Your browser doesn't support javascript.
loading
Mostrar: 20 | 50 | 100
Resultados 1 - 10 de 10
Filtrar
1.
Cell Rep ; 42(5): 112446, 2023 05 30.
Artigo em Inglês | MEDLINE | ID: mdl-37119135

RESUMO

Common variable immune deficiency (CVID) is a heterogeneous disorder characterized by recurrent infections, low levels of serum immunoglobulins, and impaired vaccine responses. Autoimmune manifestations are common, but B cell central and peripheral selection mechanisms in CVID are incompletely understood. Here, we find that receptor editing, a measure of central tolerance, is increased in transitional B cells from CVID patients and that these cells have a higher immunoglobulin κ:λ ratio in CVID patients with autoimmune manifestations than in those with infection only. Contrariwise, the selection pressure in the germinal center on CD27bright memory B cells is decreased in CVID patients with autoimmune manifestations. Finally, functionally, T cell-dependent activation showed that naive B cells in CVID patients are badly equipped for activation and induction of mismatch repair genes. We conclude that central tolerance is functional whereas peripheral selection is defective in CVID patients with autoimmune manifestations, which could underpin the development of autoimmunity.


Assuntos
Imunodeficiência de Variável Comum , Humanos , Imunodeficiência de Variável Comum/genética , Linfócitos B , Centro Germinativo , Células Precursoras de Linfócitos B , Autoimunidade
2.
Front Immunol ; 14: 1094871, 2023.
Artigo em Inglês | MEDLINE | ID: mdl-36845129

RESUMO

Introduction: Hepatitis C virus (HCV) causes mixed cryoglobulinemia (MC) by driving clonal expansion of B cells expressing B cell receptors (BCRs), often encoded by the VH1-69 variable gene, endowed with both rheumatoid factor (RF) and anti-HCV specificity. These cells display an atypical CD21low phenotype and functional exhaustion evidenced by unresponsiveness to BCR and Toll-like receptor 9 (TLR9) stimuli. Although antiviral therapy is effective on MC vasculitis, pathogenic B cell clones persist long thereafter and can cause virus-independent disease relapses. Methods: Clonal B cells from patients with HCV-associated type 2 MC or healthy donors were stimulated with CpG or heath-aggregated IgG (as surrogate immune complexes) alone or in combination; proliferation and differentiation were then evaluated by flow cytometry. Phosphorylation of AKT and of the p65 NF-kB subunit were measured by flow cytometry. TLR9 was quantified by qPCR and by intracellular flow cytometry, and MyD88 isoforms were analyzed using RT-PCR. Discussion: We found that dual triggering with autoantigen and CpG restored the capacity of exhausted VH1-69pos B cells to proliferate. The signaling mechanism for this BCR/TLR9 crosstalk remains elusive, since TLR9 mRNA and protein as well as MyD88 mRNA were normally expressed and CpG-induced phosphorylation of p65 NF-kB was intact in MC clonal B cells, whereas BCR-induced p65 NF-kB phosphorylation was impaired and PI3K/Akt signaling was intact. Our findings indicate that autoantigen and CpG of microbial or cellular origin may unite to foster persistence of pathogenic RF B cells in HCV-cured MC patients. BCR/TLR9 crosstalk might represent a more general mechanism enhancing systemic autoimmunity by the rescue of exhausted autoreactive CD21low B cells.


Assuntos
Crioglobulinemia , Hepatite C , Humanos , Autoantígenos , Proliferação de Células , Crioglobulinemia/etiologia , Hepacivirus , Fator 88 de Diferenciação Mieloide/metabolismo , NF-kappa B/metabolismo , Fosfatidilinositol 3-Quinases/metabolismo , Proteínas Proto-Oncogênicas c-akt/metabolismo , Fator Reumatoide , Receptor Toll-Like 9/metabolismo , Ilhas de CpG , Receptores de Complemento 3d/imunologia , Linfócitos B/imunologia
3.
Front Immunol ; 12: 690534, 2021.
Artigo em Inglês | MEDLINE | ID: mdl-34367150

RESUMO

High quality medical assistance and preventive strategies, including pursuing a healthy lifestyle, result in a progressively growing percentage of older people. The population and workforce is aging in all countries of the world. It is widely recognized that older individuals show an increased susceptibility to infections and a reduced response to vaccination suggesting that the aged immune system is less able to react and consequently protect the organism. The SARS-CoV-2 pandemic is dramatically showing us that the organism reacts to novel pathogens in an age-dependent manner. The decline of the immune system observed in aging remains unclear. We aimed to understand the role of B cells. We analyzed peripheral blood from children (4-18 years); young people (23-60 years) and elderly people (65-91 years) by flow cytometry. We also measured antibody secretion by ELISA following a T-independent stimulation. Here we show that the elderly have a significant reduction of CD27dull memory B cells, a population that bridges innate and adaptive immune functions. In older people, memory B cells are mostly high specialized antigen-selected CD27bright. Moreover, after in vitro stimulation with CpG, B cells from older individuals produced significantly fewer IgM and IgA antibodies compared to younger individuals. Aging is a complex process characterized by a functional decline in multiple physiological systems. The immune system of older people is well equipped to react to often encountered antigens but has a low ability to respond to new pathogens.


Assuntos
Envelhecimento/imunologia , Linfócitos B/imunologia , COVID-19 , Memória Imunológica , Pandemias , SARS-CoV-2/imunologia , Adolescente , Adulto , Idoso , Idoso de 80 Anos ou mais , COVID-19/epidemiologia , COVID-19/imunologia , Criança , Pré-Escolar , Citocinas/imunologia , Feminino , Humanos , Imunoglobulina A/imunologia , Imunoglobulina M/imunologia , Masculino , Pessoa de Meia-Idade
4.
Cell Rep ; 30(9): 2963-2977.e6, 2020 03 03.
Artigo em Inglês | MEDLINE | ID: mdl-32130900

RESUMO

Memory B cells (MBCs) epitomize the adaptation of the immune system to the environment. We identify two MBC subsets in peripheral blood, CD27dull and CD27bright MBCs, whose frequency changes with age. Heavy chain variable region (VH) usage, somatic mutation frequency replacement-to-silent ratio, and CDR3 property changes, reflecting consecutive selection of highly antigen-specific, low cross-reactive antibody variants, all demonstrate that CD27dull and CD27bright MBCs represent sequential MBC developmental stages, and stringent antigen-driven pressure selects CD27dull into the CD27bright MBC pool. Dynamics of human MBCs are exploited in pregnancy, when 50% of maternal MBCs are lost and CD27dull MBCs transit to the more differentiated CD27bright stage. In the postpartum period, the maternal MBC pool is replenished by the expansion of persistent CD27dull clones. Thus, the stability and flexibility of human B cell memory is ensured by CD27dull MBCs that expand and differentiate in response to change.


Assuntos
Linfócitos B/imunologia , Memória Imunológica , Membro 7 da Superfamília de Receptores de Fatores de Necrose Tumoral/metabolismo , Adulto , Idoso , Idoso de 80 Anos ou mais , Criança , Pré-Escolar , Feminino , Perfilação da Expressão Gênica , Humanos , Switching de Imunoglobulina/genética , Região Variável de Imunoglobulina/genética , Memória Imunológica/genética , Lactente , Recém-Nascido , Pessoa de Meia-Idade , Modelos Imunológicos , Gravidez , Hipermutação Somática de Imunoglobulina/genética , Doadores de Tecidos , Transcrição Gênica
5.
Support Care Cancer ; 27(3): 1041-1047, 2019 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-30084104

RESUMO

BACKGROUND: Fatigue is one of the most distressing symptoms of cancer patients. Its characteristics and impact on quality of life have not been fully explored and treatment of cancer-related fatigue in Italian oncological centers has not been codified. METHODS: A cross-sectional study was carried out on all patients attending for any reason the 24 participating centers in two non-consecutive days. Patients with fatigue filled out the Brief Fatigue Inventory (BFI) questionnaire and reported any pharmacological or non-pharmacological treatment for fatigue. RESULTS: From October 2014 to May 2015, 1394 cancer patients agreed to participate in the study. Fatigue was referred by 866 (62.1%) of patients; its duration was > 4 months in 441 patients (50.9%). In the investigators' opinion, the most important (probable or almost sure) determinants of fatigue were reduced physical activity (271 patients), anxiety (149), pain (131), insomnia (125), anemia (123), and depression (123). Fatigue of moderate/severe intensity was reported by 43%/29.2% of patients, while usual fatigue in the last 24 h by 45%/33.1%, and the worst fatigue in the last 24 h by 33%/54.8%, respectively. Concerning the impact on quality of life, fatigue interfered moderately/severely with general activity in 30.8%/38.6% of patients, with mood in 26.1%/32.8%, with the ability to work in 27.9%/35.6%, with normal work in 26.7%/38.9%, with relationships with others in 21%/23.4% and with the ability to amuse themselves in 22.2%/33.1%. Only 117/866 patients (13.5%) received a pharmacological treatment represented by a corticosteroid in 101 patients (86.3%) while 188 patients (21.7%) received a non-pharmacological treatment such as physical exercise (120 patients, 63.8%) and various alimentary supplements (52 patients, 27.6%). CONCLUSIONS: Cancer-related fatigue is frequently reported by oncological patients; its intensity and impact on quality of life is relevant.


Assuntos
Fadiga/epidemiologia , Fadiga/etiologia , Neoplasias/complicações , Adulto , Idoso , Idoso de 80 Anos ou mais , Ansiedade/complicações , Dor do Câncer/complicações , Estudos Transversais , Depressão/complicações , Exercício Físico/psicologia , Terapia por Exercício , Fadiga/terapia , Feminino , Humanos , Itália/epidemiologia , Masculino , Pessoa de Meia-Idade , Prevalência , Qualidade de Vida , Inquéritos e Questionários , Adulto Jovem
7.
J Hered ; 101(2): 240-5, 2010.
Artigo em Inglês | MEDLINE | ID: mdl-19939967

RESUMO

Microsatellites have been used for parentage testing and individual identification in forensic science because they are highly polymorphic and show abundant sequences dispersed throughout most eukaryotic nuclear genomes. At present, genetic testing based on DNA technology is used for most domesticated animals, including horses, to confirm identity, to determine parentage, and to validate registration certificates. But if genetic data of one of the putative parents are missing, verifying a genealogy could be questionable. The aim of this paper is to illustrate a new approach to analyze complex cases of disputed relationship with microsatellites markers. These cases were solved by analyzing the genotypes of the offspring and other horses' genotypes in the pedigrees of the putative dam/sire with probabilistic expert systems (PESs). PES was especially efficient in supplying reliable, error-free Bayesian probabilities in complex cases with missing pedigree data. One of these systems was developed for forensic purposes (FINEX program) and is particularly valuable in human analyses. We applied this program to parentage analysis in horses, and we will illustrate how different cases have been successfully worked out.


Assuntos
Sistemas Inteligentes , Genética Forense/métodos , Marcadores Genéticos , Cavalos/genética , Linhagem , Animais , Cruzamento , DNA/análise , Feminino , Masculino , Modelos Estatísticos , Probabilidade , Análise de Sequência de DNA/métodos , Análise de Sequência de DNA/veterinária , Estudos de Validação como Assunto
8.
Cancer Chemother Pharmacol ; 54(5): 398-406, 2004 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-15543656

RESUMO

PURPOSE: Malignant pleural mesothelioma(MM), a rare tumor characterized by high local invasiveness and low metastatic efficiency, is poorly responsive to current therapeutic approaches. The aim of the present study was to evaluate the cytotoxic efficacy of the hybrid polar compound hexamethylene bisacetamide(HMBA), either as a single agent or in combination with the anthracycline doxorubicin (DOX), against MM cells. METHODS: The MM cell lines MM-B1 and MM-El were treated with HMBA, DOX or with combinations of the two drugs. Cell survival and death were assessed by the MTS assay and trypan blue staining/TUNEL, respectively. The interactions between drugs were evaluated by the method of Kern et al. Western blot analysis was used to investigate the expression of Bcl-2 family proteins. RESULTS: When administered alone, HMBA dose-dependently decreased the number of viable cells and increased the death rate of MM-B1 and MM-E1 cultures. Combinations of HMBA and DOX achieved a synergistic inhibition of MM cell survival, and the simultaneous administration of HMBA counteracted the resistance induced by DOX in MM-El cells. HMBA,used at cytostatic concentrations, reduced the ratio be-tween antiapoptotic (Bcl-2, Bcl-XL) and proapoptotic(Bax) members of the Bcl-2 family of proteins, thus lowering the threshold for MM cell death commitment. CONCLUSIONS: HMBA has therapeutic potential in MM both as a single agent and through potentiation of DOX toxicity. These results support future investigations on the feasibility of intrapleural chemotherapy with this hybrid polar compound.


Assuntos
Acetamidas/toxicidade , Morte Celular/efeitos dos fármacos , Sobrevivência Celular/efeitos dos fármacos , Doxorrubicina/toxicidade , Mesotelioma/patologia , Antineoplásicos/toxicidade , Linhagem Celular Tumoral , Primers do DNA , Relação Dose-Resposta a Droga , Sinergismo Farmacológico , Humanos , RNA Neoplásico/genética , RNA Neoplásico/isolamento & purificação
9.
Radiother Oncol ; 66(1): 49-56, 2003 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-12559520

RESUMO

BACKGROUND AND PURPOSE: The relationship between the radiation dose and the risk of the osteoradionecrosis is well known. However, the dose to the mandible is not routinely assessed in the radiotherapy for head and neck cancer. The aim of our study was to analyze the mandibular dose distribution in the patients administered curative radiotherapy for squamous cell carcinoma of the oropharynx. Moreover, the clinical results have been analyzed. MATERIAL AND METHODS: We examined the clinical records and treatment plans in 18 patients treated with bifractionated radiotherapy for stage II-IV oropharyngeal cancer. In 17 patients, the total radiotherapy dose prescribed in the International Committee of Radiation Units and Measurements (ICRU) reference point was 74.4 Gy administered in 62 fractions (1.2 Gy twice daily with 6h interfraction interval) and one patient received a dose of 75.6 Gy. The whole dose to the mandibular-orophryngeal region was delivered with 6 MV photons. The mandible was contoured manually on computed tomographic scans and the point doses at the both mandibular condyles, ascending ramus, mental symphysis, molar and retromolar regions were assessed. Moreover, the cumulative dose-volume histograms (DHVs) were evaluated. The median follow-up period for alive patients is 30 months (range, 21-44+ months). RESULTS: Tumor remission was observed in 17 patients: in 11 cases, complete remission was achieved and in six cases, only partial remission was possible. One patient was lost to follow-up before the first response evaluation. The median survival for all patients is 22 months (range, 3-44+ months). Ten patients are alive and seven died. In six cases, the cause of death was head and neck tumor and in one died due to pancreatic cancer (second primary). No late bone post-radiation complication was seen. The highest radiotherapy doses were observed in the retromolar regions. The mean percentage doses at the right and left retromolar regions were 101.3+/-3.8% (range, 90.2-109.1%) and 101.7+/-2.5% (range, 95.2-105.8%), respectively. Lower doses were seen in ascending ramus (the mean percentage doses at right and left ascending ramus were 97.3+/-8.5% and 97.8+/-7.6%, respectively), the molar regions (the mean percentage doses at right and left molar regions were 86.0+/-13.5% and 88.1+/-12.9%, respectively), and at the mandibular condyles (the mean percentage doses at the right and left mandibular condyles were 72.6+/-18% and 77.0+/-16.5%, respectively). The volume of the mandible ranged from 60.1 to 110.1cm(3) (a mean of of 82.3 cm(3)). In all patients, the maximum dose absorbed in the mandible was higher than the dose prescribed in the ICRU point and the mean maximum dose absorbed in the mandible was 105.7+/-2.1% (range, 102.4-110.6%). The percentage of mandibular volume receiving a dose higher than prescribed was 28.6+/-14.9% (range 10.2-58.1%). The area underlying the DVH curve, the maximum mandibular doses and the retromolar doses did not appear to statistically depend on use of wedge or mandibular volume. CONCLUSIONS: Radiotherapy for oropharyngeal cancer is associated with high doses to the retromolar mandibular regions (the dose can be higher than prescribed in the ICRU reference point), ascending ramus and molar regions. Lower doses are absorbed at the condyles and mental symphysis. The single dose point (for example, the ICRU reference point) could be not used as a representative for the mandibular dose. In our small series of patients treated with hyperfractionated irradiation, these dose heterogeneities were not correlated to the patient- and treatment-related factors and are not related to the increased risk of late bone complications. The clinical relevance of mandibular dose distribution remains to be established in larger series of patients treated with conventionally and unconventionally fractionated irradiation.


Assuntos
Mandíbula/efeitos da radiação , Neoplasias Orofaríngeas/radioterapia , Radioterapia Conformacional/métodos , Adulto , Idoso , Estudos de Coortes , Fracionamento da Dose de Radiação , Relação Dose-Resposta à Radiação , Feminino , Seguimentos , Humanos , Masculino , Dose Máxima Tolerável , Pessoa de Meia-Idade , Estadiamento de Neoplasias , Neoplasias Orofaríngeas/mortalidade , Neoplasias Orofaríngeas/patologia , Osteorradionecrose/prevenção & controle , Estudos Prospectivos , Doses de Radiação , Radioterapia Conformacional/efeitos adversos , Medição de Risco , Análise de Sobrevida , Resultado do Tratamento
10.
Tumori ; 88(5): 355-60, 2002.
Artigo em Inglês | MEDLINE | ID: mdl-12487550

RESUMO

Delineation of target volumes is increasingly recognized as the most crucial step within the process of modern conformal radiotherapy. In the field of head and neck radiation oncology, the need for a standardized methodology in the delineation of nodal regions of the neck on computed tomography (CT) images has recently emerged. To address this issue, a consensus document has been prepared by the Head and Neck Working Party of the AIRO-Lombardia Cooperative Group, based on the proceedings of multidisciplinary meetings and on literature findings. The document contains detailed guidelines for the delineation on CT images of the nodal regions of the neck, including for each nodal region (1 to 7) the description of anatomical limits as seen on CT images.


Assuntos
Neoplasias de Cabeça e Pescoço/diagnóstico por imagem , Linfonodos/diagnóstico por imagem , Tomografia Computadorizada por Raios X , Neoplasias de Cabeça e Pescoço/patologia , Neoplasias de Cabeça e Pescoço/radioterapia , Humanos , Linfonodos/patologia , Metástase Linfática , Guias de Prática Clínica como Assunto , Radioterapia Conformacional , Tomografia Computadorizada por Raios X/métodos
SELEÇÃO DE REFERÊNCIAS
DETALHE DA PESQUISA
...