Your browser doesn't support javascript.
loading
Mostrar: 20 | 50 | 100
Resultados 1 - 20 de 50
Filtrar
1.
Pers Soc Psychol Bull ; 50(5): 780-792, 2024 May.
Artículo en Inglés | MEDLINE | ID: mdl-36722363

RESUMEN

We test the hypothesis that the perception of stability in one's self-concept (i.e., future self-continuity) enables the experience of meaning in life because perceiving a stable sense of self confers a sense of certainty to the self-concept. Study 1 provided initial evidence of the influence of future self-continuity on feelings of meaning in life (MIL) in a nationally representative sample. In Studies 2a and 2b, we manipulated future self-continuity by varying the expectedness of one's future self, demonstrating the causal influence of future self-continuity on self-certainty and feelings of MIL. Study 3 again manipulated future self-continuity, finding an indirect effect on feelings of meaning in life via self-certainty. Our findings thus suggest the experience of meaning in life arises from the perception of a stable sense of self. We discuss the implications for the antecedents and conceptualization of MIL as well as the nature of the self-concept.


Asunto(s)
Emociones , Autoimagen , Humanos , Satisfacción Personal
4.
Leuk Res ; 129: 107072, 2023 06.
Artículo en Inglés | MEDLINE | ID: mdl-37003030

RESUMEN

Monoclonal antibody induced infusion reactions (IRs) can be serious and even fatal. We used clinical data and blood samples from 37 treatment naïve patients with chronic lymphocytic leukemia/small lymphocytic lymphoma (CLL) initiating therapy for progressive disease with a single 50 mg dose of intravenous (IV) rituximab at 25 mg/h. Twenty-four (65 %) patients had IRs at a median of 78 min (range 35-128) and rituximab dose of 32 mg (range 15-50). IR risk did not correlate with patient or CLL characteristics, CLL counts or CD20 levels, or serum rituximab or complement concentrations. Thirty-five (95 %) patients had cytokine release response with a ≥ 4-fold increase in serum concentration of ≥ 1 inflammatory cytokine. IRs were associated with significantly higher post-infusion serum concentrations of gamma interferon induced cytokines IP-10, IL-6 and IL-8. IP-10 concentrations increased ≥ 4-fold in all patients with an IR and were above the upper limit of detection (40,000 pg/ml) in 17 (71 %). In contrast, to only three (23 %) patients without an IR had an ≥ 4-fold increase in serum concentrations of IP-10 (highest 22,013 pg/ml). Our data suggest that cytokine release could be initiated by activation of effector cells responsible for clearance of circulating CLL cells with IRs occurring in those with higher levels of gamma interferon induced cytokines. These novel insights could inform future research to better understand and manage IRs and understand the role of cytokines in the control of cytotoxic immune responses to mAb.


Asunto(s)
Antineoplásicos , Leucemia Linfocítica Crónica de Células B , Humanos , Rituximab , Citocinas , Quimiocina CXCL10/uso terapéutico , Leucemia Linfocítica Crónica de Células B/patología , Interferón gamma/uso terapéutico , Anticuerpos Monoclonales de Origen Murino , Antineoplásicos/uso terapéutico
5.
J Pers Soc Psychol ; 125(5): 1055-1071, 2023 Nov.
Artículo en Inglés | MEDLINE | ID: mdl-37053416

RESUMEN

We propose that self-essentialist reasoning is a foundational mechanism of the similarity-attraction effect. Our argument is that similarity breeds attraction in two steps: (a) people categorize someone with a shared attribute as a person like me based on the self-essentialist belief that one's attributes are caused by an underlying essence and (b) then apply their essence (and the other attributes it causes) to the similar individual to infer agreement about the world in general (i.e., a generalized shared reality). We tested this model in four experimental studies (N = 2,290) using both individual difference and moderation-of-process approaches. We found that individual differences in self-essentialist beliefs amplified the effect of similarity on perceived generalized shared reality and attraction across both meaningful (Study 1) and minimal (Study 2) dimensions of similarity. We next found that manipulating (i.e., interrupting) the two crucial steps of the self-essentialist reasoning process-that is, by severing the connection between a similar attribute and one's essence (Study 3) and deterring people from applying their essence to form an impression of a similar other (Study 4)-attenuated the effect of similarity on attraction. We discuss the implications for research on the self, similarity-attraction, and intergroup phenomena. (PsycInfo Database Record (c) 2023 APA, all rights reserved).


Asunto(s)
Actitud , Solución de Problemas , Humanos , Individualidad
6.
Endocr Relat Cancer ; 30(1)2023 01 01.
Artículo en Inglés | MEDLINE | ID: mdl-36356297

RESUMEN

It has long been recognised that cancer cells critically depend on reprogrammed patterns of metabolism that can enable robust and abnormally high levels of cell proliferation. As mitochondria form hubs of cellular metabolic activity, it is reasonable to propose that pathways within these organelles can form targets that can be manipulated to compromise the ability of cancer cells to cause disease. However, mitochondria are highly multi-functional, and the full range of mechanistic inter-connections are still being unravelled to enable the full potential of targeting mitochondria in cancer therapeutics. Here, we aim to highlight the potential of modulating mitochondrial dynamics to target key metabolic or apoptotic pathways in cancer cells. Distinct roles have been demonstrated for mitochondrial fission and fusion in different cancer contexts. Targeting of factors mediating mitochondrial dynamics may be directly related to impairment of oxidative phosphorylation, which is essential to sustain cancer cell growth and can also alter sensitivity to chemotherapeutic compounds. This area is still lacking a unified model, although further investigation will more comprehensively map the underlying molecular mechanisms to enable better rational therapeutic strategies based on these pathways.


Asunto(s)
Dinámicas Mitocondriales , Neoplasias , Humanos , Mitocondrias/metabolismo , Neoplasias/tratamiento farmacológico , Neoplasias/metabolismo , Proliferación Celular
7.
Cell Rep ; 40(7): 111198, 2022 08 16.
Artículo en Inglés | MEDLINE | ID: mdl-35977476

RESUMEN

The relationship between nutrient starvation and mitochondrial dynamics is poorly understood. We find that cells facing amino acid starvation display clear mitochondrial fusion as a means to evade mitophagy. Surprisingly, further supplementation of glutamine (Q), leucine (L), and arginine (R) did not reverse, but produced stronger mitochondrial hyperfusion. Interestingly, the hyperfusion response to Q + L + R was dependent upon mitochondrial fusion proteins Mfn1 and Opa1 but was independent of MTORC1. Metabolite profiling indicates that Q + L + R addback replenishes amino acid and nucleotide pools. Inhibition of fumarate hydratase, glutaminolysis, or inosine monophosphate dehydrogenase all block Q + L + R-dependent mitochondrial hyperfusion, which suggests critical roles for the tricarboxylic acid (TCA) cycle and purine biosynthesis in this response. Metabolic tracer analyses further support the idea that supplemented Q promotes purine biosynthesis by serving as a donor of amine groups. We thus describe a metabolic mechanism for direct sensing of cellular amino acids to control mitochondrial fusion and cell fate.


Asunto(s)
Aminoácidos , Dinámicas Mitocondriales , Aminas/metabolismo , Aminoácidos/metabolismo , Mitocondrias/metabolismo , Proteínas Mitocondriales/metabolismo , Purinas/metabolismo
9.
Alcohol Clin Exp Res ; 45(11): 2217-2230, 2021 11.
Artículo en Inglés | MEDLINE | ID: mdl-34585422

RESUMEN

BACKGROUND: Arterial endothelium plays a critical role in maintaining vessel homeostasis and preventing atherosclerotic cardiovascular disease (CVD). Low-to-moderate alcohol (EtOH) consumption is associated with reduced atherosclerosis and stimulates Notch signaling in endothelial cells. The aim of this study was to determine whether EtOH protects the endothelium against serum amyloid A1 (SAA1)-induced activation/injury, and to determine whether this protection is exclusively Notch-dependent. METHODS AND RESULTS: Human coronary artery endothelial cells (HCAEC) were stimulated or not with "pro-atherogenic" SAA1 (1 µM) in the absence or presence of EtOH (25 mM), the Notch ligand DLL4 (3 µg/ml), or the Notch inhibitor DAPT (20 µM). EtOH stimulated Notch signaling in HCAEC, as evidenced by increased expression of the Notch receptor and hrt target genes. Treatment with EtOH alone or stimulation of Notch signaling by DLL4 increased eNOS activity and enhanced HCAEC barrier function as assessed by trans-endothelial electrical resistance. Moreover, EtOH and DLL4 both inhibited SAA1-induced monolayer leakiness, cell adhesion molecule (ICAM, VCAM) expression, and monocyte adhesion. The effects of EtOH were Notch-dependent, as they were blocked with DAPT and by Notch receptor (N1, N4) knockdown. In contrast, EtOH's inhibition of SAA1-induced inflammatory cytokines (IL-6, IFN-γ) and reactive oxygen species (ROS) was Notch-independent, as these effects were unaffected by DAPT or by N1 and/or N4 knockdown. CONCLUSIONS: EtOH at moderate levels protects against SAA1-induced endothelial activation via both Notch-dependent and Notch-independent mechanisms. EtOH's maintenance of endothelium in a nonactivated state would be expected to preserve vessel homeostasis and protect against atherosclerosis development.


Asunto(s)
Vasos Coronarios/efectos de los fármacos , Células Endoteliales/efectos de los fármacos , Endotelio Vascular/efectos de los fármacos , Receptor Notch1/metabolismo , Receptores Notch/metabolismo , Proteínas Amiloidogénicas/metabolismo , Movimiento Celular/efectos de los fármacos , Vasos Coronarios/metabolismo , Relación Dosis-Respuesta a Droga , Endotelio Vascular/metabolismo , Etanol/farmacología , Humanos , Sustancias Protectoras
11.
Antibodies (Basel) ; 9(4)2020 Dec 01.
Artículo en Inglés | MEDLINE | ID: mdl-33271825

RESUMEN

Unconjugated monoclonal antibodies (mAb) have revolutionized the treatment of B-cell malignancies. These targeted drugs can activate innate immune cytotoxicity for therapeutic benefit. mAb activation of the complement cascade results in complement-dependent cytotoxicity (CDC) and complement receptor-mediated antibody-dependent cellular phagocytosis (cADCP). Clinical and laboratory studies have showed that CDC is therapeutically important. In contrast, the biological role and clinical effects of cADCP are less well understood. This review summarizes the available data on the role of complement activation in the treatment of mature B-cell malignancies and proposes future research directions that could be useful in optimizing the efficacy of this important class of drugs.

12.
Blood ; 136(18): 2065-2079, 2020 10 29.
Artículo en Inglés | MEDLINE | ID: mdl-32556153

RESUMEN

Macrophage antibody (Ab)-dependent cellular phagocytosis (ADCP) is a major cytotoxic mechanism for both therapeutic unconjugated monoclonal Abs (mAbs) such as rituximab and Ab-induced hemolytic anemia and immune thrombocytopenia. Here, we studied the mechanisms controlling the rate and capacity of macrophages to carry out ADCP in settings of high target/effector cell ratios, such as those seen in patients with circulating tumor burden in leukemic phase disease. Using quantitative live-cell imaging of primary human and mouse macrophages, we found that, upon initial challenge with mAb-opsonized lymphocytes, macrophages underwent a brief burst (<1 hour) of rapid phagocytosis, which was then invariably followed by a sharp reduction in phagocytic activity that could persist for days. This previously unknown refractory period of ADCP, or hypophagia, was observed in all macrophage, mAb, and target cell conditions tested in vitro and was also seen in vivo in Kupffer cells from mice induced to undergo successive rounds of αCD20 mAb-dependent clearance of circulating B cells. Importantly, hypophagia had no effect on Ab-independent phagocytosis and did not alter macrophage viability. In mechanistic studies, we found that the rapid loss of activating Fc receptors from the surface and their subsequent proteolytic degradation were the primary mechanisms responsible for the loss of ADCP activity in hypophagia. These data suggest hypophagia is a critical limiting step in macrophage-mediated clearance of cells via ADCP, and understanding such limitations to innate immune system cytotoxic capacity will aid in the development of mAb regimens that could optimize ADCP and improve patient outcome.


Asunto(s)
Anticuerpos Monoclonales/farmacología , Citotoxicidad Celular Dependiente de Anticuerpos/inmunología , Inmunidad Innata/efectos de los fármacos , Macrófagos/patología , Fagocitos/inmunología , Fagocitosis , Rituximab/farmacología , Animales , Citotoxicidad Celular Dependiente de Anticuerpos/efectos de los fármacos , Femenino , Macrófagos/efectos de los fármacos , Macrófagos/inmunología , Masculino , Ratones , Ratones Endogámicos C57BL , Fagocitos/efectos de los fármacos
13.
J Cell Sci ; 133(5)2020 03 05.
Artículo en Inglés | MEDLINE | ID: mdl-32005699

RESUMEN

Phagocytosis is a dynamic process central to immunity and tissue homeostasis. Current methods for quantification of phagocytosis largely rely on indirect or static measurements, such as target clearance or dye uptake, and thus provide limited information about engulfment rates or target processing. Improved kinetic measurements of phagocytosis could provide useful, basic insights in many areas. We present a live-cell, time-lapse and high-content microscopy imaging method based on the detection and quantification of fluorescent dye 'voids' within phagocytes that result from target internalization to quantify phagocytic events with high temporal resolution. Using this method, we measure target cell densities and antibody concentrations needed for optimal antibody-dependent cellular phagocytosis. We compare void formation and dye uptake methods for phagocytosis detection, and examine the connection between target cell engulfment and phagolysosomal processing. We demonstrate how this approach can be used to measure distinct forms of phagocytosis, and changes in macrophage morphology during phagocytosis related to both engulfment and target degradation. Our results provide a high-resolution method for quantifying phagocytosis that provides opportunities to better understand the cellular and molecular regulation of this fundamental biological process.


Asunto(s)
Microscopía , Fagocitos , Macrófagos , Fagocitosis , Imagen de Lapso de Tiempo
14.
Curr Opin Psychol ; 33: 162-166, 2020 06.
Artículo en Inglés | MEDLINE | ID: mdl-31446300

RESUMEN

Research on the dysfunctions of power for group interactions is covered in this review. While individuals generally benefit from possessing power, groups often are plagued by power struggles when one or more individuals within the group possess power, such as in groups with high intra-group power dispersion (e.g. a clear job title hierarchy or differences in salary levels) or a high average level of member power (e.g. management teams, all-star sports teams). In such groups with at least one powerful member, research shows that intragroup power struggles are likely and detract from group outcomes, including performance, viability, and creativity. Groups have the highest quality interactions when they minimize the salience of power within their group by helping individuals expand the 'power pie' in group, such as by identifying multiple sources of power within oneself or the group and having power-holders whom can dynamically flex the perceived power-distance within the group.


Asunto(s)
Conflicto Psicológico , Procesos de Grupo , Relaciones Interpersonales , Poder Psicológico , Humanos , Análisis y Desempeño de Tareas
15.
Clin Cancer Res ; 26(11): 2704-2710, 2020 06 01.
Artículo en Inglés | MEDLINE | ID: mdl-31796517

RESUMEN

PURPOSE: Patients with triple-negative breast cancer (TNBC) with homologous recombination deficient tumors achieve significantly higher pathologic complete response (pCR) rates when treated with neoadjuvant platinum-based therapy. Tumor-infiltrating lymphocytes (TIL) are prognostic and predictive of chemotherapy benefit in early stage TNBC. The relationship between TILs, BRCA1/2 mutation status, and homologous recombination deficiency (HRD) status in TNBC remains unclear. EXPERIMENTAL DESIGN: We performed a pooled analysis of five phase II studies that included patients with TNBC treated with neoadjuvant platinum-based chemotherapy to evaluate the association of TILs with HRD status (Myriad Genetics) and tumor BRCA1/2 mutation status. Furthermore, the relationship between pathologic response assessed using the residual cancer burden (RCB) index and HRD status with adjustment for TILs was evaluated. RESULTS: Among 161 patients, stromal TIL (sTIL) density was not significantly associated with HRD status (P = 0.107) or tumor BRCA1/2 mutation status (P = 0.391). In multivariate analyses, sTIL density [OR, 1.23; 95% confidence interval (CI), 0.94-1.61; P = 0.139] was not associated with pCR, but was associated with RCB 0/I status (OR 1.62; 95% CI, 1.20-2.28; P = 0.001). HRD was significantly associated with both pCR (OR 12.09; 95% CI, 4.11-44.29; P = 7.82 × 10-7) and RCB 0/I (OR 10.22; 95% CI, 4.11-28.75; P = 1.09 × 10-7) in these models. CONCLUSIONS: In patients with TNBC treated with neoadjuvant platinum-based therapy, TIL density was not significantly associated with either tumor BRCA1/2 mutation status or HRD status. In this pooled analysis, HRD and sTIL density were independently associated with treatment response, with HRD status being the strongest predictor.


Asunto(s)
Proteína BRCA1/genética , Proteína BRCA2/genética , Biomarcadores de Tumor/genética , Recombinación Homóloga , Linfocitos Infiltrantes de Tumor/inmunología , Mutación , Neoplasias de la Mama Triple Negativas/patología , Adulto , Anciano , Ensayos Clínicos Fase II como Asunto , Femenino , Estudios de Seguimiento , Humanos , Metaanálisis como Asunto , Persona de Mediana Edad , Estudios Multicéntricos como Asunto , Pronóstico , Estudios Prospectivos , Tasa de Supervivencia , Neoplasias de la Mama Triple Negativas/genética , Neoplasias de la Mama Triple Negativas/inmunología , Neoplasias de la Mama Triple Negativas/cirugía , Adulto Joven
16.
J Med Case Rep ; 13(1): 71, 2019 Mar 07.
Artículo en Inglés | MEDLINE | ID: mdl-30841901

RESUMEN

BACKGROUND: Primary small cell carcinoma of the kidney is an extremely rare neoplasm. The clinical features of small cell carcinoma of the kidney are not well established due to its rarity and scarcity of case reports. We present an unusual case of small cell carcinoma of the kidney complicated by syndrome of inappropriate antidiuretic hormone secretion. We identify cases using a population-based dataset from the Surveillance, Epidemiology, and End Results registry and compare small cell carcinoma of the kidney with small cell carcinoma of the lung. CASE PRESENTATION: A 69-year-old Filipino man presented with hematuria for 1 month. A computed tomography scan demonstrated a large left kidney mass with biopsy demonstrating small cell carcinoma. Within 2 months he developed dizziness and was found to have a metastatic lesion to his brain. He was hyponatremic due to syndrome of inappropriate antidiuretic hormone secretion. He did not receive chemotherapy due to his poor functional status. He died within 8 months of presentation. RESULTS: From 1973 to 2013, 60 cases with small cell carcinoma of the kidney were identified in the Surveillance, Epidemiology, and End Results registry. Most (62%) presented with extensive stage, which occurred predominantly in white men in their seventh decade. The median overall survival with extensive stage small cell carcinoma of the kidney was 3 months versus 11 months with limited stage of small cell carcinoma of the kidney; this was worse than small cell carcinoma of the lung with a median survival of 5 and 13 months, respectively. CONCLUSION: We present a rare case of small cell carcinoma of the kidney complicated by syndrome of inappropriate antidiuretic hormone secretion. This adds to our understanding of the clinical features of small cell carcinoma of the kidney. Furthermore, this is the first population-based study of small cell carcinoma of the kidney using the Surveillance, Epidemiology, and End Results database. Analysis shows that overall survival is worse in small cell carcinoma of the kidney relative to that of small cell carcinoma of the lung. Small cell carcinoma of the kidney presents very aggressively, and further studies are needed to develop a standard of care.


Asunto(s)
Neoplasias Encefálicas/secundario , Carcinoma de Células Pequeñas/patología , Síndrome de Secreción Inadecuada de ADH/complicaciones , Neoplasias Renales/patología , Anciano , Carcinoma de Células Pequeñas/etiología , Resultado Fatal , Hematuria/etiología , Humanos , Neoplasias Renales/etiología , Masculino , Sistema de Registros , Programa de VERF , Tomografía Computarizada por Rayos X
17.
Cancer Immunol Res ; 6(10): 1150-1160, 2018 10.
Artículo en Inglés | MEDLINE | ID: mdl-30089638

RESUMEN

CD20 monoclonal antibodies (CD20 mAb) induce cellular cytotoxicity, which is traditionally measured by antibody-dependent cellular cytotoxicity (ADCC) assays. However, data suggest that antibody-dependent cellular phagocytosis (ADCP) is the primary cytotoxic mechanism. We directly compared in vitro ADCP versus ADCC using primary human cells. After establishing the primacy of ADCP, we examined next-generation CD20 mAbs, including clinically relevant drug combinations for their effects on ADCP. ADCP and ADCC induction by rituximab, ofatumumab, obinutuzumab, or ocaratuzumab was measured using treatment-naïve chronic lymphocytic leukemia (CLL) target cells and either human monocyte-derived macrophages (for ADCP) or natural killer (NK) cells (for ADCC). Specific effects on ADCP were evaluated for clinically relevant drug combinations using BTK inhibitors (ibrutinib and acalabrutinib), PI3Kδ inhibitors (idelalisib, ACP-319, and umbralisib), and the BCL2 inhibitor venetoclax. ADCP (∼0.5-3 targets/macrophage) was >10-fold more cytotoxic than ADCC (∼0.04-0.1 targets/NK cell). ADCC did not correlate with ADCP. Next-generation mAbs ocaratuzumab and ofatumumab induced ADCP at 10-fold lower concentrations than rituximab. Ofatumumab, selected for enhanced complement activation, significantly increased ADCP in the presence of complement. CD20 mAb-induced ADCP was not inhibited by venetoclax and was less inhibited by acalabrutinib versus ibrutinib and umbralisib versus idelalisib. Overall, ADCP was a better measure of clinically relevant mAb-induced cellular cytotoxicity, and next-generation mAbs could activate ADCP at significantly lower concentrations, suggesting the need to test a wide range of dose sizes and intervals to establish optimal therapeutic regimens. Complement activation by mAbs can contribute to ADCP, and venetoclax, acalabrutinib, and umbralisib are preferred candidates for multidrug therapeutic regimens. Cancer Immunol Res; 6(10); 1150-60. ©2018 AACR.


Asunto(s)
Anticuerpos Monoclonales/farmacología , Citotoxicidad Celular Dependiente de Anticuerpos , Antígenos CD20/inmunología , Células Asesinas Naturales/inmunología , Macrófagos/inmunología , Línea Celular Tumoral , Humanos , Leucemia Linfocítica Crónica de Células B , Fagocitosis
19.
Clin Cancer Res ; 23(17): 5292-5301, 2017 Sep 01.
Artículo en Inglés | MEDLINE | ID: mdl-28536306

RESUMEN

Purpose: We sought to investigate whether B cell receptor immunoglobulin (BcR IG) stereotypy is associated with particular clinicobiological features among chronic lymphocytic leukemia (CLL) patients expressing mutated BcR IG (M-CLL) encoded by the IGHV4-34 gene, and also ascertain whether these associations could refine prognostication.Experimental Design: In a series of 19,907 CLL cases with available immunogenetic information, we identified 339 IGHV4-34-expressing cases assigned to one of the four largest stereotyped M-CLL subsets, namely subsets #4, #16, #29 and #201, and investigated in detail their clinicobiological characteristics and disease outcomes.Results: We identified shared and subset-specific patterns of somatic hypermutation (SHM) among patients assigned to these subsets. The greatest similarity was observed between subsets #4 and #16, both including IgG-switched cases (IgG-CLL). In contrast, the least similarity was detected between subsets #16 and #201, the latter concerning IgM/D-expressing CLL. Significant differences between subsets also involved disease stage at diagnosis and the presence of specific genomic aberrations. IgG subsets #4 and #16 emerged as particularly indolent with a significantly (P < 0.05) longer time-to-first-treatment (TTFT; median TTFT: not yet reached) compared with the IgM/D subsets #29 and #201 (median TTFT: 11 and 12 years, respectively).Conclusions: Our findings support the notion that BcR IG stereotypy further refines prognostication in CLL, superseding the immunogenetic distinction based solely on SHM load. In addition, the observed distinct genetic aberration landscapes and clinical heterogeneity suggest that not all M-CLL cases are equal, prompting further research into the underlying biological background with the ultimate aim of tailored patient management. Clin Cancer Res; 23(17); 5292-301. ©2017 AACR.


Asunto(s)
Cadenas Pesadas de Inmunoglobulina/genética , Región Variable de Inmunoglobulina/genética , Leucemia Linfocítica Crónica de Células B/genética , Hipermutación Somática de Inmunoglobulina/genética , ADP-Ribosil Ciclasa 1/genética , ADP-Ribosil Ciclasa 1/inmunología , Secuencia de Aminoácidos/genética , Femenino , Regulación Neoplásica de la Expresión Génica/inmunología , Humanos , Inmunogenética , Cadenas Pesadas de Inmunoglobulina/inmunología , Región Variable de Inmunoglobulina/inmunología , Leucemia Linfocítica Crónica de Células B/inmunología , Leucemia Linfocítica Crónica de Células B/patología , Masculino
20.
Mol Med ; 23: 1-12, 2017 Mar.
Artículo en Inglés | MEDLINE | ID: mdl-28097289

RESUMEN

Amino acid replacement mutations in certain CLL stereotyped B-cell receptor (BCR) immunoglobulins (IGs) at defined positions within antigen-binding sites strongly imply antigen selection. Prime examples of this are CLL subset 4 BCR IGs using IGHV4-34/IGHD5-18/IGHJ6 and IGKV2-30/IGKJ2 rearrangements. Conspicuously and unlike most CLL IGs, subset 4 IGs do not bind apoptotic cells. By testing the (auto)antigenic reactivities of subset 4 IGs toward viable lymphoid-lineage cells and specific autoantigens typically bound by IGHV4-34+ IGs, we found IGs from both subset 4 and non-subset 4 IGHV4-34-expressing CLL cases bind naïve B cells. However, only subset 4 IGs react with memory B cells. Furthermore, subset 4 IGs do not bind DNA nor i or I carbohydrate antigens, common targets of IGHV4-34-utilizing antibodies in systemic lupus erythematosus and cold agglutinin disease, respectively. Notably, we found that subset 4 IG binding to memory B lymphocytes depends on an aspartic acid at position 66 of FR3 in the rearranged IGKV2-30 gene; this amino acid residue is acquired by somatic mutation. Our findings illustrate the importance of positive and negative selection criteria for structural elements in CLL IGs and suggest that autoantigens driving normal B cells to become subset 4 CLL cells differ from those driving IGHV4-34+ B cells in other diseases.

SELECCIÓN DE REFERENCIAS
DETALLE DE LA BÚSQUEDA
...