RESUMO
This retrospective multicenter study in patients with chronic myeloid leukemia in chronic phase was undertaken to confirm the clinical relevance of imatinib plasma concentrations monitoring in daily practice. Forty-one patients, with 47 imatinib plasma measurements, were analyzed during treatment with imatinib given at a fixed 400mg daily dose. A significant inverse relationship of imatinib concentration with the patients' weight was observed (Pearson's test: p=0.02, R2=0.1). More interestingly, patients with poor response (switched to another tyrosine kinase inhibitor because of imatinib failure, or because of disease progression after an initial response) displayed a significantly lower mean imatinib concentration as compared to patients maintained on imatinib (822ng/mL vs 1099ng/mL; Student's t-test, p=0.04). Failure or disease progression occurred more often in patients in the lowest quartile of imatinib concentrations compared to patients in the highest quartile (p=0.02, logrank test). No correlation could be established with other biological or clinical parameter, including complete cytogenic response and major molecular response. IN CONCLUSION: in patients treated with imatinib at a fixed daily dose of 400mg, imatinib plasma concentrations decreased with increasing body weight and were lower in patients switched to another tyrosine kinase inhibitor due to imatinib failure. Systematic determination of imatinib plasma trough levels should be encouraged in such patients.
Assuntos
Monitoramento de Medicamentos/métodos , Mesilato de Imatinib/farmacocinética , Leucemia Mielogênica Crônica BCR-ABL Positiva/sangue , Leucemia Mielogênica Crônica BCR-ABL Positiva/tratamento farmacológico , Adolescente , Adulto , Idoso , Idoso de 80 Anos ou mais , Bélgica , Feminino , Humanos , Mesilato de Imatinib/administração & dosagem , Masculino , Pessoa de Meia-Idade , Estudos RetrospectivosAssuntos
Doenças dos Ductos Biliares/diagnóstico , Linfoma Difuso de Grandes Células B/complicações , Protocolos de Quimioterapia Combinada Antineoplásica/uso terapêutico , Doenças dos Ductos Biliares/tratamento farmacológico , Doenças dos Ductos Biliares/etiologia , Humanos , Linfoma Difuso de Grandes Células B/tratamento farmacológico , Masculino , Pessoa de Meia-Idade , Síndromes Paraneoplásicas , Indução de Remissão , Resultado do TratamentoRESUMO
The functional evaluation of ataxia telangiectasia mutated (ATM) and p53 was recently developed in B-cell chronic lymphocytic leukaemia (B-CLL), a disease in which the response to DNA damage is frequently altered. We identified a novel biomarker of chemosensitivity based on the induction of DNA damage by the purine nucleoside analogues (PNA) fludarabine and 2-chlorodeoxyadenosine (CdA). Using genome-wide expression profiling, it was observed that, in chemosensitive samples, PNA predominantly increased the expression of p53-dependent genes, among which PLK2 was the most highly activated at early time points. Conversely, in chemoresistant samples, p53-dependent and PLK2 responses were abolished. Using a quantitative real time polymerase chain reaction, we confirmed that PNA dose- and time-dependently increased PLK2 expression in chemosensitive but not chemoresistant B-CLL samples. Analysis of a larger cohort of B-CLL patients showed that cytotoxicity induced by PNA correlated well with PLK2 mRNA induction. Interestingly, we observed that failure to up-regulate PLK2 following PNA and chemoresistance were not strictly correlated with structural alterations in the TP53 gene. In conclusion, we propose that testing PLK2 activation after a 24-h incubation with PNA could be used to investigate the functional integrity of DNA damage-response pathways in B-CLL cells, and predict clinical sensitivity to these drugs.
Assuntos
Antineoplásicos/farmacologia , Biomarcadores Tumorais/biossíntese , Leucemia Linfocítica Crônica de Células B/enzimologia , Proteínas Serina-Treonina Quinases/biossíntese , Regulação para Cima/efeitos dos fármacos , Idoso , Idoso de 80 Anos ou mais , Biomarcadores Tumorais/genética , Morte Celular/efeitos dos fármacos , Cladribina/farmacologia , Estudos de Coortes , Dano ao DNA , DNA de Neoplasias/genética , Resistencia a Medicamentos Antineoplásicos , Feminino , Perfilação da Expressão Gênica/métodos , Regulação Enzimológica da Expressão Gênica/efeitos dos fármacos , Humanos , Leucemia Linfocítica Crônica de Células B/genética , Masculino , Pessoa de Meia-Idade , Análise de Sequência com Séries de Oligonucleotídeos/métodos , Proteínas Serina-Treonina Quinases/genética , RNA Mensageiro/genética , RNA Neoplásico/genética , Reação em Cadeia da Polimerase Via Transcriptase Reversa/métodos , Células Tumorais Cultivadas , Vidarabina/análogos & derivados , Vidarabina/farmacologiaRESUMO
From cancerous and non-cancerous patients, we derived stable clones of CD4(+) Treg, defined as clones that expressed high CD25 at rest, were anergic in vitro, and suppressed the proliferation of co-cultured CD4(+) cells. A conserved region of FOXP3 intron 1 was demethylated in all Treg clones, whereas it was methylated in non-regulatory Th and CTL clones. In our panel of human clones, this stable epigenetic mark correlated better with suppressive activity than did FOXP3 mRNA or protein expression. We used expression microarrays to compare Treg and Th clones after activation, which is required for suppressive function. The transcriptional profile that is specific of activated Treg clones includes a TGF-beta signature. Both activated Treg and Th clones produced the latent form of TGF-beta. However, SMAD2 phosphorylation was observed after activation in the Treg but not in the Th clones, indicating that only activated Treg clones produced the bioactive form of TGF-beta. A TGF-beta signature was also displayed by a Th clone "suppressed" by a Treg clone. In conclusion, the hallmark of our panel of activated human Treg clones is to produce bioactive TGF-beta which has autocrine actions on Tregs and can have paracrine actions on other T cells.
Assuntos
Fatores de Transcrição Forkhead/imunologia , Proteína Smad2/imunologia , Linfócitos T Auxiliares-Indutores/imunologia , Linfócitos T Reguladores/imunologia , Fator de Crescimento Transformador beta/imunologia , Células Clonais/imunologia , Células Clonais/metabolismo , Metilação de DNA/genética , Metilação de DNA/imunologia , Feminino , Fatores de Transcrição Forkhead/genética , Fatores de Transcrição Forkhead/metabolismo , Perfilação da Expressão Gênica , Humanos , Ativação Linfocitária/genética , Ativação Linfocitária/imunologia , Masculino , Melanoma/imunologia , Melanoma/metabolismo , Neoplasias Cutâneas/imunologia , Neoplasias Cutâneas/metabolismo , Proteína Smad2/metabolismo , Linfócitos T Auxiliares-Indutores/metabolismo , Linfócitos T Reguladores/metabolismo , Fator de Crescimento Transformador beta/metabolismoRESUMO
Tumor regressions have been observed in a small proportion of melanoma patients vaccinated with a MAGE-A3 peptide presented by HLA-A1, administered as peptide, ALVAC canarypox virus containing a MAGE-A3 minigene, or peptide-pulsed dendritic cells (DC). There was a correlation between tumor regression and the detection of anti-MAGE-3.A1 CTL responses. These responses were monoclonal and often of a very low magnitude after vaccination with peptide or ALVAC, and usually polyclonal and of a higher magnitude after DC vaccination. These results suggested that, at least in some patients, surprisingly few anti-MAGE-3.A1 T-cells could initiate a tumor regression process. To understand the role of these T cells, we carried out a functional analysis of anti-MAGE-3.A1 CTL clones derived from vaccinated patients who displayed tumor regression. The functional avidities of these CTL clones, evaluated in lysis assays, were surprisingly low, suggesting that high avidity was not part of the putative capability of these CTL to trigger tumor rejection. Most anti-MAGE-3.A1 CTL clones obtained after DC vaccination, but not after peptide or ALVAC vaccination, produced interleukin 10. Transcript profiling confirmed these results and indicated that approximately 20 genes, including CD40L, prostaglandin D2 synthase, granzyme K, and granzyme H, were highly differentially expressed between the anti-MAGE-3.A1 CTL clones derived from patients vaccinated with either peptide-ALVAC or peptide-pulsed DC. These results indicate that the modality of vaccination with a tumor-specific antigen influences the differentiation pathway of the antivaccine CD8 T-cells, which may have an effect on their capacity to trigger a tumor rejection response.
Assuntos
Antígenos de Neoplasias/química , Vacinas Anticâncer , Antígeno HLA-A1/química , Melanoma/imunologia , Melanoma/patologia , Proteínas de Neoplasias/química , Antígenos de Neoplasias/metabolismo , Ligante de CD40/biossíntese , Comunicação Celular , Células Dendríticas/metabolismo , Perfilação da Expressão Gênica , Regulação Neoplásica da Expressão Gênica , Humanos , Modelos Biológicos , Análise de Sequência com Séries de Oligonucleotídeos , Peptídeos/químicaAssuntos
Antibióticos Antineoplásicos/efeitos adversos , Bleomicina/efeitos adversos , Fluordesoxiglucose F18 , Doença de Hodgkin/tratamento farmacológico , Pneumonia/induzido quimicamente , Adulto , Diagnóstico Precoce , Humanos , Masculino , Pessoa de Meia-Idade , Tomografia por Emissão de PósitronsRESUMO
In recent years, several clinical trials have involved the vaccination of cancer patients with tumor-specific antigens that are recognized by T lymphocytes. Anti-vaccine T-cell responses in these patients have been monitored on the assumption that their magnitude would correlate with clinical efficacy. Although analysis of these data show that such a correlation is emerging, detailed analyses of the few patients who benefit clinically from the vaccinations suggest that the function of the anti-vaccine T cells might be more important than their number. Recent studies show that in cancer patients numerous tumor-specific T cells appear to be quiescent in the presence of the tumor. Understanding how an efficient vaccine interferes with this coexistence is one of the current challenges of cancer immunotherapy.
Assuntos
Antígenos de Neoplasias/imunologia , Vacinas Anticâncer/imunologia , Linfócitos do Interstício Tumoral/imunologia , Animais , Vacinas Anticâncer/administração & dosagem , Humanos , Contagem de Linfócitos , Camundongos , Neoplasias/imunologia , Neoplasias/prevenção & controleRESUMO
The cancer-germline gene MAGE-3 codes for tumor-specific antigens recognized on many tumors by T lymphocytes. A MAGE-3 antigen presented by HLA-A1 has been used in several vaccination trials on metastatic melanoma patients. Only a small minority of patients have shown evidence of tumor regression. Attempts to correlate the tumor rejections with the cytotoxic T lymphocyte (CTL) response against the vaccine have been hampered by the low level of these responses. In noncancerous individuals, the frequency of the T cell precursors against antigen MAGE-3.A1 is approximately 4 x 10(-7) CD8 T cells. The diversity of the T cell receptor repertoire of these anti-MAGE-3.A1 precursors was analyzed in one individual. The results indicate that it is very likely that the repertoire comprises >100 clonotypes. On this basis, it is possible to use not only the frequency of CTL precursors in the blood but also the presence of dominant clonotypes to ascertain in patients the existence of anti-MAGE-3.A1 responses as low as 10(-6) of CD8. With this approach, we observed a correlation between tumor regression and anti-MAGE-3.A1 CTL responses in patients vaccinated with a recombinant virus encoding the antigen and also in patients vaccinated with peptide-pulsed dendritic cells. In contrast, for patients showing tumor regression after vaccination with peptide alone, CTL responses were almost never observed. It is possible that even those CTL responses that are below our present detection level can trigger a sequence of events that leads to tumor regression.
Assuntos
Antígenos de Neoplasias , Vacinas Anticâncer/uso terapêutico , Melanoma/imunologia , Melanoma/terapia , Proteínas de Neoplasias , Linfócitos T Citotóxicos/imunologia , Sequência de Aminoácidos , Antígenos de Neoplasias/genética , Vírus da Varíola dos Canários/genética , Vacinas Anticâncer/genética , Vacinas Anticâncer/imunologia , Linhagem Celular Tumoral , Regiões Determinantes de Complementaridade , Citotoxicidade Imunológica , Células Dendríticas/imunologia , Humanos , Técnicas In Vitro , Melanoma/secundário , Proteínas de Neoplasias/genéticaRESUMO
We have analyzed the T cell responses of HLA-A1 metastatic melanoma patients with detectable disease, following vaccination with a recombinant ALVAC virus, which bears short MAGE-1 and MAGE-3 sequences coding for antigenic peptides presented by HLA-A1. To evaluate the anti-MAGE CTL responses, we resorted to antigenic stimulation of blood lymphocytes under limiting dilution conditions, followed by tetramer analysis and cloning of the tetramer-positive cells. The clones were tested for their specific lytic ability and their TCR sequences were obtained. Four patients who showed tumor regression were analyzed, and an anti-MAGE-3.A1 CTL response was observed in three of these patients. Postvaccination frequencies of anti-MAGE-3.A1 CTL were 3 x 10(-6), 3 x 10(-3), and 3 x 10(-7) of the blood CD8 T cells, respectively. These three responses were monoclonal. No anti-MAGE-1.A1 CTL response was observed. These results indicate that, like peptide immunization, ALVAC immunization produces monoclonal responses. They also suggest that low-level antivaccine CTL responses can initiate a tumor regression process. Taken together, our analysis of anti-MAGE-3.A1 T cell responses following peptide or ALVAC vaccination shows a degree of correlation between CTL response and tumor regression, but firm conclusions will require larger numbers.
Assuntos
Antígenos de Neoplasias/imunologia , Vírus da Varíola dos Canários/imunologia , Vacinas Anticâncer/imunologia , Melanoma/imunologia , Melanoma/prevenção & controle , Proteínas de Neoplasias/imunologia , Linfócitos T Citotóxicos/imunologia , Antígenos de Neoplasias/administração & dosagem , Antígenos de Neoplasias/genética , Vírus da Varíola dos Canários/genética , Vacinas Anticâncer/administração & dosagem , Vacinas Anticâncer/genética , Células Clonais , Feminino , Humanos , Injeções Intradérmicas , Injeções Subcutâneas , Metástase Linfática/imunologia , Metástase Linfática/prevenção & controle , Melanoma/secundário , Proteínas de Neoplasias/administração & dosagem , Proteínas de Neoplasias/genética , Reação em Cadeia da Polimerase , Receptores de Antígenos de Linfócitos T/biossíntese , Receptores de Antígenos de Linfócitos T/sangue , Linfócitos T Citotóxicos/metabolismo , Vacinas de Subunidades Antigênicas/administração & dosagem , Vacinas de Subunidades Antigênicas/genética , Vacinas de Subunidades Antigênicas/imunologia , Vacinas Sintéticas/administração & dosagem , Vacinas Sintéticas/genética , Vacinas Sintéticas/imunologia , Vacinas Virais/administração & dosagem , Vacinas Virais/genética , Vacinas Virais/imunologiaRESUMO
The specificity of recognition of pMHC complexes by T lymphocytes is determined by the V regions of the TCR alpha- and beta-chains. Recent experimental evidence has suggested that Ag-specific TCR repertoires may exhibit a more V alpha- than V beta-restricted usage. Whether V alpha usage is narrowed during immune responses to Ag or if, on the contrary, restricted V alpha usage is already defined at the early stages of TCR repertoire selection, however, has remained unexplored. Here, we analyzed V and CDR3 TCR regions of single circulating naive T cells specifically detected ex vivo and isolated with HLA-A2/melan-A peptide multimers. Similarly to what was previously observed for melan-A-specific Ag-experienced T cells, we found a relatively wide V beta usage, but a preferential V alpha 2.1 usage. Restricted V alpha 2.1 usage was also found among single CD8(+) A2/melan-A multimer(+) thymocytes, indicating that V alpha-restricted selection takes place in the thymus. V alpha 2.1 usage, however, was independent from functional avidity of Ag recognition. Thus, interaction of the pMHC complex with selected V alpha-chains contributes to set the broad Ag specificity, as underlined by preferential binding of A2/melan-A multimers to V alpha 2.1-bearing TCRs, whereas functional outcomes result from the sum of these with other interactions between pMHC complex and TCR.
Assuntos
Autoantígenos/imunologia , Epitopos de Linfócito T/imunologia , Rearranjo Gênico da Cadeia alfa dos Receptores de Antígenos dos Linfócitos T/fisiologia , Antígeno HLA-A2/imunologia , Melanoma/imunologia , Proteínas de Neoplasias/imunologia , Receptores de Antígenos de Linfócitos T alfa-beta/fisiologia , Sequência de Aminoácidos , Antígenos de Neoplasias , Autoantígenos/genética , Autoantígenos/metabolismo , Diferenciação Celular/genética , Diferenciação Celular/imunologia , Células Clonais , Citotoxicidade Imunológica/genética , Epitopos de Linfócito T/biossíntese , Epitopos de Linfócito T/genética , Epitopos de Linfócito T/metabolismo , Rearranjo Gênico da Cadeia beta dos Receptores de Antígenos dos Linfócitos T/fisiologia , Antígeno HLA-A2/biossíntese , Antígeno HLA-A2/genética , Antígeno HLA-A2/metabolismo , Células-Tronco Hematopoéticas/imunologia , Células-Tronco Hematopoéticas/metabolismo , Humanos , Antígeno MART-1 , Melanoma/genética , Dados de Sequência Molecular , Proteínas de Neoplasias/genética , Proteínas de Neoplasias/metabolismo , RNA Mensageiro/análise , Receptores de Antígenos de Linfócitos T alfa-beta/biossíntese , Receptores de Antígenos de Linfócitos T alfa-beta/genética , Reação em Cadeia da Polimerase Via Transcriptase Reversa , Linfócitos T Citotóxicos/imunologia , Linfócitos T Citotóxicos/metabolismo , Células Tumorais CultivadasRESUMO
'Cancer-germline' genes such as the MAGE gene family are expressed in many tumors and in male germline cells but not in normal tissues. They encode shared tumor-specific antigens, which have been used in therapeutic vaccination trials of metastatic melanoma patients. To establish whether there is a correlation between tumoral regressions and T-cell responses against the vaccine antigen, we evaluated the responses of patients vaccinated with a MAGE-3 antigenic peptide or a recombinant virus coding for the peptide. Blood lymphocytes were stimulated with antigenic peptide followed by detection with tetramer, T-cell cloning, and TCR analysis. In 4/9 regressor patients and in 1/14 progressors we found a low level, usually monoclonal cytolytic T lymphocyte response against the MAGE-3 peptide.
Assuntos
Antígenos de Neoplasias/imunologia , Vacinas Anticâncer/uso terapêutico , Imunoterapia Ativa , Melanoma/terapia , Proteínas de Neoplasias/imunologia , Linfócitos T Citotóxicos/imunologia , Citotoxicidade Imunológica , Progressão da Doença , Evolução Fatal , Feminino , Rearranjo Gênico do Linfócito T , Vetores Genéticos/imunologia , Humanos , Imunidade Celular , Ativação Linfocitária , Melanoma/imunologia , Melanoma/patologia , Metástase Neoplásica , Fragmentos de Peptídeos/imunologia , Receptores de Antígenos de Linfócitos T alfa-beta/genética , Indução de Remissão , Neoplasias Cutâneas/imunologia , Neoplasias Cutâneas/terapia , Resultado do Tratamento , Vacinação , Vacinas de Subunidades Antigênicas/imunologia , Vacinas Sintéticas/imunologia , Vacinas ViraisRESUMO
We have studied the TCR features and functional responses of three sets of human cytolytic T cell (CTL) clones, recognizing antigenic peptides presented by HLA-A2 and derived from the Epstein-Barr virus proteins BMLF1 and BRLF1 and from the melanoma protein Melan-A/MART-1. Within each set, a majority of clones used a recurrent V alpha region, even though they expressed highly diverse TCR beta chains and V(D)J junctional sequences. Functional assays and peptide/MHC multimer binding studies indicated that this restricted V alpha usage was not associated with the affinity/avidity of the CTL clones. The V alpha dominance, which may be a frequent feature of antigen-specific T cells, likely reflects a restricted geometry of TCR/peptide/MHC complexes, primarily determined by V alpha CDR.