RESUMO
Chromosomal translocations juxtaposing the MYC protooncogene with regulatory sequences of immunoglobulin (Ig) H chain or kappa (Ig kappa) or lambda (Ig lambda) L chain genes and effecting deregulated expression of MYC are the hallmarks of human Burkitt lymphoma (BL). Here we report that lymphomas with striking similarities to BL develop in mice bearing a mutated human MYC gene controlled by a reconstructed Ig lambda locus encompassing all the elements required for establishment of locus control in vitro. Diffusely infiltrating lymphomas with a typical starry sky appearance occurred in multiple founders and an established line, indicating independence from positional effects. Monoclonal IgM(+)CD5(-)CD23(-) tumors developed from an initially polyclonal population of B cells. These results demonstrate that the phenotype of B lineage lymphomas induced by MYC dysregulation is highly dependent on cooperativity among the regulatory elements that govern expression of the protooncogene and provide a new system for studying the pathogenesis of BL.
Assuntos
Linfoma de Burkitt/imunologia , Genes myc , Animais , Linfoma de Burkitt/genética , Linfoma de Burkitt/patologia , Modelos Animais de Doenças , Éxons , Humanos , Camundongos , Camundongos Endogâmicos C57BL , Camundongos Transgênicos , Proteínas Proto-Oncogênicas c-myc/análise , Proteínas Proto-Oncogênicas c-myc/genética , Baço/imunologia , Baço/patologiaRESUMO
Histiocytic sarcoma (HS) and histiocyte-associated lymphoma (HAL) of mice are difficult to distinguish histologically. Studies of multiple cases initially diagnosed as HS or HAL allowed us to define HS as round, fusiform, or mixed cell types that were F4/80+, Mac-2+, and PAX5-; that lacked markers for other sarcomas; and that had immune receptor genes in germline configuration. Two other subsets had clonal populations of lymphocytes. The first, HAL, featured malignant lymphocytes admixed with large populations of normal-appearing histiocytes. The second appeared to be composites of lymphoma and HS. Several cases suggestive of B myeloid-lineage plasticity were also observed.
Assuntos
Sarcoma Histiocítico/veterinária , Linfoma/veterinária , Camundongos , Doenças dos Roedores/diagnóstico , Animais , Antígenos de Diferenciação/metabolismo , Biomarcadores Tumorais/metabolismo , Feminino , Galectina 3/metabolismo , Sarcoma Histiocítico/diagnóstico , Sarcoma Histiocítico/patologia , Linfoma/diagnóstico , Linfoma/patologia , Masculino , Muramidase/metabolismo , Fator de Transcrição PAX5/metabolismo , Doenças dos Roedores/metabolismo , Doenças dos Roedores/patologiaRESUMO
In mammals, a subset of genes inherit gametic marks that establish parent of origin-dependent expression patterns in the soma ([1] and references therein). The currently most extensively studied examples of this phenomenon, termed genomic imprinting, are the physically linked Igf2 (insulin-like growth factor II) and H19 genes, which are expressed mono-allelically from opposite parental alleles [1] [2]. The repressed status of the maternal Igf2 allele is due to cis elements that prevent the H19 enhancers [3] from accessing the Igf2 promoters on the maternal chromosome [4] [5]. A differentially methylated domain (DMD) in the 5' flank of H19 is maintained paternally methylated and maternally unmethylated [6] [7]. We show here by gel-shift and chromatin immunopurification analyses that binding of the highly conserved multivalent factor CTCF ([8] [9] and references therein) to the H19 DMD is methylation-sensitive and parent of origin-dependent. Selectively mutating CTCF-contacting nucleotides, which were identified by methylation interference within the extended binding sites initially revealed by nuclease footprinting, abrogated the H19 DMD enhancer-blocking property. These observations suggest that molecular mechanisms of genomic imprinting may use an unusual ability of CTCF to interact with a diverse spectrum of variant target sites, some of which include CpGs that are responsible for methylation-sensitive CTCF binding in vitro and in vivo.
Assuntos
Proteínas de Ligação a DNA/metabolismo , Proteínas Musculares/genética , RNA não Traduzido , Proteínas Repressoras , Fatores de Transcrição/metabolismo , Animais , Sequência de Bases , Sítios de Ligação/genética , Fator de Ligação a CCCTC , DNA/química , DNA/genética , DNA/metabolismo , Metilação de DNA , Elementos Facilitadores Genéticos , Feminino , Fator de Crescimento Insulin-Like II/genética , Masculino , Camundongos , Dados de Sequência Molecular , Ligação Proteica , RNA Longo não Codificante , Dedos de ZincoRESUMO
Thirty-six primary human colorectal tumors, 43 noninvolved colon samples that were adjacent to either carcinomas of adenomas, 22 adenomas, and nine normal colon specimens were immunohistochemically examined for the presence and localization of two epidermal growth factor-related peptides, amphiregulin (AR) and cripto. Within the primary tumors, 18 (50%) showed moderate levels of AR expression. Approximately 60% of the tubular and tubulovillous adenomas were positive for AR expression, whereas only 15% of the adjacent, noninvolved colon mucosa expressed AR. A greater proportion of well-differentiated tumors (71%) were positive for AR expression than were poorly differentiated tumors (18%). All of the nine normal colon specimens were positive. Consequently, AR expression appeared to be associated with both normal and malignant epithelial cells that were more differentiated. The distribution of cripto expression was different. Seventy-nine % of the colon tumors expressed cripto with a frequency of expression that was approximately equivalent between well-differentiated and poorly differentiated tumors. Approximately 86% of the tubulovillous adenomas, but only 43% of the tubular adenomas, were positive for cripto expression. In contrast, whereas AR was expressed in normal colon specimens, none of these tissues expressed cripto, and only 12% of the noninvolved normal colon samples adjacent to tumors or adenomas were positive for cripto. Cripto expression therefore appeared related to neoplasia. These data suggest that AR and cripto may be functioning as potential autocrine and/or paracrine growth factors in the colon and that the differential expression of cripto may serve as a potential tumor marker for colonic carcinogenesis.
Assuntos
Biomarcadores Tumorais/análise , Colo/química , Neoplasias Colorretais/química , Fator de Crescimento Epidérmico , Glicoproteínas/análise , Substâncias de Crescimento/análise , Peptídeos e Proteínas de Sinalização Intercelular , Glicoproteínas de Membrana , Proteínas de Neoplasias/análise , RNA Mensageiro/análise , RNA Neoplásico/análise , Adenoma/química , Anfirregulina , Biomarcadores Tumorais/genética , Neoplasias da Mama/química , Carcinoma/química , Pólipos do Colo/química , Família de Proteínas EGF , Proteínas Ligadas por GPI , Glicoproteínas/genética , Substâncias de Crescimento/genética , Humanos , Técnicas Imunoenzimáticas , Mucosa Intestinal/química , Proteínas de Neoplasias/genética , Fenótipo , Células Tumorais CultivadasRESUMO
The moderately differentiated human colon tumor cell line, HT-29, constitutively expresses low levels of the high molecular weight mucin, tumor-associated glycoprotein 72 (TAG-72), and the M(r) 180,000 carcinoembryonic antigen (CEA) when grown as s.c. tumors in athymic mice. We report that the in vivo administration of gamma-interferon (IFN-gamma) resulted in a time- and dose-dependent increase in both TAG-72 and CEA expression in the HT-29 tumors. Immunohistochemical staining revealed a more homogeneous TAG-72-positive tumor cell population after IFN-gamma. Furthermore, both anti-TAG-72 and anti-CEA monoclonal antibodies (MAbs) showed enhanced localization to the HT-29 tumors in mice treated with IFN-gamma. Using that experimental model, subsequent studies presented evidence showing that the combination of IFN-gamma with 131I-CC49, an anti-TAG-72 MAb, resulted in a statistically significant improvement in therapeutic efficacy when compared with 131I-CC49 alone. For example, treatment with 300 microCi of 131I-CC49 initially suppressed HT-29 tumor growth; however, that reduction in tumor growth was transient as evidenced by the emergence of additional tumor growth at later time points. In contrast, an 8-day treatment with IFN-gamma in combination with 300 microCi 131I-CC49 resulted in sustained suppression of HT-29 tumor growth. Thus, IFN-gamma in vivo can substantially increase the TAG-72 expression in human colon tumor xenografts which leads to an increased tumor localization of anti-TAG-72 MAbs and seems to be responsible for the enhanced antitumor effects when IFN-gamma was combined with 131I-CC49. The results provide further evidence for including a biological response modifier, such as IFN-gamma, which can increase the expression of specific tumor antigens (i.e., TAG-72 and CEA) subsequently leading to a dramatic improvement in the antitumor efficacy of a radionuclide-conjugated MAb.
Assuntos
Neoplasias do Colo/terapia , Imunotoxinas/uso terapêutico , Interferon gama/farmacologia , Radioisótopos do Iodo/uso terapêutico , Radioimunoterapia , Animais , Anticorpos Monoclonais/uso terapêutico , Anticorpos Antineoplásicos/imunologia , Antígenos de Neoplasias/imunologia , Antígenos de Neoplasias/fisiologia , Antígeno Carcinoembrionário/fisiologia , Neoplasias do Colo/imunologia , Neoplasias do Colo/metabolismo , Terapia Combinada , Relação Dose-Resposta a Droga , Humanos , Imunotoxinas/metabolismo , Camundongos , Camundongos Nus , Proteínas Recombinantes , Transplante HeterólogoRESUMO
Homeostasis requires the immunologically silent clearance of apoptotic cells before they become pro-inflammatory necrotic cells. CD300f (CLM-1) is a phosphatidylserine receptor known to positively regulate efferocytosis by macrophages, and CD300f gene-deficient mice are predisposed to develop a lupus-like disease. Here we show that, in contrast to CD300f function in macrophages, its expression inhibits efferocytosis by DC, and its deficiency leads to enhanced antigen processing and T-cell priming by these DC. The consequences are the expansion of memory T cells and increased ANA levels in aged CD300f-deficient mice, which predispose CD300f-deficient mice to develop an overt autoimmune disease when exposed to an overload of apoptotic cells, or an exacerbated autoimmunity when combined with FcγRIIB deficiency. Thus, our data demonstrates that CD300f helps to maintain immune homeostasis by promoting macrophage clearance of self-antigens, while conversely inhibiting DC uptake and presentation of self-antigens.
Assuntos
Receptores Imunológicos/genética , Animais , Antígenos CD/metabolismo , Antígenos de Diferenciação de Linfócitos T/metabolismo , Apoptose , Autoanticorpos/metabolismo , Doenças Autoimunes/metabolismo , Doenças Autoimunes/patologia , Linfócitos T CD4-Positivos/citologia , Linfócitos T CD4-Positivos/imunologia , Linfócitos T CD4-Positivos/metabolismo , Linfócitos T CD8-Positivos/citologia , Linfócitos T CD8-Positivos/imunologia , Linfócitos T CD8-Positivos/metabolismo , Células Dendríticas/citologia , Células Dendríticas/imunologia , Células Dendríticas/metabolismo , Receptores de Hialuronatos/metabolismo , Lectinas Tipo C/metabolismo , Macrófagos/citologia , Macrófagos/metabolismo , Camundongos , Camundongos Endogâmicos C57BL , Camundongos Knockout , Receptores de IgG/deficiência , Receptores de IgG/genética , Receptores Imunológicos/deficiência , Baço/efeitos dos fármacos , Baço/metabolismo , Baço/patologia , Terpenos/farmacologia , Timócitos/citologia , Timócitos/metabolismoRESUMO
PURPOSE: COL-1 is a high-affinity murine monoclonal antibody (MAb) specific for carcinoembryonic antigen (CEA). A phase I trial was conducted in which a uniform quantity of antibody labeled with escalating doses of iodine 131 (131I) was administered to patients with advanced gastrointestinal (GI) malignancies to evaluate tolerance and pharmacokinetics. PATIENTS AND METHODS: Eighteen patients with advanced, assessable GI malignancies (16 colon, one pancreas, and one gastric) previously treated with conventional chemotherapy (but no pelvic radiation) received 20 mg of COL-1 labeled with 131I, with doses from 10 mCi/m2 to 75 mCi/m2. In this cohort, the baseline serum CEA level ranged from 6 to 2,739 ng/mL (mean +/- SD, 500 +/- 639). RESULTS: Nuclear imaging detected at least one tumor site in all 18 patients; 82% of all tumor involved organs were positive and 58% of all lesions > or = 1.0 cm were detected. Immune complexes were detected in 89% of patients 5 minutes after completion of infusion, and levels correlated with CEA levels (r = .71). Elevated CEA (> 500 ng/mL) and tumor bulk (total tumor area > 150 cm2) correlated directly with clearance of serum radioactivity and inversely with serum half-life and cumulative serum radioactivity parameters. Nonhematologic toxicity was mild and non-dose-limiting. Hematologic toxicity, particularly thrombocytopenia, was both dose-related and dose-limiting. The maximal-tolerated dose is 65 mCi/m2. The correlation between dose (millicuries per square meter) and thrombocytopenia was made stronger, by accounting for either variation in pharmacokinetics, or variation in serum CEA and tumor bulk. CONCLUSION: 131I-COL-1 is well tolerated, except for hematologic toxicity. These data suggest that patients with highly elevated circulating CEA levels and/or increased tumor bulk may clear 131I-labeled COL-1 more rapidly from the circulation and experience less myelosuppression.
Assuntos
Antígeno Carcinoembrionário/sangue , Neoplasias Gastrointestinais/radioterapia , Radioisótopos do Iodo/uso terapêutico , Radioimunoterapia , Anticorpos Monoclonais , Antígeno Carcinoembrionário/imunologia , Neoplasias Colorretais/radioterapia , Relação Dose-Resposta à Radiação , Neoplasias Gastrointestinais/diagnóstico por imagem , Neoplasias Gastrointestinais/imunologia , Neoplasias Gastrointestinais/patologia , Humanos , Radioisótopos do Iodo/efeitos adversos , Radioisótopos do Iodo/farmacocinética , Neoplasias Pancreáticas/radioterapia , Radioimunoterapia/efeitos adversos , Cintilografia , Dosagem Radioterapêutica , Neoplasias Gástricas/radioterapiaRESUMO
Germinal centers (GC) are the sites of antigen-driven B cell switch recombination, V(D)J gene hypermutation, and selection to generate high-afinity CD38+ memory B cells. A marked expansion of GC associated with hypergammaglobulinemia followed by complete disruption of normal splenic architecture and a striking drop in immunoglobulin levels are prominent features of the murine retrovirus-induced immunodeficiency syndrome, MAIDS. B cell lymphomas are frequent in long-term infected mice. Normal GC formation is critically dependent on a number of genes including the transcription factor, Bcl6. Deregulated expression of BCL6 protein has been implicated in the development of human and mouse B cell lymphomas. Another nuclear protein, SWAP-70, has been identified as a subunit of the protein complex, SWAP, that recombines switch regions in vitro. To develop a fuller understanding of B cell biology in MAIDS, we examined the characteristics of BCL6, SWAP-70, CD38, and peanut agglutinin (PNA)-staining cells during the course of the disease. The levels of both nuclear proteins increased rapidly until 6-8 weeks after infection. During this time frame, BCL6 was expressed at highest levels in the usually rare CD4+ Thyl- T cell subset as well as in B cells. At later times. BCL6 levels dropped to undetectable levels while SWAP-70 levels continued to increase. Changes in the levels of either protein could not be ascribed to transcriptional regulation. PNA-reactive cells decreased in concert with BCL6 while CD38 staining increased with SWAP-70. These results demonstrate that progression of MAIDS results in the massive accumulation of B cells with the morphology of secretory cells that behave like post-GC cells for expression of BCL6 and CD38, and for PNA-staining but with abnormally high-level expression of SWAP-70.
Assuntos
Antígenos CD , Proteínas de Ligação a DNA/genética , Centro Germinativo/imunologia , Fatores de Troca do Nucleotídeo Guanina , Síndrome de Imunodeficiência Adquirida Murina/genética , Síndrome de Imunodeficiência Adquirida Murina/imunologia , Proteínas Nucleares/genética , Proteínas Proto-Oncogênicas/genética , Fatores de Transcrição/genética , ADP-Ribosil Ciclase , ADP-Ribosil Ciclase 1 , Animais , Antígenos de Diferenciação/genética , Linfócitos B/imunologia , Linfócitos B/metabolismo , Linfócitos B/patologia , Sequência de Bases , Linfócitos T CD4-Positivos/imunologia , Linfócitos T CD4-Positivos/patologia , Linhagem Celular , Primers do DNA/genética , Feminino , Regulação da Expressão Gênica , Genes de Troca , Centro Germinativo/metabolismo , Centro Germinativo/patologia , Humanos , Glicoproteínas de Membrana , Camundongos , Camundongos Endogâmicos C57BL , Antígenos de Histocompatibilidade Menor , Síndrome de Imunodeficiência Adquirida Murina/patologia , NAD+ Nucleosidase/genética , Proteínas Proto-Oncogênicas c-bcl-6 , Recombinação GenéticaRESUMO
Antibody-dependent cellular cytotoxicity (ADCC) has been suggested to be an important defense mechanism against tumors. The effects of recombinant human macrophage colony-stimulating factor (rhM-CSF) on ADCC activity of human monocytes were investigated. Human peripheral monocytes were pre-incubated for 72 h with rhM-CSF at various concentrations (50, 100, 200, 400 U/ml) and then used as effector cells in a 24-h 111-Indium release assay. Human carcinoma cell lines LS-174T, CBS, and KLE were used as targets to react with anti-carcinoma monoclonal antibodies (mAbs: murine D612, murine CC49, and chimeric CC49). A significant increase in ADCC activity was observed after monocytes were incubated in 100-400 U/ml of human rhM-CSF. Variation in ADCC activity of monocytes among donors was observed. The enhancement of ADCC activity was blocked by the addition of a neutralizing antibody to rhM-CSF. Less D612 mAb was required for the rhM-CSF-treated monocytes to mediate an equivalent level of ADCC activity as compared to the untreated monocytes. Because of the low levels of rhM-CSF required in these studies to enhance ADCC, treatment of monocytes alone with comparable levels of rhM-CSF did not enhance antibody-independent cytotoxicity. Moreover, it is demonstrated here that recombinant human interleukin-4 (rhIL-4) and rhM-CSF can have a synergistic effect of monocyte-mediated ADCC on human tumor cells. These results thus indicate that rhM-CSF augments ADCC of human peripheral blood monocytes using mAbs to human carcinomas, suggesting a potential role for rhM-CSF in cancer immunotherapy.
Assuntos
Adjuvantes Imunológicos/farmacologia , Citotoxicidade Celular Dependente de Anticorpos/efeitos dos fármacos , Carcinoma/imunologia , Neoplasias do Colo/imunologia , Fator Estimulador de Colônias de Macrófagos/farmacologia , Anticorpos Monoclonais/farmacologia , Antígenos CD11/imunologia , Antígeno CD56/imunologia , Carcinoma/terapia , Neoplasias do Colo/terapia , Relação Dose-Resposta Imunológica , Humanos , Interleucina-4/farmacologia , Depleção Linfocítica , Fator Estimulador de Colônias de Macrófagos/imunologia , Monócitos/efeitos dos fármacos , Proteínas Recombinantes/farmacologia , Células Tumorais CultivadasRESUMO
cDNA encoding the human IL gene (580 bp), inserted into a retroviral expression vector carrying neomycin resistance selective marker, was introduced into HT-29 human colon carcinoma cells by lipofection. Interleukin-6 activity was measured by ELISA and bioassay using B9 cells. Interleukin-6 secreted by transfected HT-29 cells was shown to be biologically active. The expression of the human tumor associated antigen CEA (carcinoembryonic antigen), HLA classes I and II, and ICAM-1 antigens in the transfected HT-29 cells were also analyzed by flow cytometry. Significant enhancement in the expression of CEA but not in the expression of HLA class I, HLA class II and ICAM-1 antigens, was observed in the transfected HT-29 cells as compared to the parental HT-29 cells. These results provide experimental evidence that enhancement of tumor antigen expression on tumor cells can be induced by IL-6 gene transfection, and suggest another potential role for the use of IL-6 gene transfer in the immunotherapy of human cancers.
Assuntos
Antígenos de Neoplasias/biossíntese , Carcinoma/patologia , Neoplasias Colorretais/patologia , Regulação Neoplásica da Expressão Gênica , Genes , Interleucina-6/genética , Antígenos de Neoplasias/genética , Antígeno Carcinoembrionário/biossíntese , Antígeno Carcinoembrionário/genética , Antígeno Carcinoembrionário/imunologia , Carcinoma/imunologia , Moléculas de Adesão Celular/biossíntese , Moléculas de Adesão Celular/genética , Moléculas de Adesão Celular/imunologia , Neoplasias Colorretais/imunologia , DNA/genética , Citometria de Fluxo , Antígenos HLA/biossíntese , Antígenos HLA/genética , Antígenos HLA/imunologia , Humanos , Molécula 1 de Adesão Intercelular , Interleucina-6/biossíntese , Interleucina-6/fisiologia , Lipossomos , Proteínas de Neoplasias/biossíntese , Proteínas de Neoplasias/genética , Proteínas de Neoplasias/imunologia , Receptores Imunológicos/biossíntese , Receptores Imunológicos/genética , Receptores de Interleucina-6 , Transfecção , Células Tumorais CultivadasRESUMO
The G1 cyclin, cyclin D1, has been implicated in the development of human and mouse tumors. Here we describe immunohistochemical analyses of cyclin D1 for a large panel of mouse B cell tumors. In addition, we characterize cyclin D1 expression in a series of cultured cell lines that represent transformed B cells at different stages of development. Immunohistochemical analysis showed that for low-grade lymphomas, cyclin D1 was expressed by 83% of centroblastic centrocytic (CBCC) and 14% of small lymphocytic lymphomas (SLL). For high-grade tumors, 28% of B lymphoblastic and 23% of centroblastic tumors expressed cyclin D1, while all immunoblastic lymphomas were negative. Studies of RNA and protein prepared from cultured B lineage tumors showed that cyclin D1 was expressed by all pre-B and most B cell tumors but not by cell lines representative of late B cell differentiation or by plasma cells. Expression of cyclin D1 in the lymphomas was not associated with alterations in the genomic structure of the Fis-1 (Bcl-1) common proviral integration site or cyclin D1 itself or with cell growth activity as assessed by expression of proliferating cell nuclear antigen (PCNA).
Assuntos
Ciclina D1/genética , Linfoma de Células B/genética , Animais , Proteínas de Transporte/genética , Diferenciação Celular , DNA/análise , Fator Proteico para Inversão de Estimulação , Expressão Gênica , Genes myc/genética , Imuno-Histoquímica , Fatores Hospedeiros de Integração , Linfoma de Células B/química , Linfoma de Células B/patologia , Linfoma de Células T/genética , Camundongos , Hibridização de Ácido Nucleico , Antígeno Nuclear de Célula em Proliferação/biossíntese , RNA Mensageiro/análise , Células Tumorais CultivadasRESUMO
BCL6 encodes a transcription factor deregulated by chromosomal translocations in human diffuse large cell B lymphomas (DLCL). This study was designed to determine whether Bcl6 might also be involved in lymphomas of mice. BCL6 protein was expressed at high levels in 90% or more of DLCL but not in low grade B lymphomas. Southern hybridisation studies demonstrated altered organisation of Bcl6 in three primary DLCL and the WEHI 231 B-cell lymphoma cell line but not in low grade tumours. Chromosomal painting and fluorescence in situ hybridisation (FISH) analyses of the WEHI 231 metaphase spreads revealed a T(5;16) translocation with Bcl6 on Chromosome 16 at the translocation breakpoint. Deregulated expression of BCL6 is thus likely to contribute to the genesis of DLCL of mice as well as of humans.
Assuntos
Proteínas de Ligação a DNA/genética , Linfoma de Células B/genética , Proteínas Proto-Oncogênicas/genética , Fatores de Transcrição/genética , Animais , Mapeamento Cromossômico , Genoma , Humanos , Cariotipagem , Camundongos , Proteínas Proto-Oncogênicas c-bcl-6 , Células Tumorais Cultivadas , Dedos de ZincoRESUMO
Hematopoietic neoplasms developing in AKXD recombinant inbred, NFS.V(+) and ICSBP knockout mice were assessed using morphologic, cytologic and molecular criteria that relate these disorders to human lymphoma and leukemia. Lymphoma types included precursor T-cell and B-cell lymphoblastic, small lymphocytic, splenic marginal zone, follicular, and diffuse large cell (DLCL). In addition to previously defined subtypes of DLCL composed of centroblasts or immunoblasts, two additional subtypes are defined here: lymphoblastic lymphoma like (LL) and lymphoma characterized by a histiocytic reaction (HS). DLCL(HS) were distinguished from true histiocytic lymphomas by the presence of clonal Ig gene rearrangements.
Assuntos
Linfoma não Hodgkin/patologia , Animais , Cruzamentos Genéticos , Modelos Animais de Doenças , Feminino , Rearranjo Gênico , Rearranjo Gênico da Cadeia beta dos Receptores de Antígenos dos Linfócitos T/genética , Genes Codificadores da Cadeia beta de Receptores de Linfócitos T/genética , Cadeias Pesadas de Imunoglobulinas/genética , Cadeias kappa de Imunoglobulina/genética , Linfoma Difuso de Grandes Células B/classificação , Linfoma Difuso de Grandes Células B/genética , Linfoma Difuso de Grandes Células B/patologia , Linfoma não Hodgkin/classificação , Linfoma não Hodgkin/genética , Camundongos , Camundongos Endogâmicos AKR , Camundongos Endogâmicos DBA , Camundongos Knockout , Leucemia-Linfoma Linfoblástico de Células Precursoras/classificação , Leucemia-Linfoma Linfoblástico de Células Precursoras/genética , Leucemia-Linfoma Linfoblástico de Células Precursoras/patologiaAssuntos
Linfoma de Células B/patologia , Animais , Proteínas de Ligação a DNA/genética , Modelos Animais de Doenças , Expressão Gênica , Humanos , Linfoma de Células B/genética , Camundongos , Mutação , Proteínas Proto-Oncogênicas/genética , Proteínas Proto-Oncogênicas c-bcl-6 , Fatores de Transcrição/genéticaAssuntos
Linfoma Difuso de Grandes Células B/patologia , Animais , Animais Congênicos , Biomarcadores Tumorais/análise , Cruzamentos Genéticos , DNA de Neoplasias/genética , Proteínas de Ligação a DNA/genética , Modelos Animais de Doenças , Rearranjo Gênico do Linfócito B , Humanos , Vírus da Leucemia Murina/patogenicidade , Linfoma Difuso de Grandes Células B/química , Linfoma Difuso de Grandes Células B/genética , Camundongos , Camundongos Endogâmicos , Proteínas de Neoplasias/análise , Proteínas de Neoplasias/genética , Proteínas Proto-Oncogênicas/genética , Proteínas Proto-Oncogênicas c-bcl-6 , Especificidade da Espécie , Fatores de Transcrição/genética , Translocação GenéticaRESUMO
BACKGROUND: Interleukin-2 (IL-2), a potent inducer of cellular immune responses, has been used for biological therapy of human cancer; however, the high doses of IL-2 required to mediate patients' immune responses can cause considerable systemic toxicity. The murine monoclonal antibody (MAb) CC49, which reacts with tumor-associated glycoprotein (TAG)-72, expressed on a variety of human carcinomas, has shown excellent tumor localization in recent clinical trials. OBJECTIVES: Development and characterization of a single-chain immunoglobulin-IL-2 (SCIg-IL-2) fusion protein which, by delivering IL-2 selectively to the tumor site, can serve as an effective reagent for CC49/IL-2 combination therapy. STUDY DESIGN: A single-gene encoding the SCIg-IL-2 fusion protein derived from the chimeric (c) CC49 was designed, generated and inserted in an expression vector. The monomeric single-chain protein consisted of the CC49 heavy and light chain variable domains covalently jointed through a (GGGGS)3 linker peptide. The carboxyl end of the variable domain of the light chain was linked to the amino terminus of the human gamma 1 Fc through the hinge region, and the carboxyl end of the CH3 domain was linked to the amino terminus of the human IL-2 through a GGGSGGG linker peptide. The SCIg-IL-2, expressed from the murine myeloma cells transfected with the expression construct, was characterized for its antigen-binding specificity, antibody effector functions and IL-2 biological activity. RESULTS AND CONCLUSION: Transfection of murine myeloma cells with the single-gene expression construct SCIg-IL-2 expressed a single-chain protein of approximately 70 kD, which was secreted into tissue culture fluid as a homodimer of approximately 140 kD. SCIg-IL-2 competed completely with cCC49 for binding to the TAG-72 antigen, but approximately three- to four-fold more of the SCIg-IL-2 was required to achieve levels of competition similar to those observed with the murine or chimeric CC49. With human effector cells, the fusion protein mediated lysis of TAG-72-positive human carcinoma cells. Prior treatment of human effector cells with 100 U/ml of human IL-2 enhanced the fusion protein-mediated cytolysis from 32 to 65%. At doses of > or = 1 ng/ml, the stimulatory effect of SCIg-IL-2 on IL-2 dependent murine HT-2 cell proliferation was comparable to that of the recombinant human IL-2. The single-gene construct may also facilitate inoculation of the gene in animal tissue for in vivo expression of the fusion protein.
Assuntos
Interleucina-2/genética , Proteínas Recombinantes de Fusão/genética , Anticorpos Monoclonais , Dimerização , Eletroforese em Gel de Poliacrilamida , Humanos , Imunidade Celular , Imunoensaio , Fragmentos Fc das Imunoglobulinas/administração & dosagem , Fragmentos Fc das Imunoglobulinas/genética , Fragmentos Fc das Imunoglobulinas/imunologia , Interleucina-2/administração & dosagem , Interleucina-2/imunologia , Mieloma Múltiplo/metabolismo , Ligação Proteica , Engenharia de Proteínas , Proteínas Recombinantes de Fusão/administração & dosagem , Proteínas Recombinantes de Fusão/imunologia , Células Tumorais CultivadasRESUMO
We describe construction of a single gene encoding a single-chain immunoglobulin-like molecule. This single-gene approach circumvents inefficiencies inherent in delivering two genes into a mammalian cell and in the assembly of a functional immunoglobulin molecule. It would also facilitate ex vivo transfection of cells for gene-therapy protocols. SP2/0 murine myeloma cells transfected with the single gene SG delta CLCH1 expressed a single-chain protein, SC delta CLCH1, comprising approximately 60 kDa of the anti-carcinoma monoclonal antibody (mAb) CC49. The single-chain protein consisted of the heavy- and light-chain variable (VH and VL) domains of the mAb covalently joined through a short linker peptide, while the carboxyl end of the VL domain was linked to the amino terminus of the human gamma 1 Fc region through the hinge region. The single-chain protein assembled into a dimeric molecule, termed SCA delta CLCH1, of approximately 120 kDa and was secreted into the tissue culture fluid. SDS/PAGE analysis of the secreted immunoglobulin purified by protein G affinity chromatography confirmed the size of the molecule. The native mAb CC49 and SCA delta CLCH1 of CC49 showed similar binding to the tumor-associated glycoprotein TAG-72, and the chimeric mAb CC49 and SCA delta CLCH1 showed similar cytotoxic activity. This single-gene construct approach provides a way of generating an immunoglobulin-like molecule which retains the specificity, binding properties, and cytolytic activity of the chimeric mAb CC49. The immunoglobulin-like molecule SCA delta CLCH1 is potentially a therapeutic and diagnostic reagent against a range of human carcinomas.
Assuntos
Genes de Imunoglobulinas , Imunoglobulinas/biossíntese , Mieloma Múltiplo/imunologia , Animais , Sequência de Bases , Ensaio de Imunoadsorção Enzimática , Amplificação de Genes , Vetores Genéticos , Humanos , Imunoglobulinas/análise , Imunoglobulinas/genética , Substâncias Macromoleculares , Camundongos , Dados de Sequência Molecular , Mieloma Múltiplo/genética , Oligodesoxirribonucleotídeos , Transfecção , Células Tumorais CultivadasRESUMO
Mouse cell lines transfected with carcinoembryonic antigen (CEA) and with 2 other members of the human CEA gene family, non-specific cross-reacting antigen (NCA) and biliary glycoprotein (BGP), were used to analyze the specificity of several monoclonal antibodies (MAbs). MAbs COL-1 and COL-6 were shown to react with the transfected CEA gene product but not with NCA, confirming previous results. Cells expressing the transfected BGP gene product also failed to react with COL-1 and COL-6. The MAb B6.2 reacted with cells expressing the NCA gene product but not with those expressing CEA or BGP. The MAb B1.1 reacted strongly with the transfected CEA and BGP gene products but only weakly with the NCA gene product. These antibodies were then utilized in the histochemical analysis of a number of primary and secondary breast and lung tumors. The results indicate that a majority of breast and lung tumors express CEA, and nearly all breast and lung tumors express NCA. Fairly homogeneous expression of CEA and NCA was seen in the majority of both breast and lung tumors. Our results indicate that CEA may be an important target for immunotherapy in a large number of patients with breast and lung tumors.
Assuntos
Adenocarcinoma/imunologia , Neoplasias da Mama/imunologia , Antígeno Carcinoembrionário/genética , Carcinoma Intraductal não Infiltrante/imunologia , Moléculas de Adesão Celular , Neoplasias Pulmonares/imunologia , Glicoproteínas de Membrana/genética , Adenocarcinoma/patologia , Animais , Anticorpos Monoclonais , Especificidade de Anticorpos , Antígenos de Neoplasias/genética , Antígenos de Neoplasias/imunologia , Antígeno Carcinoembrionário/imunologia , Carcinoma Intraductal não Infiltrante/patologia , Células Cultivadas , Neoplasias do Colo/imunologia , Neoplasias do Colo/patologia , Fibroblastos/fisiologia , Secções Congeladas , Expressão Gênica/genética , Humanos , Neoplasias Pulmonares/patologia , Glicoproteínas de Membrana/imunologia , Camundongos , TransfecçãoRESUMO
The expression of three epidermal growth factor (EGF)-related peptides, transforming growth factor alpha (TGF-alpha), amphiregulin (AR) and cripto-1 (CR-1), was examined by immunocytochemistry (ICC) in 68 primary infiltrating ductal (IDCs) and infiltrating lobular breast carcinomas (ILCs), and in 23 adjacent non-involved human mammary tissue samples. Within the 68 IDC and ILC specimens, 54 (79%) expressed immunoreactive TGF-alpha, 52 (77%) expressed AR and 56 (82%) expressed CR-1. Cytoplasmic staining was observed with all of the antibodies, and this staining could be eliminated by preabsorption of the antibodies with the appropriate peptide immunogen. Cytoplasmic staining with all of the antibodies was confined to the carcinoma cells, since no specific immunoreactivity could be detected in the surrounding stromal or endothelial cells. In addition to cytoplasmic reactivity, the AR antibody also exhibited nuclear staining in a number of the carcinoma specimens. No significant correlations were found between the percentage of carcinoma cells that were positive for TGF-alpha, AR or CR-1 and oestrogen receptor status, axillary lymph node involvement, histological grade, tumour size, proliferative index, loss of heterozygosity on chromosome 17p or overall patient survival. However, a highly significant inverse correlation was observed between the average percentage of carcinoma cells that expressed AR in individual tumours and the presence of a point-mutated p53 gene. Likewise, a significantly higher percentage of tumour cells in the ILC group expressed AR as compared with the average percentage of tumour cells that expressed AR in the IDC group. Of the 23 adjacent, non-involved breast tissue samples, CR-1 could be detected by ICC in only three (13%), while TGF-alpha was found in six (26%) and AR in ten (43%) of the non-involved breast tissues. These data demonstrate that breast carcinomas express multiple EGF-related peptides and show that the differential expression of CR-1 in malignant breast epithelial cells may serve as a potential tumour marker for breast cancer.
Assuntos
Biomarcadores Tumorais/análise , Neoplasias da Mama/química , Fator de Crescimento Epidérmico , Glicoproteínas/análise , Substâncias de Crescimento/análise , Peptídeos e Proteínas de Sinalização Intercelular , Glicoproteínas de Membrana , Proteínas de Neoplasias/análise , Fator de Crescimento Transformador alfa/análise , Anfirregulina , Família de Proteínas EGF , Feminino , Proteínas Ligadas por GPI , Genes p53/genética , Humanos , Mutação Puntual/genética , RNA Mensageiro/análise , RNA Neoplásico/análiseRESUMO
Alleles at the Fv1 gene of inbred mice confer resistance to infection and spread of vertically or horizontally transmitted murine leukemia viruses (MuLV). The nucleotide sequence of Fv1 bears similarity to the gag of a human endogenous retrovirus, HERV-L, but is more closely related to the gag-coding sequence of a newly described class of HERV-L-related mouse endogenous retroviruses designated MuERV-L. Both observations suggest an origin of Fv1 from endogenous gag sequences. The molecular definition of Fv1 provided an opportunity to determine the phylogeny of the gene among wild mice and its relation to MuERV-L. PCR primers, chosen to include most of the coding region of Fv1 for both the n and b alleles, were used to amplify sequences from animals of the genus Mus, which were then sequenced. Closely related products were obtained from almost all animals examined that evolved after the separation from Rattus, in which the homologous gene was shown to be absent. A phylogenetic tree generated with Fv1 sequence data differs noticeably from that developed with sequence data from other genes. In addition, non-synonymous changes were found to be present twice as frequently as synonymous changes, a fact that departs from the standard behavior of a structural gene. These observations suggest that the Fv1 gene may have been subjected to possible horizontal transfers as well as to positive Darwinian selection.