Your browser doesn't support javascript.
loading
Mostrar: 20 | 50 | 100
Resultados 1 - 20 de 41
Filtrar
1.
Cancer Prev Res (Phila) ; 12(10): 701-710, 2019 10.
Artigo em Inglês | MEDLINE | ID: mdl-31427275

RESUMO

Self-sampling for human papillomavirus (HPV) testing is an alternative to physician sampling particularly for cervical cancer screening nonattenders. The GRECOSELF study is a nationwide observational cross-sectional study aiming to suggest a way to implement HPV-DNA testing in conjunction with self-sampling for cervical cancer screening in Greece, utilizing a midwifery network. Women residing in remote areas of Greece were approached by midwives, of a nationwide network, and were provided with a self-collection kit (dry swab) for cervicovaginal sampling and asked to answer a questionnaire about their cervical cancer screening history. Each sample was tested for high-risk (hr) HPV with the Cobas HPV test. HrHPV-Positive women were referred to undergo colposcopy and, if needed, treatment according to colposcopy/biopsy results. Between May 2016 and November 2018, 13,111 women were recruited. Of these, 12,787 women gave valid answers in the study questionnaire and had valid HPV-DNA results; hrHPV prevalence was 8.3%; high-grade cervical/vaginal disease or cancer prevalence was 0.6%. HrHPV positivity rate decreased with age from 20.7% for women aged 25-29 years to 5.1% for women aged 50-60 years. Positive predictive value for hrHPV testing and for HPV16/18 genotyping ranged from 5.0% to 11.6% and from 11.8% to 27.0%, respectively, in different age groups. Compliance to colposcopy referral rate ranged from 68.6% (for women 25-29) to 76.3% (for women 40-49). For women residing in remote areas of Greece, the detection of hrHPV DNA with the Cobas HPV test, on self-collected cervicovaginal samples using dry cotton swabs, which are provided by visiting midwives, is a promising method for cervical cancer secondary prevention.


Assuntos
Testes de DNA para Papilomavírus Humano , Programas de Rastreamento/organização & administração , Tocologia/organização & administração , Infecções por Papillomavirus/diagnóstico , Manejo de Espécimes/métodos , Displasia do Colo do Útero/diagnóstico , Neoplasias do Colo do Útero/diagnóstico , Adolescente , Adulto , Idoso , Colposcopia/estatística & dados numéricos , Redes Comunitárias/organização & administração , Redes Comunitárias/normas , Estudos Transversais , DNA Viral/análise , DNA Viral/genética , Autoavaliação Diagnóstica , Detecção Precoce de Câncer/métodos , Detecção Precoce de Câncer/normas , Detecção Precoce de Câncer/estatística & dados numéricos , Feminino , Grécia/epidemiologia , Testes de DNA para Papilomavírus Humano/métodos , Testes de DNA para Papilomavírus Humano/normas , Testes de DNA para Papilomavírus Humano/estatística & dados numéricos , Humanos , Ciência da Implementação , Programas de Rastreamento/métodos , Programas de Rastreamento/normas , Pessoa de Meia-Idade , Tocologia/métodos , Enfermeiros Obstétricos/organização & administração , Enfermeiros Obstétricos/normas , Enfermeiros Obstétricos/estatística & dados numéricos , Papel do Profissional de Enfermagem , Papillomaviridae/genética , Papillomaviridae/isolamento & purificação , Infecções por Papillomavirus/complicações , Infecções por Papillomavirus/epidemiologia , Infecções por Papillomavirus/patologia , População Rural/estatística & dados numéricos , Manejo de Espécimes/normas , Manejo de Espécimes/estatística & dados numéricos , Neoplasias do Colo do Útero/epidemiologia , Neoplasias do Colo do Útero/etiologia , Esfregaço Vaginal/métodos , Esfregaço Vaginal/estatística & dados numéricos , Adulto Jovem , Displasia do Colo do Útero/epidemiologia , Displasia do Colo do Útero/etiologia
2.
Leuk Lymphoma ; 60(7): 1685-1692, 2019 07.
Artigo em Inglês | MEDLINE | ID: mdl-30652530

RESUMO

Rituximab is known to affect T cell immune responses. We and others have reported expansions of T large granular lymphocytes (T-LGLs) in lymphoma patients after Rituximab. We report here the immunogenetic profiling of the T cell receptor (TR) gene repertoire in 14 patients who received Rituximab post allo-HCT and explore clinicobiological correlations. All experienced antigenic triggers, CMV, EBV re-activation and chronic GvHD and had been treated with Rituximab. Skewing of TRBV genes was observed: 3 TRBV genes accounted for half of the repertoire. Oligoclonal pattern with expanded clonotypes was common. Patients with oligoclonality exhibited frequently cGvHD. Longitudinal samples in one revealed distinct clonotypes, suggesting clonal drift. T-LGL leukemia of donor origin with mixed chimerism eventually developed. In conclusion, we report development of oligoclonal T-LGLs after Rituximab post allo-HCT, alluding to antigen selection. Persistence of this phenomenon likely reflects strong antigenic stimulation by viruses and/or cGVHD aggravated by Rituximab.


Assuntos
Evolução Clonal , Rearranjo Gênico do Linfócito T/imunologia , Doença Enxerto-Hospedeiro/tratamento farmacológico , Transplante de Células-Tronco Hematopoéticas/efeitos adversos , Leucemia Linfocítica Granular Grande/patologia , Receptores de Antígenos de Linfócitos T alfa-beta/imunologia , Rituximab/efeitos adversos , Adolescente , Adulto , Antineoplásicos Imunológicos/efeitos adversos , Feminino , Seguimentos , Rearranjo Gênico do Linfócito T/genética , Doença Enxerto-Hospedeiro/etiologia , Doença Enxerto-Hospedeiro/patologia , Neoplasias Hematológicas/terapia , Humanos , Leucemia Linfocítica Granular Grande/induzido quimicamente , Leucemia Linfocítica Granular Grande/imunologia , Masculino , Pessoa de Meia-Idade , Prognóstico , Estudos Retrospectivos , Taxa de Sobrevida , Transplante Homólogo , Ativação Viral/efeitos dos fármacos , Adulto Jovem
3.
Methods Mol Biol ; 1881: 51-62, 2019.
Artigo em Inglês | MEDLINE | ID: mdl-30350197

RESUMO

The formation of B-cell receptor immunoglobulin (BcR IG) is the result of a multi-step process that starts at the pro-B cell stage with the VDJ gene recombination of IG genes of the heavy chain, followed by VJ recombination of the light chain genes at the pre-B II cell stage. As a result, a fully functional BcR IG is expressed on the surface of any given naive B cell. After antigen encounter, somatic hypermutation (SHM) and class-switch recombination (CSR) act on the rearranged IG genes within the context of affinity maturation, leading to the expression of a BcR IG with unique immunogenetic and functional characteristics. Since B-cell neoplasms arise from the transformation of a single B cell, this renders IG gene rearrangements ideal clonal markers as they will be identical in all neoplastic cells of each individual clone. Furthermore, the rearranged IG sequence can also serve as a cell development/maturation marker, given that its configuration is tightly linked to specific B-cell developmental stages. Finally, in certain instances, as in the case of chronic lymphocytic leukemia (CLL), the clonotypic IG sequence and, more specifically, the load of somatic hypermutations within the rearranged IG heavy variable (IGHV) gene, holds prognostic and potentially predictive value. However, in order to take full advantage of the information provided from the analysis of the clonotypic IG gene rearrangement sequences, robust methods and tools need to be applied. Here, we provide details regarding the methodologies necessary to ensure reliable IG sequence analysis based on the recognized expertise of the European Research initiative on CLL (ERIC). All methodological and analytical steps are described below, starting from the isolation of blood mononuclear cells (PBMC), moving to the identification of the clonotypic IG rearrangement and ending with the accurate interpretation of the SHM status.


Assuntos
Análise Mutacional de DNA/métodos , Genes de Imunoglobulinas/genética , Switching de Imunoglobulina/genética , Leucemia Linfocítica Crônica de Células B/genética , Receptores de Antígenos de Linfócitos B/genética , DNA/genética , DNA/isolamento & purificação , Análise Mutacional de DNA/instrumentação , Humanos , Leucemia Linfocítica Crônica de Células B/sangue , Leucócitos Mononucleares , RNA/genética , RNA/isolamento & purificação , Reação em Cadeia da Polimerase Via Transcriptase Reversa/instrumentação , Reação em Cadeia da Polimerase Via Transcriptase Reversa/métodos , Hipermutação Somática de Imunoglobulina
4.
J Pathol ; 247(4): 416-421, 2019 04.
Artigo em Inglês | MEDLINE | ID: mdl-30484876

RESUMO

The B cell receptor immunoglobulin (Ig) gene repertoires of marginal zone (MZ) lymphoproliferations were analyzed in order to obtain insight into their ontogenetic relationships. Our cohort included cases with MZ lymphomas (n = 488), i.e. splenic (SMZL), nodal (NMZL) and extranodal (ENMZL), as well as provisional entities (n = 76), according to the WHO classification. The most striking Ig gene repertoire skewing was observed in SMZL. However, restrictions were also identified in all other MZ lymphomas studied, particularly ENMZL, with significantly different Ig gene distributions depending on the primary site of involvement. Cross-entity comparisons of the MZ Ig sequence dataset with a large dataset of Ig sequences (MZ-related or not; n = 65 837) revealed four major clusters of cases sharing homologous ('public') heavy variable complementarity-determining region 3. These clusters included rearrangements from SMZL, ENMZL (gastric, salivary gland, ocular adnexa), chronic lymphocytic leukemia, but also rheumatoid factors and non-malignant splenic MZ cells. In conclusion, different MZ lymphomas display biased immunogenetic signatures indicating distinct antigen exposure histories. The existence of rare public stereotypes raises the intriguing possibility that common, pathogen-triggered, immune-mediated mechanisms may result in diverse B lymphoproliferations due to targeting versatile progenitor B cells and/or operating in particular microenvironments. Copyright © 2018 Pathological Society of Great Britain and Ireland. Published by John Wiley & Sons, Ltd.


Assuntos
Genes de Imunoglobulinas/genética , Linfoma de Zona Marginal Tipo Células B/genética , Regiões Determinantes de Complementaridade/genética , Rearranjo Gênico do Linfócito B/genética , Genes de Cadeia Pesada de Imunoglobulina/genética , Humanos , Região Variável de Imunoglobulina/genética , Mutação/genética , Receptores de Antígenos de Linfócitos B/genética , Microambiente Tumoral
5.
Haematologica ; 104(2): 360-369, 2019 02.
Artigo em Inglês | MEDLINE | ID: mdl-30262567

RESUMO

Chronic lymphocytic leukemia (CLL) patients with differential somatic hypermutation status of the immunoglobulin heavy variable genes, namely mutated or unmutated, display fundamental clinico-biological differences. Considering this, we assessed prognosis separately within mutated (M-CLL) and unmutated (U-CLL) CLL in 3015 patients, hypothesizing that the relative significance of relevant indicators may differ between these two categories. Within Binet A M-CLL patients, besides TP53 abnormalities, trisomy 12 and stereotyped subset #2 membership were equivalently associated with the shortest time-to-first-treatment and a treatment probability at five and ten years after diagnosis of 40% and 55%, respectively; the remaining cases exhibited 5-year and 10-year treatment probability of 12% and 25%, respectively. Within Binet A U-CLL patients, besides TP53 abnormalities, del(11q) and/or SF3B1 mutations were associated with the shortest time-to-first-treatment (5- and 10-year treatment probability: 78% and 98%, respectively); in the remaining cases, males had a significantly worse prognosis than females. In conclusion, the relative weight of indicators that can accurately risk stratify early-stage CLL patients differs depending on the somatic hypermutation status of the immunoglobulin heavy variable genes of each patient. This finding highlights the fact that compartmentalized approaches based on immunogenetic features are necessary to refine and tailor prognostication in CLL.


Assuntos
Biomarcadores Tumorais , Suscetibilidade a Doenças , Leucemia Linfocítica Crônica de Células B/etiologia , Leucemia Linfocítica Crônica de Células B/mortalidade , Idoso , Idoso de 80 Anos ou mais , Aberrações Cromossômicas , Feminino , Humanos , Imunogenética , Estimativa de Kaplan-Meier , Leucemia Linfocítica Crônica de Células B/patologia , Leucemia Linfocítica Crônica de Células B/terapia , Masculino , Mutação , Estadiamento de Neoplasias , Prognóstico , Tempo para o Tratamento
6.
Int J Cancer ; 144(11): 2695-2706, 2019 06 01.
Artigo em Inglês | MEDLINE | ID: mdl-30447004

RESUMO

Chronic lymphocytic leukemia (CLL) stereotyped subsets #6 and #8 include cases expressing unmutated B cell receptor immunoglobulin (BcR IG) (U-CLL). Subset #6 (IGHV1-69/IGKV3-20) is less aggressive compared to subset #8 (IGHV4-39/IGKV1(D)-39) which has the highest risk for Richter's transformation among all CLL. The underlying reasons for this divergent clinical behavior are not fully elucidated. To gain insight into this issue, here we focused on epigenomic signatures and their links with gene expression, particularly investigating genome-wide DNA methylation profiles in subsets #6 and #8 as well as other U-CLL cases not expressing stereotyped BcR IG. We found that subset #8 showed a distinctive DNA methylation profile compared to all other U-CLL cases, including subset #6. Integrated analysis of DNA methylation and gene expression revealed significant correlation for several genes, particularly highlighting a relevant role for the TP63 gene which was hypomethylated and overexpressed in subset #8. This observation was validated by quantitative PCR, which also revealed TP63 mRNA overexpression in additional nonsubset U-CLL cases. BcR stimulation had distinct effects on p63 protein expression, particularly leading to induction in subset #8, accompanied by increased CLL cell survival. This pro-survival effect was also supported by siRNA-mediated downregulation of p63 expression resulting in increased apoptosis. In conclusion, we report that DNA methylation profiles may vary even among CLL patients with similar somatic hypermutation status, supporting a compartmentalized approach to dissecting CLL biology. Furthermore, we highlight p63 as a novel prosurvival factor in CLL, thus identifying another piece of the complex puzzle of clinical aggressiveness.


Assuntos
Metilação de DNA/genética , Regulação Neoplásica da Expressão Gênica , Leucemia Linfocítica Crônica de Células B/genética , Receptores de Antígenos de Linfócitos B/metabolismo , Fatores de Transcrição/genética , Proteínas Supressoras de Tumor/genética , Apoptose/genética , Epigenômica/métodos , Feminino , Perfilação da Expressão Gênica/métodos , Humanos , Leucemia Linfocítica Crônica de Células B/sangue , Leucemia Linfocítica Crônica de Células B/patologia , Masculino , Cultura Primária de Células , Regiões Promotoras Genéticas/genética , RNA Interferente Pequeno/metabolismo , Análise de Sequência de RNA , Fatores de Transcrição/metabolismo , Células Tumorais Cultivadas , Proteínas Supressoras de Tumor/metabolismo , Regulação para Cima
7.
J Vis Exp ; (141)2018 11 26.
Artigo em Inglês | MEDLINE | ID: mdl-30531723

RESUMO

During B cell maturation, the complex process of immunoglobulin (IG) gene V(D)J recombination coupled with somatic hypermutation (SHM) gives rise to a unique DNA sequence within each individual B cell. Since B cell malignancies result from the clonal expansion of a single cell, IG genes represent a unique molecular signature common to all the malignant cells within an individual patient; thus, IG gene rearrangements can be used as clonal markers. In addition to serving as an important clonal identifier, the IG gene sequence can act as a 'molecular timeline' since it is associated with specific developmental stages and hence reflects the history of the B cell involved in the neoplastic transformation. Moreover, for certain malignancies, in particular chronic lymphocytic leukemia (CLL), the IG gene sequence holds prognostic and potentially predictive capabilities. That said, extrapolating meaningful conclusions from IG gene sequence analysis would be impossible if robust methods and tools were not available to aid in their analysis. This article, drawing on the vast experience of the European Research Initiative on CLL (ERIC), details the technical aspects and essential requirements necessary to ensure reliable and reproducible IG gene sequence analysis in CLL, a test that is now recommended for all CLL patients prior to treatment. More specifically, the various analytical stages are described ranging from the identification of the clonotypic IG gene rearrangement and the determination of the nucleotide sequence to the accurate clinical interpretation of the IG gene sequence data.


Assuntos
Linfócitos B/fisiologia , Genes de Imunoglobulinas/genética , Leucemia Linfocítica Crônica de Células B/genética , Análise de Sequência de Proteína/métodos , Linfócitos B/patologia , Sequência de Bases , Humanos , Região Variável de Imunoglobulina/genética , Leucemia Linfocítica Crônica de Células B/patologia
9.
Oncotarget ; 8(59): 99209-99210, 2017 Nov 21.
Artigo em Inglês | MEDLINE | ID: mdl-29245889
11.
Leuk Lymphoma ; 58(12): 2926-2933, 2017 12.
Artigo em Inglês | MEDLINE | ID: mdl-28535087

RESUMO

Chronic idiopathic neutropenia (CIN) is an acquired disorder of granulopoiesis characterized by female predominance and mostly uncomplicated course. Crucial to CIN pathophysiology is the presence of activated T lymphocytes with myelosuppressive properties in both peripheral blood (PB) and bone marrow (BM). We systematically profiled the T cell receptor beta chain (TRB) gene repertoire in CD8+ cells of 34 CIN patients through subcloning/Sanger sequencing analysis of TRBV-TRBD-TRBJ gene rearrangements. Remarkable repertoire skewing and oligoclonality were observed, along with shared clonotypes between different patients, alluding to antigen selection. Cross-comparison of our sequence dataset with public TRB sequence databases revealed that CIN may rarely share common immunogenetic features with other entities, however, the CIN TRB repertoire is largely disease-biased. Overall, these findings suggest that CIN may be driven by long-term exposure to a restricted set of specific CIN-associated antigens.


Assuntos
Regulação da Expressão Gênica , Neutropenia/etiologia , Receptores de Antígenos de Linfócitos T alfa-beta/genética , Linfócitos T Citotóxicos/imunologia , Linfócitos T Citotóxicos/metabolismo , Adulto , Idoso , Idoso de 80 Anos ou mais , Alelos , Doença Crônica , Feminino , Rearranjo Gênico da Cadeia beta dos Receptores de Antígenos dos Linfócitos T/genética , Antígenos HLA/genética , Humanos , Contagem de Leucócitos , Masculino , Pessoa de Meia-Idade , Mutação , Neutropenia/diagnóstico , Neutropenia/metabolismo , Receptores de Antígenos de Linfócitos T alfa-beta/metabolismo , Fator de Transcrição STAT3/genética , Adulto Jovem
12.
Am J Pathol ; 187(7): 1454-1458, 2017 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-28457696

RESUMO

To obtain insight into the ontogeny of mantle cell lymphoma (MCL), we assessed 206 patients from a morphological, immunohistochemical, and immunogenetic perspective. Our series included nodal (n = 151), extranodal (n = 28), and primary splenic (n = 27) MCL cases. Skewing of the immunoglobulin heavy variable (IGHV) gene repertoire was noted, with only four IGHV genes accounting for 46% of cases and approximately 70% of cases (107/154) bearing an imprint of somatic hypermutation (SHM) ranging from minimal to pronounced. Interestingly, a distinctive immunophenotypic and immunogenetic profile was identified for primary splenic MCL, which was enriched for DBA.44-positive cases (P < 0.001) and used the IGHV1-8 gene more frequently (P = 0.02) compared to nodal or extranodal cases, alluding to distinct immunopathogenetic and antigen selection processes. Expression of CD27 (considered a marker of activated B cells) was generally dissociated from SHM and was more prevalent in cases with no or minimal/borderline SHM. These findings support the idea that antigen drive is relevant for most MCL cases, although the specific antigens and the precise location of affinity maturation remain to be elucidated. Moreover, they raise the intriguing hypothesis of multiple cellular origins for MCL.


Assuntos
Biomarcadores Tumorais/genética , Imunogenética , Imunoglobulinas/genética , Linfoma de Célula do Manto/genética , Antígenos/genética , Antígenos/metabolismo , Biomarcadores Tumorais/metabolismo , Medula Óssea/metabolismo , Medula Óssea/patologia , Estudos de Coortes , Europa (Continente) , Humanos , Imunoglobulinas/metabolismo , Imuno-Histoquímica , Imunofenotipagem , Linfoma de Célula do Manto/imunologia , Linfoma de Célula do Manto/patologia , Baço/metabolismo , Baço/patologia , Membro 7 da Superfamília de Receptores de Fatores de Necrose Tumoral/genética , Membro 7 da Superfamília de Receptores de Fatores de Necrose Tumoral/metabolismo
14.
BMC Bioinformatics ; 17 Suppl 5: 173, 2016 Jun 06.
Artigo em Inglês | MEDLINE | ID: mdl-27295298

RESUMO

BACKGROUND: Somatic Hypermutation (SHM) refers to the introduction of mutations within rearranged V(D)J genes, a process that increases the diversity of Immunoglobulins (IGs). The analysis of SHM has offered critical insight into the physiology and pathology of B cells, leading to strong prognostication markers for clinical outcome in chronic lymphocytic leukaemia (CLL), the most frequent adult B-cell malignancy. In this paper we present a methodology for integrating multiple immunogenetic and clinocobiological data sources in order to extract features and create high quality datasets for SHM analysis in IG receptors of CLL patients. This dataset is used as the basis for a higher level integration procedure, inspired form social choice theory. This is applied in the Towards Analysis, our attempt to investigate the potential ontogenetic transformation of genes belonging to specific stereotyped CLL subsets towards other genes or gene families, through SHM. RESULTS: The data integration process, followed by feature extraction, resulted in the generation of a dataset containing information about mutations occurring through SHM. The Towards analysis performed on the integrated dataset applying voting techniques, revealed the distinct behaviour of subset #201 compared to other subsets, as regards SHM related movements among gene clans, both in allele-conserved and non-conserved gene areas. With respect to movement between genes, a high percentage movement towards pseudo genes was found in all CLL subsets. CONCLUSIONS: This data integration and feature extraction process can set the basis for exploratory analysis or a fully automated computational data mining approach on many as yet unanswered, clinically relevant biological questions.


Assuntos
Imunogenética/métodos , Leucemia Linfocítica Crônica de Células B/genética , Hipermutação Somática de Imunoglobulina/genética , Adulto , Bases de Dados Genéticas , Feminino , Mutação em Linhagem Germinativa , Humanos , Região Variável de Imunoglobulina/genética , Imunoglobulinas/genética , Leucemia Linfocítica Crônica de Células B/patologia
15.
Haematologica ; 101(8): 959-67, 2016 08.
Artigo em Inglês | MEDLINE | ID: mdl-27198719

RESUMO

We report on markedly different frequencies of genetic lesions within subsets of chronic lymphocytic leukemia patients carrying mutated or unmutated stereotyped B-cell receptor immunoglobulins in the largest cohort (n=565) studied for this purpose. By combining data on recurrent gene mutations (BIRC3, MYD88, NOTCH1, SF3B1 and TP53) and cytogenetic aberrations, we reveal a subset-biased acquisition of gene mutations. More specifically, the frequency of NOTCH1 mutations was found to be enriched in subsets expressing unmutated immunoglobulin genes, i.e. #1, #6, #8 and #59 (22-34%), often in association with trisomy 12, and was significantly different (P<0.001) to the frequency observed in subset #2 (4%, aggressive disease, variable somatic hypermutation status) and subset #4 (1%, indolent disease, mutated immunoglobulin genes). Interestingly, subsets harboring a high frequency of NOTCH1 mutations were found to carry few (if any) SF3B1 mutations. This starkly contrasts with subsets #2 and #3 where, despite their immunogenetic differences, SF3B1 mutations occurred in 45% and 46% of cases, respectively. In addition, mutations within TP53, whilst enriched in subset #1 (16%), were rare in subsets #2 and #8 (both 2%), despite all being clinically aggressive. All subsets were negative for MYD88 mutations, whereas BIRC3 mutations were infrequent. Collectively, this striking bias and skewed distribution of mutations and cytogenetic aberrations within specific chronic lymphocytic leukemia subsets implies that the mechanisms underlying clinical aggressiveness are not uniform, but rather support the existence of distinct genetic pathways of clonal evolution governed by a particular stereotyped B-cell receptor selecting a certain molecular lesion(s).


Assuntos
Biomarcadores Tumorais , Leucemia Linfocítica Crônica de Células B/genética , Leucemia Linfocítica Crônica de Células B/metabolismo , Mutação , Receptores de Antígenos de Linfócitos B/genética , Receptores de Antígenos de Linfócitos B/metabolismo , Regiões Determinantes de Complementaridade/genética , Análise Citogenética , Feminino , Frequência do Gene , Rearranjo Gênico do Linfócito B , Genes de Imunoglobulinas , Humanos , Cadeias Pesadas de Imunoglobulinas/genética , Região de Junção de Imunoglobulinas/genética , Região Variável de Imunoglobulina/genética , Leucemia Linfocítica Crônica de Células B/mortalidade , Masculino , Polimorfismo de Nucleotídeo Único , Prognóstico
17.
Clin Cancer Res ; 22(8): 2032-40, 2016 Apr 15.
Artigo em Inglês | MEDLINE | ID: mdl-26647217

RESUMO

PURPOSE: Prompted by the extensive biases in the immunoglobulin (IG) gene repertoire of splenic marginal-zone lymphoma (SMZL), supporting antigen selection in SMZL ontogeny, we sought to investigate whether antigen involvement is also relevant post-transformation. EXPERIMENTAL DESIGN: We conducted a large-scale subcloning study of the IG rearrangements of 40 SMZL cases aimed at assessing intraclonal diversification (ID) due to ongoing somatic hypermutation (SHM). RESULTS: ID was identified in 17 of 21 (81%) rearrangements using the immunoglobulin heavy variable (IGHV)1-2*04 gene versus 8 of 19 (40%) rearrangements utilizing other IGHV genes (P= 0.001). ID was also evident in most analyzed IG light chain gene rearrangements, albeit was more limited compared with IG heavy chains. Identical sequence changes were shared by subclones from different patients utilizing the IGHV1-2*04 gene, confirming restricted ongoing SHM profiles. Non-IGHV1-2*04 cases displayed both a lower number of ongoing SHMs and a lack of shared mutations (per group of cases utilizing the same IGHV gene). CONCLUSIONS: These findings support ongoing antigen involvement in a sizable portion of SMZL and further argue that IGHV1-2*04 SMZL may represent a distinct molecular subtype of the disease.


Assuntos
Alelos , Antígenos/imunologia , Linfoma de Zona Marginal Tipo Células B/genética , Linfoma de Zona Marginal Tipo Células B/imunologia , Receptores de Antígenos de Linfócitos B/genética , Neoplasias Esplênicas/genética , Neoplasias Esplênicas/imunologia , Motivos de Aminoácidos , Sequência de Aminoácidos , Substituição de Aminoácidos , Regiões Determinantes de Complementaridade/química , Regiões Determinantes de Complementaridade/genética , Perfilação da Expressão Gênica , Rearranjo Gênico de Cadeia Pesada de Linfócito B , Humanos , Cadeias Pesadas de Imunoglobulinas/química , Cadeias Pesadas de Imunoglobulinas/genética , Região Variável de Imunoglobulina/química , Região Variável de Imunoglobulina/genética , Linfoma de Zona Marginal Tipo Células B/patologia , Modelos Biológicos , Mutação , Neoplasias Esplênicas/patologia , Transcriptoma
18.
Clin Cancer Res ; 22(1): 167-74, 2016 Jan 01.
Artigo em Inglês | MEDLINE | ID: mdl-26338994

RESUMO

PURPOSE: The role of antigen(s) in shaping the T-cell repertoire in chronic lymphocytic leukemia, although relevant for understanding malignant cell interactions with cognate T cells, is largely unexplored. EXPERIMENTAL DESIGN: Here we profiled the T-cell receptor ß chain gene repertoire in 58 chronic lymphocytic leukemia patients, focusing on cases assigned to well-characterized subsets with stereotyped clonotypic B-cell receptor immunoglobulins, therefore those cases most evidently selected by antigen (subsets #1, #2, and #4). RESULTS: Remarkable repertoire skewing and oligoclonality were observed, and differences between subsets were noted regarding both T-cell receptor ß chain gene usage and the extent of clonality, with subset #2 being the least oligoclonal. Longitudinal analysis of subset #4 cases revealed that although the repertoire may fluctuate over time, certain clonotypes persist, thus alluding to persistent antigenic stimulation. Shared ("stereotyped") clonotypes were found between different patients, reflecting selection by common antigenic elements. Cross-comparison of our dataset with public databases showed that some T-cell clonotypes may have expanded secondary to common viral infections; however, the majority of clonotypes proved to be disease-specific. CONCLUSIONS: Overall, the T-cell receptor ß chain repertoire in chronic lymphocytic leukemia is likely shaped by antigen selection and the implicated antigenic elements may concern epitopes that also select the malignant B-cell progenitors or, more intriguingly, chronic lymphocytic leukemia-derived epitopes.


Assuntos
Seleção Clonal Mediada por Antígeno/imunologia , Epitopos de Linfócito T/imunologia , Leucemia Linfocítica Crônica de Células B/imunologia , Linfócitos T/imunologia , Linfócitos T/metabolismo , Idoso , Idoso de 80 Anos ou mais , Estudos de Casos e Controles , Evolução Clonal/genética , Bases de Dados Genéticas , Rearranjo Gênico , Humanos , Leucemia Linfocítica Crônica de Células B/genética , Pessoa de Meia-Idade , Receptores de Antígenos de Linfócitos T alfa-beta/genética , Receptores de Antígenos de Linfócitos T alfa-beta/metabolismo
19.
Bioinformatics ; 31(23): 3844-6, 2015 Dec 01.
Artigo em Inglês | MEDLINE | ID: mdl-26249808

RESUMO

MOTIVATION: An ever-increasing body of evidence supports the importance of B cell receptor immunoglobulin (BcR IG) sequence restriction, alias stereotypy, in chronic lymphocytic leukemia (CLL). This phenomenon accounts for ∼30% of studied cases, one in eight of which belong to major subsets, and extends beyond restricted sequence patterns to shared biologic and clinical characteristics and, generally, outcome. Thus, the robust assignment of new cases to major CLL subsets is a critical, and yet unmet, requirement. RESULTS: We introduce a novel application, ARResT/AssignSubsets, which enables the robust assignment of BcR IG sequences from CLL patients to major stereotyped subsets. ARResT/AssignSubsets uniquely combines expert immunogenetic sequence annotation from IMGT/V-QUEST with curation to safeguard quality, statistical modeling of sequence features from more than 7500 CLL patients, and results from multiple perspectives to allow for both objective and subjective assessment. We validated our approach on the learning set, and evaluated its real-world applicability on a new representative dataset comprising 459 sequences from a single institution. AVAILABILITY AND IMPLEMENTATION: ARResT/AssignSubsets is freely available on the web at http://bat.infspire.org/arrest/assignsubsets/ CONTACT: nikos.darzentas@gmail.com. SUPPLEMENTARY INFORMATION: Supplementary data are available at Bioinformatics online.


Assuntos
Leucemia Linfocítica Crônica de Células B/classificação , Receptores de Antígenos de Linfócitos B/genética , Análise de Sequência de DNA/métodos , Humanos , Modelos Estatísticos
SELEÇÃO DE REFERÊNCIAS
DETALHE DA PESQUISA