RESUMO
The gamma-2 herpesvirus of rhesus monkeys, rhesus monkey rhadinovirus (RRV), persists principally in B cells of its host. We constructed recombinant strains of RRV expressing the rhesus monkey-derived anti-SIV monoclonal antibodies 4L6 and 5L7 and compared the RRV-mediated in vivo delivery of these antibodies in rhesus monkeys with previous studies that utilized intramuscular delivery with an adeno-associated virus (AAV) vector. Recombinant RRV-4L6 and RRV-5L7 were both shown to stably produce the antibodies in persistently infected B-cell lines in culture. Two RRV-negative rhesus monkeys were experimentally infected with recombinant RRV-4L6 and two with recombinant RRV-5L7. Following infection, the appearance of the delivered antibody was readily detected in all four animals. However, the levels of the delivered antibody were considerably lower than what has been typically observed following intramuscular AAV delivery. Furthermore, three of the four monkeys had an antibody response to the delivered antibody as had been observed previously with intramuscular AAV delivery of these same antibodies. We conclude that this recombinant herpesvirus has no inherent advantage over AAV for delivery of potentially therapeutic monoclonal antibodies in a rhesus monkey model.
Assuntos
Anticorpos Monoclonais/genética , Terapia Genética/métodos , Vetores Genéticos/administração & dosagem , Rhadinovirus/genética , Animais , Anticorpos Monoclonais/imunologia , Anticorpos Monoclonais/metabolismo , Linhagem Celular , Células Cultivadas , Vetores Genéticos/efeitos adversos , Macaca mulatta , Vírus da Imunodeficiência Símia/imunologiaRESUMO
Gammadelta T cells show preferential homing that is characterized by biased TCR repertoire at different anatomical locations. The processes that regulate this compartmentalization are largely unknown. A model that allows repeated multiple sample procurement under different conditions and enables with relatively straightforward extrapolation to a human situation will facilitate our understanding. The peripheral blood Vgamma2 T cell population is the best-characterized human gammadelta T cell subset. To determine its diversity at multiple immunocompartments matching blood, colon, and vagina samples from rhesus macaques were investigated. Four joining segments used in Vgamma2-Jgamma transcripts were identified, including one segment with no human counterpart. Like in humans, the rhesus peripheral blood Vgamma2 TCR repertoire was limited and contained common sequences that were shared by genetically heterogeneous animals. Furthermore, this subset comprised several phylogenetically conserved Vgamma2 complementarity-determining region 3 (CDR3) motifs between rhesus and humans. Common sequences were also found within the colon and vagina of the same animal, and within the peripheral blood and intestine of different unrelated animals. These results validate rhesus macaques as a useful model for gammadelta TCR repertoire and homing studies. Moreover, they provide evidence that the concept of limited but overlapping Vgamma TCR repertoire between unrelated individuals can be extended including the mucosa of the digestive and reproductive tract.
Assuntos
Especificidade de Órgãos/genética , Especificidade de Órgãos/imunologia , Receptores de Antígenos de Linfócitos T gama-delta/biossíntese , Receptores de Antígenos de Linfócitos T gama-delta/genética , Motivos de Aminoácidos/genética , Motivos de Aminoácidos/imunologia , Sequência de Aminoácidos , Animais , Sequência de Bases , Colo Sigmoide/imunologia , Colo Sigmoide/metabolismo , Feminino , Genes Codificadores da Cadeia gama de Receptores de Linfócitos T , Humanos , Mucosa Intestinal/imunologia , Mucosa Intestinal/metabolismo , Macaca mulatta , Masculino , Dados de Sequência Molecular , Receptores de Antígenos de Linfócitos T gama-delta/sangue , Alinhamento de Sequência , Homologia de Sequência de Aminoácidos , Homologia de Sequência do Ácido Nucleico , Transcrição Gênica/imunologia , Vagina/imunologia , Vagina/metabolismoRESUMO
BACKGROUND: Until recently, there were no CD3 antibodies that crossreacted with rhesus macaque T cells. Consequently, studies relying on CD8 counts or CD4/CD8 ratios enumerated this subpopulation on the basis of CD8+ or CD8bright+ staining. We used a rhesus-specific, anti-CD3 antibody to better define the CD8+ T-cell population, and to show the effects of better measurements on CD4/CD8 ratios and changes in T cells as macaques age. METHODS: We used three-color flow cytometry to measure CD4 and CD8 populations with and without CD3 costaining. Venous blood samples were obtained from 52 colony-bred macaques between 2 months and 9 years of age. RESULTS: The CD8+ T cells defined by CD3 and CD8 double staining were approximately 60% of all cells that were stained by CD8 alone. Improved detection of this lymphocyte subset showed that CD4/CD8 ratios were close to the range of 1.5-2.0. Declining CD4/CD8 ratios during aging are predominantly due to decreasing CD4+ T-cell counts. CONCLUSIONS: Better quantitation of the CD8+ T-cell population showed that the CD4/CD8 ratio was not inverted as had been reported, but is actually very similar to the values observed in human beings. Although the two species differ in the pattern of CD8 expression, the general immune system characteristics are very similar.
Assuntos
Complexo CD3/análise , Complexo CD3/imunologia , Relação CD4-CD8/métodos , Citometria de Fluxo/métodos , Fatores Etários , Animais , Antígenos CD4/análise , Antígenos CD4/imunologia , Linfócitos T CD4-Positivos/química , Linfócitos T CD4-Positivos/imunologia , Antígenos CD8/análise , Antígenos CD8/imunologia , Linfócitos T CD8-Positivos/química , Linfócitos T CD8-Positivos/imunologia , Reações Cruzadas , Feminino , Macaca mulatta , MasculinoRESUMO
Although their precise roles are not well defined, gammadelta T lymphocytes are recognized as regular components of immune responses. These cells express a limited T cell receptor repertoire and they can be stimulated by soluble ligands without conventional processing and presentation by major histocompatibility antigens. Progress in this area has been limited by the substantial differences between murine and human gammadelta T cells and the lack of knowledge about these cells in nonhuman primates. We used molecular analysis of T cell receptor diversity to characterize gammadelta T cell populations from peripheral blood and colon of rhesus macaques (Macaca mulatta). The gammadelta T cell receptor diversity was limited and distinct for these tissue compartments, particularly in the TCRGV2 family. Furthermore, the TCRDV1 + subset of peripheral blood gammadelta T cells showed signs of progressive oligoclonalization as a function of age. Similar observations have been reported for human tissue samples and our results validate rhesus macaques as an appropriate animal model for studying primate gammadelta T cell populations.
Assuntos
Mucosa Intestinal/imunologia , Macaca mulatta/imunologia , Receptores de Antígenos de Linfócitos T gama-delta/genética , Sequência de Aminoácidos , Animais , Sequência de Bases , Colo Sigmoide/citologia , Colo Sigmoide/imunologia , Regiões Determinantes de Complementaridade/análise , Variação Genética , Mucosa Intestinal/citologia , Leucócitos Mononucleares/imunologia , Macaca mulatta/sangue , Modelos Animais , Biologia Molecular , Reação em Cadeia da Polimerase , RNA Mensageiro/análise , Receptores de Antígenos de Linfócitos T gama-delta/sangue , Receptores de Antígenos de Linfócitos T gama-delta/química , Reprodutibilidade dos TestesRESUMO
The purpose of the present studies was to determine whether acute vaginal infection with Herpes virus 2 altered the vaginal population of gammadelta T cells, and whether gammadelta T cells influenced the vaginal clearance of HSV-2. BALB/c mice were infected intravaginally with the progressively lethal wild type 333 strain, or the non-lethal thymidine kinase deficient (deltaTK- -HSV-2) mutant strain of HSV-2 virus. Changes in vaginal T cell composition were examined by FACS analysis 4 days after infection. Clearance of vaginal deltaTK- -HSV-2 infection was compared between mice with normal gammadelta T cell populations (BALB/c) and transgenic mice in which all the gammadelta T cells express a receptor that is specific for the b allotype of MHC class Ib T10 antigen (G8/BALB/c). In HSV-2 infected BALB/c mice, but not G8/BALB/c, a subset of gammadelta T cells that express a Vgamma2 TCR accumulated in the vaginal mucosa by the fourth day after infection. Unexpectedly, we found that gammadelta TCR transgenic mice exhibited a more rapid clearance of the virus than control mice (P < 0.05). These findings argue against the hypothesis that the normal populations of vaginal intraepithelial gammadelta T cells play a direct role in the elimination of virally infected epithelial cells.
Assuntos
Herpes Genital/imunologia , Herpesvirus Humano 2/imunologia , Receptores de Antígenos de Linfócitos T gama-delta/metabolismo , Linfócitos T/imunologia , Vagina/imunologia , Animais , Feminino , Citometria de Fluxo , Herpes Genital/virologia , Herpesvirus Humano 2/fisiologia , Camundongos , Camundongos Endogâmicos BALB C , Vagina/virologia , Replicação ViralRESUMO
The vaginal epithelium of normal mice contains lymphocytes of fetal thymic origin that express an invariant Vgamma4/Vdelta1 TCR. The apparent lack of other gammadelta TCR species suggests that a selection mechanism might operate to regulate the localization of gammadelta T cells at this anatomical site. Selection might be connected to the Vgamma4/Vdelta1 TCR or to some homing characteristic of the fetal thymic lineage that appears at day 17-18 of embryonic life. In the present studies, we investigated whether transgenic gammadelta cells expressing a TCR species characteristic of the subpopulation of gammadelta T cells found in the blood, spleen and lymph would translocate to the vaginal epithelium. We found that the transgenic Vgamma2 TCR+ cells did accumulate in the vagina of transgenic mice. Furthermore, like normal vaginal gammadelta T cells, the transgenic vaginal gammadelta T cells expressed the phenotype of recently activated memory/effector T cells (CD44(hi), CD62L-, CD45RB(lo), CD69+). Vaginal gammadelta T cells in normal mice do not express the CD2 and CD28 antigens, but both of these markers are present on transgenic vaginal gammadelta T cells. We observed that a small fraction of splenic transgenic gammadelta T cells had the same surface phenotype as the vaginal transgenic gammadelta T cells, raising the possibility that the gammadelta T cells present in the vaginal epithelium of transgenic mice originated from the peripheral lymphoid organs. Data in support of this possibility came from experiments in which co-incubation of splenic transgenic gammadelta T cells with vaginal epithelial cell suspensions induced the vaginal gammadelta phenotype on the splenic gammadelta T cells. The finding of transgenic gammadelta T cells in the vaginal epithelium suggests that homing of gammadelta T cells to this site is not restricted to gammadelta T cells that express the V4/NS1 invariant TCR. Furthermore, these findings imply that retention of gammadelta T cells in the vaginal epithelium of normal mice is affected by a Vgamma4/Vdelta1-specific mechanism. The finding of a significant level of apoptosis in the transgenic vaginal gammadelta T cells, but not in the normal vaginal gammadelta T cells, could reflect that the mechanism of retention of Vgamma4/Vdelta1 + in the vaginal epithelium involves selective survival at the site.
Assuntos
Receptores de Antígenos de Linfócitos T gama-delta/biossíntese , Receptores de Retorno de Linfócitos/genética , Linfócitos T/citologia , Linfócitos T/metabolismo , Vagina/citologia , Animais , Antígenos CD/biossíntese , Antígenos de Diferenciação de Linfócitos T/biossíntese , Apoptose , Biomarcadores/análise , Antígenos CD2/biossíntese , Antígenos CD28/biossíntese , Movimento Celular , Células Cultivadas , Epitélio , Feminino , Receptores de Hialuronatos/biossíntese , Selectina L/biossíntese , Lectinas Tipo C , Antígenos Comuns de Leucócito/biossíntese , Ativação Linfocitária/imunologia , Camundongos , Camundongos Endogâmicos BALB C , Camundongos Transgênicos , Baço/citologia , Baço/fisiologia , Linfócitos T/fisiologia , Transgenes , Vagina/fisiologiaRESUMO
Schistosome granulomas from normal or IL-4-deficient C57BL/6 mice make little IFN-gamma and show no Th1 polarization. This could signify that these granulomas have few cells capable of IFN-gamma synthesis or that such cells are under tight control. Granulomas can make IL-10 and TGF-beta, which can regulate IFN-gamma synthesis. Using FACS analysis and ELISA, we explored the origin and regulation of IFN-gamma in schistosome granulomas from both IL-4(-/-) and IL-4(+/+) mice. FACS analysis of intracytoplasmic IFN-gamma staining showed that some granuloma Thy1.2+ T cells (CD8+ and CD4+) express IFN-gamma. Granulomas had NK1.1+ cells, but they appeared to produce little or no IFN-gamma. Purified granuloma Thy1.2+ cells made IFN-gamma in vitro, whereas isolated NK1.1+ lymphocytes secreted little even with rIL-12 stimulation. Culture of granuloma cells with blocking anti-IL-10 or anti-TGF-beta mAb or with rIL-12 substantially increased T cell IFN-gamma synthesis, particularly in the IL-4(-/-) animals. Cultured granuloma cells depleted of Thy1.2+ lymphocytes by Ab and C released no IFN-gamma. It is concluded that granuloma IFN-gamma comes from T cells, not NK cells. Also, this T cell-derived IFN-gamma is subject to IL-10 and TGF-beta regulation, which is particularly evident in IL-4(-/-) mice. Thus, the Th2 granuloma of schistosomiasis has large numbers of activated Th1 or Th0 lymphocytes that are under tight restraint.
Assuntos
Granuloma/imunologia , Interferon gama/biossíntese , Interleucina-4/fisiologia , Esquistossomose/imunologia , Animais , Feminino , Interleucina-10/fisiologia , Interleucina-4/deficiência , Células Matadoras Naturais/metabolismo , Camundongos , Camundongos Endogâmicos C57BL , Linfócitos T/fisiologia , Fator de Crescimento Transformador beta/fisiologiaRESUMO
Chronic infection with Schistosoma mansoni induces in humans and mice a Th2-dominant immune response in which eosinophils and IgE are conspicuously elevated. Human eosinophils express IgE receptors that participate in an IgE-dependent eosinophil-mediated ADCC reaction against Schistosomula larvae in vitro. To investigate the expression of IgE receptors on murine eosinophils, they were purified (>95% pure by Giemsa-stained cytospin preparations) from liver granulomas of Schistosoma-infected mice. Flow cytometric analysis showed the absence of the low-affinity IgE receptor Fc-epsilon RII (CD23) and Mac-2 and the absence of binding of murine IgE. Reverse transcription-polymerase chain reaction (RT-PCR) analysis of granuloma eosinophil mRNA did not detect transcripts for Fc-epsilon RII or the alpha-chain of the high-affinity IgE receptor Fc-epsilon RI, but did detect transcripts that encode Mac-2 and the low-affinity IgG receptors Fc-gamma RIIb2, Fc-gamma RIII, and the FcR-associated gamma-chain. In vitro stimulation of granuloma eosinophils with interleukin-4 (IL-4) did not induce IgE binding, surface expression of Mac-2, or the transcription of Fc-epsilon receptors (Fc-epsilon RI, Fc-epsilon RII/CD23). To investigate normal murine eosinophils, we cultured normal mouse bone marrow cells with recombinant IL-3, recombinant IL-5, and recombinant granulocyte-macrophage colony-stimulating factor, conditions that promote eosinophil differentiation. Flow cytometric analysis of bone marrow-derived eosinophils failed to detect IgE binding or cell surface expression of Fc-epsilon RII and Mac-2, and RT-PCR analysis of fluorescence-activated cell sorted bone marrow-derived eosinophils failed to detect transcripts that encode Fc-epsilon RI or Fc-epsilon RII. These findings show that, in contrast to human eosinophils, murine eosinophils do not express cell surface receptors that bind IgE. However, because IgG receptors (Fc-gamma RIIb2, Fc-gamma RII) were present on eosinophils purified from granulomas, we investigated whether they might be involved in eosinophil activation. We found that an oxidative burst in eosinophils could be triggered through their IgG receptors.
Assuntos
Eosinofilia/etiologia , Eosinófilos/química , Imunoglobulina E/imunologia , Receptores de IgE/análise , Esquistossomose mansoni/imunologia , Animais , Antígenos de Diferenciação/análise , Medula Óssea/efeitos dos fármacos , Células da Medula Óssea , Diferenciação Celular/efeitos dos fármacos , Células Cultivadas , Espectroscopia de Ressonância de Spin Eletrônica , Peroxidase de Eosinófilo , Citometria de Fluxo , Galectina 3 , Fator Estimulador de Colônias de Granulócitos e Macrófagos/farmacologia , Granuloma/etiologia , Granuloma/patologia , Células-Tronco Hematopoéticas/citologia , Células-Tronco Hematopoéticas/efeitos dos fármacos , Humanos , Interleucina-3/farmacologia , Interleucina-5/farmacologia , Fígado/patologia , Camundongos , Camundongos Endogâmicos CBA , Peroxidases/análise , Reação em Cadeia da Polimerase , RNA Mensageiro/análise , Proteínas Recombinantes/farmacologia , Esquistossomose mansoni/complicaçõesRESUMO
While little is known about their activation requirements and function, the intraepithelial T cells of the murine vagina express TCR complexes in which the antigen recognition components and the signaling components have unusual features. These vaginal T cells express an invariant V gamma 4/V delta 1 TCR and appear to be the only intraepithelial gamma delta T cells that exclusively use FcR gamma chains in their TCR complex. To further characterize the vaginal gamma delta T cells we isolated them from normal mice and from mice injected systemically with an activation-inducing dose of anti-TCR mAb. The isolated gamma delta T cells were examined by flow cytometry for their surface expression of a panel of adhesion, proteins, activation antigens and cellular interaction molecules (CD44, CD62L, CD45RB, LFA-1, CD2 and CD28). The patterns of expression observed indicate that the vaginal gamma delta T cells of normal mice show the phenotype of effector T cells. The adhesion/co-stimulatory molecules CD28 and CD2 were not detected on vaginal gamma delta T cells, an interesting finding since the absence of CD2 from other T cells has been suggested to result in anergy. However, vaginal gamma delta T cells are responsive to TCR-mediated signals since injection of normal mice with pan-anti-TCR antibody or stimulating anti-gamma delta TCR antibody resulted in an increase in cell number and increased expression of transferrin and IL-2 receptors. These results indicate that vaginal gamma delta T cells might utilize other co-stimulatory molecules, if any, in connection with TCR-induced activation and differentiation. While the physiological function of vaginal gamma delta T cells remains unknown, the expression of an invariant V gamma 4/V delta 1 TCR, their exclusive use of gamma chain homodimers in their TCR, and the absence of CD2 and CD28 co-stimulatory molecules are a novel combination of properties that suggests specialized functional properties. Although vaginal gamma delta T cells share some features in common with gamma delta T cells that reside in other epithelial tissues, such as skin and intestine, the present studies provide additional evidence that vaginal gamma delta T cells are a highly specialized and distinct T cell population.
Assuntos
Antígenos CD2/biossíntese , Antígenos CD28/biossíntese , Ativação Linfocitária , Receptores de Antígenos de Linfócitos T gama-delta/imunologia , Subpopulações de Linfócitos T/imunologia , Vagina/imunologia , Animais , Antígenos CD/biossíntese , Moléculas de Adesão Celular/biossíntese , Células Epiteliais , Epitélio/imunologia , Epitélio/metabolismo , Feminino , Mucosa Intestinal/citologia , Mucosa Intestinal/imunologia , Mucosa Intestinal/metabolismo , Intestino Delgado , Camundongos , Camundongos Endogâmicos BALB C , Camundongos Endogâmicos C57BL , Camundongos Endogâmicos DBA , Subpopulações de Linfócitos T/metabolismo , Vagina/citologia , Vagina/metabolismoRESUMO
The epithelium of the murine vagina contains a resident population of gamma delta T-cells that expresses a homogenous Vgamma4/Vdelta1 TCR lacking N-region junctional diversity, implying that these T-cells recognize a very limited array of antigenic structures. The vaginal gamma delta T-cells express a pattern of surface markers characteristic of memory/effector T-cells that have previously been activated. Although vaginal gamma delta T-cells do not express the major costimulatory molecules CD28 and CD2, they do proliferate in response to a systemically delivered anti gamma delta TCR stimulus. Vaginal gamma delta T-cells contain mRNA that encodes the keratinocyte growth factor raising the possibility that these cells play a role in the repair of vaginal epithelium following injury. While the antigen recognized by the vaginal gamma delta TCR is unknown, a model is proposed which attempts to relate some of the unusual phenotypic features of vaginal gamma delta T-cells to the physiological injury and shedding of vaginal epithelium that occurs during the estrous cycle.
Assuntos
Ativação Linfocitária/imunologia , Receptores de Antígenos de Linfócitos T gama-delta/imunologia , Linfócitos T/imunologia , Animais , Antígenos CD2/imunologia , Antígenos CD28/imunologia , Células Cultivadas , Células Epiteliais , Feminino , Receptores de Hialuronatos/imunologia , Selectina L/imunologia , Antígenos Comuns de Leucócito/imunologia , Antígeno-1 Associado à Função Linfocitária/imunologia , Camundongos , Camundongos Endogâmicos DBA , Receptores de Antígenos de Linfócitos T gama-delta/genética , Linfócitos T/citologia , Vagina/citologia , Vagina/imunologiaRESUMO
The role of the inflammatory cytokines on glucocorticosteroid binding (GCSB) and glucocorticosteroid receptor (GR) level was studied. We incubated a B cell line--CESS--, a promonocytic cell line--U937--and a hepatoma cell line--HepG2--in the presence of varying concentrations of IL-1 beta, IL-6 and TNF-alpha for 24 hours. Glucocorticosteroid binding was determined by the method of "whole cell uptake," and characterized by Scatchard analysis. A considerable increase in the glucocorticosteroid binding was induced by all the three cytokines. Northern analysis of the glucocorticoid receptor expression demonstrates that the action of the cytokines is likely not pretranslational. Present data suggest that local imbalance in the ratio of these three cytokines in different pathological cases might influence the glucocorticosteroid sensitivity of the lymphocytes, monocytes and hepatocytes as target cells.
Assuntos
Interleucina-1/farmacologia , Interleucina-6/farmacologia , Receptores de Glucocorticoides/metabolismo , Fator de Necrose Tumoral alfa/farmacologia , Células Cultivadas , Humanos , Técnicas In Vitro , Triancinolona Acetonida/metabolismo , Fator de Necrose Tumoral alfa/químicaRESUMO
Interleukin-6 receptor (IL-6R) is a member of the cytokine receptor superfamily characterised by the obligatory presence of WSXWS (Trp-Ser-X-Trp-Ser) sequence motif near the transmembrane domain. To more clearly understand the role of this motif, we treated the HepG2 hepatoma cell line with synthetic WSEWS peptide (E is glutamic acid) and checked the spontaneous and IL-6-induced production of acute-phase protein fibrinogen and C1-inhibitor (C1-INH). The peptide revealed a definitely stimulatory effect both on the constitutive synthesis of C1-INH and on the IL-6-induced fibrinogen synthesis of HepG2 cells. Monoclonal antibody specific for WSEWS pentapeptide was stimulatory for the spontaneous secretion of both fibrinogen and C1-INH. However, the IL-6-induced elevations of these acute-phase proteins were oppositely regulated, since the anti-WSEWS monoclonal antibody was inhibitory on the production of fibrinogen induced by IL-6 but strongly augmented the IL-6 induced production of C1-INH. Our study indicates that the WSEWS motif is critical in the effect of IL-6 on the acute-phase protein production influencing either the ligand binding by the WSEWS-containing receptor molecule or the signal transduction.
Assuntos
Proteínas de Fase Aguda/biossíntese , Anticorpos Monoclonais/farmacologia , Carcinoma Hepatocelular/imunologia , Interleucina-6/farmacologia , Neoplasias Hepáticas/imunologia , Peptídeos/imunologia , Proteínas de Fase Aguda/efeitos dos fármacos , Sequência de Aminoácidos , Animais , Proteínas Inativadoras do Complemento 1/biossíntese , Proteínas Inativadoras do Complemento 1/efeitos dos fármacos , Fibrinogênio/biossíntese , Fibrinogênio/efeitos dos fármacos , Humanos , Camundongos , Camundongos Endogâmicos BALB C , Dados de Sequência Molecular , Oligopeptídeos/farmacologia , Células Tumorais CultivadasRESUMO
The role of an androgen, dehydroepiandrosterone (DHEA) has been studied on the constitutive and IL-6 induced fibrinogen production of HepG-2 cells. DHEA markedly augments the constitutive fibrinogen production of the hepatoma cells in a dose dependent fashion. Oppositely, for IL-6 induced fibrinogen production, DHEA is strongly inhibitory. The effectiveness of DHEA on the constitutive fibrinogen production is further potentiated if the hepatoma cells are preincubated with a glucocorticosteroid, dexamethasone. These findings demonstrate that the complex interaction between the steroid- and cytokine-directed regulation of the production of acute phase proteins is further coloured by the action of androgens on immune and hormonal systems.
Assuntos
Carcinoma Hepatocelular/metabolismo , Desidroepiandrosterona/farmacologia , Fibrinogênio/biossíntese , Fatores Imunológicos/farmacologia , Interleucina-6/farmacologia , Neoplasias Hepáticas/metabolismo , Dexametasona/farmacologia , Humanos , Proteínas Recombinantes/farmacologia , Células Tumorais CultivadasRESUMO
In addition to specific ligand binding elements, receptor assembly for interleukin(IL)-6, oncostatin-M, leukaemia inhibitory factor, ciliary neurotrophic factor and IL-11 includes an additional unit, gp130. This molecule is a transmembrane glycoprotein of 130 kDa. In this paper, reviewing molecular, biochemical and functional data on gp130, we describe the dissimilar action of IL-3 on the expression of the binding unit of the IL-6 receptor and that of gp130. According to FACS studies, resting basophils express only IL-6 receptors and no gp130 molecules on the plasma membranes. After incubation with IL-3, the surface appearance and de novo transcription of gp130 was shown by FACS and mRNA polymerase chain reaction analysis.
Assuntos
Antígenos CD , Interleucina-6/metabolismo , Glicoproteínas de Membrana/metabolismo , Receptores de Citocinas/metabolismo , Receptores de Interleucina/metabolismo , Sequência de Bases , Basófilos/metabolismo , Receptor gp130 de Citocina , Citometria de Fluxo , Humanos , Interleucina-3/farmacologia , Interleucina-6/farmacologia , Dados de Sequência Molecular , Reação em Cadeia da Polimerase , Ligação Proteica , RNA Mensageiro/análise , Receptores de Interleucina-6 , Regulação para Cima/efeitos dos fármacosRESUMO
In order to elucidate the role of the inflammatory cytokines in regulating glucocorticosteroid binding (GCSB) and glucocorticosteroid receptor (GR) level we incubated a B-cell line (CESS), a promonocytic cell line (U937) and a hepatoma cell line (HepG2) in the presence of varying concentrations of IL-1 beta, IL-6 and TNF-alpha for 24 h. Glucocorticosteroid binding was determined by the method of 'whole cell uptake', and the cellular appearance of the glucocorticosteroid receptor was detected by immunocytochemistry. A rise in the glucocorticosteroid binding was induced by all three cytokines. The increase in level of glucocorticosteroid receptors in the cells shown by immunocytochemistry was much more pronounced. However, antagonistic effects were demonstrated by both methods between IL-6 and TNF-alpha, and between IL-1 beta and TNF-alpha when they were applied simultaneously, in U937. Present data suggest that local imbalance in the ratio of these three cytokines in different pathological cases might influence the glucocorticosteroid sensitivity of the lymphocytes, monocytes and hepatocytes as target cells.
Assuntos
Citocinas/farmacologia , Receptores de Glucocorticoides/efeitos dos fármacos , Animais , Relação Dose-Resposta a Droga , Humanos , Interleucina-1/farmacologia , Interleucina-6/farmacologia , Neoplasias Hepáticas Experimentais/patologia , Receptores de Glucocorticoides/antagonistas & inibidores , Células Tumorais Cultivadas/patologia , Fator de Necrose Tumoral alfa/farmacologiaRESUMO
The effect of cytosine arabinoside on adenosylmethionine synthesis in relation to its proliferation-inhibiting ability was investigated in HT/29 and SW 620 human colon-tumor cell lines. A significant decrease in adenosylmethionine synthetase (E. C.2.4.2.13) activity was found after 2.5 h incubation with the drug, suggesting that depletion of adenosylmethionine pools might occur. Both this possible loss of adenosylmethionine and the cytostatic effect of cytosine arabinoside could partly be reversed by the exogenous administration of the former drug. Our data show that the cytostatic effect of cytosine arabinoside may be due in part to a shortage of adenosylmethionine; this finding is important for the design of combination chemotherapy regimens.