Asunto(s)

Bancos de Muestras Biológicas , Línea Celular , Células Madre Pluripotentes , Guías de Práctica Clínica como Asunto , Bancos de Muestras Biológicas/ética , Pruebas de Carcinogenicidad , Inestabilidad Genómica , Humanos , Cooperación Internacional , Medición de Riesgo , Seguridad , Donantes de Tejidos , Conservación de Tejido/métodos

RESUMEN

Recent studies on BAFF, a member of the tumor necrosis factor family, and the discovery of a new BAFF receptor have revealed that this ligand-receptor pair is essential for B-cell survival and differentiation, holding promise for a better understanding and treatment of some autoimmune diseases and lymphomas.

Asunto(s)

Proteínas de la Membrana/metabolismo , Factor de Necrosis Tumoral alfa/metabolismo , Animales , Factor Activador de Células B , Linfocitos B/citología , Supervivencia Celular/fisiología , Proteínas de la Membrana/fisiología , Ratones , Factor de Necrosis Tumoral alfa/fisiología

RESUMEN

Dendritic cells (DC) are potent antigen presenting cells that activate naive T cells. It is becoming increasingly clear that DC are not a homogeneous cell population, but comprise different subpopulations that differ in ontogeny and function. To further the molecular characterisation of DC, we screened for genes that were differentially expressed amongst DC subsets and could therefore give insight into their varying biological functions. Using Representational Difference Analysis (RDA) we identified a gene (CIRE) that is expressed at higher levels in the myeloid-related CD8alpha(-) DC than in the lymphoid-related CD8alpha(+) DC. CIRE is a 238 amino acid type II membrane protein, of approximately 33 kDa in size, whose extracellular region contains a C-type lectin domain. Northern blot analysis revealed that CIRE is almost exclusively expressed in DC and was not detected in organs such as heart, brain, kidney, liver, and thymus. T cells failed to express message for CIRE, whilst B cells expressed very low levels. These data here further substantiated by Northern blot analysis of 18 cell lines of various origins (myeloid, macrophage, B and T cell) where only one cell line, which was of myeloid origin and could give rise to DC, expressed mRNA for CIRE. Semi-quantitative RT-PCR suggested that CIRE is down-regulated upon activation. CIRE shares 57% identity with human DC-SIGN, a molecule that has been shown to be the ligand of ICAM-3 and that is also a receptor that binds HIV and facilitates trans-infection of T cells.

Asunto(s)

Antígenos CD8 , Moléculas de Adhesión Celular , Células Dendríticas/metabolismo , Lectinas/genética , Proteínas de la Membrana/genética , Secuencia de Aminoácidos , Animales , Secuencia de Bases , Células CHO , Clonación Molecular , Cricetinae , ADN Complementario , Regulación hacia Abajo , Expresión Génica , Lectinas/clasificación , Lectinas/metabolismo , Lectinas Tipo C , Proteínas de la Membrana/clasificación , Proteínas de la Membrana/metabolismo , Ratones , Ratones Endogámicos C57BL , Datos de Secuencia Molecular , Receptores de Superficie Celular/clasificación , Receptores de Superficie Celular/genética , Homología de Secuencia de Aminoácido , Bazo/citología , Activación Transcripcional

RESUMEN

A novel dendritic cell (DC) surface molecule termed F4/80-like-receptor (FIRE) has been selected based on its differential expression between DC subsets. The gene encoding FIRE has been cloned and sequenced, and mAbs specific for FIRE have been produced. FIRE is a seven-transmembrane-spanning molecule with two epidermal growth factor-like domains in the extracellular region. It is a novel member of the epidermal growth factor/transmembrane-7 protein subfamily and shows similarity to the macrophage marker F4/80. FIRE is expressed by CD8- DC, but not by CD8+ DC, and it is down-regulated on DC activation. It is expressed by blood monocytes and by some tissue macrophages, but not by most macrophage cell lines or by lymphoid cells. FIRE is a useful marker of myeloid cells with a DC developmental potential.

Asunto(s)

Células Dendríticas/inmunología , Factor de Crecimiento Epidérmico , Macrófagos/inmunología , Proteínas de la Membrana/genética , Proteínas de la Membrana/metabolismo , Monocitos/inmunología , Secuencia de Aminoácidos , Animales , Anticuerpos Monoclonales/inmunología , Células de la Médula Ósea/metabolismo , Células Cultivadas , Clonación Molecular , Regulación hacia Abajo , Activación de Macrófagos , Proteínas de la Membrana/inmunología , Ratones , Ratones Endogámicos C57BL , Datos de Secuencia Molecular , ARN Mensajero/biosíntesis , Homología de Secuencia de Aminoácido , Distribución Tisular , Transcripción Genética

RESUMEN

Analysis of the critical cellular processes of self-generation, commitment, and maturation induction ideally requires the use of clonal cultures using cells with a capacity to undergo all three processes. Preprogenitor cells from normal mouse marrow are proving useful cells for such studies. Cells of a newly established cloned leukemic cell line, the GB2, are providing a useful analogous leukemic system because GB2 cells form stratified subpopulations of clonogenic cells able to be clonally analyzed in vitro in which self-renewal is demonstrable, but in which near-normal maturation can be induced by a wide range of hematopoietic regulators.

Asunto(s)

Células Madre Hematopoyéticas/efectos de los fármacos , Leucemia Experimental/patología , Células Madre Neoplásicas/efectos de los fármacos , Animales , Células de la Médula Ósea/citología , Células de la Médula Ósea/efectos de los fármacos , Células de la Médula Ósea/efectos de la radiación , Diferenciación Celular/efectos de los fármacos , Linaje de la Célula , Células Cultivadas/efectos de los fármacos , Células Clonales/efectos de los fármacos , Ensayo de Unidades Formadoras de Colonias , Medios de Cultivo Condicionados , Células Madre Hematopoyéticas/citología , Interleucina-3/farmacología , Linfocitos/citología , Factor Estimulante de Colonias de Macrófagos/farmacología , Proteínas de la Membrana/farmacología , Ratones , Ratones Endogámicos C57BL , Células Mieloides/citología , Células Madre Neoplásicas/citología , Factor de Células Madre/farmacología , Células Tumorales Cultivadas/efectos de los fármacos , Ensayo de Tumor de Célula Madre , Irradiación Corporal Total

RESUMEN

The cloned pro-B-lymphocyte murine leukemic cell line GB2, was established from a leukemic Max41 x Emu-myc double transgenic mouse. Its Igh alleles are rearranged and its surface markers are primarily B-lymphoid, but a small proportion of the cells also express surface Gr-1 and some cells develop the morphology of maturing granulocytes. The cell line grows continuously in suspension culture without the addition of growth factors, but expresses mRNA for M-CSF, TPO and Flt-3-ligand. When stimulated in agar cultures by GM-CSF, G-CSF, M-CSF, IL-3, SCF, IL-6, leukemia inhibitory factor (LIF), IL-5 or IFNgamma, GB2 cells generated blast colonies or colonies of maturing granulocytes and macrophages. There was a striking similarity in colony types, relative colony numbers and maturation of colony cells to those formed by normal bone marrow cells in response to the same stimuli. GB2 blast colony-forming cells exhibited self-renewal as well as an ability to form granulocyte-macrophage colony-forming progeny, with evidence that a hierarchical sequence of clonogenic cells is generated in the cell line even after subcloning. Factor-specific maturation was clearly initiated by the action of the added growth factors. In contrast, FACS-sorting experiments showed that commitment to various types of colony-forming cell occurs in maintenance suspension cultures in the apparent absence of potentially relevant growth factors.

Asunto(s)

Diferenciación Celular , Granulocitos/citología , Leucemia de Células B/patología , Macrófagos/citología , Animales , División Celular/efectos de los fármacos , Factor Estimulante de Colonias de Granulocitos y Macrófagos/farmacología , Ratones , Fenotipo , Células Tumorales Cultivadas

RESUMEN

As if the TNF receptor and ligand superfamily was not big enough, two new receptors and their ligands have now been added to it. As Laâbi and Strasser explain in their Perspective, the receptors BCMA and TACI and their ligands BAFF/BLys and APRIL, respectively, are important for B lymphocyte survival, proliferation, and differentiation.

Asunto(s)

Linfocitos B/citología , Linfocitos B/inmunología , Proteínas de la Membrana/metabolismo , Receptores del Factor de Necrosis Tumoral/metabolismo , Factor de Necrosis Tumoral alfa/metabolismo , Animales , Apoptosis , Factor Activador de Células B , Antígeno de Maduración de Linfocitos B , Linfocitos B/metabolismo , Ligando de CD40 , Diferenciación Celular , División Celular , Supervivencia Celular , Citocinas/metabolismo , Humanos , Ligandos , Activación de Linfocitos , Glicoproteínas de Membrana/metabolismo , Ratones , FN-kappa B/metabolismo , Neoplasias/etiología , Neoplasias/patología , Receptores de Antígenos de Linfocitos B/metabolismo , Transducción de Señal , Factores de Transcripción/metabolismo , Proteína Activadora Transmembrana y Interactiva del CAML , Miembro 13 de la Superfamilia de Ligandos de Factores de Necrosis Tumoral

RESUMEN

The BCMA gene is a new gene discovered by the molecular analysis of a t(4;16) translocation, characteristic of a human T cell lymphoma. It has no significant similarity with any known protein or motif, so that its function was unknown. This report describes the cloning of murine BCMA cDNA and its genomic counterpart. The mouse gene is organized into three exons, like the human gene, and lies in murine chromosome 16, in the 16B3 band, the counterpart of the human chromosome 16p13 band, where the human gene lies. Murine BCMA cDNA encodes a 185 amino acids protein (184 residues for the human), has a potential central transmembrane segment like the human protein and is 62% identical to it. The murine BCMA mRNA is found mainly in lymphoid tissues, as is human BCMA mRNA. Alignment of the murine and human BCMA protein sequences revealed a conserved motif of six cysteines in the N-terminal part, which strongly suggests that the BCMA protein belongs to the tumor necrosis factor receptor (TNFR) superfamily. Human BCMA is the first member of the TNFR family to be implicated in a chromosomal translocation.

Asunto(s)

Proteínas de la Membrana/genética , Secuencia de Aminoácidos , Animales , Antígeno de Maduración de Linfocitos B , Linfocitos B/metabolismo , Secuencia de Bases , Mapeo Cromosómico , Clonación Molecular , ADN Complementario , Humanos , Hibridación Fluorescente in Situ , Proteínas de la Membrana/química , Ratones , Datos de Secuencia Molecular , Receptores del Factor de Necrosis Tumoral/química , Receptores del Factor de Necrosis Tumoral/genética , Mapeo Restrictivo , Alineación de Secuencia , Análisis de Secuencia de ADN , Translocación Genética

RESUMEN

The human TEL gene is involved in several 12p13 chromosomal abnormalities present in various human hematological malignancies, the most frequent being the t(12;21)(p13;q22), specific for childhood acute lymphoblastic leukemia. The predicted product of TEL harbours an amino acid region similar to the ETS DNA binding domain. We now report the isolation of the murine TEL cDNA and the characterization of the human TEL proteins. Human and murine TEL proteins are particularly homologous within their aminoterminal regions and their ETS domains. TEL proteins are nuclear and display specific DNA binding activity toward classical ETS binding sites. In addition, we show that TEL mRNAs initiate translation at either of the two first inframe ATGs (codon 1 and 43) to encode 50 kDa and 57 kDa TEL proteins. In vivo, each of these primary translational products is modified by multiple phosphorylation events.

Asunto(s)

ADN Complementario/genética , Proteínas de Unión al ADN/genética , Proteínas Nucleares/genética , Fosfoproteínas/genética , Proteínas Represoras , Factores de Transcripción/genética , Animales , Secuencia de Bases , Western Blotting , Células COS , Cromosomas Humanos Par 12 , Cromosomas Humanos Par 21 , Clonación Molecular , ADN/metabolismo , ADN Complementario/aislamiento & purificación , Proteínas de Unión al ADN/aislamiento & purificación , Humanos , Hibridación Fluorescente in Situ , Leucemia de Células B/genética , Ratones , Datos de Secuencia Molecular , Proteínas Nucleares/aislamiento & purificación , Fosfoproteínas/aislamiento & purificación , Fosforilación , Proteínas Proto-Oncogénicas c-ets , ARN Mensajero/aislamiento & purificación , Factores de Transcripción/aislamiento & purificación , Translocación Genética , Células Tumorales Cultivadas , Proteína ETS de Variante de Translocación 6

RESUMEN

BCMA is a human gene expressed preferentially in mature B lymphocytes as a 1.2 kb mRNA, which encodes a 184 amino acid peptide (BCMAp). The study of BCMA mRNA expression, using human malignant B cell lines characteristic of different stages of B lymphocyte differentiation, demonstrated that the BCMA mRNA is absent in the pro-B lymphocyte stage. It is expressed faintly at the pre-B cell stage and its expression increases with B lymphocyte maturation. Polyclonal antibodies were used to show, by cellular fractionation and immunoprecipitation, that BCMAp is a non-glycosylated integral membrane protein. Furthermore, BCMAp inserts, in vitro, into canine microsomes, as a type I integral membrane protein. Cell surface labeling showed that BCMAp is not expressed in the plasma membrane of mature B lymphocytes. Immunofluorescence studies revealed that BCMAp lies in a cap-like structure near the nucleus, that was identified as the Golgi apparatus by co-localization of BCMAp with CTR433, a marker of the medial cisternae of the Golgi apparatus. Confocal scanning laser microscopy of U266 plasma cells labeled with markers of various Golgi apparatus subcompartments strongly suggests that BCMAp is located in the cis part of the Golgi apparatus. Thus, BCMAp is the first Golgi resident protein with a tissue specificity and whose expression is linked to the stage of differentiation of B lymphocytes. The location of BCMAp in the Golgi apparatus and its high expression in plasmocytes (secreting large amounts of Ig) suggest that BCMAp is implicated in the intracellular traffic of Ig.

Asunto(s)

Linfocitos B/química , Aparato de Golgi/química , Proteínas de la Membrana/química , Receptores del Factor de Necrosis Tumoral , Antígeno de Maduración de Linfocitos B , Compartimento Celular , Técnica del Anticuerpo Fluorescente , Aparato de Golgi/inmunología , Humanos , Glicoproteínas de Membrana/química , Glicoproteínas de Membrana/genética , Proteínas de la Membrana/genética , Microscopía Confocal , Microsomas/química , Conformación Proteica , ARN Mensajero/química , Células Tumorales Cultivadas

RESUMEN

In a previous study of a t(4;16)(q26;p13) translocation, found in a human malignant T-cell lymphoma the BCMA gene, located on chromosome band 16p13.1, has been characterized. In this study we show that the BCMA gene is organized into three exons and its major initiation transcription site is located 69 nucleotides downstream of a TATA box. RNase protection assays demonstrated that the BCMA gene is preferentially expressed in mature B cells, suggesting a role for this gene in the B-cell developmental process. A cDNA complementary to the BCMA cDNA was cloned and sequenced and its presence was assessed by RNase protection assay and anchor-PCR amplification. This antisense-BCMA RNA is transcribed from the same locus as BCMA, and exhibits mRNA characteristic features, e.g. polyadenylation and splicing. It also contains an ORF encoding a putative 115 aa polypeptide, presenting no homology with already known sequences. RNase protection assays demonstrated the simultaneous expression of natural sense and antisense-BCMA transcripts in the majority of human B-cell lines tested.

Asunto(s)

Linfocitos B/metabolismo , Proteínas/genética , Receptores del Factor de Necrosis Tumoral , Transcripción Genética , Secuencia de Aminoácidos , Antígeno de Maduración de Linfocitos B , Secuencia de Bases , Southern Blotting , Diferenciación Celular , Células Cultivadas , Cromosomas Humanos Par 16 , Clonación Molecular , ADN , Exones , Humanos , Interleucina-2/genética , Linfoma de Células T , Datos de Secuencia Molecular , Poli A , Proteínas/metabolismo , ARN Mensajero/metabolismo , Ribonucleasas , TATA Box , Translocación Genética

RESUMEN

A t(4;16)(q26;p13.1) chromosome translocation found in tumour cells from a patient with a T cell lymphoma was shown to rearrange the interleukin 2 gene, normally located on chromosome band 4q26, with sequences from chromosome band 16p13.1. A cDNA library of tumour cells was screened with an interleukin 2 gene-specific probe. Three clones were isolated, which consisted, from 5' to 3', of the three first exons of the interleukin 2 gene followed by a 16p13 in-frame sequence encoding 181 amino acids. A probe derived from this sequence detected a 1.2 kb transcript in various cell lines exhibiting mature B lymphoid cell features, but this was not detected in other cell lines representative of other haematopoietic lineages, or in other organs. For this reason, the novel gene was termed BCM for B cell maturation. The open reading frame of BCM normal cDNA predicted a 184 amino acid protein with a single transmembrane domain which had no homology with any protein sequence stored in data banks. Our data indicate that BCM is a new gene whose expression coincides with B cell terminal maturation.

Asunto(s)

Cromosomas Humanos Par 16 , Cromosomas Humanos Par 4 , Reordenamiento Génico , Interleucina-2/genética , Linfoma de Células T/genética , Translocación Genética , Secuencia de Aminoácidos , Secuencia de Bases , Northern Blotting , Southern Blotting , Bandeo Cromosómico , Clonación Molecular , ADN/genética , ADN de Neoplasias/genética , ADN de Neoplasias/aislamiento & purificación , Exones , Biblioteca de Genes , Humanos , Hibridación in Situ , Cariotipificación , Datos de Secuencia Molecular , ARN Neoplásico/genética , Valores de Referencia , Mapeo Restrictivo , Homología de Secuencia de Ácido Nucleico