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1.
Br J Haematol ; 2024 Jul 08.
Artículo en Inglés | MEDLINE | ID: mdl-38977858

RESUMEN

For over a century, the need to identify malaria in the peripheral blood has been the driving force behind the development of fundamental clinical microscopy techniques. In the study by Moysis et al., artificial intelligence-based model was utilized to identify and provide quantitative morphological characteristics of red blood cells typical to severe malaria anaemia, irrespective to the actual presence of visible parasites. Commentary on: Moysis et al. Leveraging deep learning for detecting red blood cell morphological changes in blood films from children with severe malaria anaemia. Br J Haematol 2024 (Online ahead of print). doi: 10.1111/bjh.19599.

2.
Mod Pathol ; : 100542, 2024 Jun 17.
Artículo en Inglés | MEDLINE | ID: mdl-38897451

RESUMEN

Bone marrow aspiration (BMA) smear analysis is essential for diagnosis, treatment and monitoring of a variety of benign and neoplastic hematological conditions. Currently this analysis is performed by manual microscopy. We conducted a multi-center study to validate a computational microscopy approach with an artificial intelligence (AI)-driven decision support system. A total of 795 BMA specimens (615 Romanowsky-stained and 180 Prussian blue-stained) from patients with neoplastic and other clinical conditions were analyzed, comparing the performance of the Scopio Labs X100 Full Field BMA system (test method) with manual microscopy (reference method). The system provided an average of 1385±536 (range 0-3131) cells per specimen for analysis. An average of 39.98±19.64 fields of view (range 0-140) per specimen were selected by the system for analysis, of them 87±21% (range 0-100%) were accepted by the qualified operators. These regions were included in an average of 17.62±7.24 regions of interest (range 1-50) per specimen. The efficiency, sensitivity, and specificity for primary and secondary marrow aspirate characteristics (maturation, morphology, and count assessment), as well as overall inter-user agreement, were evaluated. The test method showed high correlation with the reference method for comprehensive BMA evaluation, both on Romanowsky (90.85% efficiency, 81.61% sensitivity; specificity 92.88%) and Prussian blue (90.0% efficiency, 81.94% sensitivity; 93.38% specificity) stained samples. The overall agreement between the test and reference method for BMA assessment was 91.1%. For repeatability and reproducibility, all standard deviations and coefficients of variation values were below the pre-defined acceptance criteria both for discrete measurements (CV below 20%) and for differential measurements (SD below 5%). The high degree of correlation between the digital decision support system and manual microscopy demonstrates the potential of this system to provide a high-quality, accurate digital BMA analysis, -expediting expert review and diagnosis of BMA specimens, with practical applications including remote BMA evaluation, and possibly new opportunities for the research of normal and neoplastic hematopoiesis.

3.
Cancers (Basel) ; 15(23)2023 Nov 28.
Artículo en Inglés | MEDLINE | ID: mdl-38067314

RESUMEN

Chimeric Antigen Receptor T-cell (CAR T) therapy has become the preferable treatment in relapsed/refractory diffuse large B-cell lymphomas (DLBCL) patients. Detection of CAR Ts in peripheral blood smear (PBS) is challenging due to insufficient data regarding their morphology and low sensitivity. The morphological evolution of CAR Ts along their production process, and in patients, was established by Full-Field Morphology (FFM), a novel digital microscopy approach that provides highly sensitive PBS analysis. At day 8 of production, 42.7 ± 10.8% of the CAR T transduced cells exhibited activated morphology compared with 9.3 ± 3.8% in untransduced cells. Moreover, engagement of transduced CAR Ts with target cells resulted in further morphological transformation into activated morphology (83 ± 5.6% of the cells). In patients, the average number of day 5 CAR Ts, and their sustained presence, were significantly higher in patients obtaining complete response. A high number of activated morphology CAR Ts at day 14 was associated with prolonged cytokine release storm. Overall, CAR Ts exhibited heterogeneous morphology, with the activated morphology attributed predominantly to transduced cells following engagement with target cells. Post-transfusion CAR T detection was associated with increased complete responses. FFM CAR T surveillance in PBS may serve as a simple inexpensive method to provide clinically relevant insights into this treatment modality.

4.
J Am Chem Soc ; 145(6): 3346-3360, 2023 02 15.
Artículo en Inglés | MEDLINE | ID: mdl-36738297

RESUMEN

Electrophiles for covalent inhibitors that are suitable for in vivo administration are rare. While acrylamides are prevalent in FDA-approved covalent drugs, chloroacetamides are considered too reactive for such purposes. We report sulfamate-based electrophiles that maintain chloroacetamide-like geometry with tunable reactivity. In the context of the BTK inhibitor ibrutinib, sulfamate analogues showed low reactivity with comparable potency in protein labeling, in vitro, and cellular kinase activity assays and were effective in a mouse model of CLL. In a second example, we converted a chloroacetamide Pin1 inhibitor to a potent and selective sulfamate acetamide with improved buffer stability. Finally, we show that sulfamate acetamides can be used for covalent ligand-directed release (CoLDR) chemistry, both for the generation of "turn-on" probes as well as for traceless ligand-directed site-specific labeling of proteins. Taken together, this chemistry represents a promising addition to the list of electrophiles suitable for in vivo covalent targeting.


Asunto(s)
Acetamidas , Inhibidores de Proteínas Quinasas , Ratones , Animales , Ligandos , Inhibidores de Proteínas Quinasas/farmacología
5.
Appl Clin Inform ; 13(5): 1108-1115, 2022 10.
Artículo en Inglés | MEDLINE | ID: mdl-36208622

RESUMEN

BACKGROUND: The demand for morphological diagnosis by peripheral blood smear (PBS) analysis with clearly defined turnaround times (TAT), coupled with a shortage of morphologists and increasing cost containment, is driving digitalization to the forefront of laboratory workflow. Labor-intensive manual PBS review affects weekend workflow with limited staff availability. The impact of remote analysis of PBS on the performance of hematology laboratories has not yet been assessed. OBJECTIVES: Following implementation of fully remote digital microscopy within our laboratory, we measured its impact on morphology workflow efficiency, TAT, and hours saved per month. METHODS: A retrospective study of the effects of remote PBS analysis on the morphology workflow in a tertiary medical center using the Scopio Labs X100 Full-Field PBS system was conducted. 10,704 PBS samples were analyzed pre-and post -implementation, over a 5-month period. Overall PBS workload, and average TAT of PBS samples over weekends and the first two weekdays were collected and evaluated. RESULTS: Remote weekend viewing resulted in a 15.8% reduction in the overall morphology TAT of the laboratory (p <0.03) over a 5-month period, despite similar overall workload. PBS analysis TAT on Fridays was reduced by 41.4% (p <0. 006), and by 59.1% on the first weekday (p <0.02). The additional hours incurred over the weekend were offset against a reduced need for double weekday shifts resulting in approximately 12.76 work hours saved per month. Internet links to clinically relevant cases are provided. CONCLUSION: The Scopio Labs Full-Field X100 PBS system with remote analysis capacity significantly reduced PBS TAT and improved the morphology workflow of the hematology laboratory. PBSs with significant clinical findings are now available for remote viewing by on-call clinicians located outside the medical center perimeter. Remote PBS viewing, coupled with the overall monthly cost savings, merit consideration for the implementation of full digitalization for remote PBS review.


Asunto(s)
Hematología , Laboratorios , Humanos , Flujo de Trabajo , Microscopía , Estudios Retrospectivos
6.
Biomedicines ; 10(9)2022 Sep 07.
Artículo en Inglés | MEDLINE | ID: mdl-36140319

RESUMEN

High-grade serous ovarian carcinoma (HGSOC) is the most common type of epithelial ovarian cancer. The majority of cases are diagnosed at advanced stages, when intraperitoneal (IP) spread has already occurred. Despite significant surgical and chemotherapeutic advances in HGSOC treatment over the past decades, survival rates with HGSOC have only modestly improved. Chimeric antigen receptor (CAR)-T cells enable T cells to directly bind to tumor-associated antigens in a major histocompatibility complex-independent manner, thereby inducing tumor rejection. While CAR-T cell therapy shows great promise in hematological malignancies, its use in solid tumors is limited. Therefore, innovative approaches are needed to increase the specificity of CAR-modified T cells against solid tumors. The aim of this study was to assess the efficacy and safety of intraperitoneal (IP) versus intravenous (IV) CAR-T cell therapy in the treatment of HGSOC. We constructed a CAR that targets the ErbB2/HER2 protein (ErbB2CAR), which is overexpressed in HGSOC, and evaluated the functionality of ErbB2CAR on ovarian cancer cell lines (OVCAR8, SKOV3, and NAR). Our findings show that an IP injection of ErbB2CAR-T cells to tumor-bearing mice led to disease remission and increased survival compared to the IV route. Moreover, we found that IP-injected ErbB2CART cells circulate to a lesser extent, making them safer for non-tumor tissues than IV-injected cells. Further supporting our findings, we show that the effect of ErbB2CAR-T cells on primary HGSOC tumors is correlated with ErbB2 expression. Together, these data demonstrate the advantages of an IP administration of CAR-T cells over IV administration, offering not only a safer strategy but also the potential for counteracting the effect of ErbB2CAR in HGSOC. Significance: IP-injected ErbB2CAR-T cells led to disease remission and increased survival compared to the IV route. These findings demonstrate the advantages of IP administration, offering a safe treatment strategy with the potential for counteracting the effect of ErbB2CAR in HGSOC.

7.
Front Immunol ; 13: 953660, 2022.
Artículo en Inglés | MEDLINE | ID: mdl-36016925

RESUMEN

Most chronic lymphocytic leukemia (CLL) clones express B-cell receptors (BcR) of both IgM/IgD isotypes; however, 5%-10% of CLL cases express isotype-switched immunoglobulin G (IgG). The early signaling and spatial patterning of the various BcRs at steady state and after activation are still fully unresolved. Herein, we show higher expression of the BcR signalosome elements and a more robust constitutive cell-intrinsic proximal BcR signaling in CLL with unmutated IGHV expressing IgM isotype (IgM U-CLL), compared with IGHV-mutated CLL (M-CLL) expressing either IgM or IgG isotypes. IgM in U-CLL is frequently located in the membrane plane in polarized patches, occasionally in caps, and sometimes inside the cells. Among M-CLL, IgM is scattered laterally in the membrane plane in a similar pattern as seen in normal B cells, whereas IgG is dispersed around the cell membrane in smaller clusters than in IgM U-CLL. Upon BcR engagement, both IgG and IgM expressing M-CLL showed attenuated signaling and only slight spatial reorganization dynamics of BcR microclusters and internalization, compared with the extensive reorganization and internalization of the BcR in IgM expressing U-CLL. The global gene signature of IgG M-CLL was closely related to that of IgM M-CLL rather than IgM U-CLL. Overall, we report fundamental differences in the basal composition, biochemical status, and spatial organization of the BcR in the three examined immunogenetic CLL subtypes that correlate with their clinical behavior. On the basis of our findings, IgG class-switched M-CLL likely represents the same disease as IgM M-CLL rather than a different biological and/or clinical entity.


Asunto(s)
Leucemia Linfocítica Crónica de Células B , Humanos , Inmunoglobulina G , Inmunoglobulina M , Leucemia Linfocítica Crónica de Células B/genética , Leucemia Linfocítica Crónica de Células B/metabolismo , Receptores de Antígenos de Linfocitos B/genética , Receptores de Antígenos de Linfocitos B/metabolismo , Transducción de Señal
8.
Acta Haematol ; 145(2): 184-192, 2022.
Artículo en Inglés | MEDLINE | ID: mdl-34727546

RESUMEN

INTRODUCTION: Cord blood (CB) is becoming a valuable source for stem cells utilized in a variety of cell therapy applications, as well as for newborn diagnostics. Some parameters of the CB cellular components can be provided by automated analyzers, while others, such as immature or aberrant cells, require blood film morphological assessment. The objectives of the study were to establish normal CB morphology and to determine the prevalence of morphologically aberrant leukocytes in CB. METHODS: We performed a comprehensive morphological analysis of 100 CB samples taken from healthy term and appropriate-for-gestational-age neonates born to healthy mothers, preterm neonates, neonates of diabetic mothers, and small-for-gestational-age neonates. Blood counts were assessed, and manual morphological analyses were performed by laboratory specialists. RESULTS: The manual differential count of normal CB samples established the following values: 47.8 ± 10.7% neutrophils, 31.2 ± 9.8% lymphocytes, 10.0 ± 4.0% monocytes, and 3.0 ± 2.5% eosinophils, with no significant sex-related differences. Blasts were observed in 44/100 samples with an average of 0.5 ± 0.7% per sample, and only a minor left shift was observed. There were significant populations of large granular lymphocytes (19.1 ± 10.6% of the total lymphocytes) and morphologically aberrant lymphocytes (12.4 ± 5.4% of the total lymphocytes) in the samples, irrespective of neonatal status. The differentials of preterm CB samples differ significantly from normal term CB samples, including the reverse of neutrophils/lymphocytes ratio, and the lack of basophils. CONCLUSIONS: Normal values and unique morphological features in the CB of neonates are described. The abundant morphologically aberrant lymphocytes in CB may represent an immature state of the immune system at birth.


Asunto(s)
Sangre Fetal , Leucocitos , Humanos , Recién Nacido , Recuento de Leucocitos , Prevalencia , Valores de Referencia
9.
Thromb J ; 19(1): 79, 2021 Nov 04.
Artículo en Inglés | MEDLINE | ID: mdl-34736472

RESUMEN

BACKGROUND: COVID-19 infection is associated with a hypercoagulable state. Severe COVID-19 patients present with high plasma fibrinogen levels, continuous deposition of fibrin and the presence of microthrombi in their lungs, accompanied by significant fibrinolysis, resulting in high D-dimer levels. Due to the role of FXIII in fibrin crosslinking and clot stabilization, we analyzed its activity levels and dynamics in COVID-19 patients hospitalized in the intensive care unit (ICU). METHODS: FXIII levels were measured in thirty four COVID-19 patients hospitalized in the ICU and in fourteen non-severe COVID-19 patients. FVIII levels were measured for comparison. Laboratory data and clinical variables were recorded. RESULTS: The average FXIII activity level in 34 ICU hospitalized COVID-19 patients was 69.9±33 %, significantly lower compared to an average of 120±20.9 % FXIII activity in 14 non-severe COVID-19 patients. FXIII activity levels were below the low normal value (< 79 % FXIII activity) in 74 % of the ICU hospitalized COVID-19 patients. In contrast, high FVIII activity was measured among all severe COVID-19 patients. Consecutive measurements, performed in fourteen ICU hospitalized COVID-19 patients, pointed to a significant decrease in FXIII activity from the average of 85.7±28.2 %, (which is in the normal range), to an average of 68.0±20.4 %, below the low normal range, within 6.4±3.4 days of ICU hospitalization. Liver functions did not differentiate between patients with low and normal FXIII activity. No inhibitor to FXIII activity was found in the plasma of severe COVID-19 patients. Levels of FXIII-A antigen correlated with FXIII activity, and were low in severe COVID-19 patients. CONCLUSIONS: Low FXIII activity levels were found in COVID-19 patients hospitalized in the ICU, with gradual decline during their hospitalization. A mechanism of consumption may account for the low FXIII activity in these patients.

10.
Int J Lab Hematol ; 43(6): 1408-1416, 2021 Dec.
Artículo en Inglés | MEDLINE | ID: mdl-34546630

RESUMEN

BACKGROUND: Current digital cell imaging systems perform peripheral blood smear (PBS) analysis in limited regions of the PBS and require the support of manual microscopy without achieving full digital microscopy. We report a multicenter study that validated the Scopio Labs X100 Full Field PBS, a novel digital imaging system that utilizes a full field view approach for cell recognition and classification, in a decision support system mode. METHODS: We analyzed 335 normal and 310 abnormal PBS from patients with various clinical conditions and compared the performance of Scopio's Full Field PBS as the test method, with manual PBS analysis as the reference method. Deming regression analysis was utilized for comparisons of WBC and platelet estimates. Measurements of WBC and platelet estimation accuracy along with the agreement on RBC morphology evaluation were performed. Reproducibility and repeatability (R&R) of the system were also evaluated. RESULTS: Scopio's Full Field PBS WBC accuracy was evaluated with an efficiency of 96.29%, sensitivity of 87.86%, and specificity of 97.62%. The agreement between the test and reference method for RBC morphology reached 99.77%, and the accuracy for platelet estimation resulted in an efficiency of 94.89%, sensitivity of 90.00%, and specificity of 96.28%, with successful R&R tests. The system enabled a comprehensive review of full field PBS as shown in representative samples. CONCLUSIONS: Scopio's Full Field PBS showed a high degree of correlation of all tested parameters with manual microscopy. The novel full field view of specimens facilitates the long-expected disengagement between the digital application and the manual microscope.


Asunto(s)
Inteligencia Artificial , Células Sanguíneas/patología , Procesamiento de Imagen Asistido por Computador , Recuento de Células Sanguíneas/métodos , Células Sanguíneas/citología , Humanos , Procesamiento de Imagen Asistido por Computador/métodos , Microscopía/métodos , Reproducibilidad de los Resultados
11.
Ther Adv Hematol ; 12: 20406207211035272, 2021.
Artículo en Inglés | MEDLINE | ID: mdl-34377384

RESUMEN

BACKGROUND: Daratumumab (Dara) is generally well tolerated, but is associated with increased risk of infection. METHODS: We investigated hypogammaglobinemia occurrence in different Dara-based regimens. Multiple myeloma (MM) patients were treated with ⩾2 cycles of Dara-based therapy during 2016-2020, mainly for relapsed/refractory disease. Data on patient characteristics, treatment regimens, polyclonal IgG (poly-IgG) and uninvolved free light chain (Un-FLC) levels during treatment, as well as predictors for hypogammaglobinemia and predictors for infections, were evaluated retrospectively. RESULTS: A total of 84 patients, median age 67.2 years, were included. Dara, mainly as ⩾2 line therapy (88.1%, n = 74), was combined with immunomodulating drugs (IMiDs) (53%), proteasome inhibitors (PIs) (15%), IMiDs-PIs (11%), or dexamethasone only (21%). Median treatment duration was 13 months. Median Poly-IgG levels at 0, 2, and 4 months were 7.1 g/l, 4.5 g/l, and 4 g/l, respectively, and remained low throughout treatment. Lower poly-IgG pre-Dara (p = 0.001) and Dara-PIs (±IMiDs) regimen were associated with lower poly-IgG levels at 4 months (p = 0.03). Only patients treated with Dara monotherapy had partial immune reconstitution, reflected by resumption of IgM levels. Most (85%) patients developed ⩾1 infections, mostly grade 1-2 respiratory (76%). A lower poly-IgG level post Dara (RR = 1.137 p = 0.026) predicted increased risk of any infection. Intravenous immunoglobulin (IVIG) was associated with a significant decrease in all infections. CONCLUSION: Relapsed MM patients treated with Dara, often experience persistent hypogammaglobinemia, irrespective of responsiveness to treatment. Infections, especially respiratory, are frequent and apparently related to low Poly-IgG levels. IVIG should be considered for reducing infections in these patients.

12.
Front Oncol ; 11: 646971, 2021.
Artículo en Inglés | MEDLINE | ID: mdl-34055615

RESUMEN

Proteolysis targeting chimeras (PROTACs) are small molecules that form ternary complexes between their target and E3 ligase, resulting in ubiquitination and proteasomal degradation of the target protein. Using our own designed Bruton's tyrosine kinase (BTK) PROTAC compounds, we show herein efficient BTK degradation in chronic lymphocytic leukemia (CLL) cells. The reversible non-covalent compound (NC-1) was the most potent and therefore we focused on this PROTAC to investigate its subsequent effects on the BCR pathway. NC-1 decreased baseline BTK phosphorylation as well as activation of BTK and other signaling molecules downstream of the BCR pathway, following IgM engagement. These effects were also obtained in samples from CLL patients with clinical resistance to ibrutinib and mutations at C481. NC-1 treatment further decreased baseline CD69 surface levels, completely abrogated its upregulation following IgM activation, decreased CLL cells migration toward SDF-1 and overcame stromal anti-apoptotic protection. In conclusion, our results indicate that targeting BTK using the PROTAC strategy could be a potential novel therapeutic approach for CLL.

15.
J Am Chem Soc ; 142(27): 11734-11742, 2020 07 08.
Artículo en Inglés | MEDLINE | ID: mdl-32369353

RESUMEN

Proteolysis targeting chimeras (PROTACs) represent an exciting inhibitory modality with many advantages, including substoichiometric degradation of targets. Their scope, though, is still limited to date by the requirement for a sufficiently potent target binder. A solution that proved useful in tackling challenging targets is the use of electrophiles to allow irreversible binding to the target. However, such binding will negate the catalytic nature of PROTACs. Reversible covalent PROTACs potentially offer the best of both worlds. They possess the potency and selectivity associated with the formation of the covalent bond, while being able to dissociate and regenerate once the protein target is degraded. Using Bruton's tyrosine kinase (BTK) as a clinically relevant model system, we show efficient degradation by noncovalent, irreversible covalent, and reversible covalent PROTACs, with <10 nM DC50's and >85% degradation. Our data suggest that part of the degradation by our irreversible covalent PROTACs is driven by reversible binding prior to covalent bond formation, while the reversible covalent PROTACs drive degradation primarily by covalent engagement. The PROTACs showed enhanced inhibition of B cell activation compared to ibrutinib and exhibit potent degradation of BTK in patient-derived primary chronic lymphocytic leukemia cells. The most potent reversible covalent PROTAC, RC-3, exhibited enhanced selectivity toward BTK compared to noncovalent and irreversible covalent PROTACs. These compounds may pave the way for the design of covalent PROTACs for a wide variety of challenging targets.

18.
Haematologica ; 102(5): 874-882, 2017 05.
Artículo en Inglés | MEDLINE | ID: mdl-28154084

RESUMEN

A novel therapeutic approach in cancer, attempting to stimulate host anti-tumor immunity, involves blocking of immune checkpoints. Lymphocyte activation gene 3 (LAG3) is an immune checkpoint receptor expressed on activated/exhausted T cells. When engaged by the major histocompatibility complex (MHC) class II molecules, LAG3 negatively regulates T-cell function, thereby contributing to tumor escape. Intriguingly, a soluble LAG3 variant activates both immune and malignant MHC class II-presenting cells. In the study herein, we examined the role of LAG3 in the pathogenesis of chronic lymphocytic leukemia, an MHC class II-presenting malignancy, and show that chronic lymphocytic leukemia cells express and secrete LAG3. High levels of surface and soluble LAG3 were associated with the unmutated immunoglobulin variable heavy chain leukemic subtype and a shorter median time from diagnosis to first treatment. Utilizing a mechanism mediated through MHC class II engagement, recombinant soluble LAG3-Ig fusion protein, LAG3-Fc, activated chronic lymphocytic leukemia cells, induced anti-apoptotic pathways and protected the cells from spontaneous apoptosis, effects mediated by SYK, BTK and MAPK signaling. Moreover, LAG3 blocking antibody enhanced in vitro T-cell activation. Our data suggest that soluble LAG3 promotes leukemic cell activation and anti-apoptotic effects through its engagement with MHC class II. Furthermore, MHC class II-presenting chronic lymphocytic leukemia cells may affect LAG3-presenting T cells and impose immune exhaustion on their microenvironment; hence, blocking LAG3-MHC class II interactions is a potential therapeutic target in chronic lymphocytic leukemia.


Asunto(s)
Antígenos CD/inmunología , Antígenos de Histocompatibilidad Clase II/inmunología , Leucemia Linfocítica Crónica de Células B/inmunología , Activación de Linfocitos/inmunología , Anticuerpos Bloqueadores/inmunología , Anticuerpos Bloqueadores/farmacología , Células Presentadoras de Antígenos/inmunología , Células Presentadoras de Antígenos/metabolismo , Antígenos CD/genética , Antígenos CD/metabolismo , Apoptosis/efectos de los fármacos , Apoptosis/inmunología , Antígenos de Histocompatibilidad Clase II/metabolismo , Humanos , Leucemia Linfocítica Crónica de Células B/tratamiento farmacológico , Leucemia Linfocítica Crónica de Células B/genética , Leucemia Linfocítica Crónica de Células B/metabolismo , Activación de Linfocitos/efectos de los fármacos , Activación de Linfocitos/genética , Terapia Molecular Dirigida/métodos , Unión Proteica/efectos de los fármacos , Transducción de Señal/efectos de los fármacos , Transducción de Señal/inmunología , Linfocitos T/inmunología , Linfocitos T/metabolismo , Proteína del Gen 3 de Activación de Linfocitos
19.
Haematologica ; 101(12): 1553-1562, 2016 12.
Artículo en Inglés | MEDLINE | ID: mdl-27443285

RESUMEN

I In the last decade, the B-cell receptor has emerged as a pivotal stimulus in the pathogenesis of chronic lymphocytic leukemia, and a very feasible therapeutic target in this disease. B-cell receptor responsiveness in chronic lymphocytic leukemia cells is heterogeneous among patients and correlates with aggressiveness of the disease. Here we show, for the first time, that SLP76, a key scaffold protein in T-cell receptor signaling, is ectopically expressed in chronic lymphocytic leukemia cells, with variable levels among patients, and correlates positively with unmutated immunoglobulin heavy chain variable gene status and ZAP-70 expression. We found that SLP76 was functionally active in chronic lymphocytic leukemia cells. A SYK-dependent basal level of phosphorylated SLP76 exists in the cells, and upon B-cell receptor engagement, SLP76 tyrosine phosphorylation is significantly enhanced concomitantly with increased physical association with BTK. B-cell receptor-induced SLP76 phosphorylation is mediated by upstream signaling events involving LCK and SYK. Knockdown of SLP76 in the cells resulted in decreased induction of BTK, PLCγ2 and IκB phosphorylation, as well as cell viability after B-cell receptor activation with anti-IgM. Consistent with our biochemical findings, high total SLP76 expression in chronic lymphocytic leukemia cells correlated with a more aggressive disease course. IN CONCLUSION: SLP76 is ectopically expressed in chronic lymphocytic leukemia cells where it plays a role in B-cell receptor signaling.


Asunto(s)
Proteínas Adaptadoras Transductoras de Señales/metabolismo , Leucemia Linfocítica Crónica de Células B/metabolismo , Leucemia Linfocítica Crónica de Células B/patología , Fosfoproteínas/metabolismo , Receptores de Antígenos de Linfocitos B/metabolismo , Transducción de Señal , Proteínas Adaptadoras Transductoras de Señales/genética , Progresión de la Enfermedad , Regulación Leucémica de la Expresión Génica , Técnicas de Silenciamiento del Gen , Humanos , Cadenas Pesadas de Inmunoglobulina/genética , Estimación de Kaplan-Meier , Leucemia Linfocítica Crónica de Células B/genética , Leucemia Linfocítica Crónica de Células B/mortalidad , Fosfoproteínas/genética , Fosforilación , Pronóstico , Unión Proteica , Quinasa Syk/metabolismo , Proteína Tirosina Quinasa ZAP-70/genética , Proteína Tirosina Quinasa ZAP-70/metabolismo
20.
Cytometry B Clin Cytom ; 90(3): 257-66, 2016 05.
Artículo en Inglés | MEDLINE | ID: mdl-26082241

RESUMEN

BACKGROUND: Cellular aggregation is a physiological response of lymphocytes to various extracellular stimuli. Currently, lymphocytes aggregation is only evaluated qualitatively or by semiquantitative methods. In this study, we assessed the capacity of flow cytometry to measure lymphocytes aggregation in a quantitative, accurate, and reproducible manner, and examined the significance of aggregation responses in various lymphoproliferative diseases. METHODS: Extracellular triggers such as anti-CD19 antibodies or phorbol ester were utilized to induce lymphoid cells aggregation in a concentration dependent manner. Aggregation was quantified by flow cytometry based on the forward or side scatter (SSC), or by dark-field SSC of aggregates measured by ImageStreamX. Accuracy, reproducibility, and limitations of the methodology were evaluated. Aggregation responses were measured in various types of lymphoproliferative diseases, and correlated with immunophenotyping and IGHV mutational status in chronic lymphocytic leukemia. RESULTS: Lymphoid aggregates provoked by extracellular stimuli elevate the forward and SSC signals relatively to the number of cells in each event. Aggregation responses vary among different types of lymphoproliferative diseases. Moreover, elevated levels of CD19-induced aggregation are associated with aberrant chronic lymphocytic leukemia characteristics, but not with IGHV mutational status of the disease CONCLUSIONS: We have demonstrated that flow cytometry can provide accurate and reproducible measurement of both primary as well as T and B cell lines aggregation in response to extracellular stimuli. The use of quantitative evaluation of activation driven or other cellular aggregation may provide an analytical tool to elucidate biochemical and molecular mechanisms associated with lymphoproliferative diseases. © 2015 International Clinical Cytometry Society.


Asunto(s)
Citometría de Flujo , Leucemia Linfocítica Crónica de Células B/diagnóstico , Adulto , Anciano , Anciano de 80 o más Años , Antígenos CD/análisis , Antígenos CD/inmunología , Linfocitos B/inmunología , Citometría de Flujo/métodos , Humanos , Inmunofenotipificación/métodos , Leucemia Linfocítica Crónica de Células B/inmunología , Trastornos Linfoproliferativos/diagnóstico , Trastornos Linfoproliferativos/inmunología , Trastornos Linfoproliferativos/patología , Persona de Mediana Edad , Reproducibilidad de los Resultados
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