variants for the differential diagnosis of NHL and therapy., Competing Interests: None.

Chronic lymphocytic leukemia (CLL) is the most common leukemia in Western countries, and mainly originates from an accumulation of abnormal B cells caused by the dysregulation of cell proliferation and apoptosis. The aberration of proliferation-related gene in CLL cells induces cell arrest at G0/G1 phase, or a small section shows rapid cell growth, which further complicates the pathogenesis of CLL. The constitutively photomorphogenic 1 (COP1), as an E3 ubiquitin ligase, is involved in many biological processes in mammalian cells, but its role in chronic lymphocytic leukemia (CLL) progression remains unclear. In the present study, we analyzed the expression of COP1 in peripheral blood mononuclear cells (PBMCs) from 23 CLL patients and 3 healthy donors. The observed upregulated expression of COP1 in CLL patients was positively correlated with CLL clinical stage and ZAP-70 expression, but not del(13q14) and del(17q-). Overexpression of COP1 significantly promoted cell colony formation and proliferation, especially contributing to the accumulation of cells in S-phase by inhibition of FoxO1 and p21. Moreover, overexpression of COP1 accelerated tumorigenicity of HG3 cells and promoted xenograft growth. Therefore, the present study revealed that COP1 plays an important role in CLL cell proliferation and tumorigenicity, and may be a useful indicator of the chronic lymphocytic leukemia processes.

Unlabelled: BACKGROUND/ AIM: The prognostic significance of hyperleukocytosis in chronic lymphocytic leukemia (CLL) remains uncertain. The aim of the present study was to evaluate the clinical characteristics and outcome of patients with CLL and white blood count (WBC) >150×10(6)/l at the time of diagnosis., Patients and Methods: Using the database of the Israeli CLL Study Group, which includes 1,507 cases, we identified 41 patients diagnosed with WBC >150×10(6)/l and analyzed the survival in the group that was 62 months compared to 174 months in patients without hyperleukocytosis (p<0.001). However, multivariate analysis demonstrated that the WBC count had no predictive value in relation to survival time. While in the entire patient cohort advanced age and Binet stage, presence of thrombocytopenia and ZAP-70 expression were independently associated with poor prognosis, these parameters lost their prognostic value in patients with hyperleukocytosis., Conclusion: Although our results do not confirm that high initial levels of WBC are independently associated with shorter survival in CLL, the clinical course in these cases appears to be aggressive and conventional prognostic factors are not valid in this patient sub-group., (Copyright© 2015 International Institute of Anticancer Research (Dr. John G. Delinassios), All rights reserved.)

Background/aims: Several limiting factors for human health and performance in microgravity have been clearly identified arising from the immune system, and substantial research activities are required in order to provide the basic information for appropriate integrated risk management. The gravity-sensitive nature of cells of the immune system renders them an ideal biological model in search for general gravity-sensitive mechanisms and to understand how the architecture and function of human cells is related to the gravitational force and therefore adapted to life on Earth., Methods: We investigated the influence of altered gravity in parabolic flight and 2D clinostat experiments on key proteins of activation and signaling in primary T lymphocytes. We quantified components of the signaling cascade 1.) in non-activated T lymphocytes to assess the "basal status" of the cascade and 2.) in the process of activation to assess the signal transduction., Results: We found a rapid decrease of CD3 and IL-2R surface expression and reduced p-LAT after 20 seconds of altered gravity in non-activated primary T lymphocytes during parabolic flight. Furthermore, we observed decreased CD3 surface expression, reduced ZAP-70 abundance and increased histone H3-acetylation in activated T lymphocytes after 5 minutes of clinorotation and a transient downregulation of CD3 and stable downregulation of IL-2R during 60 minutes of clinorotation., Conclusion: CD3 and IL-2R are downregulated in primary T lymphocytes in altered gravity. We assume that a gravity condition around 1g is required for the expression of key surface receptors and appropriate regulation of signal molecules in T lymphocytes., (© 2015 S. Karger AG, Basel.)

EZH2, a histone methyltransferase, is overexpressed in several human tumors, but whether it exerts any impact in chronic lymphocytic leukemia (CLL) remains unknown. We used real time PCR to investigate the expression profile of EZH1 and EZH2 in 59 CLL patients, 10 samples of purified B-cells from healthy donors and 12 normal adult tissues. EZH2 was overexpressed in CLL patients and correlates with high white blood cell count, ZAP-70 expression and chromosomal abnormalities. EHZ1 expression does not correlate with CLL progression. EZH2 overexpression is related to a poor prognosis of CLL and could be a useful tool to assess its aggressiveness., (Copyright © 2014 Elsevier Inc. All rights reserved.)

Survival of naive T cells requires engagement of TCR with self-peptide major histocompatibility Ags. The signaling pathways required to transmit this survival signal are poorly understood. In this study, we asked whether the tyrosine kinase Zap70 is required to transmit survival signals in naive CD8 T cells. In the absence of Zap70 expression, thymic development is completely blocked. Using a tetracycline-inducible Zap70 transgene (TetZap70), thymic development of Zap70-deficient TCR transgenic F5 mice was restored. Feeding mice doxycycline to induce Zap70 expression resulted in repopulation of the peripheral naive compartment. Zap70 transgene expression was then ablated by withdrawal of doxycycline. Survival of Zap70-deficient naive CD8 T cells depended on host environment. In hosts with a replete T cell compartment, naive T cells died rapidly in the absence of Zap70 expression. In lymphopenic hosts, Zap70-deficient T cells survived far longer, in an IL-7-dependent manner, but failed to undergo lymphopenia-induced proliferation. Analyzing mixed bone marrow chimeras revealed that intact Zap70-dependent signaling was important for integration of recent thymic emigrants into the mature naive compartment. Finally, we asked whether adaptor function conferred by Zap70 tyrosines 315 and 319 was necessary for transmission of homeostatic TCR signals. This was done by analyzing F5 mice expressing mutant Zap70 in which these residues had been mutated to alanines (Zap70(YYAA)). Inducible Zap70 expression rescued thymic development in F5 TetZap70 Zap70(YYAA) mice. However, in the absence of wild-type Zap70 expression, the Zap70(YYAA) mutant failed to transmit either survival or proliferative homeostatic signals., (Copyright © 2014 by The American Association of Immunologists, Inc.)

The E2997 Phase III trial included preservation of valuable chronic lymphocytic leukemia (CLL) patient specimens and relevant clinical outcome data. Using a novel high-resolution technology on a flow cytometry platform, we assessed 79 E2997 samples for the expression of 27 analytes that reflected the activity of signaling pathways and apoptosis. We found that the expression levels of ZAP70 segregated the samples into two subpopulations with the distribution showing a peak-trough-peak configuration. Although prior assessment of ZAP70 by standard procedures did not reveal any prognostic information, we found by using the trough in the distribution as a cutpoint that ZAP70 expression levels were significantly correlated with both progression-free survival and overall survival. Additionally, the cells expressing high versus low levels of ZAP70 demonstrated distinct molecular organization as indicated by the other analytes assessed. Our analysis demonstrates the value of ZAP70 expression as a prognostic indicator and suggests that the different clinical results may be due to the distinct molecular biology of the ZAP70-low versus the ZAP70-high CLL samples., (© 2014 International Society for Advancement of Cytometry.)

The generation of T cell anergy is associated with upregulation of ubiquitin E3 ligases including Casitas B-lineage lymphoma (Cbl-b), Itch, gene related to anergy in lymphocyte, and deltex1 (DTX1). These E3 ligases attenuate T cell activation by targeting to signaling molecules. For example, Cbl-b and Itch promote the degradation of protein kinase Cθ (PKCθ) and phospholipase C-γ1 (PLC-γ1) in anergic Th1 cells. How these anergy-associated E3 ligases coordinate during T cell anergy remains largely unknown. In the current study, we found that PKCθ and PLC-γ1 are also downregulated by DTX1. DTX1 interacted with PKCθ and PLC-γ1 and stimulated the degradation of PKCθ and PLC-γ1. T cell anergy-induced proteolysis of PKCθ was prevented in Dtx1(-/-) T cells, supporting the essential role of DTX1 in PKCθ downregulation. Similar to Cbl-b and Itch, DTX1 promoted monoubiquitination of PKCθ. Proteasome inhibitor did not inhibit DTX1-directed PKCθ degradation, but instead DTX1 directed the relocalization of PKCθ into the lysosomal pathway. In addition, DTX1 interacted with Cbl-b and increased the protein levels of Cbl-b. We further demonstrated the possibility that, through the downregulation of PKCθ, DTX1 prevented PKCθ-induced Cbl-b degradation and increased Cbl-b protein stability. Our results suggest the coordination between E3 ligases during T cell anergy; DTX1 acts with Cbl-b to assure a more extensive silencing of PKCθ, whereas DTX1-mediated PKCθ degradation further stabilizes Cbl-b., (Copyright © 2014 by The American Association of Immunologists, Inc.)

Background: ZAP-70 upregulation in B chronic lymphocytic leukemia (B-CLL) cells is a recognized marker of poor prognosis in these patients; the biological basis of this differential clinical outcome nonetheless remains unknown. ZAP-70 overexpression is considered a surrogate marker of a B-CLL cell subset. To test whether the differential biological characteristics of these patients also include the T helper population, we studied naïve, non-terminated memory (NTEM), terminated memory (TEM) and central memory (CM) cells, and cytokine expression by CD4 T lymphocytes from ZAP-70(+) and ZAP-70(-) B-CLL patients., Methods: Expression of CD3, CD8, CD45RA, CD27, and CD28 antigens and intracytoplasmic cytokine production (IFNγ, IL-2, IL-4, IL-10, and TNFα) were assessed simultaneously by nine-color flow-cytometry in peripheral blood lymphocytes from B-CLL patients. B cell ZAP-70 expression in B-CLL cells was also analyzed by flow cytometry., Results: Compared to ZAP-70(-) B-CLL patients, ZAP-70(+) B-CLL patients showed 1) significant reduction in the naïve T helper subset and expansion of NTEM and TEM subsets, 2) a decrease in the percentage of activated CD4 T lymphocytes expressing IFNγ, TNFα, and IL-2, and 3) an increase in the percentage of CD4 T lymphocytes expressing IL-4 or IL-10., Conclusions: In conclusion, in early stage B-CLL patients, ZAP-70 upregulation is associated with distinct patterns of activation/differentiation stage subset distribution and of cytokine expression in CD4 T lymphocytes., (© 2013 Clinical Cytometry Society.)

Chronic lymphocytic leukaemia (CLL) is a disease with a highly variable prognosis. The clinical course can however be predicted thanks to prognostic markers. Poor prognosis is associated with expression of a B cell receptor (BCR) from unmutated immunoglobulin variable heavy-chain genes (IGHV) and expression of zeta-associated protein of 70 kDa (ZAP70). The reason why ZAP70 expression is associated with poor prognosis and whether the protein has a direct pathogenic function is at present unknown. By transfer of ZAP70 to CLL cells, we show here that expression of ZAP70 in CLL cells leads to increased expression of the nuclear factor (NF)-κB target genes interleukin-1β (IL1B), IL6 and IL8 upon BCR triggering. This could be blocked by inhibition of NF-κB signalling through inhibition of IκB kinases (IKK). Transcriptome analysis identified a NF-κB RELA signature imposed by ZAP70 expression in BCR-stimulated CLL cells. We conclude that ZAP70 acts directly as an amplifier of NF-κB signalling in CLL cells which could be an underlying mechanism for its association with poor prognosis and which may represent a therapeutic target., (© 2013 John Wiley & Sons Ltd.)

Aim of Study: Chronic lymphocytic leukemia (CLL) is the most common chronic lympho-proliferative disorder. This study was undertaken to know the prevalence of ZAP-70 and CD 38 in the treatment naive patients of CLL seen at a tertiary care centre of north India., Materials and Methods: ZAP-70 and CD 38 were tested by flow cytometry on peripheral blood samples. ZAP-70 positive and CD 38 positivity was defined as positive expression on 20% and 30% of CLL cells, respectively. Clinico-hematological profile and its correlation with ZAP-70 and CD 38 were assessed in consecutive 80 CLL patients., Results: There were 64 males and median age of the group was 58 years. Sixteen patients (20%) were asymptomatic and diagnosed incidentally. Median total lymphocyte count (TLC) at presentation was 62 × 10 9 /L. Rai stage distribution was: Stage 0-6, stage I-20, stage II-36, stage III-5, and stage IV-13. ZAP-70 and CD 38 positivity were detected in 20 patients (25%) and 29 patients (36%), respectively. Eleven patients were positive and 34 were negative for both ZAP-70 and CD 38 yielding a concordance rate of 56%. There was no statistically significant difference between ZAP-70 and CD 38 positivity and negativity with regard to age, sex, Lymphocyte count, lymphadenopathy, organomegaly, and Rai staging., Conclusion: ZAP-70 and CD 38 positivity were detected 25% and 36%, respectively, with concordance rate of 56%, which is higher than Western literature. There was no correlation of ZAP-70 and CD 38 positivity with age, sex, lymphadenopathy, organomegaly, and Rai staging.

Background: Some allergic diseases may be accompanied by inappropriate number or malfunction of regulatory T cells, which seems to be modified by specific immunotherapy (SIT)., Objectives: To assess if immunotherapy affects regulatory T lymphocytes (Tregs) and their expression of zeta chain associated protein kinase (Zap70), which is essential for T cell activation and intracellular signal downstream transduction., Methods: A 3-year prospective, placebo-controlled, double-blind trial of grass SIT was conducted. Forty-one patients sensitized to grass pollen with intermittent allergic rhinitis were randomized to receive SIT (n = 21) or placebo (n = 20) and 15 healthy were included as a control. Concentration of exhaled nitric oxide (ENO), lung function, symptom scores, the subsets of regulatory T cells (CD4(+)  CD25hiCD127low) which express ZAP70 and the level of ZAP70 expression in this subset were assessed at baseline and during the treatment period: before the onset, at the height of the pollen season and after the end of the pollen season., Results: The concentration of nitric oxide and the symptom score were significantly higher in allergic rhinitis patients as compared with the control group. Natural allergen stimulation diminished both the numbers of regulatory T cells that express ZAP70 and the expression of Zap70 within these cells. In the second year of treatment, immunotherapy reduced significantly the symptom scores, concentrations of ENO (P < 0.01), intensively increased expression of ZAP70 in regulatory T cells (P < 0.001) and the percentage of cells that express ZAP70 (P < 0.05) at the height of the pollen season. Placebo treatment did not reduce scores, ENO (P > 0.05) nor had influence on Zap70 expression (P > 0.05)., Conclusions: SIT with grass pollen effectively reduces rhinitis severity and affects allergic airway inflammation reflected by reduction of ENO. Beneficial role of immunotherapy may result not only from the induction of Treg numbers but especially from cell activation and restitution of Treg intracellular signal transduction., (© 2013 John Wiley & Sons Ltd.)

Flow cytometry is the reference technique for assessing ZAP70 expression, a marker of poor prognosis in CLL. One of the most common methods is to assess ZAP70 levels in CLL cells by calculating the ratio between ZAP70 mean fluorescence intensities (MFIs) in residual T-cells and CLL B-cells (ZAP70 T/B ratio). In this study, we developed a new method for ZAP70 labeling. Cells were labeled with a combination of anti ZAP70 phycoerythrin-conjugated SBZAP monoclonal antibody (mAb) and mAbs against CD45, CD19, and CD5. The latter three were used to specifically gate on different lymphocyte subsets. Staining was performed in absence (test) or in presence of excess unconjugated SBZAP mAb (isoclonic control). A so-called ZAP70 isoclonic ratio between SBZAP MFIs in the test and isoclonic control was calculated. A series of 32 patients with CLL and 10 normal controls were studied. Prediction of IGHV mutation status by ZAP70 isoclonic and T/B ratios was similar. By using the ZAP70 isoclonic ratio, we showed that ZAP70 expression was increased in T-cells from CLL patients. Nearly all cases with increased ZAP70 expression in CLL cells were associated with high ZAP70 expression in cognate T-cells. Therefore, the ZAP70 isoclonic ratio was more likely to closely reflect the biology of ZAP70 dysregulation rather than the T/B ratio. These results also explained why ZAP70 T/B ratios were artefactually close to normal in cells from CLL patients with high levels of ZAP70., (Copyright © 2012 International Clinical Cytometry Society.)

Chronic lymphocytic leukemia (CLL) is the most common leukemia in adults in Western countries. It is characterized by heterogeneous clinical course of the disease and new prognostic factors are still needed. CD74 plays an important role in signal transduction in B cell proliferation and survival pathway. CD74 expression has been shown in solid tumors and has been connected with poor prognosis and tumor progression. The aim of the study was to evaluate the expression of CD74 in chronic lymphocytic leukemia patients with combination with other known prognostic factors. Expression of CD74 was determined in 90 patients and 28 healthy controls. CD74 expression was significantly higher in CLL group than in controls. There was positive correlation between CD74 and ZAP70 expression (p = 0.008). High expression of CD74 was positively correlated with more advanced stage of the disease (p = 0.02). No correlation was shown between CD74 and sex, mutational status IgVH and time to first treatment.

Objectives/hypothesis: To explore the molecular genetic background of juvenile nasopharyngeal angiofibromas and to identify biological processes and putative factors determining the different growth patterns of these tumors., Study Design: By comparing copy number and gene expression level changes of two clinically different phenotypes of juvenile nasopharyngeal angiofibromas, we aimed to find processes essential in the growth and development of these tumors. Based on the results and prior knowledge of the proteins significance for growth, we studied the expression of tyrosine kinase SYK in 27 tumor samples., Methods: Comparative genomic hybridization and gene expression analyses were performed for the two tumor samples, and protein expression of SYK was studied in 27 samples by immunohistochemical staining., Results: Between low- and high-stage juvenile nasopharyngeal angiofibromas, 1,245 genes showed at least a two-fold change in expression. The corresponding proteins of these transcripts were enriched in different biological processes. Protein kinase SYK was expressed in all 27 samples, and its intensity significantly correlated with tumor stage., Conclusions: Because the molecular genetic background of juvenile nasopharyngeal angiofibroma is unknown, our aim was to investigate genomic alterations that could associate to low- and high-stage tumors. We were able to identify gene expression changes that relate to particular biological processes, but assessing clinically relevant molecular profiles still requires further characterization. Due to the low incidence of juvenile angiofibroma, in the future a combination of molecular profiling data from several studies would be useful in understanding the molecular background of the disease., (Copyright © 2012 The American Laryngological, Rhinological, and Otological Society, Inc.)

Zeta-associated protein of 70 kDa (ZAP-70) is a tyrosine kinase that plays a role in signal transduction from the T-cell receptor. ZAP-70 is expressed in normal T-cells and NK-cells. Increased expression of ZAP-70 has been identified in chronic lymphocytic leukemia (CLL). CLL patients with increased ZAP-70 expression have significantly worse prognosis in terms of both progression-free survival and overall survival. There are several methods to quantify ZAP-70: polymerase chain reaction (PCR), immunoblotting, immunohistochemistry, and flow cytometry. Use of flow cytometry for ZAP-70 detection seems to be advantageous as this technique enables us to assess the presence of ZAP-70 separately on CLL clone, T-cells, and NK-cells. On the other hand, detection of ZAP-70 by flow cytometry is substantially influenced by many variables. The principal drawback of flow cytometry is the absence of consensus regarding selection of optimal anti-ZAP-70 antibody, fluorochrome conjugate, the most reliable staining technique, and optimal positivity threshold. This article summarizes pitfalls of flow cytometric analysis of ZAP-70 in CLL.

To determine whether prognostic factors remain relevant to chronic lymphocytic leukemia (CLL) patients treated with fludarabine and cyclophosphamide (FC), we prospectively evaluated 86 Chinese CLL patients who received FC in first-line therapy. Twenty-four patients (27.9%) achieved complete remission (CR), and overall response rate was 75.6%. With a median follow-up of 41 months, the median progression-free survival (PFS) was 36.0 months and median overall survival (OS) has not been reached. The strong correlations of lower CR rate with advanced Binet stage, unmutated IGHV, cytogenetic abnormalities of del(17p13) or del(11q23), and p53 mutations were observed by univariable analyses. Stepwise logistic regression identified that unmutated IGHV and p53 abnormality (p53 deletion or mutation) were associated with a decreased odds of achieving CR. The less cycles of treatment, not achieving CR, advanced Binet stage, and p53 abnormality significantly correlated with a shortened PFS. Furthermore, in a multivariate analysis, p53 abnormality and advanced Binet stage were identified as being significant risk factors for early relapse. Not achieving CR, advanced Binet stage, ZAP-70-positive, and p53 abnormality were the adverse factors in determining OS. Only p53 aberration was independently associated with significantly shorter OS by a multivariate analysis. These results suggest that patients with p53 abnormality should be considered for alternative therapies.

The b-cell chronic lymphatic leukemia is the most common among all lymphatic proliferative diseases and is characterized by significant variability of its clinical course. The mutation status of genes of variable region of heavy chains of immunoglobulins (IgVH) is the most reliable prognostic factor forecasting time until beginning of treatment in case of b-cell chronic lymphatic leukemia. However its detection nowadays is inaccessible for routine diagnostics. Among surrogate markers of mutation status the indicator of expression of ZAP-70 by tumor cells estimated using flow cytofluorometry. However, in publications there are different guidelines concerning the technique of mentioned marker. To establish the optimal approach to evaluation of expression of ZAP-70 the peripheral blood samples of 5I patients with b-cell chronic lymphatic leukemia and 10 healthy persons were analyzed. The comparison with the results of detection of mutation status of IgVH-genes revealed the advantage of applying the technique of calculation of MFI ratio during interpretation of data of expression of ZAP-70 obtained with flow cytofluorometry. In this framework, the indicator of expression of ZAP-70 can be applied in assessing the course of disease and time until the beginning of treatment of b-cell chronic lymphatic leukemia.

Background: Flow cytometric immunophenotyping has an established role in the diagnosis and monitoring of B-lymphoblastic leukemia (B-LL). However, the search continues for an optimal reagent set that can identify leukemic blasts with specificity, reproducibility, and sensitivity, at any point during the course of the disease and in every specimen type., Methods: This study evaluated the diagnostic utility of detecting the intracytoplasmic antigens zeta-associated protein (ZAP-70) and Bcl-2 in the distinction between the leukemic blasts of B-LL and hematogones., Results: In comparison with hematogones in reference specimens, significantly higher levels of Bcl-2 were identified in 21 of 23 (91%) B-LL. In particular, Bcl-2 expression was consistently higher in leukemic blasts with bright intensity CD10 expression than the equivalent most immature (CD10 bright intensity) hematogones. As previously reported, Bcl-2 expression was lower in B-LL with BCR-ABL1 gene rearrangement, but the fluorescence intensity of this group of specimens was still significantly higher than that seen for hematogones. In contrast, ZAP-70 was expressed at significantly higher levels in only 7 of 23 (30%) B-LL and demonstrated other findings that might limit clinical utility, including differences in the level of ZAP-70 expression during therapy and between blasts in the peripheral blood and bone marrow., Conclusions: Bcl-2 over-expression provides a useful tool for the distinction between B-LL and hematogones. In contrast, although further optimization of the ZAP-70 assay might increase the sensitivity of detection, over-expression of ZAP-70 was identified in only a minority of B-LL., (Copyright © 2011 International Clinical Cytometry Society.)

Several prognostic markers based on genetic, phenotypic, and molecular characteristics of chronic lymphocytic leukemia (CLL) B cells have emerged in the past decade. The clinical utility of these newer prognostic indicators, alone or in combination with each other and other clinical predictive systems, is still being determined. This chapter attempts to define biologic and molecular underpinnings of 3 sets of prognostic indicators in CLL: genetic abnormalities quantified by FISH and/or defined by exploratory sensitive molecular techniques, expression of specific proteins in or on CLL cells (ie, CD38, CD49d, and ZAP-70), and the IGHV mutation status of a CLL clone. Although not demonstrated conclusively, each probably reflects the biologic properties of the leukemic cells of individual CLL patients. This reflection may be direct, indicating a specific property of the CLL cell itself, or indirect, representing how the CLL cell interacts with the host's microenvironment. The new tyrosine kinase inhibitors that are currently in clinical trials support this interpretation. These and other biology-based indicators of patient clinical course and outcome can be used as starting points from which to understand and treat CLL.

The D cyclins are important cell cycle regulatory proteins involved in the pathogenesis of some lymphomas. Cyclin D1 overexpression is a hallmark of mantle cell lymphoma, whereas cyclins D2 and D3 have not been shown to be closely associated with any particular subtype of lymphoma. In the present study, we found that cyclin D2 was specifically overexpressed in the proliferation centers (PC) of all cases of chronic lymphocytic leukemia/small lymphocytic lymphoma (CLL/SLL) examined (19/19). To examine the molecular mechanisms underlying this overexpression, we immunohistochemically examined the expression of nuclear factor (NF)-κB, p15, p16, p18, and p27 in the PC of six patients. Five cases showed upregulation of NF-κB expression, which is known to directly induce cyclin D2 by binding to the promoter region of CCND2. All six PC examined demonstrated downregulation of p27 expression. In contrast, upregulation of p15 expression was detected in five of six PC examined. This discrepancy suggests that unknown cell cycle regulatory mechanisms involving NF-κB-related pathways are also involved, because NF-κB upregulates cyclin D2 not only directly, but also indirectly through c-Myc, which is believed to downregulate both p27 and p15. In conclusion, cyclin D2 is overexpressed in the PC of CLL/SLL and this overexpression is due, in part, to the upregulation of NF-κB-related pathways., (© 2011 Japanese Cancer Association.)

Chromosomal abnormalities and ZAP70 expression profile are two major independent prognostic markers in B-cell chronic lymphocytic leukemia. We investigated a possible correlation between these two markers. ZAP70 expression using real-time RT-PCR was examined in 20 B-cell chronic lymphocytic leukemia patients with del13q14, 13 patients with del11q22, 15 patients with trisomy 12, and 16 patients with no detected chromosomal abnormalities. Molecular analysis revealed that ZAP70 expression in the del13q subgroup was the same as in the control group, while it increased 2.78-fold in the del11q subgroup and 2.95-fold in the trisomy 12 subgroup, compared to the 15 cases in the control group. Comparison of the mean and standard deviation of the ZAP70 expression profile within the subgroups showed it to be highly variable among the individuals of the del11q and trisomy 12 subgroups, versus tight clustering for the del13q subgroup. Therefore, there is a correlation between del13q aberration, which has good prognosis with normal levels of ZAP70 expression. Due to a high degree of variation, no conformity is seen for del11q and trisomy 12 subgroups, making this grouping poor for prognostic discrimination. As a result, neither of these markers can serve as sole discriminators to determine the course of the disease; the use of both markers improves prognostic assessment.

An increasing number of data involve immunoreceptors in brain development, synaptic plasticity and behavior. However it has yet to be determined whether these proteins in fact transmit an immunoreceptor-like signal in non-hematopoietic neuronal cells. The recruitment and activation of the Syk family tyrosine kinases, Syk and ZAP-70, being a critical step in this process, we conducted a thorough analysis of Syk/ZAP-70 expression pattern in nervous tissues. Syk/ZAP-70 is present in neurons of different structures including the cerebellum, the hippocampus, the visual system and the olfactory system. During the olfactory system ontogeny the protein is detected from the 16th embryonic day and persists in adulthood. Importantly, Syk was phosphorylated on tyrosine residues representative of an active form of the kinase in specialized neuronal subpopulations comprising rostral migratory stream neuronal progenitor cells, hippocampal pyramidal cells, retinal ganglion cells and cerebellar granular cells. Phospho-Syk staining was also observed in synapse-rich regions such as the olfactory bulb glomeruli and the retina inner plexiform layer. Furthermore, our work on cultured primary hippoccampal neurons indicates that as for hematopoietic cells, Syk phosphorylation is readily induced upon pervanadate treatment. Therefore, Syk appears to be a serious candidate in connecting immunoreceptors to downstream adaptor/effector molecules in neurons., (Copyright © 2011 Elsevier Ireland Ltd and the Japan Neuroscience Society. All rights reserved.)

The TNF-related apoptosis-inducing ligand was shown to provide a costimulatory signal that cooperates with the TCR/CD3 complex to induce T cell proliferation and cytokine production. Although a number of signaling pathways were linked to the TCR/CD3 complex, it is not known how these two receptors cooperate to induce T cell activation. In this study, we show that TRAIL-induced costimulation of T cells depends on activation of the NF-κB pathway. TRAIL induced the NF-κB pathway by phosphorylation of inhibitor of κB factor kinase and protein kinase C in conjunction with anti-CD3. Furthermore, we demonstrated that TRAIL costimulation induced phosphorylation of the upstream TCR-proximal tyrosine kinases, Lck and ZAP70. Ligation of the TRAIL by its soluble receptor, DR4-Fc, alone was able to induce the phosphorylation of Lck and ZAP70 and to activate the NF-κB pathway; however, it was insufficient to fully activate T cells to support T cell proliferation. In contrast, TRAIL engagement in conjunction with anti-CD3, but not TRAIL ligation alone, induced lipid raft assembly and recruitment of Lck and PKC. These results demonstrate that TRAIL costimulation mediates NF-κB activation and T cell proliferation by lipid raft assembly and recruitment of Lck. Our results suggest that in TRAIL costimulation, lipid raft recruitment of Lck integrates mitogenic NF-κB-dependent signals from the TCR and TRAIL in T lymphocytes.

As known from mammalia, the co-receptors CD4 or CD8 associate with a lymphocyte cell-specific kinase (Lck) upon T-cell activation. Lck phosphorylates tyrosine residues within the CD3 chains, providing docking sites for a 70 kDa zeta-associated-protein (ZAP-70), a tyrosine protein kinase important for T-cell signaling. The sequences of a CD4-like gene (CD4-2), Lck, and ZAP-70 were cloned, characterized, and the relative expression pattern was explored in several organs of Atlantic halibut (Hippoglossus hippoglossus L.). Important structural features, as a signal peptide, two Ig-like domains followed by a connecting peptide, a transmembrane region, and a CxC motif within the cytoplasmic tail were conserved within the predicted halibut CD4-2 protein. The deduced halibut Lck protein sequence was found to be composed of a N-terminal Src homology (SH) 4 domain, required for membrane attachment and CD4/CD8 binding, SH3 and SH2 adapter domains, and a SH1 domain followed by a regulatory C-terminal tail (COOH-domain). Tyrosine residues important in Lck activation were conserved within the SH1 and COOH-domain. Structural features of ZAP-70 as tandem SH2 domains and a C-terminal SH1 domain were predicted within the halibut ZAP-70 sequence, having the highest level of conservation within these regions. Several important phosphorylation sites found to play a critical role in T-cell antigen receptor signaling in mammalian were conserved. The overall expression pattern of the three genes was highly similar, showing the highest mRNA level of all three genes in thymus. Some expression was seen in spleen, anterior and posterior kidney, gills, and fin, as seen for other halibut T-cell markers. This study will enable further experiments on halibut T-cell signaling and activation, and enhance understanding about the development of immunological memory T-cells of halibut., (Copyright © 2010 Elsevier Ltd. All rights reserved.)

We analyzed the correlation between well-established biological parameters of prognostic relevance in B-cell chronic lymphocytic leukemia (CLL) [i.e. mutational status of the immunoglobulin heavy chain variable region (IgVH), ZAP-70 and CD38 expression] and serum levels of B cell-activating factor (BAFF of the TNF family) by evaluating the impact of these variables on the time to first treatment (TFT) in a series of 169 previously untreated CLL patients in Binet stage A. Higher levels of BAFF were more frequently associated with female gender (P=0.02), younger age (P=0.01), Rai stage 0 (P=0.002), higher platelet count (P=0.005), mutated IgVH disease (P=0.002), higher occurrence of normal cytogenetic profile or presence of 13q deletion (P=0.02), low ZAP-70- (P=0.003), and CD38-expression (P=0.02). Maximally selected log-rank statistic plot identified a serum BAFF concentration of 0.313 ng/mL as the best cut-off (P<0.0001). This threshold recognized two subsets of patients with different TFT (P<0.0001). Because in multivariate analysis soluble BAFF [Hazard ratio (HR), 8.23; confidence Interval (CI) 95%,3.0-22.6, P<0.0001] and mutational status of IgVH (HR=2.60; CI 95% 1.10-6.14, P=0.03) maintained the discriminating power their combined effect on clinical outcome was assessed. When three groups were considered: (1) low-risk (n=93), patients with concordant IgVH(mut) and higher soluble BAFF; (2) intermediate-risk (n=50), patients with IgVH(mut) and low BAFF levels or IgVH(unmut) and soluble higher BAFF;(3) high-risk (n=26), patients with concordant IgVH (unmut) and low soluble BAFF, the 2-yr TFTs were, respectively, 95%, 85%, and 41% (P<0.0001). In conclusion, our results indicate that in early B-cell CLL, the biological profile including among other parameters soluble BAFF may provide a useful insight into the complex interrelationship of prognostic variables., (© 2010 John Wiley & Sons A/S.)

Serum thymidine kinase 1 (TK1) levels have been reported to have prognostic significance in patients with chronic lymphocytic leukemia (CLL). Until recently, serum TK1 levels were assessed using inconvenient radioenzyme assays. In this study, we used a novel chemiluminescence assay to assess serum TK1 levels in patients with CLL at the time of first examination. We show that high serum TK1 levels predict poorer overall survival and correlate with unmutated immunoglobulin variable region genes, CD38 and ZAP-70 expression, and subsequent risk of developing large B-cell lymphoma (Richter syndrome). Similar findings were observed in a subset of patients treated with current fludarabine-based chemotherapy regimens. We suggest that serum TK1 levels analyzed using this convenient chemiluminescence assay may be useful in the risk assessment of patients with CLL.

Background: T cells from patients with chronic lymphocytic leukemia may play an important role in contributing to the onset, sustenance, and exacerbation of the disease by providing survival and proliferative signals to the leukemic clone within lymph nodes and bone marrow., Design and Methods: By performing chemotaxis assays towards CXCL12, CCL21 and CCL19, we sought to evaluate the migratory potential of T cells from chronic lymphocytic leukemia patients. We next analyzed the chemokine-induced migration of T cells, dividing the chronic lymphocytic leukemia samples according to their expression of the poor prognostic factors CD38 and ZAP-70 in leukemic cells determined by flow cytometry., Results: We found that T cells from patients with chronic lymphocytic leukemia are less responsive to CXCL12, CCL21 and CCL19 than T cells from healthy adults despite similar CXCR4 and CCR7 expression. Following separation of the patients into two groups according to ZAP-70 expression, we found that T cells from ZAP-70-negative samples showed significantly less migration towards CXCL12 compared to T cells from ZAP-70-positive samples and that this was not due to defective CXCR4 down-regulation, F-actin polymerization or to a lesser expression of ZAP-70, CD3, CD45, CD38 or CXCR7 on these cells. Interestingly, we found that leukemic cells from ZAP-70-negative samples seem to be responsible for the defective CXCR4 migratory response observed in their T cells., Conclusions: Impaired migration towards CXCL12 may reduce the access of T cells from ZAP-70-negative patients to lymphoid organs, creating a less favorable microenvironment for leukemic cell survival and proliferation.

Background: New prognostic factors such as IgVh mutational status, ZAP-70 protein expression and cytogenetic abnormalities have shown to offer important prognostic information for patients with chronic lymphocytic leukemia (CLL). Our aim was to evaluate the optimal cut-off for IgVh mutational status, ZAP-70 expression and cytogenetic abnormalities in association with disease progression defined as the need for treatment within 3~years from diagnosis in 170 patients with B-CLL., Design and Methods: Receiver operating characteristics (ROC) analysis and multivariate general linear models (GLMs) were used to investigate the most significant cut-off values of these biomarkers and their prognostic impact., Results: Our findings estimated that the optimal cut-off for IgVh mutation status and for ZAP-70 protein expression was 97% and 16.5% respectively and a high concordance between the two was demonstrated. We identified 30% as being the best-cut-off for 17p-, 11q- and 6q-. In univariate analysis 17p- was found to be a significant predictor of the event only for the whole population. Multivariate analysis including all biological parameters, identified 11q deletion as the only significant regressor., Conclusions: We assessed that IgVh mutational status, ZAP-70 protein and 6q- are powerful prognostic markers. Analyses of all these factors revealed that 11q deletion was the strongest predictor of disease progression in B-CLL.

In chronic lymphocytic leukemia (CLL), inhibition of spontaneous apoptosis determines a worse prognosis and increasing evidences show that disease progression relies also upon cycling CLL cells. We investigated bcl-2, as measure of apoptosis, and CD71, as measure of proliferation, by flow cytometry in 265 patients with CLL. Combining bcl-2 with CD71 values, we defined three subgroups: (1) bcl2 - CD71-; (2) bcl2 + CD71+; and (3) bcl2 + CD71- or bcl2- CD71+. Both a shorter progression-free survival (PFS) and overall survival (OS) were observed in ZAP-70+ (p < 0.00001) and in patients with bcl2 + CD71+ (p < 0.00001 and p = 0.02). The patients with discordant in bcl2 + CD71- and bcl2- CD71+ showed an intermediate outcome. Noteworthy, patients with bcl2 + CD71+ showed a shorter PFS within ZAP-70 negative subgroup (p = 0.00009). In multivariate analysis of PFS, age (p = 0.005), beta-(2) microglobulin (B(2)-M) (p = 0.003), bcl-2 (p = 0.004), CD49d (p = 0.001), and ZAP-70 (p < 0.001) resulted to be significant prognostic factors. The independent prognostic significance of B(2)-M (p = 0.009) and bcl-2 (p = 0.03) was confirmed within ZAP-70 negative patients. Bcl-2 and CD71 can be considered as interesting progression indicators, which should be validated in an independent cohort of patients, to take timely therapeutic decisions in CLL.

Transformed cells in lymphomas usually maintain the phenotype of the postulated normal lymphocyte from which they arise. By contrast, anaplastic large cell lymphoma (ALCL) is a T-cell lymphoma with aberrant phenotype because of the defective expression of the T-cell receptor and other T-cell-specific molecules for still undetermined mechanisms. The majority of ALCL carries the translocation t(2;5) that encodes for the oncogenic tyrosine kinase NPM-ALK, fundamental for survival, proliferation, and migration of transformed T cells. Here, we show that loss of T-cell-specific molecules in ALCL cases is broader than reported previously and involves most T-cell receptor-related signaling molecules, including CD3epsilon, ZAP70, LAT, and SLP76. We further show that NPM-ALK, but not the kinase-dead NPM-ALK(K210R), downregulated the expression of these molecules by a STAT3-mediated gene transcription regulation and/or epigenetic silencing because this downregulation was reverted by treating ALCL cells with 5-aza-2-deoxycytidine or by knocking down STAT3 through short hairpin RNA. Finally, NPM-ALK increased the methylation of ZAP70 intron 1-exon 2 boundary region, and both NPM-ALK and STAT3 regulated the expression levels of DNA methyltransferase 1 in transformed T cells. Thus, our data reveal that oncogene-deregulated tyrosine kinase activity controls the expression of molecules that determine T-cell identity and signaling.

CD49d plays a critical role in leucocyte trafficking, activation and survival, and facilitates interactions between leucocytes and stromal cells. Recent data give evidence for the prognostic relevance of CD49d protein expression in B-CLL. In our study we analyzed both the expression of CD49d protein and mRNA in a cohort of 101 CLL patients. The percentage of leukemic B-cells expressing CD49d determined by flow cytometry ranged from 0 to 100%. 37 patients with high CD49d protein expression >or=45% (according to ROC analysis) had a significantly shorter treatment-free survival (TFS) and overall survival (OS) than 64 patients with low CD49d expression (median TFS: 116 versus 43 months, p=0.015; median OS: not reached in both groups, p=0.018). CD49d protein expression was strongly associated with CD38 status (p=0.0001) and ZAP-70 status (p=0.03) but not with IGVH mutation. In multivariate analysis high CD49d expression was a significantly independent prognostic factor (HR 3.0; p=0.005). According to the strong correlation of CD49d protein expression with CD49d mRNA expression (r=0.39; p<0.0001) we could confirm the results on mRNA level with worse prognosis for patients with high mRNA level. Collectively, our data confirm the prognostic significance supporting the idea to use CD49d as target molecules for therapeutic approaches in B-CLL.

B-cell chronic lymphocytic leukaemia (B-CLL) is a heterogeneous disease with some patients having an indolent course never needs treatment, while others having rapidly progressive one requires intensive treatment. In recent decades, numerous prognostic markers, such as immunoglobulin variable region heavy-chain (IgVH) mutational status, ZAP-70 and the expression of CD38 on leukaemic cells were introduced to screen for patients likely to have progressive course of B-CLL bearing the potential to facilitate risk-adapted treatment strategies. In B-CLL, T cell function is shown to be dysregulated. CD38 has been demonstrated to be an important transmembrane signalling molecule of T cell with a direct effect on its function. The present study was conducted to analyse CD38 expression on T cells by flow cytometry to evaluate its impact on the clinical course of 88 unselected B-CLL patients and correlate it with other risk factors. CD38 expression level on T cells was shown to predict the clinical course of B-CLL in male patients but not in female patients. Male patients showed CD38 expression on T cells in a stage-dependent manner, in contrast to female patients who showed higher expression irrespective to clinical staging. CD38 expression on T cells negatively interacted with treatment-free survival in male patients. Multivariate analysis revealed that CD38 expression level on T cells is an independent prognostic factor in B-CLL male patients. Simultaneous evaluation of CD38 expression on both B-CLL cells and T cells allowed predicting male patient groups with the most favourable prognosis as well as those with the worst.

Zeta-chain-associated protein (ZAP-70) and spleen tyrosine kinase (Syk) are structurally and functionally homologous tyrosine kinases playing a role in the T- and B-cell signal transduction. Their activation can lead to lymphokine production, cytolitic activity, antibody secretion, cell proliferation, differentiation, survival and phagocytosis. Anomalous ZAP-70 and Syk expression is reported to be related to tumor formation and progression, and ZAP-70 immunoreactivity is a good prognostic marker of disease progression in human chronic lymphocytic leukaemia (CLL). Until now, to our knowledge, there are no reports about canine ZAP-70 and Syk expression profiles. In the present study, a RT-PCR procedure for the quali-quantitative evaluation of canine ZAP-70 and Syk transcripts was designed. The expression patterns of canine ZAP-70 and Syk mRNAs were evaluated in canine leukocyte subpopulations and in peripheral whole blood samples from healthy dogs and from dogs with different types of leukaemia. Similarly to humans, normal canine CD4+ and CD8+ T cells showed high expression of ZAP-70, whereas Syk was abundantly expressed in normal CD21+ B cells. The expression profile of ZAP-70 and Syk was markedly different in canine normal and leukaemic blood. Decreased Syk expression was detected in dogs with T-cell CLL, whereas decreased ZAP-70 expression was detected in dogs with B-cell CLL and B-cell acute lymphocytic leukaemia (ALL). The comparison of ZAP-70 and Syk mRNA levels between normal and leukaemic peripheral whole blood showed that the expression ratio ZAP-70/Syk is subjected to modification depending on the leukaemia status of patients. The results of the present work open an interesting topic for leukaemogenesis investigation and are the basis for further studies for a proper evaluation of the potential utility of these parameters for the diagnosis and prognosis of canine T- and B-cell leukaemia.

Chronic lymphocytic leukemia (CLL) is characterized by a malignant clonal population of lymphocytes, which are usually of the B cell lineage. Classical Rai and Binet staging of CLL is being superseded by new prognostic markers. The mutational status of the immunoglobulin variable region heavy-chain genes segregates the disease into more benign and more malignant versions, and has been confirmed as an important prognostic marker in prospective clinical trials. A search for surrogate markers for this assay has led to flow cytometric assays for CD38 and ZAP-70 expression. The human leukocyte antigen G (HLA-G) molecule exhibits limited tissue distribution and a low polymorphism that generate seven HLA-G isoforms. HLA-G exerts multiple immunoregulatory functions. Recent studies indicate an ectopic up-regulation in tumor cells that may favor their escape from anti-tumor immune responses. For this report we studied HLA-G in parallel with CD38 and ZAP-70 in B-cell chronic lymphocytic leukemia (B-CLL) patients. HLA-G expression was studied retrospectively in circulating B-CLL cells from 20 patients by flow cytometry using the anti-HLA-G specific monoclonal antibody MEM/G9. The proportion of leukemic cells expressing HLA-G varied from 1 to 34%. We detected a statistically significant correlation between HLA-G positive (>12%) expression and progression free survival (p=0.045), but no correlation with CD38 and ZAP-70. We also detected a statistically significant difference between Binet stage A; B and C (p=0.046) and a positive correlation between IL-10 and HLA-G (p=0.044). We conclude that positive HLA-G has an effect on progression - free survival, when compared with CD38 and ZAP-70.

B cells have acquired an important role in the pathogenesis of rheumatoid arthritis (RA) since B cell depletion allowed to rescue patients poorly responders to TNFalpha blockers. This study focused on the involvement of ZAP-70 as a bio-marker of B cells immune activation in RA. ZAP-70 expression in synovial fluid (SF) B cells obtained from RA patients was increased compared to SF B cells of osteoarthritis (OA) patients. Moreover we found that ZAP-70 positive/CD38 positive and ZAP-70 positive/CD5 positive B cells were enriched in SF. The analysis of B cell apoptosis in vitro showed that the percentage of ZAP-70 negative B cells spontaneously undergoing apoptosis was significantly higher than ZAP-70 positive B cells. The ZAP-70 positive B cell ratio (SF/peripheral blood (PB)) showed a positive correlation with SF autoantibody levels and with local levels of BAFF and IL6. ZAP-70 positive B cells seem to define a subset characterized by increased survival and high relationship with local inflammation and autoimmunity.

This paper shows a protocol for the detection of ZAP-70 expression in B-CLL (B cell chronic lymphocytic leukemia) tumor cells by common immunohistochemical methods. The study was conducted on bone marrow trephine biopsies from 62 B-CLL patients at the time of diagnosis. Immunohistochemical reactions based on peroxidase and alkaline phosphatase reactions were used, as well as double immunofluorescent labeling for ZAP-70 detection as an indirect marker of mutated and unmutated CLL. Clinical relevance of the ZAP-70 expression detection method was assessed using chi2 test between ZAP-70 positivity data and other known prognostic factors, i.e., clinical and cytogenetics data. ZAP-70 was detected in 13 out of 62 patients. Statistically significant results were obtained for ZAP-70 positive cases and known indicators of worse prognosis. Immunohistochemical analysis supported by double immunofluorescent labeling, as shown here, is an easy and reliable technique for the detection of ZAP-70 expression in B-CLL tumor cells applicable in every hematopathology laboratory.

In the past, ZAP70 was considered a T cell-specific kinase, and its aberrant expression in B-CLL cells was interpreted as a sign of malignant transformation and dedifferentiation. It was only recently that ZAP70 was detected in normal human B cells. In this study, we show that TLR9-activated B cells resemble B-cell chronic lymphocytic leukemia cells with regard to CD5, CD23, CD25, and heat shock protein 90 expression. Furthermore, stimulatory CpG and GpC DNA oligonucleotides target CD27(+)IgM(+) and CD27(-)IgM(+) B cells (but not IgM(-) B cells) and enhance ZAP70 expression predominantly in the IgM(+)CD27(+) B cell subset. ZAP70 is induced via activation of TLR-7 or -9 in a MyD88-dependent manner, depends on protein kinase B (PKB)/mammalian target of rapamycin signaling and is rapamycin sensitive. Furthermore, ZAP70 expression levels correlate with induction of cyclin A2, prolonged B cell proliferation, and sustained induction of PKB. These events are not observed upon CD40 ligation. However, this deficit can be overcome by the expression of constitutively active PKB, given that CD40 ligation of PKB-transgenic B cells induces B cell proliferation and ZAP70 expression. These results highlight a major difference between CD40- and TLR-7/9-mediated B cell activation and suggest that ZAP70 expression levels in B cells give an estimate of the proliferative potential and the associated PKB availability.

Purpose: A single nucleotide polymorphism (SNP) at position 309 in the promoter region of MDM2 leading to increased expression of MDM2 and attenuated function of p53 has been negatively associated with onset and outcome of disease in solid tumors. Because inactivation of p53 by deletion and/or mutations also impacts on the clinical course of B-cell chronic lymphocytic leukemia (B-CLL), we assessed the role of the SNP309 genotype in B-CLL., Patients and Methods: The frequency of SNP309 T/T, T/G, or G/G genotypes and the p53 status (wild type, mutated, or deleted) were assessed and correlated with clinical outcome in 140 B-CLL patients and a second independent cohort. In addition, the correlation of the MDM2 SNP309 genotype with the MDM2 protein expression level in B-CLL cells was evaluated by immunoblotting., Results: A significant negative association of the SNP309 T/G and G/G genotypes with overall survival was seen (T/G genotype, relative risk = 3.7; 95% CI, 1.2 to 11.5; P = .02; G/G genotype, relative risk = 9.1; 95% CI, 2.4 to 35.1; P = .001), but no correlation with incidence or onset of B-CLL was observed. The influence of the heterozygous SNP309 T/G genotype on treatment-free survival depended on the p53 status but not on the CD38, Zap-70, or IgVH mutational status or Rai stage of B-CLL patients. The unfavorable SNP309 T/G and G/G genotypes were associated with a gene-dosage-dependent increase of MDM2 expression., Conclusion: The MDM2 SNP309 genotype influencing MDM2 expression levels was identified as an additional independent risk factor in B-CLL. Targeting MDM2-p53 interactions might emerge as a successful treatment strategy for B-CLL.

Background: Flow cytometry allows specific assessment of the expression of ZAP-70, a promising new prognostic factor in B-cell chronic lymphocytic leukemia (B-CLL), but suffers from a lack of multicenter standardization., Design and Methods: An optimized method for direct detection of ZAP-70 in flow cytometry was tested in a multicenter fashion. Adapted for frozen cells, this method includes a normalization step by addition of B cells from a pool of peripheral blood mononuclear cells collected from normal donors. ZAP-70 expression levels were assessed for 153 patients with typical B-cell chronic lymphocytic leukemia chronic lymphocytic leukemia. Results were expressed as the ratio of ZAP-70 mean fluorescence intensity between B-CLL cells and normal B cells., Results: The statistically optimized cut-off of ZAP-70 positivity was a ratio of 1.4. Concordance between ZAP-70 and CD38 expression was 67%. Concordance between the mutational status of IgVH genes and ZAP-70 or CD38 expression was 87% and 65%, respectively. ZAP-70 was significantly expressed in 28%, 54% and 61% of patients with Binet stages A, B and C B-cell chronic lymphocytic leukemia, respectively (p=0.008). The absence of ZAP-70 expression was associated with isolated del(13q14), a cytogenetic abnormality with a good prognosis, while most patients with the del(17p13) poor prognosis cytogenetic marker expressed ZAP-70 (p<10(-5)). ZAP-70 expression was not related to the other poor prognosis cytogenetic abnormality del(11q22.3) nor to trisomy 12., Conclusions: This new technique provides highly reliable results well correlated with the mutational status of IgVH genes, CD38 expression, Binet stage and cytogenetic abnormalities. This robust discriminative technique appears of particular interest for routine diagnosis and assessment of ZAP-70 expression in large, prospective, multicenter therapeutic trials.

Purpose: Fludarabine, cyclophosphamide, and mitoxantrone (FCM) results in a high response rate in previously treated patients with chronic lymphocytic leukemia (CLL). The aim of this study was to investigate FCM as frontline therapy in CLL., Experimental Design: Sixty-nine patients under the age of 65 years with active CLL were treated. Patients received six cycles of fludarabine 25 mg/m(2) i.v. x 3 days, cyclophosphamide 200 mg/m(2) i.v. x 3 days, and mitoxantrone 6 mg/m(2) i.v. x 1 day. Treatment outcome was correlated with clinical and biological variables. The clinical significance of eradicating minimal residual disease (MRD) was also analyzed., Results: The overall response, MRD-negative complete response (CR), MRD-positive CR, nodular partial response (PR), and PR rates were 90%, 26%, 38%, 14%, and 12%, respectively. Severe (grades 3 or 4) neutropenia developed in 10% of the patients. Major and minor infections were reported in 1% and 8% of cases, respectively. Median response duration was 37 months. Patients with del(17p) failed to attain CR. Patients achieving MRD-negative CR had a longer response duration and overall survival than patients with an inferior response. Low serum lactate dehydrogenase levels, low ZAP-70 expression, and mutated IgV(H) genes predicted longer response duration. Finally, both low ZAP-70 and CD38 expression in leukemic cells correlated with MRD-negativity achievement., Conclusion: FCM induces a high response rate, including MRD-negative CRs in untreated patients with active CLL. Treatment toxicity is acceptable. Both high ZAP-70 and increased CD38 expression predict failure to obtain MRD-negative response. Patients in whom MRD can be eradicated have longer response duration and overall survival than those with inferior response. These results indicate that FCM can be an ideal companion for chemoimmunotherapy of patients with CLL.

In CLL data from chromosome banding analysis (CBA) have been scarce due to the low proliferative activity of CLL cells in vitro. We improved the cultivation technique using an immunostimulatory CpG-oligonucleotide DSP30 and IL-2. A total of 506 CLL samples were analysed with CBA and interphase FISH using probes for the detection of trisomy 12, IgH rearrangements and deletions of 6q21, 11q22.3 (ATM), 13q14 (D13S25 and D13S319) and 17p13 (TP53). A total of 500 of 506 (98.8%) cases were successfully stimulated for metaphase generation and are subject to this study. Aberrations were detected in 415 of 500 (83.0%) cases by CBA and in 392 of 500 (78.4%) cases by FISH. CBA detected 832 abnormalities and FISH only 502. Therefore, CBA offers important information in addition to FISH. (1) CLL is characterized mainly by genomic imbalances and reciprocal translocations are rare. (2) A subgroup with complex aberrant karyotype (16.4%) is identified which is associated with an unmutated IgV(H) status and CD38 expression (P=0.034 and 0.02, respectively). (3) Additional abnormalities are detectable providing new biological insights into different CLL subclasses revealing a much more heterogeneous pattern of cytogenetic abnormalities as assumed so far based on FISH data only. Therefore, prospective clinical trials should evaluate the prognostic impact of newly available CBA data.

Mechanisms for the rapid recall response mediated by memory T cells remain unknown. In this study, we present a novel, multiparameter analysis of TCR-coupled signaling and function in resting and activated naive and memory CD4 T cells, revealing a biochemical basis for immunological recall. We identify a striking elevation in expression of the proximal tyrosine kinase Zap70 in resting Ag-specific and polyclonal mouse memory vs naive CD4 T cells that is stably maintained independent of protein synthesis. Elevated Zap70 protein levels control effector function as IFN-gamma production occurs exclusively from the Zap70(high) fraction of activated T cells in vitro and in vivo, and specific down-modulation of Zap70 expression in memory CD4 T cells by small interfering RNA or protein inhibition significantly reduces rapid IFN-gamma production. Downstream of Zap70, we show quantitative differences in distal phosphorylation associated with effector function in naive and memory subsets, with low accumulation of phosphorylation in memory T cells producing IFN-gamma at early time points, contrasting extensive phosphorylation associated with IFN-gamma production following sustained activation of naive T cells. Our results reveal a novel biochemical signature imparted to memory CD4 T cells enabling efficacious responses through increased Zap70 expression and reduced accumulation of downstream signaling events.