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Targeted next-generation sequencing (NGS) based on molecular tagging technology allowed considerable improvement in the approaches of cell-free DNA (cfDNA) analysis. Previously, we demonstrated the feasibility of the OncomineTM Lung cell-free DNA Assay (OLcfA) NGS panel when applied on plasma samples of post-tyrosine kinase inhibitors (TKIs) non-small cell lung cancer (NSCLC) patients. Here, we explored in detail the coverage metrics and variant calling of the assay and highlighted strengths and challenges by analyzing 92 plasma samples collected from a routine cohort of 76 NSCLC patients. First, performance of OLcfA was assessed using Horizon HD780 reference standards and sensitivity and specificity of 92.5% and 100% reported, respectively. The OLcfA was consequently evaluated in our plasma cohort and NGS technically successful in all 92 sequenced libraries. We demonstrated that initial cfDNA amount correlated positively with library yields (p &lt, 0.0001) and sequencing performance (p &lt, 0.0001). In addition, 0.1% limit of detection could be achieved even when &lt, 10 ng cfDNA was employed. In contrast, the cfDNA amount seems to not affect the EGFR mutational status (p = 0.16). This study demonstrated an optimal performance of the OLcfA on routine plasma samples from NSCLC patients and supports its application in the liquid biopsy practice for cfDNA investigation in precision medicine laboratories.

Molecular characterization of Circulating Tumor Cells (CTCs) is still challenging, despite attempts to minimize the drawbacks of Whole Genome Amplification (WGA). In this paper, we propose a Next-Generation Sequencing (NGS) optimized protocol based on molecular tagging technology, in order to detect CTCs mutations while skipping the WGA step. MDA-MB-231 and MCF-7 cell lines, as well as leukocytes, were sorted into pools (2&ndash, 5 cells) using a DEPArray&trade, system and were employed to set up the overall NGS procedure. A substantial reduction of reagent volume for the preparation of libraries was performed, in order to fit the limited DNA templates directly derived from cell lysates. Known variants in TP53, KRAS, and PIK3CA genes were detected in almost all the cell line pools (35/37 pools, 94.6%). No additional alterations, other than those which were expected, were found in all tested pools and no mutations were detected in leukocytes. The translational value of the optimized NGS workflow is confirmed by sequencing CTCs pools isolated from eight breast cancer patients and through the successful detection of variants. In conclusion, this study shows that the proposed NGS molecular tagging approach is technically feasible and, compared to traditional NGS approaches, has the advantage of filtering out the artifacts generated during library amplification, allowing for the reliable detection of mutations and, thus, making it highly promising for clinical use.

Background The demonstration of EGFR T790M gene mutation in plasma is crucial to assess the eligibility of Non Small Cell Lung Cancer (NSCLC) patients, who have acquired resistance to first or second generation Tyrosine Kinase Inhibitors (TKIs), to receive a subsequent treatment with osimertinib. Since circulating tumor DNA (ctDNA) is present in very low amounts in plasma, high sensitive and specific methods are required for molecular analysis. Improving sensitivity of T790M mutation detection in plasma ctDNA enables a larger number of NSCLC patients to receive the appropriate therapy without any further invasive procedure. Methods A tag-based next generation sequencing (NGS) platform capable of tagging rare circulating tumor DNA alleles was employed in this study for the identification of T790M mutation in 42 post-TKI NSCLC patients. Results Compared to Real Time PCR, tag-based NGS improved the T790M detection rate (42.85% versus 21.4%, respectively), especially in those cases with a low median mutation abundance (i.e. 0.24, range 0.07–0.78). Moreover, the tag-based NGS identified EGFR activating mutations more efficiently than Real Time PCR (85.7% versus 61.9% detection rate, respectively), particularly of the L858R variant type (0.06–0.75 mutation abundance range). Patients in whom the T790M mutation was detected in plasma, achieved an objective response to osimertinib (9/14, 64.28%). Conclusions Tag-based NGS represents an accurate and sensitive tool in a clinical setting for non-invasive assessment and monitoring of T790M variant in NSCLC patients. Electronic supplementary material The online version of this article (10.1186/s10020-019-0082-5) contains supplementary material, which is available to authorized users.

A risk score based on three biological features (CD38, ZAP-70, and IGHV mutational status) was previously developed to predict progression-free survival (PFS) in untreated Binet A CLL patients. Here we perform a score validation analysis in a prospective and independent cohort of patients. Biological markers (CD38, ZAP-70, and IGHV mutational status) and gene expression profiles (GEP) of leukemic cells from CLL patients included in a prospective multicenter observational study (O-CLL1-GISL protocol, clinicaltrial.gov ID:NCT00917549) were used to assess the value and reproducibility of this score. To date, 468 Binet A patients were classified as low- (0 positive marker), intermediate- (1 positive marker), or high-risk (2 or 3 positive markers) using the progression risk score. The 3-year PFS probability was 91.7%, 82.9%, and 57.4% for low-, intermediate-, and high-risk (P < 0.0001) cases, respectively. These values were similar to those found in the original cohort. At Cox multivariate analysis, Rai stage, absolute lymphocyte count, progression risk score, and β-2 microglobulin maintained an independent prognostic impact on PFS. This score remained a predictor of progression when analysis was limited to 371 Rai 0 cases (P < 0.0001). Finally, the cells from the different CLL risk groups showed differences in their gene expression patterns. These results confirm the ability of this progression risk score to predict PFS among Binet A patients. The utility of the score was also extended by demonstrating that it retains prognostic value when applied exclusively to Rai 0 patients. Specific transcriptional patterns were significantly associated with risk groups.

Metastatic colorectal cancer (mCRC) is frequently characterized by the presence of mutations of the KRAS oncogene, which are generally associated with a poor response to treatment with anti-epidermal growth factor receptor (anti-EGFR) monoclonal antibodies. With the methods currently used, a case is classified as KRAS-mutated when approximately 20% of the cells bear an activating KRAS mutation. These considerations raise the question of whether cells with a mutated KRAS can be found in mCRC cases classified as KRAS wild-type when more sensitive methods are used. In addition, the issue arises of whether these mCRC cases with low proportion of KRAS-mutated cells could account at least in part for the therapeutic failure of anti-EGFR therapies that occur in 40-60% of cases classified as KRAS wild type. In this study, we compared the classical assays with a very sensitive test, a locked nucleic acid (LNA) polymerase chain reaction (PCR), capable of detecting KRAS-mutated alleles at extremely low frequency (detection sensitivity limit 0.25% mutated DNA/wild-type DNA). By analyzing a cohort of 213 mCRC patients for KRAS mutations, we found a 20.6% discordance between the sequencing/TheraScreen methods and the LNA-PCR. Indeed, 44 mCRC patients initially considered KRAS wild type were reclassified as KRAS mutated by using the LNA-PCR test. These patients were more numerous among individuals displaying a clinical failure to anti-EGFR therapies. Failure to respond to these biological treatments occurred even in the absence of mutations in other EGFR pathway components such as BRAF.

Objective Interleukin (IL)-21, a member of the IL-2 family, has antitumor activity and is now being tested in non-Hodgkin's lymphoma in combination with anti-CD20 antibodies. IL-21 may either induce apoptosis or promote growth in different lymphoid malignancies. We therefore investigated the IL-21/IL-21R system in follicular lymphoma (FL) cells. Materials and Methods IL-21R expression was studied by reverse transcription polymerase chain reaction, immunofluorescence, and Western blot analyses. Apoptosis was measured by Annexin-V−propidium iodide staining. Signaling via IL-21R was studied using antibodies specific for phosphorylated Janus-activating kinase and signal transducers and activators of transcription proteins by Western Blot. Results IL-21R was found on primary FL cells in 15 of 15 cases at diagnosis and IL-21 increased apoptosis in 10 of 10 FL samples. However, cells from areas of diffuse growth in FL and from two diffuse lymphomas evolved from previous FL, showed low IL-21R expression. The latter were also resistant to IL-21−mediated apoptosis. Among lymphoma cell lines bearing the t(14;18) translocation, only 1 of 7 showed increased apoptosis in response to IL-21 stimulation. This cell line was IL-21R−positive, whereas five of six nonresponsive cell lines showed very low IL-21R expression. Intriguingly, one of the IL-21-resistant cell lines (DOHH2) expressed high levels of IL-21R. Treatment with IL-21 or IL-4 upregulated suppressor of cytokine signaling 3 gene expression in the IL-21−responsive cell line, but not in DOHH2 cells, which showed defective Janus-activating kinase/signal transducers and activators of transcription signaling in response to IL-21, in relationship to the lack of Janus-activating kinase 3 gene expression. Conclusion These data indicate that low IL-21R expression or defective signal transduction downstream IL-21R may cause refractoriness to IL-21−mediated effects in some FL cells.

Objective: We performed an external and multicentric validation of the predictive value of abdominal computed tomography (aCT) on time to first treatment (TTFT) in early stage chronic lymphocytic leukemia (CLL) patients. Methods: aCT was performed at diagnosis in 181 Rai 0 patients enrolled in the O-CLL1GISL trial (clinicaltrial.gov ID:NCT00917549). Results: Fifty-five patients showed an abnormal aCT. Patients with an abnormal aCT showed a significantly shorter TTFT than those with normal aCT (P < 0.0001). At multivariate analysis, aCT (P = 0.011), b-2 microglobulin (P = 0.019), and CD38 expression (P = 0.047) correlated with TTFT. Following IWCLL 2008 criteria, 112 (61.9%) cases remained at Rai 0, while 69 (38.1%) satisfied the criteria of clinical monoclonal B-cell lymphocytosis (cMBL). Reclassified Rai 0 patients with an abnormal aCT showed a significantly shorter TTFT than those with a normal aCT (P < 0.0001). At multivariate analysis, only aCT (P = 0.011) correlated with TTFT. Eleven cMBL cases (15.9%) showed an abnormal aCT and were reclassified as small lymphocytic lymphomas (SLL); nonetheless, TTFT was similar for cMBLs and SLLs. Conclusion: Our results confirm the ability of the abnormal aCT to predict progression in early stage cases.

Background: The course of chronic lymphocytic leukaemia/small lymphocytic lymphoma (CLL/SLL) partly depends on the mutational status of the variable region of immunoglobulin heavy chain genes (IgV H ), which defines two subgroups of tumours: mutated and unmutated. The expression of zeta-associated protein 70 (ZAP70) is significantly associated with the more aggressive unmutated forms. Aims: To assess the feasibility of the ZAP70 immunohistochemical test on bone-marrow biopsy (BMB) specimens and to compare the results with those of western blotting (WB) and IgV H mutational status assessed on neoplastic cells from peripheral blood. Methods: 26 patients with CLL/SLL detected on BMB and with known IgV H mutational status were selected. ZAP70 was determined by immunohistochemistry (IHC) comparing three antibodies from different sources (Upstate, Cell Signaling, Santa Cruz, California, USA) and two different methods (APAAP and EnVision + ). In 23 cases, ZAP70 WB results were also available. Results: ZAP70 determination on BMB specimens turned out to be easily feasible with routine procedures with reagents from Upstate and Cell Signaling. The results were concordant with those obtained with WB and mutational status analysis in >80% of the cases with both reagents. Three of four discordant cases were mutated/ZAP70 positive, with two staining weakly for ZAP70 on both WB and IHC. Conclusions: The study confirms the role of ZAP70 as a possible surrogate of mutational status and emphasises its application in routine diagnostics; it discloses a small subset of discordant cases (mutated/ZAP70 weakly positive) that clinically cluster with the more favourable forms.

Deficiency of glycosylphosphatidylinositol (GPI)–anchored molecules on blood cells accounts for most features of paroxysmal nocturnal hemoglobinuria (PNH) but not for the expansion of PNH (GPI−) clone(s). A plausible model is that PNH clones expand by escaping negative selection exerted by autoreactive T cells against normal (GPI+) hematopoiesis. By a systematic analysis of T-cell receptor beta (TCR-β) clonotypes of the CD8+ CD57+ T-cell population, frequently deranged in PNH, we show recurrent clonotypes in PNH patients but not in healthy controls: 11 of 16 patients shared at least 1 of 5 clonotypes, and a set of closely related clonotypes was present in 9 patients. The presence of T-cell clones bearing a set of highly homologous TCR-β molecules in most patients with hemolytic PNH is consistent with an immune process driven by the same (or similar) antigen(s)—probably a nonpeptide antigen, because patients sharing clonotypes do not all share identical HLA alleles. These data confirm that CD8+ CD57+ T cells play a role in PNH pathogenesis and provide strong new support to the hypothesis that the expansion of the GPI− blood cell population in PNH is due to selective damage to normal hematopoiesis mediated by an autoimmune attack against a nonpeptide antigen(s) that could be the GPI anchor itself.

Several factors support CLL cell survival in the microenvironment. Under different experimental conditions, IL21 can either induce apoptosis or promote CLL cell survival. To investigate mechanisms involved in the effects of IL21, we studied the ability of IL21 to modulate gene and miRNA expressions in CD40-activated CLL cells. IL21 was a major regulator of chemokine production in CLL cells and it modulated the expression of genes involved in cell movement, metabolism, survival and apoptosis. In particular, IL21 down-regulated the expression of the chemokine genes CCL4, CCL3, CCL3L1, CCL17, and CCL2, while it up-regulated the Th1-related CXCL9 and CXCL10. In addition, IL21 down-regulated the expression of genes encoding signaling molecules, such as CD40, DDR1 and PIK3CD. IL21 modulated a similar set of genes in CLL and normal B-cells (e.g. chemokine genes), whereas other genes, including MYC, TNF, E2F1, EGR2 and GAS-6, were regulated only in CLL cells. An integrated analysis of the miRNome and gene expression indicated that several miRNAs were under IL21 control and these could, in turn, influence the expression of potential target genes. We focused on hsa-miR-663b predicted to down-regulate several relevant genes. Transfection of hsa-miR-663b or its specific antagonist showed that this miRNA regulated CCL17, DDR1, PIK3CD and CD40 gene expression. Our data indicated that IL21 modulates the expression of genes mediating the crosstalk between CLL cells and their microenvironment and miRNAs may take part in this process.

We analyzed individual VH gene rearrangements in 55 consecutive B-chronic lymphocytic leukemia (B-CLL) patients collected from a northeastern region of Italy, stressing the possible differences related to geographic characteristics of the cohorts studied. Considering the percentage of somatic mutations present in the VH gene sequences and using the 98% cut-off value, 38 of the 55 B-CLL (69%) patients displayed somatic hypermutations and 17 (31%) had a germline configuration. Our results confirm and extend the observations of a bias in the use of certain VH, DH, and JH genes among B-CLL cells. The most frequently used VH genes were VH1-69 (12.7%) with VH3-23 (12.7%) and VH4-34 (10.9%). Collectively these genes accounted for 36.3% of the cases. In the mutated cases, the range of mutations varied from 2% to 15%, with a median of 6.5%. VH1-69 (7 cases, all unmutated) carried few mutations as opposed to VH3-23 (7 cases, 5 of which mutated), VH4-34 (6 cases, all mutated), and VH3-30 (5 cases, all mutated), which show a high load of mutations. D3 family genes were found frequently (38.1%) followed by D2 (27.2%) and D6 (18.1%). The individual D segment most frequently used was D3-3, which was present in 16.3% of cases. There was predominance of the JH4 gene (49%) followed by JH6 (40%). Analysis of the distribution of replacement and silent mutations in the mutated sequences using the method of Lossos showed in 39.4% of cases evidence of antigen selection in the framework region and/or complementary determining regions. In comparison with a recent study on B-CLL patients from the Mediterranean area, the VH4-34 gene was significantly overused in the mutated group at a percentage double that of the Italian cohort reported in this study (10.9% vs. 5%), but at a frequency similar to the entire Mediterranean region (10.7%). We also found an over-representation of VH1-69 usage in the germline group, at a frequency (12.7%) higher than previously described by the same authors (Italian 8%, Mediterranean 10.7%). On the contrary, VH3-07 and VH3-49 were not much used in our study (5.4% and 1.8%, respectively) compared with the Italian group (8% and 5.1%). In our study, VH3-23 gene segment was frequently expressed, at frequency as high as that of VH1-69, a finding in keeping with reported B-CLL Italian data, but higher than the entire series of the Mediterranean area (12.7% vs. 9.2%); VH3-21 gene, frequently expressed in northern European CLL but rarely in the Mediterranean area, was completely absent. This biased usage of VH family genes may reflect a geographic leukemic repertoire, perhaps owing to a peculiar genetic background, depending on variations in germline composition of the IgVH locus or to the effect of a potential environmental element less frequently encountered in different regions.

In the last two decades, many efforts have been made to better understand the biology of B-lymphoproliferative disorders through the knowledge of physiology and function of the postulated normal counterpart. The follicular mantle B-cells express a typical CD23+ IgM+ IgD+ phenotype and surround the germinal center area in secondary lymphoid organs. CD5+ B-cells with FM phenotype can be isolated from different sources and all share similar morphologic, phenotypic and functional features (small cells, scanty nucleus/cytoplasm ratio, unmutated VH genes, response to polyclonal activators but not to T independent antigens, production of "natural" antibodies). While the CD5+ B-cells predominate in fetal life, their number decreases with age. However, the CD5+ B-cells have been demonstrated to increase again in elderly both in man and mouse. This finding may explain the incidence of B-CLL and of MCL that are believed to represent the malignant transformation of the normal CD5+ B-cells, among elderly and middle aged individuals, respectively.

The aim of the study was to determine the safety and efficacy of the combination of fludarabine (FLU), cyclophosphamide (CY) and mitoxantrone (FLU/CY/MITO) in untreated follicular lymphomas (FL), Sixty patients with newly diagnosed stage II bulky to IV FL, median age 59 years (range 36-70), received FLU/CY/MITO regimen (FLU 25 mg/m2 days 1-3, CY 300 mg/m2 days 1-3, Mito 10 mg/m2 day 1). Patients received antibiotic oral prophylaxis during all treatments, and growth factors (G-CSF) when grade III granulocytopenia (WHO) occurred. The overall response rate was 87%: 46 patients achieved complete response (CR) (77%), 6 a partial response (10%) and 8 were non-responders. Fifty patients are surviving with a median observation time of 31 months. The 4-year estimated probability of overall survival and failure-free survival were 78.2% and 45% respectively. Thirty-five patients (58%) are still in CR. Sixty percent of patients experienced grade III-IV granulocytopenia. Two patients suffered grade III pulmonary infection and one grade III liver toxicity. In a subset of 46 patients, bcl-2 translocation was positive in bone marrow (BM) and/or peripheral blood (PB) of 36 patients. At the end of treatment, 25 of these patients had CR and 19 (76%) converted to polymerase chain reaction (PCR) negativity. FLU/CY/MITO regimen showed a high level of activity in follicular lymphoma. Toxicity, mainly hematological, was acceptable and the treatment was made feasible by the use of antibiotic prophylaxis and G-CSF. Significant non-hematological toxicities were seen, but no patients died. The conversion of bcl-2 from positive to negative by PCR in BM and/or PB suggests a possible role for this treatment in clearing minimal residual disease and improving patients' outcome.

The majority of splenic marginal zone lymphoma (SMZL) patients experience an indolent clinical course; however, some cases transform to a high-grade lymphoma. Cytogenetic analyses have shown that chromosome 7 is the most frequently altered chromosome and, in some cases, 7q deletion has been found as a single aberration, suggesting its association with the development of SMZL. We studied one patient showing clinical features of SMZL with an aggressive course. Immunophenotypic, conventional and molecular cytogenetic techniques were applied to support the diagnosis. The immunophenotype of peripheral blood mononuclear cells showed the presence of 90% B-lymphocytes. Cytogenetic analysis indicated the presence of a stem-line lacking normal chromosomes 7, but showing a der(7) and a ring, and a side-line with additional aberrations: t(2;22), add(8). Fluorescence in situ hybridization analysis revealed a loss of the 7q32 region. Nonclonal rearrangements involving chromosome 7 were also detected. Chromosome 7 rearrangements were studied to investigate their evolution during the development of the pathology. We have shown that in this patient both chromosomes 7 underwent different rearrangements leading to a loss of the 7q32 region and that the ring chromosome originated from chromosome 7 and was associated with a t(7;7) (p22;q31). We conclude that not only the 7q deletion but also the proneness of chromosome 7 to rearrange might have played a role in the progression of this SMZL.

Two decades after the discovery of the first animal microRNA (miRNA), the number of miRNAs in animal genomes remains a vexing question. Here, we report findings from analyzing 1,323 short RNA sequencing samples (RNA-seq) from 13 different human tissue types. Using stringent thresholding criteria, we identified 3,707 statistically significant novel mature miRNAs at a false discovery rate of ≤0.05 arising from 3,494 novel precursors; 91.5% of these novel miRNAs were identified independently in 10 or more of the processed samples. Analysis of these novel miRNAs revealed tissue-specific dependencies and a commensurate low Jaccard similarity index in intertissue comparisons. Of these novel miRNAs, 1,657 (45%) were identified in 43 datasets that were generated by cross-linking followed by Argonaute immunoprecipitation and sequencing (Ago CLIP-seq) and represented 3 of the 13 tissues, indicating that these miRNAs are active in the RNA interference pathway. Moreover, experimental investigation through stem-loop PCR of a random collection of newly discovered miRNAs in 12 cell lines representing 5 tissues confirmed their presence and tissue dependence. Among the newly identified miRNAs are many novel miRNA clusters, new members of known miRNA clusters, previously unreported products from uncharacterized arms of miRNA precursors, and previously unrecognized paralogues of functionally important miRNA families (e.g., miR-15/107). Examination of the sequence conservation across vertebrate and invertebrate organisms showed 56.7% of the newly discovered miRNAs to be human-specific whereas the majority (94.4%) are primate lineage-specific. Our findings suggest that the repertoire of human miRNAs is far more extensive than currently represented by public repositories and that there is a significant number of lineage- and/or tissue-specific miRNAs that are uncharacterized.

Micro-RNAs ( miR genes) are a large family of highly conserved noncoding genes thought to be involved in temporal and tissue-specific gene regulation. MiRs are transcribed as short hairpin precursors (≈70 nt) and are processed into active 21- to 22-nt RNAs by Dicer, a ribonuclease that recognizes target mRNAs via base-pairing interactions. Here we show that miR15 and miR16 are located at chromosome 13q14, a region deleted in more than half of B cell chronic lymphocytic leukemias (B-CLL). Detailed deletion and expression analysis shows that miR15 and miR16 are located within a 30-kb region of loss in CLL, and that both genes are deleted or down-regulated in the majority (≈68%) of CLL cases.

Using immunofluorescence, RT-PCR, and Western blotting, we have demonstrated the ability of human B cells to express CD4. In each of the 10 lymphoblastoid cell lines (LCL) tested there was variable, but definite, proportion of CD4-positive B cells. Expression of CD4 was related to the cell cycle; CD4 was expressed in the G1 phase and continued at later phases of the cell cycle. CD4 was in part internalized and degraded by the LCL B cells. Surface CD4 was associated to lck and its crosslinking resulted in tyrosine phosphorylation. Additional experiments conducted on freshly prepared tonsillar B cells demonstrated that CD4 was expressed by large activated B cells, but not by small resting B cells. However, not all the activated tonsillar B cells had surface CD4 since germinal center cells were CD4-negative. Crosslinking of CD4 on LCL or on tonsillar activated B cells resulted in apoptosis in vitro, a finding that indicates the capacity of CD4 to deliver functional signals to B cells and to play a regulatory function in their physiology. Exposure of CD4 expressing B cells to gp120 under conditions that resulted in CD4 crosslinking also caused apoptosis suggesting some implications for the pathophysiology of AIDS.

Reactive oxygen species (ROS) are metabolism by-products that may act as signaling molecules to sustain tumor growth. Antioxidants have been used to impair cancer cell survival. Our goal was to determine the mechanisms involved in the response to antioxidants of a human cell culture (PT4) containing glioblastoma (GBM) tumorigenic initiating cells (TICs). ROS production in the absence or presence of N-acetyl-L-cysteine (NAC), tiron, and trolox was evaluated by flow cytometry (FCM). The effects of these antioxidants on cell survival and apoptosis were evaluated by 3-(4,5-Dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide assay (MTT) and FCM. The biological processes modulated by these drugs were determined by oligonucleotide microarray gene expression profiling. Our results showed that NAC, tiron and trolox impaired PT4 cell survival, had minor effects on ROS levels and caused wide deregulation of cell cycle genes. Furthermore, tiron and trolox caused inhibition of cell survival in two additional cell cultures containing TICs, FO-1 and MM1, established from a melanoma and a mesothelioma patient, respectively. NAC, instead, impaired survival of the MM1 cells but not of the FO-1 cells. However, when used in combination, NAC enhanced the inhibitory effect of PLX4032 (BRAF V600E inhibitor) and Gefitinib (EGFR inhibitor), on FO-1 and PT4 cell survival. Collectively, NAC, tiron and trolox modulated gene expression and impaired the growth of cultures containing TICs primarily by inhibiting cell cycle progression.

Heterogeneous expression of the collagen receptor DDR1 in chronic lymphocytic leukaemia and correlation with progression

Total body computed tomography (TB-CT) scan is not mandatory in the diagnostic/staging algorithm of chronic lymphocytic leukemia (CLL). The aim of this study was to determine the value and prognostic significance of TB-CT scan in early stage CLL patients. Baseline TB-CT scan was performed in 240 Binet stage A CLL patients (179 Rai low- and 61 Rai intermediate-risk) included in a prospective multicenter observational study (clinicaltrial.gov ID:NCT00917549). The cohort included 69 clinical monoclonal B lymphocytosis (cMBLs). Patients were restaged considering only radiological data. Following TB-CT scans, 20% of cases reclassified as radiologic Binet (r-Binet) stage B. r-Binet B patients showed a higher incidence of unfavorable cytogenetic abnormalities (P = 0.027), as well as a shorter PFS (P = 0.001). At multivariate analysis, r-Binet stage [HR = 2.48; P = 0.004] and IGHV mutational status [HR = 3.01; P = 0.002] retained an independent predictive value for PFS. Among 179 Rai low-risk cases, 100 were redefined as r-Rai intermediate-risk based upon TB-CT scan data, showing a higher rate of cases with higher ZAP-70 (P = 0.033) and CD38 expression (P = 0.029) and β2-microglobulin levels (P

In this study the mode of expression of CD5 by human tonsillar CD5- B cells after stimulation with different agents was investigated. Resting B cells were separated into CD5+ and CD5- cells and the two cell fractions exposed to phorbol 12-myristate 13-acetate (PMA). CD5- B cells expressed CD5 and maximum CD5 expression was achieved after approximately 60 h of culture. Based upon the proportions of cells that express CD5 as well as those of the cells surviving in culture, it was calculated that 15-25% of the total CD5- B cells were induced to express CD5. Unlike CD5- B cells, CD5+ B cells proliferated vigorously in response to PMA as assessed by [3H]thymidine incorporation and cell cycle analysis in vitro. However, the expression of CD5 by CD5- B cells was not related to the selective expansion of some CD5+ B cells left over as contaminant cells since this occurred in the absence of cell proliferation. Upon exposure to PMA, CD5- B cells remained in the G0-G1 phases of the cell cycle and did not express the Ki67 antigen or incorporate [3H]thymidine. Furthermore, mitomycin C treatment of the CD5- B cells did not prevent CD5 expression. Phenotypic studies disclosed that CD5+ B cells but not CD5- B cells expressed CD39. This finding offered the opportunity to carry out an additional control experiment. Separation of the two populations according to the expression of CD39 confirmed the finding obtained by fractionating the cells into CD5+ and CD5- B cells. The cells induced to express CD5 also expressed CD38 that was not detected on resting CD5- B cells. In this respect, the CD5- B cells that converted into CD5+ cells (inducible CD5+ B cells) resembled the cells from the CD5+ B cell fractions that up-regulated CD5 and also expressed CD38 upon exposure to PMA alone. Another example of coordinate expression of these two antigens was the finding that exposure to PMA in the presence of recombinant interleukin-4 (rIL-4) resulted in inhibition of the expression of CD5 and CD38. Although virtually all of the tonsillar CD5- B cells expressed the CD69 activation marker, no cells other than those co-expressing CD5 and CD38 were induced to express CD5 by PMA alone. Resting CD5- B cells failed to express CD5 and/or CD38 when cultured with PMA in the presence of EL4 T cells and IL-4-free T cell supernatants.(ABSTRACT TRUNCATED AT 400 WORDS)

The present study demonstrates that an agonistic anti-CD38 monoclonal antibody (mAb) (IB4) is capable of preventing apoptosis of human tonsillar germinal center (GC) B cells as measured by either morphological methods on Giemsa-stained cytospin preparations or flow cytometry on propidium iodide-stained cells. Two other anti-CD38 mAb (Leu-17 and OKT10) consistently failed to prevent apoptosis in the same cells, even when tested over a wide range of concentrations. Furthermore, exposure of GC B cells to IB4 mAb up-regulates the bcl-2 proto-oncogene product in a manner similar to that observed with CD40 ligand (CD40L). The ability of IB4 mAb to prevent apoptosis of GC B cells was inferior to that of both anti-CD40 mAb and CD40L. No synergistic or additive effects were observed when IB4 mAb was used together with CD40L. Unlike anti-CD40 mAb or CD40L, IB4 mAb neither induced a proliferation of GC B cells nor increased their proliferative response to anti-CD40, CD40L or recombinant interleukin-4, used alone or in combination. The present results are consistent with the recent findings on either the feature of the CD38 molecules to deliver activation signals and on the mechanisms of selection of B cells that operates in the GC.

The marine diatoms Cocconeis scutellum Ehrenberg (Bacillariophyceae) are known to trigger apoptosis in the androgenic gland of the Mediterranean crustacean Hippolyte inermis Leach (Decapoda), affecting the shrimp's sex reversal.The aim of this study was to evaluate a possible apoptotic effect of extracts and fractions from these microalgae also on human tissues.The chemical profile of C. scutellum was determined by gas chromatography-mass spectrometry (GC-MS) and, afterwards, organic extracts and fractions from the diatoms were used to treat to breast cancer BT20 cells. Double labeling with annexin V-FITC and isotonic propidium iodide (PI) along with flow cytometry analysis enabled the evaluate of cell apoptosis and viability, whereas hypotonic PI staining was used to analyze the cell cycle in BT20 lines. The involvement of specific caspases was studied by Western blotting.Results demonstrated that the diethyl ether extract and, in particular, fraction 3, the richest fraction in eicosapentaenoic acid (EPA) from the diethyl ether extract, selectively induced apoptosis (up to 89.2% at 1 μg/well of fraction 3) and decreased viability in BT20 cells. The apoptotic effect was displayed in a concentration and time-dependent manner, by activating caspases-8 and 3, and arresting the progression of the cell cycle from S to G2-M phase. EPA alone showed similar apoptotic effects in BT20 cells.The study demonstrates the apoptotic activity of C. scutellum diatoms on breast cancer cells and suggests their potential use as a source of apoptotic compounds.

In this study we identify and characterize a subset of human peripheral blood T cells, present in all individuals, that has features previously described for T cells either separately or in special circumstances. These cells are found in purified suspensions of resting peripheral blood lymphocytes within the CD8+ T lymphocytes, express alpha beta T cell receptor (TCR), and can be identified and isolated because of high-density expression of surface CD11b (TCR alpha beta +/CD3+/CD8+/CD11b+ cells). They coexpress constitutively the IL-2 receptor beta chain, Fc gamma RIIIA, and CD56. Although they do not mediate spontaneous cytotoxicity, CD3+/CD8+/CD11b+ cells have cytotoxic potential, demonstrated in redirected cytotoxicity assays with P815 target cells in the presence of anti-Fc gamma RIII (CD16) or anti-CD3 monoclonal antibodies. Stimulation of CD3+/CD8+/CD11b+ cells with rIL-2 induces proliferation, cytotoxicity against NK-sensitive and NK-resistant target cells, and expression of surface activation antigens, including IL-2 receptor alpha chain (CD25). CD3+/CD8+/CD16+/CD56+ cell clones with cytotoxic functions including those mediated by engagement of surface CD16 were obtained by limiting-dilution cloning of purified CD3+/CD8+/CD11b+ cells in the presence of rIL-2 and autologous feeder cells. Our data support the hypothesis that the CD3+/CD8+/CD11b+/CD16+ cells represent a discrete peripheral blood lymphocyte subset that could be the physiological counterpart of that expanded in several pathological conditions and in large granular lymphocyte lymphocytosis.

The importance of post-transcriptional mechanisms for the regulation of the homoeostasis of the immune system and the response to challenge by microorganisms is becoming increasingly appreciated. We investigated the contribution of microRNAs (miRNAs) to macrophage activation induced by lipopolysaccharide (LPS). We first observed that Dicer knockout in bone marrow-derived macrophages (BMDMs) increases the LPS-induced expression of some inflammation mediators. miRNA microarray analysis in BMDMs revealed that LPS significantly induces the expression of a single miRNA, miR-155, and this induction depends on enhanced miR-155 maturation from its precursors. The single-strand RNA-binding protein KH-type splicing regulatory protein (KSRP) binds to the terminal loop of miR-155 precursors and promotes their maturation. Both inhibition of miR-155 and KSRP knockdown enhance the LPS-induced expression of select inflammation mediators, and the effect of KSRP knockdown is reverted by mature miR-155. Our studies unveil the existence of an LPS-dependent post-transcriptional regulation of miR-155 biogenesis. Once induced, miR-155 finely tunes the expression of select inflammation mediators in response to LPS.

Adult T-lymphoblastic lymphoma is rare and has a poor prognosis. In the 80s, following the introduction of sequential, intensified chemotherapy, complete remissions in the order of 75%-95% of treated patients, were achieved. However, several patients, namely those with advanced disease, continued to relapse either in remission or during maintenance therapy. Moreover, all these early studies were not able to detect any valuable prognostic index to predict the outcome. In an attempt to reduce the relapse rate, upfront autologous stem cell transplantation in patients in complete remission was introduced. The results obtained with this approach were quite homogeneous, indicating a probability of disease-free survival of about 65%-75% and an overall survival rate of 60%. Successive therapies designed since 2000 were able to obtain complete remissions of above 90%, with a relapse rate in the order of 30% and an overall survival comparable to that obtained with the transplant procedure. Yet, these studies were also unable to detect valuable prognostic factors predictive of the outcome. Moreover, no study on the biologic profile of the disease has been developed. To improve the prognosis of T-lymphoblastic lymphoma it seems necessary to create national registries to collect both clinical and biological data of all lymphoblastic lymphoma patients. In this way it will be possible to reach critical numbers of data with which valid statistical analysis may be performed that is able to detect factors influencing the outcome. Moreover, subsets of patients needing intensified procedures such as stem cell transplant may be detected at diagnosis.

To the editor: Hematologic relapse after an allogeneic hemopoietic stem cell transplantation (HSCT) in patients with acute leukemia is associated with a poor outcome, despite further cell therapy in the form of donor lymphocyte infusions (DLIs).[1][1] This has been taken as evidence that acute

Background: Over the last two decades several phenotypic, molecular, and chromosomal markers have been identified that are significantly associated with the prognosis of CLL patients. Therefore, clinicians managing CLL patients would benefit from a simplified prognostic index. Methods: We analyzed prospectively collected data from 337 Binet A CLL patients enrolled in Italian the O-CLL1-GISL protocol with the aim of developing scores capable of predicting treatment free survival (TFS). Factors independently associated with TFS were included in the prognostic indexes. To account for differences in the magnitude of the association between the individual independent factors and TFS, we assigned a weighted risk score to each factor based on ranges of their corresponding hazard ratios (HRs) (i.e., 1 point for HR 1.1-1.9; 2 points for HR 2.0-2.9, etc.). The total risk score was then calculated by the sum of the ratings of each factor on individual basis. Risk groups were identified combining risk categories with a non-statistically different TFS. Results: We developed two scores based on weighted multivariable models: the first included clinical and laboratory parameters [clinical score (c-score)], while the second was based on biological markers [biological score (b-score)] (Table 1). The c-score allowed to predict the TFS of patients through the combination of Rai stage, b2-microglobulin and absolute lymphocyte count (ALC), while the b-score predicted TFS by IGHV mutational status and CD38 expression. The c-score showed a C-statistic of 0.72, while the b-score was 0.67, although cases stratified according to the b-score showed a more specific mRNA/microRNA profile. When the two scores were forced in a multivariate analysis, both showed an independent predictive value on TFS with a similar HR, demonstrating their complementarity. Thus, we attempted to integrate the two scores performing a further multivariate analysis in which all parameters, significantly associated with TFS at univariate analysis, were tested (Table 1). ALC, Rai stage, b2-microglobulin together with IGHV mutational status, resulted independently associated with TFS. We constructed a weighted score [comprehensive score (co-score)], including all the above 4 variables, which allowed the identification of 3 different risk groups with significantly different TFS (Figure 1). The C-statistic of the g-score was 0.75, showing a better concordance than the other two scores. Moreover, its validity was externally validated in a series of 297 newly diagnosed Binet A CLL patients from the Mayo Clinic, USA. Conclusions: Using this multistep process and external validation, we developed a score with high discriminatory power and predictive significance on the individual patient level. Table 1. Univariate and multivariate Cox proportional Hazards Models Variable Univariate analysis Multivariate analysis Clinical model Biological model Comprehensive model HR (95% CI) P HR (95% CI) P score HR (95% CI) P score HR (95% CI) P score Age (years) 60 1.12 (0.73-1.74) 0.59 - - - - - - - - - Sex Male/Female 0.93 (0.6-1.44) 0.93 - - - - - - - - - Rai stage 0/I-II 2.30 (1.47-3.50) 10 3.43 (1.99-5.92) Figure 1. TFS according to comprehensive progression risk score. Figure 1. TFS according to comprehensive progression risk score. Disclosures Shanafelt: Cephalon: Research Funding; Glaxo-Smith-Kline: Research Funding; Genentech: Research Funding; Hospira: Research Funding; Celgene: Research Funding; Jannsen: Research Funding; Polyphenon E International: Research Funding; Pharmacyclics: Research Funding. Kay:Genentech: Research Funding; Celgene Corporation: Membership on an entity's Board of Directors or advisory committees, Research Funding; Gilead: Membership on an entity's Board of Directors or advisory committees, Research Funding; Hospira: Research Funding; Tolero Pharma: Research Funding; Pharmacyclics: Research Funding.

Interleukin-21 (IL-21) is a member of the IL-2 cytokine family, which mediates proliferation or growth arrest and apoptosis of normal B cells, depending on their activation state. Here we demonstrate that surface IL-21 receptor (R) is expressed at variable levels by chronic lymphocytic leukemia (CLL) B cells freshly isolated from 33 different patients. IL-21R expression was up-regulated following cell stimulation via surface CD40. Therefore, IL-21 effects were more evident in CD40-activated CLL B cells. IL-21 induced an early signaling cascade in CLL B cells, which included JAK-1 and JAK-3 autophosphorylation and tyrosine phosphorylation of STAT-1, STAT-3, and STAT-5. IL-21 signaling failed to stimulate CLL B-cell proliferation, but induced their apoptosis. In addition, IL-21 counteracted the proliferative and antiapoptotic signals delivered by IL-15 to CLL B cells. IL-21-mediated apoptosis involved activation of caspase-8 and caspase-3, cleavage of Bid to its active form t-Bid, and cleavage of PARP and of p27Kip-1. Recent data indicate that CLL B cells require interaction with the microenvironment for their survival and expansion. The present findings thus provide a set of new mechanisms involved in the balance between cell-survival and apoptotic signals in CLL B cells.

Repair of some oxidized purines such as 8-oxo-7,8-dihydroguanine (8-oxoG) is inefficient in human cells in comparison to repair of other major endogenous lesions (e.g. uracil, abasic sites or oxidized pyrimidines). This is due to the poor catalytic properties of hOGG1, the major DNA glycosylase involved in 8-oxoG removal. The formamidopyrimidine DNA glycosylase (FPG) protein from E. coli is endowed with a potent 8-oxoG glycolytic activity coupled with a beta,delta-AP lyase. In this study, we have expressed FPG fused to the enhanced green fluorescent protein (EGFP) in human bladder cells to accelerate the repair of oxidative DNA damage. Cells expressing the fusion protein EGFP-FPG repaired 8-oxoG and AP sites at accelerated rates, in particular via the single-nucleotide insertion base excision repair (BER) pathway and were resistant to mutagenicity of the oxidizing carcinogen potassium bromate. FPG may stably protect human cells from some harmful effects of oxidative DNA damage.

Repair of 8-oxo-7,8-dihydroguanine (8-oxoG) is inefficient in human cells due to the poor catalytic properties of hOGG1, the major DNA glycosylase involved in the removal of this oxidized base. The S3 ribosomal/repair protein from Drosophila melanogaster (dS3) is endowed with a potent 8-oxoG glycolytic activity coupled with a beta, delta-AP lyase. In vitro repair experiments have shown that pure GST-tagged dS3 can stimulate a40-fold increase in the rate of 8-oxoG repair by human cell extracts. In this study, we expressed dS3 fused to the Enhanced Green Fluorescent Protein (EGFP) in T24 human bladder cells in order to accelerate the repair of 8-oxoG in vivo. Limiting dilution and Fluorescence-Activated Cell Sorting (FACS) were used in an effort to isolate cells with elevated EGFP-dS3 expression; however, the cells that were isolated invariably had severe growth impairment. Curiously, EGFP-dS3 expression was slightly increased after recovering cells from liquid nitrogen, but it was not possible under those conditions to achieve a significant acceleration of 8-oxoG repair. The data confirm and extend our previous results obtained with Chinese hamster CHO cells and indicate that elevated expression of dS3 may be toxic to at least some types of mammalian cells, thus limiting its use in vivo as a protective factor against oxidative DNA damage.

Due to its relatively slow clinical progression, B cell chronic lymphocytic leukemia (B-CLL) is classically described as a disease of accumulation rather than proliferation. However, evidence for various forms of clonal evolution suggests that B-CLL clones may be more dynamic than previously assumed. We used a nonradioactive, stable isotopic labeling method to measure B-CLL cell kinetics in vivo. Nineteen patients drank an aliquot of deuterated water (2H2O) daily for 84 days, and 2H incorporation into the deoxyribose moiety of DNA of newly divided B-CLL cells was measured by gas chromatography/mass spectrometry, during and after the labeling period. Birth rates were calculated from the kinetic profiles. Death rates were defined as the difference between calculated birth and growth rates. These analyses demonstrated that the leukemic cells of each patient had definable and often substantial birth rates, varying from 0.1% to greater than 1.0% of the entire clone per day. Those patients with birth rates greater than 0.35% per day were much more likely to exhibit active or to develop progressive disease than those with lower birth rates Thus, B-CLL is not a static disease that results simply from accumulation of long-lived lymphocytes. Rather, it is a dynamic process composed also of cells that proliferate and die, often at appreciable levels. The extent to which this turnover occurs has not been previously appreciated. A correlation between birth rates and disease activity and progression appears to exist, which may help identify patients at risk for worsening disease in advance of clinical deterioration.

Chronic lymphocytic leukemia (CLL) is the most common human leukemia and is characterized by predominantly nondividing malignant B cells overexpressing the antiapoptotic B cell lymphoma 2 (Bcl2) protein. miR-15a and miR-16-1 are deleted or down-regulated in the majority of CLLs. Here, we demonstrate that miR-15a and miR-16-1 expression is inversely correlated to Bcl2 expression in CLL and that both microRNAs negatively regulate Bcl2 at a posttranscriptional level. BCL2 repression by these microRNAs induces apoptopsis in a leukemic cell line model. Therefore, miR-15 and miR-16 are natural antisense Bcl2 interactors that could be used for therapy of Bcl2-overexpressing tumors.

Peripheral T-cell lymphoma not otherwise specified (PTCL/NOS) is a rare non Hodgkin lymphoma characterized by heterogeneous morphologic and phenotypic features, aggressive clinical behavior, poor response to conventional treatments and dismal prognosis. Its molecular basis and relationships to normal T-cells are still unclear. We performed gene expression profiling of 17 PTCL/NOS cases, collected at diagnosis before any treatment, and 20 samples of normal T-lymphocytes. The comparison of the gene expression profiles of PTCL/NOS and purified normal T-cell subpopulations, including CD4+, CD8+, resting (HLA-DR-), and activated (HLA-DR+) elements, shows that PTCLs/NOS are more related to activated peripheral T-lymphocytes either CD4+ or CD8+, suggesting derivation from these compartments. Notably, immunohistochemistry on routine sections by using anti-CD4 and CD8 antibodies does not vicariate molecular analysis, as there is no correspondence between the global gene expression profile and CD4/CD8 antigen positivity. When compared with normal T-cells, PTCLs/NOS displayed a remarkable deregulation of functional programs often involved in tumorigenesis, such as apoptosis, proliferation, cell adhesion, and matrix remodeling. In addition, our analyses identified several genes that are specifically expressed in PTCLs/NOS. Their expression was confirmed at the protein level by immunohistochemical analysis of tissue micro-arrays including 160 primary PTCL/NOS cases. We applied several different markers that provided significant information as concerns the ectopic, paraphysiologic or stromal expression of the proteins corresponding to the deregulated genes. Among others, PTCLs/NOS aberrantly express CYR61, a molecule involved in drug resistance, and PDGFRA, a tyrosine kinase receptor whose deregulation is often related to a malignant phenotype. Notably, we demonstrated the constitutive activation of PDGFRA in the majority of cases - as indicated by its phosphorylation. Finally, we showed that imatinib mesylate significantly reduces PTCL/NOS primary cells viability after in vitro exposure at 1 mM concentration, independently from their sensitivity to conventional cytotoxic agents. These results are provided with biological implications relevant to the pathogenesis of the tumor, as well as for its clinical management.

Little is known about the expression levels or function of micro-RNAs (miRNAs) in normal and neoplastic cells, although it is becoming clear that miRNAs play important roles in the regulation of gene expression during development [Ambros, V. (2003) Cell 113, 673–676; McManus, M. T. (2003) Semin. Cancer Biol. 13, 253–258]. We now report the genomewide expression profiling of miRNAs in human B cell chronic lymphocytic leukemia (CLL) by using a microarray containing hundreds of human precursor and mature miRNA oligonucleotide probes. This approach allowed us to identify significant differences in miRNome expression between CLL samples and normal CD5+ B cells; data were confirmed by Northern blot analyses and real-time RT-PCR. At least two distinct clusters of CLL samples can be identified that were associated with the presence or absence of Zap-70 expression, a predictor of early disease progression. Two miRNA signatures were associated with the presence or absence of mutations in the expressed Ig variableregion genes or with deletions at 13q14, respectively. These data suggest that miRNA expression patterns have relevance to the biological and clinical behavior of this leukemia.

We performed cytogenetic and molecular studies on an adult patient with refractory anemia with an excess of blasts with an add(11)(p15). Multicolor fluorescence in situ hybridization (FISH) identified the extra material on 11p as belonging to chromosome 15. Metaphase FISH with probes for chromosomes 5, 11, and 15 revealed a complex four-break rearrangement. Clone RP5-1173K1, containing exons 10-20 of the NUP98 gene, gave three fluorescence signals on the normal 11, the der(5), and the der(15). 3'-RACE-PCR identified an in-frame fusion between NUP98 and NSD1, which was confirmed by RT-PCR. Two different spliced forms, that is, NUP98 exon 11/NSD1 exon 6 and NUP98 exon 12/NSD1 exon 6, were detected. The reciprocal NSD1/NUP98 was not found. A dual-color experiment with RP5-1173K1 and CTC-549A4, spanning the entire NSD1 gene, indicated an insertion of NUP98 into the NSD1 locus. This is the first report of an adult with myelodysplastic syndrome (MDS) harboring an NUP98/NSD1 fusion resulting from insertion of 5'-NUP98 into the NSD1/5q35 locus.

B-cell chronic lymphocytic leukemia (B-CLL) is an accumulating disease of slowly proliferating cells. CD10 is not normally expressed on the surface of B-CLL cells. The aim of this study was to ascertain whether B-CLL cells, induced into apoptosis, expressed surface CD10, since a correlation between apoptosis and CD10 expression has been demonstrated.Peripheral blood cells from 31 untreated B-CLL patients were induced into apoptosis by etoposide, fludarabine or Ga(mu)-Ab treatment and tested for CD10 expression by flow cytometry. Normal CD5+ B cells were also induced into apoptosis and tested for CD10 expression.CD10 positive cells were absent in B-CLL cell suspensions, but were detected following in vitro culture, and their appearance paralleled that of apoptotic cells. Treatment with etoposide, fludarabine or Ga(mu)-Ab enhanced both apoptosis and CD10 expression. Inhibition of apoptosis by VAD-fmk or Ga(delta)-Ab prevented CD10 expression. Cell separation tests following induction of apoptosis demonstrated that CD10+ cells were apoptotic. CD10+ cells were observed in the peripheral blood of two patients within a few hours following fludarabine infusion. In another patient, who failed to respond, no CD10+ cells were seen. Expression of CD10 was observed also in normal CD5+ B cells when these were induced into apoptosis.This study demonstrates that B-CLL cells, as well as normal CD5+ B cells, become CD10+ following apoptosis induction in vitro. Some of the data obtained also suggest a use for CD10 to monitor apoptosis of B-CLL in a clinical setting.

B-cell chronic lymphocytic leukemia (B-CLL) results from the accumulation of monoclonal CD5+ B cells. Despite its homogeneity at cellular level, B-CLL is clinically heterogeneous. Clinical studies indicate that CD38+ B-CLL are characterized by a more aggressive clinical course than are CD38- B-CLL. On the basis of these studies and considering the established correlation between specific chromosome aberrations and the clinical course of B-CLL, it is possible that CD38+ B-CLL cases are also characterized by specific subsets of chromosomal alterations.Comparative genomic hybridization (CGH) was performed on purified B-cells from peripheral blood of 52 patients with B-CLL in order to detect chromosome imbalance. The immunophenotype of the patients, including CD38 expression, was also determined by flow cytometry. The results of CGH experiments were then compared with CD38 expression.We found a clear correlation between the presence of chromosomal imbalances and CD38 expression: 13/16 CD38+ cases had chromosome imbalances, most of them (12/13) correlated with a poor prognosis. Among the CD38- B-CLL patients, only 8/36 displayed chromosome imbalances; the only three cases with loss in 13q as a single aberration, considered a good prognostic marker, were in this group. Moreover, we found that cytogenetic alterations were also more complex in the CD38+ B-CLL subset, since 9/10 with two or more aberrations were in the CD38+ group.Collectively, the data reinforce the value of CD38 as a prognostic factor and indicate that genotypic/phenotypic features distinguish B-CLL subsets.

We read with great interest the paper by Bernal et al[1][1] on the ability of anti–human IgM antibodies to prevent spontaneous apoptosis of B-cell chronic lymphocytic leukemia (B-CLL) cells in vitro. These findings suggest that receptor engagement by certain antigens, perhaps autoantigens that are

Human tonsillar subepithelial B cells, which are a marginal zone-equivalent B cell subset, respond readily to T-independent type 2 antigens, but not to polyclonal B cell activators in vitro. In this study, subepithelial (SE) B cells were induced to proliferate and mature into plasma cells when co-cultured with activated T cells. The response of SE B cells was not observed when co-cultures were carried out in transwell chambers or in the presence of blocking anti-LFA-1 antibodies, demonstrating the need for a close T-B cell interaction. The presence of soluble CD40 also prevented the B cell response in vitro suggesting a pivotal role of CD40-CD40 ligand interactions. The data are discussed in terms of the T cell dependence of marginal zone (MZ) B cell response and the possible existence of various MZ B cell subsets.

We have previously characterized mouse H4 (mH4), a surface glycoprotein recognized by the C398.4A monoclonal antibody. We now show that C398.4A also binds its human putative homolog (hpH4). Both hpH4 and mH4 (1) are selectively expressed by activated T cells and mature thymocytes, (2) are disulfide-linked dimers of two chains (29/37 kDa in humans, 25/29 kDa in mice), whose N-deglycosylation produces a single band at 20 - 21 kDa, and (3) display a low association with CD4 and the TCR. The expression pattern of hpH4 and its biochemical features showed that it is different from other known activation molecules, and this was confirmed when analysis of the tryptic digest of the hpH4 29-kDa band by peptide mass searching using matrix-assisted laser desorption ionization mass spectrometry did not reveal any significant homology with other molecules. In normal lymphoid tissue, hpH4 is expressed by T cells located at the periphery of lymph node germinal centers and paracortical areas. In T cell neoplasia, expression of hpH4 clusters with a subset of peripheral T cell lymphomas with a large-cell component, and with cases of angioimmunoblastic T cell lymphomas. Overall, these data provide evidence for a novel T cell activation molecule that could help in the phenotypic categorization of T cell malignancies.