RESUMO
SLAMF1/CD150 receptor is a founder of signaling lymphocyte activation molecule (SLAM) family of cell-surface receptors. It is widely expressed on cells within hematopoietic system. In hematologic malignancies CD150 cell surface expression is restricted to cutaneous T-cell lymphomas, few types of B-cell non-Hodgkin's lymphoma, near half of cases of chronic lymphocytic leukemia, Hodgkin's lymphoma, and multiple myeloma. Differential expression among various types of hematological malignancies allows considering CD150 as diagnostical and potential prognostic marker. Moreover, CD150 may be a target for antibody-based or measles virus oncolytic therapy. Due to CD150 signaling properties it is involved in regulation of malignant cell fate decision and tumor microenvironment in Hodgkin's lymphoma and chronic lymphocytic leukemia. This review summarizes evidence for the important role of CD150 in pathogenesis of hematologic malignancies.
Assuntos
Neoplasias Hematológicas , Membro 1 da Família de Moléculas de Sinalização da Ativação Linfocitária , Animais , HumanosRESUMO
Signaling lymphocytic activation molecule family member 1 (SLAMF1)/CD150 is a co-stimulatory receptor expressed on a variety of hematopoietic cells, in particular on mature lymphocytes activated by specific antigen, costimulation and cytokines. Changes in CD150 expression level have been reported in association with autoimmunity and with B-cell chronic lymphocytic leukemia. We characterized the core promoter for SLAMF1 gene in human B-cell lines and explored binding sites for a number of transcription factors involved in B cell differentiation and activation. Mutations of SP1, STAT6, IRF4, NF-kB, ELF1, TCF3, and SPI1/PU.1 sites resulted in significantly decreased promoter activity of varying magnitude, depending on the cell line tested. The most profound effect on the promoter strength was observed upon mutation of the binding site for Early B-cell factor 1 (EBF1). This mutation produced a 10-20 fold drop in promoter activity and pinpointed EBF1 as the master regulator of human SLAMF1 gene in B cells. We also identified three potent transcriptional enhancers in human SLAMF1 locus, each containing functional EBF1 binding sites. Thus, EBF1 interacts with specific binding sites located both in the promoter and in the enhancer regions of the SLAMF1 gene and is critical for its expression in human B cells.
Assuntos
Regulação da Expressão Gênica , Membro 1 da Família de Moléculas de Sinalização da Ativação Linfocitária/genética , Transativadores/genética , Transcrição Gênica , Linfócitos B/citologia , Linfócitos B/metabolismo , Fatores de Transcrição Hélice-Alça-Hélice Básicos/genética , Fatores de Transcrição Hélice-Alça-Hélice Básicos/metabolismo , Sítios de Ligação , Linhagem Celular Tumoral , Elementos Facilitadores Genéticos , Genes Reporter , Células HEK293 , Humanos , Fatores Reguladores de Interferon/genética , Fatores Reguladores de Interferon/metabolismo , Luciferases/genética , Mutação , NF-kappa B/genética , NF-kappa B/metabolismo , Proteínas Nucleares/genética , Proteínas Nucleares/metabolismo , Cultura Primária de Células , Regiões Promotoras Genéticas , Ligação Proteica , Proteínas Proto-Oncogênicas/genética , Proteínas Proto-Oncogênicas/metabolismo , Fator de Transcrição STAT6/genética , Fator de Transcrição STAT6/metabolismo , Transdução de Sinais , Membro 1 da Família de Moléculas de Sinalização da Ativação Linfocitária/metabolismo , Fator de Transcrição Sp1/genética , Fator de Transcrição Sp1/metabolismo , Transativadores/metabolismo , Fatores de Transcrição/genética , Fatores de Transcrição/metabolismoRESUMO
The CD150 receptor is expressed on thymocytes, activated and memory T cells, B cells, platelets, natural killer T cells, and mature dendritic cells, and is also detected on tumor cells of Hodgkin's lymphoma (HL) and diffuse large B-cell lymphoma with an activated B cell phenotype. Here, we report that the level of CD150 expression is elevated during B cell differentiation toward plasma cells. In primary tonsillar B cells and HL cell lines, CD150 signaling regulates the phosphorylation of three types of mitogen-activated protein kinases (MAPKs): extracellular signal-regulated kinase 1/2 (ERK1/2), p38 MAPK, and Jun N-terminal kinase 1/2 (JNK1/2). CD150 induced ERK1/2 activation in primary tonsillar B cells and in two HL cell lines. CD150 mediated activation of JNK1/2 p54 and JNK2-gamma kinase isoforms in all CD150(+) B cell lines we tested. CD150 associated with the serine/threonine kinase hematopoetic progenitor kinase 1 (HPK1) regardless of CD150 tyrosine phosphorylation or binding of the SH2D1A adaptor protein to CD150, and HPK1 overexpression enhanced CD150-mediated JNK1/2 phosphorylation. CD150 ligation inhibited cell proliferation of all studied HL cell lines and induced apoptosis in L1236 HL cells that did not depend on JNK activity. As signaling through CD150 modulates MAPK activity in HL tumor cells, CD150 may contribute to regulation of tumor cell maintenance in low-rate proliferating HLs.
Assuntos
Antígenos CD/imunologia , Linfócitos B/imunologia , Ativação Enzimática/imunologia , Doença de Hodgkin/imunologia , Proteínas Quinases Ativadas por Mitógeno/imunologia , Receptores de Superfície Celular/imunologia , Transdução de Sinais/imunologia , Antígenos CD/metabolismo , Linfócitos B/citologia , Linfócitos B/metabolismo , Western Blotting , Diferenciação Celular/imunologia , Linhagem Celular Tumoral , Separação Celular , Citometria de Fluxo , Doença de Hodgkin/metabolismo , Humanos , Imuno-Histoquímica , Proteína Quinase 8 Ativada por Mitógeno/imunologia , Proteína Quinase 8 Ativada por Mitógeno/metabolismo , Proteína Quinase 9 Ativada por Mitógeno/imunologia , Proteína Quinase 9 Ativada por Mitógeno/metabolismo , Proteínas Quinases Ativadas por Mitógeno/metabolismo , Receptores de Superfície Celular/metabolismo , Membro 1 da Família de Moléculas de Sinalização da Ativação Linfocitária , TransfecçãoRESUMO
An amendment to this paper has been published and can be accessed via a link at the top of the paper.
RESUMO
Cell surface expression of CD150 and CD180 receptors in chronic lymphocytic leukemia (CLL) associates with mutational IGHV status and favourable prognosis. Here we show a direct correlation between cell surface expression and colocalization of these receptors on CLL B cells. In the absence of CD150 and CD180 on the cell surface both receptors were expressed in the cytoplasm. The CD150 receptor was colocalized with markers of the endoplasmic reticulum, the Golgi apparatus and early endosomes. In contrast, CD180 was detected preferentially in early endosomes. Analysis of CD150 isoforms differential expression revealed that regardless of CD150 cell surface expression the mCD150 isoform with two ITSM signaling motifs was a predominant CD150 isoform in CLL B cells. The majority of CLL cases had significantly elevated expression level of the soluble sCD150, moreover CLL B cells secrete this isoform. CD150 or CD180 crosslinking on CLL B cells alone led to activation of Akt, mTORC1, ERK1/2, p38MAPK and JNK1/2 networks. Both CD150 and CD180 target the translation machinery through mTOR independent as well as mTOR dependent pathways. Moreover, both these receptors transmit pro-survival signals via Akt-mediated inhibition of GSK3ß and FOXO1/FOXO3a. Unexpectedly, coligation CD150 and CD180 receptors on CLL B cells led to mutual inhibition of the Akt and MAPK pathways. While CD150 and CD180 coligation resulted in reduced phosphorylation of Akt, ERK1/2, c-Jun, RSK, p70S6K, S6RP, and 4E-BP; it led to complete blocking of mTOR and p38MAPK phosphorylation. At the same time coligation of CD150 and CD40 receptors did not result in Akt and MAPK inhibition. This suggests that combination of signals via CD150 and CD180 leads to blocking of pro-survival pathways that may be a restraining factor for neoplastic CLL B cells propagation in more than 50% of CLL cases where these receptors are coexpressed.
Assuntos
Antígenos CD/metabolismo , Linfócitos B/metabolismo , Leucemia Linfocítica Crônica de Células B/patologia , Sistema de Sinalização das MAP Quinases , Proteínas Proto-Oncogênicas c-akt/metabolismo , Transdução de Sinais , Membro 1 da Família de Moléculas de Sinalização da Ativação Linfocitária/metabolismo , Separação Celular , Citometria de Fluxo , Humanos , Leucemia Linfocítica Crônica de Células B/enzimologia , Leucemia Linfocítica Crônica de Células B/metabolismoRESUMO
Measles virus (MV) is highly contagious pathogen, which causes a profound immunosuppression, resulting in high infant mortality. This virus infects dendritic cells (DCs) following the binding of MV hemagglutinin (MV-H) to CD150 receptor and alters DC functions by a mechanism that is not completely understood. We have analyzed the effect of MV-H interaction with CD150-expressing DCs on the DC signaling pathways and consequent phenotypic and functional changes in the absence of infectious context. We demonstrated that contact between CD150 on human DCs and MV-H expressed on membrane of transfected CHO cells was sufficient to modulate the activity of two major regulatory pathways of DC differentiation and function: to stimulate Akt and inhibit p38 MAPK phosphorylation, without concomitant ERK1/2 activation. Furthermore, interaction with MV-H decreased the expression level of DC activation markers CD80, CD83, CD86, and HLA-DR and strongly downregulated IL-12 production but did not modulate IL-10 secretion. Moreover, contact with MV-H suppressed DC-mediated T-cell alloproliferation, demonstrating profound alteration of DC maturation and functions. Finally, engagement of CD150 by MV-H in mice transgenic for human CD150 decreased inflammatory responses, showing the immunosuppressive effect of CD150-MV-H interaction in vivo. Altogether, these results uncover novel mechanism of MV-induced immunosuppression, implicating modulation of cell signaling pathways following MV-H interaction with CD150-expressing DCs and reveal anti-inflammatory effects of CD150 stimulation.
Assuntos
Células Dendríticas/imunologia , Hemaglutininas/imunologia , Imunidade , Espaço Intracelular/metabolismo , Vírus do Sarampo/imunologia , Transdução de Sinais , Membro 1 da Família de Moléculas de Sinalização da Ativação Linfocitária/metabolismo , Animais , Linhagem Celular , Humanos , Inflamação/patologia , Camundongos Endogâmicos C57BL , Modelos Biológicos , Fenótipo , Fosforilação , Proteínas Proto-Oncogênicas c-akt/metabolismo , Proteínas Quinases p38 Ativadas por Mitógeno/metabolismoRESUMO
CD150 (IPO3/SLAM) belongs to the SLAM family of receptors and serves as a major entry receptor for measles virus. CD150 is expressed on normal and malignant cells of the immune system. However, little is known about its expression outside the hematopoietic system, especially tumors of the central nervous system (CNS). Although CD150 was not found in different regions of normal brain tissues, our immunohistochemical study revealed its expression in 77.6% of human CNS tumors, including glioblastoma, anaplastic astrocytoma, diffuse astrocytoma, ependymoma, and others. CD150 was detected in the cytoplasm, but not on the cell surface of glioma cell lines, and it was colocalized with the endoplasmic reticulum and Golgi complex markers. In addition to the full length mRNA of the mCD150 splice isoform, in glioma cells we found a highly expressed novel CD150 transcript (nCD150), containing an 83 bp insert. The insert is derived from a previously unrecognized exon designated Cyt-new, which is located 510 bp downstream of the transmembrane region exon, and is a specific feature of primate SLAMF1. Both mCD150 and nCD150 cDNA variants did not contain any mutations and had the leader sequence. The nCD150 transcript was also detected in normal and malignant B lymphocytes, primary T cells, dendritic cells and macrophages; however, in glioma cells nCD150 was found to be the predominant CD150 isoform. Similarly to mCD150, cell surface expression of nCD150 allows wild type measles virus entry to the cell. Our data indicate that CD150 expression in CNS tumors can be considered a new diagnostic marker and potential target for novel therapeutic approaches.
Assuntos
Antígenos CD/genética , Regulação da Expressão Gênica , Receptores de Superfície Celular/genética , Sequência de Aminoácidos , Antígenos CD/química , Antígenos CD/metabolismo , Linfócitos B/metabolismo , Encéfalo/metabolismo , Encéfalo/patologia , Linhagem Celular Tumoral , Neoplasias do Sistema Nervoso Central/metabolismo , Neoplasias do Sistema Nervoso Central/patologia , Retículo Endoplasmático/metabolismo , Complexo de Golgi/metabolismo , Células HEK293 , Humanos , Imuno-Histoquímica , Vírus do Sarampo/fisiologia , Dados de Sequência Molecular , Isoformas de Proteínas/química , Isoformas de Proteínas/genética , Isoformas de Proteínas/metabolismo , Splicing de RNA , RNA Mensageiro/metabolismo , Receptores de Superfície Celular/química , Receptores de Superfície Celular/metabolismo , Membro 1 da Família de Moléculas de Sinalização da Ativação LinfocitáriaRESUMO
FCRL6 receptor is a more recently identified representative of the FCRL family. We generated a panel of mouse mAbs to baculovirus-derived recombinant FCRL6 protein. The clone 7B2 was found to specifically recognize a 63kDa protein expressed preferentially on the surface of CD8 T and CD56 NK cells in human peripheral blood and spleen. The clone 7B2 reacts with FCRL6 in Western blotting, FACS, and immunohistochemistry. In the T cell lineage, FCRL6 functions in antigen-experienced cells. Mitogenic stimulation of PB leukocytes in vitro resulted in an abrogation of the FCRL6 gene expression. We found a significant decrease in the FCRL6 gene expression in peripheral T cells of patients with certain autoimmune and blood diseases, and its upregulation at the late stages of HIV infection. Study of the FCRL6 association with signaling molecules showed its ability to recruit SHP-1, SHP-2, SHIP-1, and SHIP-2 phosphatases, and also adaptor protein Grb2 through phosphorylated cytoplasmic tyrosines. The current results demonstrate inhibitory potential of FCRL6 and suggest its possible involvement in modulation of CTL effector functions in various immune disorders.
Assuntos
Proteínas de Transporte/imunologia , Regulação da Expressão Gênica , Receptores de Superfície Celular/genética , Receptores de Superfície Celular/imunologia , Processamento Alternativo , Sequência de Aminoácidos , Doenças Autoimunes/imunologia , Células Sanguíneas/citologia , Linfócitos T CD8-Positivos/imunologia , Doenças Hematológicas/imunologia , Humanos , Peptídeos e Proteínas de Sinalização Intracelular/imunologia , Células Matadoras Naturais/imunologia , Dados de Sequência Molecular , RNA Mensageiro/imunologia , Alinhamento de Sequência , Baço/citologiaRESUMO
AIM: To find out what signal transduction pathways are linked to CD150 in Hodgkin's lymphoma (HL) cell lines, how are they regulated, and to examine the expression of different CD150 splice forms and SH2 domain containing protein D1A (SH2D1A) adaptor protein on mRNA level in HD primary tumors and cell lines. METHODS: The expression of CD150 splicing forms and SH2D1A adaptor protein in HD primary lymphoma tissue and cell lines were analyzed by RT-PCR method. To examine CD150-SH2D1A localization in HD cell lines we performed double immunofluorescent staining of these two proteins. Total amount of SH2D1A, Syk, Lyn, SHP-2, SHIP proteins, and activated/phosphorylated ERK1/2 and Akt proteins were detected by Western blot analysis with specific antibodies. RESULTS: We showed the expression of soluble (sCD150) and full length transmembrane (mCD150) splice forms and SH2D1A adaptor protein on mRNA level in 9 cases of classical HD and three HD lines of B cell origin - L428, KM-H2 and L1236. In spite of CD150 and SH2D1A co-expression in studied HD cell lines, CD150 co-precipitated and co-localized with SH2D1A only in L1236 cells. CD150 ligation induced extracellular signal-regulated kinases (ERK) dephosphorylation in L1236 cell line, but had no effect on ERK pathway in KM-H2 and L428 cells. CD150 crosslinking induced Akt activation also only in L1236 cells. CONCLUSIONS: HD cells express sCD150 and mCD150 splice forms and SH2D1A. Association of CD150 and SH2D1A depends at least on their localization pattern. CD150 is linked to ERK and Akt pathways in HD cell lines. Our data suggest that CD150-SH2D1A association play decisive role in Akt signaling upon CD150 ligation in HD cell lines. CD150-mediated Akt activation in HD cell lines, similarly to DT40 model system, is SHIP-independent.
Assuntos
Glicoproteínas/metabolismo , Doença de Hodgkin/metabolismo , Imunoglobulinas/metabolismo , Peptídeos e Proteínas de Sinalização Intracelular/metabolismo , Isoformas de Proteínas/metabolismo , Transdução de Sinais/fisiologia , Antígenos CD , Sequência de Bases , Western Blotting , Linhagem Celular Tumoral , Eletroforese em Gel de Poliacrilamida , Precursores Enzimáticos/metabolismo , MAP Quinases Reguladas por Sinal Extracelular/metabolismo , Imunofluorescência , Humanos , Dados de Sequência Molecular , Fosfatidilinositol-3,4,5-Trifosfato 5-Fosfatases , Monoéster Fosfórico Hidrolases/metabolismo , Proteínas Serina-Treonina Quinases/metabolismo , Proteína Tirosina Fosfatase não Receptora Tipo 11 , Proteínas Tirosina Fosfatases/metabolismo , Proteínas Tirosina Quinases/metabolismo , Proteínas Proto-Oncogênicas/metabolismo , Proteínas Proto-Oncogênicas c-akt , RNA Mensageiro/análise , Receptores de Superfície Celular , Reação em Cadeia da Polimerase Via Transcriptase Reversa , Proteínas Tirosina Fosfatases Contendo o Domínio SH2 , Proteína Associada à Molécula de Sinalização da Ativação Linfocitária , Membro 1 da Família de Moléculas de Sinalização da Ativação Linfocitária , Quinase Syk , Quinases da Família src/metabolismoRESUMO
The CD150 subfamily within the CD2 family is a growing group of dual-function receptors that have within their cytoplasmic tails a characteristic signaling motif. The ITSM (immunoreceptor tyrosine-based switch motif) enables these receptors to bind to and be regulated by small SH2 domain adaptor proteins, including SH2D1A (SH2-containing adaptor protein SH2 domain protein 1A) and EAT-2 (EWS-activated transcript 2). A major signaling pathway through the prototypic receptor in this subfamily, CD150, leads to the activation of interferon-gamma, a key cytokine for viral immunity. As a result, many viruses have designed strategies to usurp or alter CD150 functions. Measles virus uses CD150 as a receptor and Molluscum contagiosum virus encodes proteins that are homologous to CD150. Thus, viruses use CD150 subfamily receptors to create a favorable environment to elude detection and destruction. Understanding the CD150 subfamily may lead to new strategies for vaccine development and antiviral therapies.
Assuntos
Glicoproteínas/metabolismo , Imunoglobulinas/metabolismo , Animais , Antígenos CD , Antígenos CD2/genética , Antígenos CD2/metabolismo , Glicoproteínas/genética , Herpesvirus Humano 4/imunologia , Humanos , Imunoglobulinas/genética , Vírus do Sarampo/imunologia , Modelos Imunológicos , Poxviridae/imunologia , Ligação Proteica , Receptores de Superfície Celular , Receptores Virais/metabolismo , Transdução de Sinais , Membro 1 da Família de Moléculas de Sinalização da Ativação Linfocitária , Vírus/imunologia , Domínios de Homologia de srcRESUMO
The CD150 receptor is expressed on activated T and B lymphocytes, dendritic cells, and monocytes. A TxYxxV/I motif in the CD150 cytoplasmic tail can bind different SH2-containing molecules, including tyrosine and inositol phosphatases, Src family kinases, and adaptor molecules. To analyze CD150-initiated signal transduction pathways, we used DT40 B-cell sublines deficient in these molecules. CD150 ligation on DT40 transfectants induced the extracellular signal-regulated kinase (ERK) pathway, which required SH2-containing inositol phosphatase (SHIP) but not SH2 domain protein 1A (SH2D1A). CD150-mediated Akt phosphorylation required Syk and SH2D1A, was negatively regulated by Lyn and Btk, but was SHIP independent. Lyn directly phosphorylated Y327 in CD150, but the Akt pathway did not depend on CD150 tyrosine phosphorylation and CD150-SHP-2 association. Analysis of CD150 and SH2D1A expression in non-Hodgkin and Hodgkin lymphomas revealed stages of B-cell differentiation where these molecules are expressed alone or coexpressed. Signaling studies in Hodgkin disease cell lines showed that CD150 is linked to the ERK and Akt pathways in neoplastic B cells. Our data support the hypothesis that CD150 and SH2D1A are coexpressed during a narrow window of B-cell maturation and SH2D1A may be involved in regulation of B-cell differentiation via switching of CD150-mediated signaling pathways.