RESUMO
The European prototype of hantavirus, Puumala virus (PUUV), isolated from a common wild rodent, the bank vole (Myodes glareolus), causes nephropathia epidemica (NE). NE can perfectly mimic haemolytic-uraemic syndrome (HUS), progressing from an aspecific flu-like syndrome to acute kidney injury with thrombocytopaenia, and presenting with some signs of haemolytic anaemia and/or coagulopathy. Moreover, both NE and HUS can occur in local outbreaks. We report an isolated case of NE, initially referred for plasmapheresis for suspected HUS, although signs of overt haemolysis were lacking. Early suspicion of hantavirus infection, later confirmed by serology and reverse transcription polymerase chain reaction (RT-PCR), prevented subsequent excessive treatment modalities.
Assuntos
Febre Hemorrágica com Síndrome Renal/diagnóstico , Virus Puumala/isolamento & purificação , Doenças dos Roedores/transmissão , Injúria Renal Aguda/virologia , Animais , Arvicolinae/virologia , Diagnóstico Diferencial , Síndrome Hemolítico-Urêmica/diagnóstico , Febre Hemorrágica com Síndrome Renal/terapia , Febre Hemorrágica com Síndrome Renal/virologia , Humanos , Masculino , Pessoa de Meia-Idade , Doenças dos Roedores/virologia , Trombocitopenia/virologiaRESUMO
HLA-C*05:99N results from a single nucleotide loss compared with its closest allele HLA-C*05:01:01:01.
Assuntos
Alelos , Antígenos HLA-C/genética , HumanosRESUMO
Many studies have demonstrated the role of the adaptive immune system in the pathogenesis of multiple sclerosis (MS). Recent data suggest that dendritic cells (DCs), which are innate immune cells, also contribute to the pathogenesis of MS. In patients with MS, DCs are abundantly present in brain lesions, and display an altered phenotype and/or function as compared with this in healthy controls. DCs are thus in the position to pathologically influence the effector function of (auto-reactive) T and B cells. Interestingly, current first-line immunomodulating therapies for MS have been shown to restore DC phenotype and function, albeit in a non-specific manner. To date, clinical trials using agents specifically targeting DC function are ongoing. Moreover, several studies worldwide are currently investigating possible strategies to develop tolerogenic DCs. This review focuses on the phenotypic and functional alterations of conventional DCs and plasmacytoid DCs in patients with MS. Furthermore, we discuss how existing immunomodulating therapies for MS patients affect DC function and address future perspectives in the development of immunotherapies specifically targeting DCs.
Assuntos
Células Dendríticas/imunologia , Imunoterapia/métodos , Esclerose Múltipla/imunologia , Animais , Humanos , Imunidade Celular , Imunoterapia/tendências , Esclerose Múltipla/terapiaRESUMO
To assess the effects of interferon gamma (IFN-gamma) on very primitive hematopoietic progenitor cells, CD34(2+)CD38- human bone marrow cells were isolated and cultured in a two-stage culture system, consisting of a primary liquid culture phase followed by a secondary semisolid colony assay. CD34(2+)CD38- cells needed at least the presence of interleukin 3 (IL-3) and kit ligand (KL) together with either IL-1, IL-6, or granulocyte-colony-stimulating factor (G-CSF) in the primary liquid phase in order to proliferate and differentiate into secondary colony-forming cells (CFC). Addition of IFN-gamma to the primary liquid cultures inhibited cell proliferation and generation of secondary CFC in a dose-dependent way. This was a direct effect since it was also seen in primary single cell cultures of CD34(2+)CD38- cells. The proliferation of more mature CD34+CD38+ cells, however, was not inhibited by IFN-gamma, demonstrating for the first time that IFN-gamma is a specific and direct hematopoietic stem cell inhibitor. IFN-gamma, moreover, preserves the viability of CD34(2+)CD38- cells in the absence of other cytokines. IFN-gamma could, therefore, play a role in the protection of the stem cell compartment from exhaustion in situations of hematopoietic stress and may be useful as stem cell protecting agent against chemotherapy for cancer.
Assuntos
Antígenos CD/análise , Antígenos de Diferenciação/análise , Células-Tronco Hematopoéticas/efeitos dos fármacos , Interferon gama/farmacologia , ADP-Ribosil Ciclase , ADP-Ribosil Ciclase 1 , Antígenos CD34 , Diferenciação Celular/efeitos dos fármacos , Divisão Celular/efeitos dos fármacos , Sobrevivência Celular/efeitos dos fármacos , Células-Tronco Hematopoéticas/imunologia , Células-Tronco Hematopoéticas/fisiologia , Humanos , Glicoproteínas de MembranaRESUMO
Since tumor necrosis factor (TNF)-alpha, interferon (IFN)-gamma, and transforming growth factor (TGF)-beta have all been shown to be specific inhibitors of early human hematopoiesis, we wanted to investigate the interactions of these three cytokines on very primitive human adult bone marrow CD34++CD38- hematopoietic progenitor cells, using a pre-colony-forming cell (pre-CFC) assay, which detects the effects of these cytokines on the initial phases of the differentiation of these primitive progenitors, which are unresponsive to interleukin (IL) 3 alone. Surprisingly, TNF-alpha was a very potent stimulator of the proliferation of CD34++CD38- cells and was the most potent synergistic factor for the IL-3-induced proliferation of these cells of all cytokines tested (IL-1, IL-6, granulocyte colony-stimulating factor, kit ligand). TNF-alpha was the only cytokine that, as a single added factor, induced substantial proliferation in CD34++CD38- cells in the presence of IL-3, except for kit ligand, which induced very limited proliferation. TNF-alpha, moreover, induced a high degree of resistance to the inhibitory effects of TGF-beta in a dose-dependent way. The inhibitory effects of IFN-gamma, however, were not affected by the presence of TNF-alpha. We hypothesize that in situations of the hematopoietic stress, TNF-alpha may abrogate the inhibitory effect of ambient TGF-beta in the bone marrow microenvironment to allow primitive stem cells to proliferate and differentiate in response to an increased demand for mature blood cells.
Assuntos
Antígenos CD , Células-Tronco Hematopoéticas/efeitos dos fármacos , Fator de Necrose Tumoral alfa/farmacologia , ADP-Ribosil Ciclase , ADP-Ribosil Ciclase 1 , Antígenos CD34 , Antígenos de Diferenciação , Células da Medula Óssea , Diferenciação Celular , Divisão Celular , Células Cultivadas , Relação Dose-Resposta a Droga , Sinergismo Farmacológico , Humanos , Glicoproteínas de Membrana , N-Glicosil Hidrolases , Fator de Crescimento Transformador beta/farmacologiaRESUMO
Leukemic cells exert immunosuppressive effects that interfere with dendritic cell (DC) function and hamper effective antileukemic immune responses. Here, we sought to enhance the immunogenicity of leukemic cells by loading them with the double-stranded (ds) RNA Toll-like receptor 3 (TLR3) ligand polyriboinosinic polyribocytidylic acid (poly(I:C)), mimicking viral infection of the tumor cells. Given the responsiveness of DC to TLR ligands, we hypothesized that the uptake of poly(I:C)-loaded leukemic cells by immature DC (iDC) would lead to DC activation. Primary acute myeloid leukemia (AML) cells and AML cell lines markedly responded to poly(I:C) electroporation by apoptosis, upregulation of TLR3 expression, enhanced expression of major histocompatibility complex (MHC) and costimulatory molecules and by production of type I interferons (IFN). Upon phagocytosis of poly(I:C)-electroporated AML cells, DC maturation and activation were induced as judged by an increased expression of MHC and costimulatory molecules, production of proinflammatory cytokines and an increase of T helper 1 (T(H)1)-polarizing capacity. These immune effects were suboptimal when AML cells were passively pulsed with poly(I:C), indicating the superiority of poly(I:C) transfection over pulsing. Our results demonstrate that poly(I:C) electroporation is a promising strategy to increase the immunogenicity of AML cells and to convert iDC into activated mature DC following the phagocytosis of AML cells.
Assuntos
Células Dendríticas/imunologia , Leucemia Mieloide/genética , RNA de Cadeia Dupla/genética , Linfócitos T/imunologia , Receptor 3 Toll-Like/metabolismo , Transfecção , Doença Aguda , Células Cultivadas , Técnicas de Cocultura , Citocinas/metabolismo , Eletroporação , Citometria de Fluxo , Humanos , Interferon Tipo I/imunologia , Interferon gama/imunologia , Leucemia Mieloide/imunologia , Leucemia Mieloide/patologia , Ativação Linfocitária , Poli I-C/metabolismo , Células Th1/imunologia , Receptor 3 Toll-Like/genéticaRESUMO
In this trial, acute myeloid leukemia patients (pts) aged 61-80 years received MICE (mitoxantrone, etoposide and cytarabine) induction chemotherapy in combination with different schedules of granulocyte colony-stimulating factor administration. Pts in complete remission were subsequently randomized for two cycles of consolidation therapy: mini-ICE regimen (idarubicin, etoposide and cytarabine) given according to either an intravenous (i.v.) or a 'non-infusional' schedule. Among the 346 pts randomized for the second step, 331 pts received consolidation-1 and 182 consolidation-2. A total of 290 events (255 relapses, 35 deaths in first CR) have been reported. The median follow-up was 4.4 years. No significant differences were detected in terms of disease-free survival (median 9 vs 10.4 months, P=0.15, hazard ratio (HR) =1.18, 95% confidence interval (CI) 0.94-1.49) - primary end point - and survival (median 15.7 vs 17.8 months, P=0.19, HR=1.17, 95% CI 0.92-1.50). In the 'non-infusional' arm grade 3-4 vomiting (10 vs 2%; P=0.001) and diarrhea (10 vs 4%; P=0.03) were higher than in the 'i.v.' arm, whereas time to platelet recovery >20 x 10(9)/l (median: 19 vs 23 days; P=0.02) and duration of hospitalization (mean: 15 vs 27 days; P<0.0001) was shorter. The 'non-infusional' consolidation regimen resulted in an antileukemic effect similar to the intravenous regimen, which was less myelosuppressive and associated with less hospitalization days.
Assuntos
Protocolos de Quimioterapia Combinada Antineoplásica/administração & dosagem , Leucemia Mieloide/tratamento farmacológico , Doença Aguda , Idoso , Idoso de 80 Anos ou mais , Antimetabólitos Antineoplásicos/administração & dosagem , Antineoplásicos/administração & dosagem , Antineoplásicos Fitogênicos/administração & dosagem , Citarabina/administração & dosagem , Intervalo Livre de Doença , Etoposídeo/administração & dosagem , Feminino , Seguimentos , Humanos , Idarubicina/administração & dosagem , Infusões Intravenosas , Tempo de Internação , Masculino , Pessoa de Meia-Idade , Mitoxantrona/administração & dosagem , Pancitopenia , Cooperação do Paciente , Fatores de RiscoRESUMO
Personalized dendritic cell- (DC-) based vaccination has proven to be safe and effective as second-line therapy against various cancer types. In terms of overall survival, there is still room for improvement of DC-based therapies, including the development of more immunostimulatory DC vaccines. In this context, we redesigned our currently clinically used DC vaccine generation protocol to enable transpresentation of interleukin- (IL-) 15 to IL-15Rßγ-expressing cells aiming at boosting the antitumor immune response. In this study, we demonstrate that upon electroporation with both IL-15 and IL-15Rα-encoding messenger RNA, mature DC become highly positive for surface IL-15, without influencing the expression of prototypic mature DC markers and with preservation of their cytokine-producing capacity and their migratory profile. Functionally, we show that IL-15-transpresenting DC are equal if not better inducers of T-cell proliferation and are superior in tumor antigen-specific T-cell activation compared with DC without IL-15 conditioning. In view of the clinical use of DC vaccines, we evidence with a time- and cost-effective manner that clinical grade DC can be safely engineered to transpresent IL-15, hereby gaining the ability to transfer the immune-stimulating IL-15 signal towards antitumor immune effector cells.
Assuntos
Vacinas Anticâncer/imunologia , Células Dendríticas/imunologia , Interleucina-15/genética , Interleucina-15/imunologia , Diferenciação Celular , Proliferação de Células , Citocinas/imunologia , Citocinas/metabolismo , Células Dendríticas/fisiologia , Eletroporação , Humanos , Imunoterapia Adotiva , Interleucina-15/administração & dosagem , Subunidade alfa de Receptor de Interleucina-15/administração & dosagem , Subunidade alfa de Receptor de Interleucina-15/genética , Subunidade alfa de Receptor de Interleucina-15/imunologia , Ativação Linfocitária , TransfecçãoRESUMO
Advances in cellular and molecular immunology have led to the characterization of leukemia-specific T-cell antigens and to the development of strategies for effective augmentation of T-cell immunity in leukemia patients. While several leukemia-related antigens have been identified, this review focuses on the Wilms' tumor 1 (WT1) antigen and the proteinase 3 (Pr3) antigen that are overexpressed in leukemic cells and are already being used in the clinical setting. Moreover, WT1 is also overexpressed in a vast number of nonhematological solid tumors, thereby expanding its use as a promising target for cancer vaccines. Examples of spontaneous immune responses against WT1 and Pr3 in leukemia patients are presented and the potential of WT1 and Pr3 for adoptive T-cell immunotherapy of leukemia is discussed. We also elaborate on the use of professional antigen-presenting cells loaded with mRNA encoding WT1 exploiting the advantage of broad HLA coverage for therapeutic vaccination purposes. Finally, the summarized data underscore the potential of WT1 for the manipulation of T-cell immunity in leukemia and in cancer in general, that will likely pave the way for the development of more effective and generic cancer vaccines.
Assuntos
Antígenos de Neoplasias/imunologia , Leucemia/imunologia , Leucemia/terapia , Humanos , Imunidade Celular , Imunoterapia Adotiva , Ativação Linfocitária , Linfócitos T/imunologiaRESUMO
The therapeutic activity and toxicity profile of gemtuzumab ozogamicin were assessed in 40 patients >60 years of age with acute myeloid leukemia (AML) who were not considered eligible for conventional chemotherapy because of advanced age or poor performance status. The drug was administered at the dose of 9 mg/m2 as a single 2-h i.v. infusion on days 1 and 15. Patients who achieved a complete remission (CR/CRp) were to receive a consolidation with two additional injections of the immunotoxin at the same dose. The overall CR/CRp rate was 17% (95% CI, 8-32%). The CR/CRp rate in patients 61-75 years old was 33% (6/18), and 5% (1/22) in patients older than 75 years. Induction death occurred in seven patients (17%), all aged above 75 years. Overall survival was significantly longer in patients aged 61-75 years than in older individuals (P=0.05), and in CD33+ cases than in CD33- cases (P=0.05). We conclude that the dose/schedule of gemtuzumab ozogamicin used in this trial is too toxic in the age group over 75 years. For these patients, additional studies with reduced doses of the immunotoxin are warranted.
Assuntos
Aminoglicosídeos/uso terapêutico , Anticorpos Monoclonais/uso terapêutico , Idoso Fragilizado , Imunotoxinas/uso terapêutico , Leucemia Mieloide/tratamento farmacológico , Doença Aguda , Idoso , Idoso de 80 Anos ou mais , Anticorpos Monoclonais Humanizados , Feminino , Gemtuzumab , Humanos , Leucemia Mieloide/classificação , Masculino , Pessoa de Meia-Idade , Indução de Remissão , Taxa de SobrevidaRESUMO
BACKGROUND: Acquired immunodeficiency syndrome (AIDS) is associated with the occurrence of tumors such as Kaposi's sarcoma (KS) and B-cell lymphoma. However, no evidence exists yet that human immunodeficiency virus type 1, the causative agent of AIDS, is directly responsible for cell transformation. It is also not clear whether KS lesions, which are of complex cellularity, contain tumor cells derived from a true monoclonal malignancy (originating from a single malignant cell) or whether the lesions are just polyclonally hyperplastic in nature (containing increased numbers of normal cells). In fact, the presence of malignant KS cells has never been unequivocally shown in AIDS-associated KS, and previously isolated KS cell cultures were not immortal or malignant. PURPOSE: Our purpose was to (a) utilize technology that could facilitate isolation and enrichment of tumor cells from AIDS-associated KS lesions, (b) establish and characterize an immortalized KS cell line, and (c) test the malignant potential of such a cell line in animal models. METHODS: Mononuclear cells were isolated from 2.5 L of pleural effusion from an AIDS-associated KS patient. T-lymphocytes, B-lymphocytes, monocytes/macrophages, and fibroblasts were removed by a cytotoxicity method, using monoclonal antibodies specific for cell surface markers and baby rabbit complement. KS cells were cultured in the absence of exogenous growth factors in an effort to select for transformed cells capable of self-sustained growth. The karyotype abnormalities were detected by G-banded marker studies, and phenotypic markers were determined by indirect immunofluorescence and immunocytochemical methods. Beige nude XID and severe combined immunodeficient mice were used to evaluate the tumorigenic, angiogenic, and metastatic potentials of cells. RESULTS: An immortalized cell line, named KS Y-1, was isolated. Its phenotype is similar to that of endothelial cells with positive CD34 and CD31 markers. Tetraploid chromosomal abnormalities were found in primary fresh KS tissue and in vitro passages of KS Y-1 cells. These cells promoted tumorigenesis, angiogenesis, and metastasis in immunodeficient mice. Tumors produced at the site of injection as well as metastases in the lung, spleen, pancreas, gastrointestinal tract, and skin showed a human tetraploid karyotype. KS Y-1 cells show high plating efficiency. CONCLUSION: The KS Y-1 cell line could be the first evidence of AIDS-associated KS cells that may develop clones with an indisputable malignant cell phenotype. IMPLICATIONS: KS Y-1 cells in the in vivo mouse model can be used to study the effects of therapeutic compounds in advanced KS.
Assuntos
Síndrome da Imunodeficiência Adquirida/complicações , Sarcoma de Kaposi/etiologia , Sarcoma de Kaposi/patologia , Animais , Modelos Animais de Doenças , Humanos , Cariotipagem , Camundongos , Camundongos Endogâmicos , Sarcoma de Kaposi/genética , Sarcoma de Kaposi/imunologia , Células Tumorais CultivadasRESUMO
The advent of new cell-based immunotherapies for leukemia offers treatment possibilities for certain leukemia subgroups. The wider acceptability of these new technologies in clinical practice will depend on its impact on survival and costs. Due to the small patient groups who have received it, these aspects have remained understudied. This non-randomized single-center study evaluated medical costs and survival for acute myeloid leukemia between 2005 and 2010 in 50 patients: patients treated with induction and consolidation chemotherapy (ICT) alone; patients treated with ICT plus allogeneic hematopoietic stem cell transplantation (HCT), which is the current preferred post-remission therapy in patients with intermediate- and poor-risk AML with few co-morbidities, and patients treated with ICT plus immunotherapy using autologous dendritic cells (DC) engineered to express the Wilms' tumor protein (WT1). Total costs including post- consolidation costs on medical care at the hematology ward and outpatient clinic, pharmaceutical prescriptions, intensive care ward, laboratory tests and medical imaging were analyzed. Survival was markedly better in HCT and DC. HCT and DC were more costly than ICT. The median total costs for HCT and DC were similar. These results need to be confirmed to enable more thorough cost-effectiveness analyses, based on observations from multicenter, randomized clinical trials and preferably using quality-adjusted life-years as an outcome measure.
Assuntos
Custos de Cuidados de Saúde , Leucemia Mieloide Aguda/economia , Leucemia Mieloide Aguda/terapia , Adolescente , Adulto , Idoso , Idoso de 80 Anos ou mais , Bélgica , Quimioterapia de Consolidação/economia , Análise Custo-Benefício , Transplante de Células-Tronco Hematopoéticas/economia , Transplante de Células-Tronco Hematopoéticas/métodos , Humanos , Imunoterapia/economia , Quimioterapia de Indução/economia , Leucemia Mieloide Aguda/mortalidade , Pessoa de Meia-Idade , Taxa de Sobrevida , Transplante Homólogo , Adulto JovemRESUMO
HHV-6 infection has been associated with several malignancies including non-Hodgkin's lymphoma and Hodgkin's disease by the presence of high antibody titer and/or the presence of HHV-6 DNA. To understand their oncogenic potential, SalI restriction fragments from HHV-6 strain U1102 were transfected into NIH3T3 cells to assess transforming ability. A 3.9-kbp SalI-L DNA fragment spanning the junction of the direct repeat left (DRL) and unique long segment (UL) regions of HHV-6 induced foci of morphologically altered cells. The SalI-L transformed NIH3T3 focal lines induced tumors in nude mice within 2 weeks. The retention of HHV-6 specific DNA observed in SalI-L transformed cells and their tumor-derived lines suggest a possible maintenance function. Since both HHV-6 infection as well as transforming fragments from other DNA viruses have been shown to transactivate the human immunodeficiency virus type 1 (HIV-1) long terminal repeat (LTR), SalI-L was examined for transactivation activity. SalI-L up-regulated HIV-1 LTR CAT 10-15 fold in both monkey CV-1 and human T Jurkat cells. The further study of the SalI-L transforming fragment exhibiting transactivation of HIV-1 LTR will elucidate whether these two activities are encoded by a single gene and will aid in the understanding of the interaction between HHV-6 and HIV-1 as it relates to progression of AIDS and/or AIDS-related malignancies.
Assuntos
Transformação Celular Neoplásica , Repetição Terminal Longa de HIV , Herpesvirus Humano 6/genética , Ativação Transcricional , Células 3T3 , Animais , Sequência de Bases , Haplorrinos , Humanos , Camundongos , Camundongos Nus , Dados de Sequência Molecular , Neoplasias Experimentais/genética , Mapeamento por Restrição , Homologia de Sequência do Ácido Nucleico , Transfecção , Células Tumorais CultivadasRESUMO
PURPOSE AND METHODS: Optimization of remission-induction and postremission therapy in elderly individuals with acute myeloid leukemia (AML) was the subject of a randomized study in patients older than 60 years. Remission-induction chemotherapy was compared between daunomycin (DNR) 30 mg/m2 on days 1, 2, and 3 versus mitoxantrone (MTZ) 8 mg/m2 on days 1, 2, and 3, both plus cytarabine (Ara-C) 100 mg/m2 on days 1 to 7. Following complete remission (CR), patients received one additional cycle of DNR or MTZ chemotherapy and were then eligible for a second randomization between eight cycles of low-dose (LD)-Ara-C 10 mg/m2 subcutaneously every 12 hours for 1 2 days every 6 weeks or no further treatment. RESULTS: A total of 242 patients was randomized to DNR and 247 to MTZ. Median age of both study groups was 68 years. Secondary AML was documented in 26% and 25% of patients in either arm. The probability of attaining CR was greater (P = .069) with MTZ (47%) than with DNR (38%). Median duration of neutropenia was 19 (DNR) and 22 days (MTZ). The greater response rate to MTZ therapy correlated with reduced occurrence of chemotherapy resistance (32% v 47%, P = .001). With a median follow-up of 6 years, 5-year disease-free survival (DFS) is 8% in each arm. Overall survival estimates are not different between the groups (6% v 9% at 5 yrs). Poor performance status at diagnosis, high WBC count, older age, secondary AML, and presence of cytogenetic abnormalities all had an adverse impact on survival. Secondary AML and abnormal cytogenetics predicted for shorter duration of CR. Among complete responders, 74 assessable patients were assigned to Ara-C and 73 to no further therapy. Actuarial DFS was significantly longer (P = .006) for Ara-C-treated (13% [SE = 4.0%] at 5 years) versus nontreated patients (7% [SE = 3%]), but overall survival was similar (P = .29): 18% (SE = 4.6%) versus 15% (SE = 4.3%). Meta-analysis on the value of Ara-C postremission therapy confirms these results. CONCLUSION: In previously untreated elderly patients with AML, MTZ induction therapy produces a slightly better CR rate than does a DNR-containing regimen, but it has no significant effect on remission duration and survival. Ara-C in maintenance may prolong DFS, but it did not improve survival.
Assuntos
Protocolos de Quimioterapia Combinada Antineoplásica/uso terapêutico , Daunorrubicina/administração & dosagem , Leucemia Mieloide/tratamento farmacológico , Mitoxantrona/administração & dosagem , Doença Aguda , Idoso , Citarabina/administração & dosagem , Daunorrubicina/efeitos adversos , Esquema de Medicação , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Mitoxantrona/efeitos adversos , Prognóstico , Indução de Remissão , Análise de SobrevidaRESUMO
Immunofluorescence microscopy of the adherent layer of human long-term bone marrow cultures (HLTBMCs) consistently revealed motility-associated features in a part of the plasma cells. Not only were small surface blebs observed, but also long extensions whose morphology was reminiscent of neuronal axons. The observations were made in all HLTBMCs established with normal as well as myelomatous bone marrow (BM). Plasma cells with long extensions were also noticed on May-Grünwald-Giemsa smears of original uncultured BM from normal individuals and patients with myelomatous disorders. This suggests that the motility-associated morphological features occur in vivo as well as in vitro. The observations were most striking in the one case of plasma cell leukemia, both in culture as well as in the BM smear.
Assuntos
Células da Medula Óssea , Plasmócitos/citologia , Movimento Celular , Células Cultivadas , Imunofluorescência , Humanos , Leucemia Plasmocitária/patologia , Coloração e RotulagemRESUMO
Ever since the development of technology allowing the transfer of new genes into eukaryotic cells, the hematopoietic system has been an obvious and desirable target for gene therapy. The last 10 years have witnessed an explosion of interest in this approach to treat human disease, both inherited and acquired, with the initiation of multiple clinical protocols. All gene therapy strategies have two essential technical requirements. These are: (1) the efficient introduction of the relevant genetic material into the target cell and (2) the expression of the transgene at therapeutic levels. Conceptual and technical hurdles involved with these requirements are still the objects of active research. To date, the most widely used and best understood vectors for gene transfer in hematopoietic cells are derived from retroviruses, although they suffer from several limitations. However, as gene transfer mechanisms become more efficient and long-term gene expression is enhanced, the variety of diseases that can be tackled by gene therapy will continue to expand. However, until the problem of delivery and subsequent expression is adequately resolved, gene therapy will not realize its full potential. The first part of this review gives an overview of the gene delivery technology available at present to transfer genetic sequences in human somatic cells. The relevance of the hematopoietic system to the development of gene therapy strategies as well as hematopoietic cell-based gene therapy is discussed in the second part.
Assuntos
Terapia Genética , Células-Tronco Hematopoéticas/metabolismo , Adenoviridae/genética , Animais , Dependovirus/genética , Eletroporação , Técnicas de Transferência de Genes , Vetores Genéticos , Humanos , Retroviridae/genética , Linfócitos T/metabolismoRESUMO
The application of gene transfer techniques to immunotherapy has animated the field of gene-based cancer vaccine research. Gene transfer strategies were developed to bring about active immunization against tumor-associated antigens (TAA) through gene transfer technology. A wide variety of viral and nonviral gene transfer methods have been investigated for immunotherapeutic purposes. Ex vivo strategies include gene delivery into tumor cells and into cellular components of the immune system, including cytotoxic T cells and dendritic cells (DC). The nature of the transferred genetic material as well as the gene transfer method has varied widely depending on the application. Several of these approaches have already been translated into clinical gene therapy trials. In this review, we will focus on the rationale and types of ex vivo gene-based immunotherapy of cancer. Critical areas for future development of gene-based cancer vaccines are addressed, with particular emphasis on use of DC and on the danger-tolerance hypothesis. Finally, the use of gene-modified DC for tumor vaccination and its prospects are discussed.
Assuntos
Vacinas Anticâncer/imunologia , Terapia Genética , Neoplasias/terapia , Animais , Células Dendríticas/fisiologia , Técnicas de Transferência de Genes , Humanos , Tolerância Imunológica , Linfócitos T Citotóxicos/imunologiaRESUMO
An immunological analysis of the nonmacrophage hemopoietic cells in the adherent layer of human long-term bone marrow cultures was performed in situ. It revealed not only the expected granulocytic and monocytic cells, but an important lymphoid population as well. The latter consisted of cells bearing the markers of mature T lymphocytes, B lymphocytes, and plasma cells. These cells were also present in the hemopoietic foci of the adherent layer, the so-called cobblestone areas. Although more CD8+ than CD4+ lymphocytes were generally present in the initial bone marrow inoculum, both the adherent layer and the nonadherent fraction disclosed a preponderance of CD4+ cells after a short period of culture. The majority of the lymphoid cells were present in the adherent layer, rather than in the nonadherent fraction of the cultures. The long-term presence of lymphoid elements in the adherent layer suggests their affinity for the bone marrow stroma and the possible enhancement of their persistence in vitro by contact with these cells.
Assuntos
Células da Medula Óssea , Adesão Celular , Células-Tronco Hematopoéticas/citologia , Linfócitos/citologia , Plasmócitos/citologia , Anticorpos Monoclonais/análise , Antígenos de Diferenciação/análise , Diferenciação Celular , Células Cultivadas , Imunofluorescência , Humanos , Células Matadoras Naturais/citologia , Células Matadoras Naturais/imunologia , Ativação Linfocitária , Linfócitos/classificação , Linfócitos/imunologia , Plasmócitos/imunologia , Fatores de TempoRESUMO
Human T-lymphotropic virus type I (HTLV-I) is the etiological agent of adult T-cell leukemia/lymphoma (ATL) and of tropical spastic paraparesis/HTLV-I-associated myelopathy (TSP/HAM). In both diseases, expression of viral message can generally only be demonstrated by the reverse transcriptase-polymerase chain reaction (RT-PCR) technique. We have previously reported on the the expression of at least four types of alternatively spliced pX mRNAs in vitro and in vivo (1). The sequence variation between HTLV-I pX cDNAs cloned from two different HTLV-I-infected cell lines and from uncultured primary peripheral blood mononuclear cells (PBMC) from two ATL patients was examined. None of the cDNA clones from one of the ATL samples was completely identical to any of the previously cloned cell line messages, establishing that the demonstration of HTLV-I mRNA in ATL is not the result of PCR contamination. Sequence analysis showed that differences between samples can be clustered according to their geographic origin. Cell line cDNAs showed a more marked sequence drift than ATL cDNAs, especially in the long terminal repeat (LTR), demonstrating association of intrastrain variability with culture in vitro. Intrastrain cDNA variability in vivo also suggests ongoing viral replication in infected individuals. A premature stop codon in the pX-II open reading frame (orf) was a common finding, suggesting that the complete putative pX-II protein is not essential for T-cell immortalization or HTLV-I replication.
Assuntos
DNA de Neoplasias/química , DNA Viral/química , Vírus Linfotrópico T Tipo 1 Humano/genética , Leucemia de Células T/genética , Sequência de Bases , Humanos , Dados de Sequência Molecular , RNA Mensageiro/química , RNA Viral/química , Especificidade da Espécie , Células Tumorais CultivadasRESUMO
Human long-term bone marrow cultures (HLTBMCs) were established with bone marrow (BM) collected from five patients with myelomatous disorders (four with multiple myeloma, one with plasma cell leukemia). In all cases, up to at least 6 weeks of culture, there was a persistence of the monoclonal plasma cell population in the adherent layer of the culture. In some cultures proliferating plasma cells could be demonstrated by the Ki-67 monoclonal antibody. In all instances a paraprotein could be shown in the conditioned medium. This study demonstrates that malignant plasma cells, in analogy to their normal counterparts, have an affinity for the BM stroma and suggests that their long-term survival might be enhanced by their interaction with it.