RESUMEN
To understand the selective accumulation of memory T helper lymphocytes and of macrophages in delayed-type hypersensitivity (DTH) granulomas, we studied the in situ production of RANTES, a chemokine initially characterized on the basis of its in vitro chemotactic properties for each of these cell populations. RANTES gene expression was studied by in situ hybridization in 15 human lymph nodes presenting typical DTH lesions related to either sarcoidosis or tuberculosis. A positive signal was detected in all cases. Labeling was specific for the DTH lesions, as very few if any positive cells were detected in the normal residual lymphoid tissue surrounding them or in reactive lymph nodes involved in a B lymphocyte response. RANTES gene expression was associated with the production of the protein, which was detected by immunochemistry in DTH lymph nodes. The morphological characteristics and distribution of positive cells in in situ hybridization and immunochemical experiments indicated that macrophages and endothelial cells, two cell populations not previously reported to produce RANTES, contributed to its production in DTH reactions. The ability of macrophages and endothelial cells to produce RANTES was confirmed by in vitro studies with alveolar macrophages and umbilical vein endothelial cells. In view of the chemotactic properties of RANTES for a limited range of cell populations, these results suggest that RANTES production in DTH granulomas may play a role in the selective accumulation of macrophages and memory T helper lymphocytes characterizing this type of cell-mediated immune reaction, and that macrophages and endothelial cells are involved in this production.
Asunto(s)
Endotelio Vascular/fisiología , Hipersensibilidad Tardía/inmunología , Linfocinas/biosíntesis , Macrófagos/inmunología , Células Cultivadas , Quimiocina CCL5 , Endotelio Vascular/citología , Humanos , Macrófagos/citología , Linfocitos T Colaboradores-Inductores/inmunologíaRESUMEN
The peroxisome proliferator-activated receptor gamma (PPARgamma) is highly expressed in the colon mucosa and its activation has been reported to protect against colitis. We studied the involvement of PPARgamma and its heterodimeric partner, the retinoid X receptor (RXR) in intestinal inflammatory responses. PPARgamma(1/)- and RXRalpha(1/)- mice both displayed a significantly enhanced susceptibility to 2,4,6-trinitrobenzene sulfonic acid (TNBS)-induced colitis compared with their wild-type littermates. A role for the RXR/PPARgamma heterodimer in the protection against colon inflammation was explored by the use of selective RXR and PPARgamma agonists. TNBS-induced colitis was significantly reduced by the administration of both PPARgamma and RXR agonists. This beneficial effect was reflected by increased survival rates, an improvement of macroscopic and histologic scores, a decrease in tumor necrosis factor alpha and interleukin 1beta mRNA levels, a diminished myeloperoxidase concentration, and reduction of nuclear factor kappaB DNA binding activity, c-Jun NH(2)-terminal kinase, and p38 activities in the colon. When coadministered, a significant synergistic effect of PPARgamma and RXR ligands was observed. In combination, these data demonstrate that activation of the RXR/PPARgamma heterodimer protects against colon inflammation and suggest that combination therapy with both RXR and PPARgamma ligands might hold promise in the clinic due to their synergistic effects.
Asunto(s)
Colitis/tratamiento farmacológico , Receptores Citoplasmáticos y Nucleares/agonistas , Receptores de Ácido Retinoico/agonistas , Tiazolidinedionas , Factores de Transcripción/agonistas , Animales , Colitis/inducido químicamente , Dimerización , Sinergismo Farmacológico , Ratones , Ratones Mutantes , Receptores Citoplasmáticos y Nucleares/genética , Receptores de Ácido Retinoico/genética , Receptores X Retinoide , Rosiglitazona , Tetrahidronaftalenos/uso terapéutico , Tiazoles/uso terapéutico , Factores de Transcripción/genética , Activación Transcripcional , Ácido Trinitrobencenosulfónico/efectos adversosRESUMEN
To document the in vivo interactions occurring between the immune system and HIV replicating cells, we analyzed using in situ hybridization the production of IL-1 beta, IL-6, IL-2, and INF-gamma in eight hyperplastic lymph nodes from HIV-1 infected patients. Numerous IL-1 beta- and IL-6-producing cells associated in clusters were detected in sinuses. Few individual IL-1 beta- and IL-6-producing cells were present in interfollicular and follicular areas. IL-2- and INF-gamma-producing cells were observed in all lymph node compartments, with a selective enrichment in germinal centers. The amount and distribution of IL-1 beta, IL-6-, and IL-2-producing cells in HIV lymph nodes were not different from those found in six HIV unrelated hyperplastic lymph nodes. In contrast, a higher level of INF-gamma production was observed in HIV-1 lymph nodes. The CD8+ cells that accumulate in germinal centers of HIV lymph nodes (and not in non-HIV germinal centers) were actively involved in this INF-gamma production. INF-gamma synthesizing cells were in direct contact with cells containing HIV core antigens and HIV RNA. Thus a high INF-gamma production may characterize anti-HIV T cell immune response, potentially contributing to control of viral spreading as well as to the development of follicle lysis.
Asunto(s)
Antígenos VIH/análisis , Infecciones por VIH/inmunología , Interferón gamma/biosíntesis , Interleucinas/biosíntesis , Ganglios Linfáticos/inmunología , Adulto , Productos del Gen gag/análisis , Proteína p24 del Núcleo del VIH , Infecciones por VIH/patología , Humanos , Interferón gamma/genética , Interleucina-1/biosíntesis , Interleucina-2/biosíntesis , Interleucina-2/genética , Interleucina-6/biosíntesis , Interleucinas/genética , Ganglios Linfáticos/patología , Hibridación de Ácido Nucleico , ARN Viral/genética , Proteínas del Núcleo Viral/análisisRESUMEN
Cytotoxic T lymphocytes (CTL) are potent effector cells that could provide long term antitumor immunity if induced by appropriate vaccines. CTL recognize 8-14 amino acid-long peptides processed intracellularly and presented by MHC class I molecules. A well-characterized example of a potential tumor antigen in childhood pre-B Acute Lymphoblastic Leukemia (ALL) results from the chromosomal translocation 12;21 leading to the fusion of the ETV6 and AML1 genes. This translocation is observed in > 25% of ALL-patients. In this study, we have examined whether the chimeric ETV6-AML1 protein could serve as a tumor specific antigen for CTL in HLA-A2.1 individuals. We have identified a nonapeptide (RIAECILGM), encoded by the fusion region of the ETV6-AML1 protein, that binds to HLA-A2.1 molecules and induces specific primary CTL in peripheral blood lymphocytes from healthy donors. These CTL specifically lysed HLA-A2.1 tumor cells endogeneously expressing the ETV6-AML fusion protein. CTL with similar functional capacities were found with high frequencies and cloned from one patient's bone marrow indicating that ETV6-AML1-specific anti-ALL CTL are, at least in some patients, spontaneously stimulated and might participate to host antileukemia defense.
Asunto(s)
Antígeno HLA-A2/inmunología , Proteínas de Neoplasias/inmunología , Proteínas de Fusión Oncogénica , Leucemia-Linfoma Linfoblástico de Células Precursoras/inmunología , Linfocitos T Citotóxicos/inmunología , Secuencia de Aminoácidos , Línea Celular , Niño , Preescolar , Subunidad alfa 2 del Factor de Unión al Sitio Principal , Pruebas Inmunológicas de Citotoxicidad , Femenino , Antígeno HLA-A2/metabolismo , Humanos , Masculino , Datos de Secuencia Molecular , Proteínas de Neoplasias/genética , Péptidos/síntesis química , Péptidos/inmunología , Péptidos/metabolismo , Proteínas Recombinantes de Fusión/genética , Proteínas Recombinantes de Fusión/inmunologíaRESUMEN
We have previously shown that the human developing pancreas, as a tissue under construction and remodeling, is composed of epithelial ducts and differentiated endocrine cells surrounded by mesenchyme. The physiologic importance of resident tissue leukocytes, expected to enter through the mesenchyme in remodeling functions, prompted us to investigate human developing pancreases for the presence of leukocyte lineages and for expression of cytokines and receptors involved in their recruitment and differentiation. Immunohistochemistry studies were performed on 69 human, paraffin-embedded pancreases at 6-12 weeks of development (WD). Cytokines and receptor transcripts were monitored by reverse transcription (RT)-PCR, by immunohistochemistry when antibodies were available or by in situ hybridization (ISH). We show that numerous cells expressing CD45RA, HLADR and CD68 antigens are cellular components of the mesenchyme of all the pancreases at 6-12 WD. So-called constitutive chemokines (SLC (CCL19), stromal-derived factor 1 (SDF1) (CXCL12)) and a macrophage-specific growth/survival factor, colony-stimulating factor 1 (CSF1), were detected in epithelial duct cells. Both epithelial and mesenchymal cells expressed chemokine receptors, suggesting a role in leukocyte recruitment and possibly in early pancreatic development. In conclusion, we demonstrated the presence of CD45RA resident leukocyte-derived lineages, mostly macrophages, in the early human pancreatic mesenchyme. These cells may have migrated in the tissue through the vascular system, attracted by constitutively expressed chemokines, and locally surviving through CSF1 signaling. The role of macrophages in epithelium/mesenchyme interaction-mediated pancreatic development remains to be demonstrated.
Asunto(s)
Inducción Embrionaria/fisiología , Macrófagos/fisiología , Mesodermo/química , Páncreas/embriología , Biomarcadores/análisis , Quimiocinas/análisis , Quimiocinas/genética , Células Epiteliales/química , Femenino , Humanos , Inmunohistoquímica/métodos , Hibridación in Situ/métodos , Antígenos Comunes de Leucocito/análisis , Leucocitos/fisiología , Factor Estimulante de Colonias de Macrófagos/análisis , Factor Estimulante de Colonias de Macrófagos/genética , Páncreas/química , Embarazo , Primer Trimestre del Embarazo , ARN Mensajero/análisis , Receptor de Factor Estimulante de Colonias de Macrófagos/análisis , Receptor de Factor Estimulante de Colonias de Macrófagos/genética , Receptores de Quimiocina/análisis , Receptores de Quimiocina/genética , Reacción en Cadena de la Polimerasa de Transcriptasa InversaRESUMEN
Mutations in the adenomatous polyposis coli gene or activating mutations in the beta-catenin gene itself are thought to be responsible for the excessive beta-catenin signaling involved in intestinal carcinogenesis. We generated transgenic mice that expressed large amounts of a NH2-terminally truncated mutant beta-catenin (deltaN131beta-catenin) in the intestine. These mice had multifocal dysplastic lesions in the small intestine, reminiscent of the early lesions observed in the mouse models of familial adenomatous polyposis. The number of apoptotic cells in the villi of these transgenic mice was 3-4-fold higher than in nontransgenic mice. Expression of the truncated beta-catenin mutant in the kidney led to the development of severe polycystic kidney disease. Our findings support the concept that deregulation of the beta-catenin signaling pathway is the major oncogenic consequence of adenomatous polyposis coli mutations in intestinal neoplasia.
Asunto(s)
Adenoma/genética , Proteínas del Citoesqueleto/genética , Regulación Neoplásica de la Expresión Génica , Neoplasias Intestinales/genética , Mutación , Transactivadores , Poliposis Adenomatosa del Colon/genética , Animales , Cadherinas/genética , Enfermedades Intestinales/genética , Ratones , Ratones Transgénicos , beta CateninaRESUMEN
Autosomal dominant polycystic kidney disease (ADPKD) is common and is a major cause of renal failure. Although the genetics of ADPKD are well known and have led to the discovery of polycystins, a new protein family, the pathogenesis of the disease remains largely unknown. Recent studies have indicated that the beta-catenin signaling pathway is one of the targets of the transduction pathway controlled by the polycystins. We have generated transgenic mice that overproduce an oncogenic form of beta-catenin in the epithelial cells of the kidney. These mice developed severe polycystic lesions soon after birth that affected the glomeruli, proximal, distal tubules and collecting ducts. The phenotype of these mice mimicked the human ADPKD phenotype. Cyst formation was associated with an increase in cell proliferation and apoptosis. The cell proliferation and apoptotic indexes was increased 4-5-fold and 3-4-fold, respectively, in cystic tubules of the transgenic mice compared to that of littermate controls. Our findings provide experimental genetic evidence that activation of the Wnt/beta-catenin signaling pathway causes polycystic kidney disease and support the view that dysregulation of the Wnt/beta-catenin signaling is involved in its pathogenesis.
Asunto(s)
Proteínas del Citoesqueleto/genética , Proteínas del Citoesqueleto/fisiología , Enfermedades Renales Poliquísticas/etiología , Transactivadores , Animales , División Celular , Ciclina D1/biosíntesis , Ciclina D1/genética , Células Epiteliales/química , Riñón/metabolismo , Riñón/patología , Ratones , Ratones Transgénicos , Mutación , Nefronas/patología , Enfermedades Renales Poliquísticas/patología , Proteínas Proto-Oncogénicas c-myc/biosíntesis , Proteínas Proto-Oncogénicas c-myc/genética , ARN Mensajero/biosíntesis , ATPasa Intercambiadora de Sodio-Potasio/análisis , beta CateninaRESUMEN
Using immunohistochemical staining, in situ hybridization and a combination of both, we demonstrate here the replication of HIV in the endometrial stroma. Infected cells do not belong to the T-lymphocyte lineage but rather to a monocyte-macrophage cell type. This report suggests a possible relationship between HIV infection and endometritis. Moreover, HIV replication in endometrial tissues could play a role in heterosexual and materno-fetal transmission.
Asunto(s)
Síndrome de Inmunodeficiencia Adquirida/complicaciones , Endometritis/complicaciones , Endometrio/microbiología , VIH/fisiología , Adulto , Endometrio/patología , Femenino , VIH/genética , Humanos , Técnicas para Inmunoenzimas , Inmunohistoquímica , Macrófagos/microbiología , Monocitos/microbiología , Hibridación de Ácido Nucleico , Sondas ARN , Linfocitos T/clasificación , Replicación ViralRESUMEN
Serine esterase B (SE B) is a protein contained in cytoplasmic granules of cytotoxic T lymphocytes and natural killer cells; SE B gene is transcribed upon activation of these cytotoxic cells. In order to show the in vivo interactions between HIV-infected cells and anti-HIV cytotoxic cells we analysed, by in situ hybridization, the expression of the SE B gene in eight hyperplastic lymph nodes from HIV-1-infected patients presenting with persistent generalized lymphadenopathy. We detected numerous cells expressing the SE B gene. The mean number of positive cells was 3.2 times higher in HIV lymph nodes than in six non-HIV hyperplastic lymph nodes studied in parallel (P less than 0.05). In control lymph nodes, the SE B gene was expressed only in interfollicular areas; virtually no cells expressed the SE B gene within follicles. In contrast, in HIV lymph nodes cells expressing the SE B gene were distributed either in interfollicular areas or within follicles. Expression of the SE B gene inside follicles was thus a specific feature of HIV lymph nodes (P less than 0.001) and was associated with the presence of HIV antigens and RNA at the same site. These results suggest that cytotoxic cells are activated in follicles of HIV lymph nodes and may be involved in the lysis of HIV-infected cells. Such a phenomenon may explain the development of follicle lysis, a specific feature of HIV lymph nodes. It may also inhibit the spreading of HIV infection.
Asunto(s)
Esterasas/genética , Infecciones por VIH/inmunología , VIH-1/inmunología , Ganglios Linfáticos/microbiología , Linfocitos T Citotóxicos/microbiología , Síndrome de Inmunodeficiencia Adquirida/inmunología , Síndrome de Inmunodeficiencia Adquirida/microbiología , Northern Blotting , Expresión Génica/genética , Antígenos VIH/análisis , Infecciones por VIH/microbiología , VIH-1/fisiología , Humanos , Hiperplasia/inmunología , Hiperplasia/microbiología , Interleucina-2/genética , Ganglios Linfáticos/inmunología , Ganglios Linfáticos/patología , Activación de Linfocitos/genética , Activación de Linfocitos/inmunología , ARN Viral/análisis , Linfocitos T Citotóxicos/enzimología , Linfocitos T Citotóxicos/inmunología , Replicación ViralRESUMEN
Recent epidemiological and virological data suggest that the incidence of maternofetal transmission of HIV-1 infection is between 20 and 30%. The available evidence points to a possible role of peri- and postnatal contamination, but the isolation of HIV from fetuses shows that transplacental transmission also occurs. We attempted to detect, by means of an immunohistochemical method, HIV proteins in frozen placentas from 75 HIV-1-positive women (30 at term, 45 induced abortions). In addition, in situ hybridization using HIV-specific probes was performed in three cases. Neither HIV proteins nor nucleic acid sequences were detected, but CD4+ mononuclear cells were present in the chorion and villi, regardless of the clinical and biological status of the mother (particularly in the nine cases in which the infants were infected). There are several possible mechanisms involving the placenta in the maternofetal transmission of HIV, including active transport of the HIV-immunoglobulin G complex via Fc receptors on trophoblastic cells, passive transplacental passage of HIV during a viraemic episode, the passage of infected maternal cells, and infection of the placenta itself. The methods we used could not rule out the presence of HIV DNA provirus within the genome of placental cells. In any event, immunohistochemical detection of HIV proteins in the placenta is not a technique suitable for the prenatal diagnosis of HIV infection or for identifying newborns likely to develop HIV infection.
Asunto(s)
Infecciones por VIH/transmisión , VIH-1 , Placenta/microbiología , Complicaciones Infecciosas del Embarazo/microbiología , Proteínas de los Retroviridae/análisis , Adulto , Linfocitos T CD4-Positivos/microbiología , Femenino , Productos del Gen gag/análisis , Antígenos VIH/análisis , Proteína p24 del Núcleo del VIH , Infecciones por VIH/microbiología , Humanos , Inmunohistoquímica , Hibridación de Ácido Nucleico , Placenta/química , Placenta/patología , Embarazo , Estudios Prospectivos , Proteínas del Núcleo Viral/análisis , Proteínas del Envoltorio Viral/análisis , Productos del Gen gag del Virus de la Inmunodeficiencia HumanaRESUMEN
Cytokines play a role in alopecia areata. We used immunohistochemical and in situ hybridization studies to demonstrate the persistence of pro-inflammatory as well as apoptotic mechanisms in skin biopsies from patients with chronic alopecia areata. In situ hybridization allows the visualization of the distribution of immunocompetent cells in vivo. We studied skin biopsies from 11 untreated alopecia areata patients and two normal controls. In situ hybridization was performed on frozen sections using 35S-radio-labeled riboprobes, specific for IL-1beta, IL-2, IL-6, INFgamma, and granzyme B mRNA. Immunohistochemistry was carried out using an anti-IL-1beta monoclonal antibody, and a monoclonal antibody directed against the human Fas protein. We demonstrated the presence of cells labeled with IL-1beta, IL-6, INFgamma, and granzyme B antisense probes. Similarly, cells labeled with anti-IL-1beta were found in 10 of 11 cases. The labeled cells were located in the mononuclear peri- and intrafollicular infiltrate. Cells expressing granzyme B were found in close contact with the follicle. Fas positivity was demonstrated in four of four cases at the level of the cytoplasmic membrane of the hair follicle keratinocytes. These results, based on visualizing the labeled cells, demonstrate that pro-inflammatory cytokines are produced by the mononuclear cell infiltrate in close contact with follicles in alopecia areata. Furthermore, they demonstrate for the first time that apoptotic mechanisms involving granzyme B and Fas-Fas ligand pathways may play a major role in the persistence of chronic alopecia areata.
Asunto(s)
Alopecia Areata/fisiopatología , Linfocitos T Citotóxicos/fisiología , Alopecia Areata/patología , Antígenos CD/metabolismo , Enfermedad Crónica , Citocinas/genética , Antígenos HLA-DR/metabolismo , Humanos , Inmunohistoquímica , Hibridación in Situ , ARN Mensajero/metabolismo , Cuero Cabelludo/metabolismo , Cuero Cabelludo/patología , Linfocitos T Citotóxicos/metabolismo , Linfocitos T Citotóxicos/patologíaRESUMEN
Biochemical investigations in rodents have shown that numerous mineralized matrix proteins share expression in bone, dentin, and cementum. Little information is available regarding the expression pattern of these proteins in human tissues, particularly during tooth formation. The aim of this study was to identify the expression pattern of the two major noncollagenous proteins of bone and dentin, osteocalcin (OC) and osteonectin (ON), in comparison to the dentin-specific protein, dentin sialophosphoprotein (DSPP). Mandibles from fetuses (5-26 weeks), neonate autopsies, forming teeth from 10-12-year-old patients, third molars extracted for orthodontic reasons, and bone tumors were collected with approval from the National Ethics Committee. Human OC, ON, and DSPP mRNAs were detected by reverse transcription-polymerase chain reaction (RT-PCR) in fetal mandibles (5-11 weeks) and in primary cell cultures of dental pulp. In addition, OC, ON, and DSPP proteins were localized in forming human mineralized tissues using immunohistochemistry. In vivo, DSPP expression was associated with tooth terminal epithelial-mesenchymal interaction events, amelogenesis and dentinogenesis. Transient DSPP expression was seen in the presecretory ameloblasts with continuous expression in the odontoblasts. In contrast, both osteoblasts and odontoblasts showed a temporal gap between OC and ON expression in early development. ON was expressed in the initial stages of cytodifferentiation, whereas OC was expressed only during the later stages, especially in the teeth. At the maturation stage of enamel formation, both proteins were detected in odontoblasts and their processes within the extracellular matrix. In contrast to bone, OC was not localized extracellularly within the collagen-rich dentin matrix (predentin or intertubular dentin), but was found in the mature enamel. ON was present mostly in the nonmineralized predentin. These results demonstrate for the first time that both OC and ON are produced by human odontoblasts and determine the expression pattern of DSPP in human teeth, and suggest that OC and ON move inside the canalicule via odontoblast cell processes becoming localized to specific extracellular compartments during dentin and enamel formation. These distinct extracellular patterns may be related to the nature of DSPP, OC, and ON interactions with other matrix-specific macromolecules (i.e., amelogenin, dentin matrix protein-1) and/or to the polarized organization of odontoblast secretion as compared with osteoblasts.
Asunto(s)
Osteocalcina/análisis , Osteonectina/análisis , Precursores de Proteínas/análisis , Diente/química , Diente/embriología , Adulto , Células Cultivadas , Niño , Proteínas de la Matriz Extracelular , Feto/química , Feto/citología , Regulación del Desarrollo de la Expresión Génica , Humanos , Recién Nacido , Odontoblastos/química , Odontoblastos/citología , Osteocalcina/genética , Osteonectina/genética , Fosfoproteínas , Precursores de Proteínas/genética , ARN Mensajero/análisis , Sialoglicoproteínas , Diente/crecimiento & desarrolloRESUMEN
Plasma cell granuloma (PCG) is a pseudotumor of unknown origin. It is frequently accompanied by acute-phase clinical and biological signs that resume after complete surgical removal, suggesting production of soluble mediators. We therefore investigated the role of cytokines in a previously healthy 10-year-old boy with a PCG of the lung and systemic symptoms. In this case, very high serum levels of interleukin-1 beta (IL-1 beta) and interleukin-6 (IL-6) were found before tumor excision, associated with inflammatory signs including major hyper-gamma-globulinemia. Pathologic analysis of the tumor showed an accumulation of fibroblasts and plasma cells producing immunoglobulins. Local production of IL-1 beta and IL-6 could be demonstrated at the messenger RNA (mRNA) level by the reverse transcriptase polymerase chain reaction and could be attributed to inflammatory cells by in situ hybridization and immunohistochemistry, whereas plasma cells exhibited membrane expression of the IL-6 receptor. Postsurgery follow-up showed rapid normalization of serum IL-1 beta and IL-6, whereas inflammatory protein levels decreased. This confirms the local production of cytokine within the PCG and raises the question of whether a dysregulation of cytokine production initiates the disease.
Asunto(s)
Interleucina-1/biosíntesis , Interleucina-6/biosíntesis , Granuloma de Células Plasmáticas del Pulmón/inmunología , Secuencia de Bases , Niño , Humanos , Interleucina-1/genética , Interleucina-6/genética , Masculino , Datos de Secuencia Molecular , Reacción en Cadena de la PolimerasaRESUMEN
Both cytokines produced by activated monocytes and T cells and direct cell-to-cell contact with antigen-primed T cells during inflammatory reactions are known to induce the expression of several adhesion proteins on endothelial cells. In this prospective longitudinal study, we analyzed the expression of ELAM-1, VCAM-1, and ICAM-1 on myocardial allograft biopsy specimens taken from 16 cardiac allograft recipients either for routine monitoring or for the investigation of suspected rejection. Infiltrating T cells were identified using anti-CD3 antibodies. Three to six sequential biopsies taken at one-week intervals were analyzed by means of conventional histology and immunohistochemistry. Seven patients did not develop rejection during the study; their biopsies were negative for VCAM-1 and ELAM-1, although faint ICAM-1 staining was present on capillaries, reflecting constitutive expression. Three patients entered the study with clear-cut clinical and histologic signs of acute rejection. Intense VCAM-1 and ICAM-1 expression was detected on capillary and postcapillary venules, together with a heavy CD3+ T cell infiltrate; VCAM-1 was also expressed on arteriolar endothelial cells. ELAM-1 was undetectable in all three cases. Six patients developed acute rejection during the course of the study. In four, ELAM-1 and VCAM-1 were expressed on both capillary and postcapillary venules one or two weeks before the histological diagnosis of rejection (heavy CD3+ cell infiltrate). Importantly, ELAM-1 expression was short-lived and had disappeared by the time CD3+ cellular infiltrate was detected, thus extending in vivo the finding that ELAM-1 expression is usually transient in vitro. Only VCAM-1 expression was observed in the other two patients, one week prior to the histological diagnosis of rejection. These results suggest that ELAM-1 and VCAM-1 might represent early predictive markers of acute cardiac allograft rejection. ELAM-1 expression is, however, usually transient, necessitating frequent testing.
Asunto(s)
Moléculas de Adhesión Celular/fisiología , Trasplante de Corazón/inmunología , Adolescente , Adulto , Biopsia , Complejo CD3/sangre , Moléculas de Adhesión Celular/sangre , Selectina E , Endotelio Vascular/química , Endotelio Vascular/inmunología , Rechazo de Injerto/sangre , Rechazo de Injerto/patología , Rechazo de Injerto/fisiopatología , Antígenos HLA-DR/sangre , Humanos , Persona de Mediana Edad , Receptores de Interleucina-2/análisis , Trasplante Homólogo , Molécula 1 de Adhesión Celular VascularRESUMEN
A 9-month-old infant developed Epstein-Barr virus-induced lymphoproliferative syndrome with mediastinal and central nervous system localizations, associated with mediastinal tuberculosis, 5 months after heart transplantation. As a combination of anti-B cell antibodies (CD21- and CD24-specific) and recombinant interferon alpha 2b, given intravenously, was not effective on the central nervous system disease, the anti-CD21 antibody was infused intrathecally via an Ommaya reservoir. High local concentrations of monoclonal antibodies were achieved, with no adverse effects. A dramatic clinical response was obtained, with clearance of abnormal cells from the cerebrospinal fluid and a clear reduction in the abnormalities on the brain images. The patient is well 7 months later. This observation indicates that treatment of B lymphoproliferative syndrome with central nervous system localization is feasible using a nontoxic, local B cell-specific approach.
Asunto(s)
Anticuerpos Monoclonales/uso terapéutico , Linfocitos B/inmunología , Trastornos Linfoproliferativos/terapia , Receptores de Complemento/inmunología , Antígenos de Diferenciación de Linfocitos B/inmunología , Trasplante de Corazón/inmunología , Herpesvirus Humano 4 , Humanos , Huésped Inmunocomprometido , Inmunoterapia , Lactante , Inyecciones Espinales , Masculino , Receptores de Complemento 3d , Infecciones Tumorales por Virus/terapiaRESUMEN
The number, distribution, and phenotype of mononuclear cells infiltrating the allograft lung transplant were determined immunohistochemically with monoclonal antibodies directed against cellular antigens (CD3, CD4, CD8, CD22, CD25, CD16, CD56, CD68, HLA-DR) on frozen sections of transbronchial biopsies. Seventy-two transbronchial biopsies from 21 patients undergoing lung or heart-lung transplantation were evaluated histologically and immunohistologically in a prospective study. Four major results were obtained in the graft lung parenchyma: (1) whatever the histological grading of rejection, T lymphocytes expressing CD3 were present and in a significantly higher number than in control subjects (P < 0.0005); (2) there was a positive correlation between histological rejection and the number of CD3+, CD8+, CD25+, CD16+ cells (P < 0.01); (3) the CD4/CD8 ratio was inverted (0.52 +/- 0.04), with no correlation with the histological rejection; and (4) the number and location of CD3+, CD25+ cells did not correlate with CMV identification in bronchoalveolar lavage. Immunohistochemical criteria could be used for diagnosis of rejection in the management of heart-lung transplantation.
Asunto(s)
Biopsia/métodos , Bronquios/patología , Trasplante de Pulmón/inmunología , Adolescente , Adulto , Líquido del Lavado Bronquioalveolar/microbiología , Niño , Citomegalovirus/aislamiento & purificación , Femenino , Rechazo de Injerto , Humanos , Inmunohistoquímica , Trasplante de Pulmón/patología , Masculino , Simplexvirus/aislamiento & purificaciónRESUMEN
With a view to investigating the implication of IGF-binding protein-6 (IGFBP-6) in the growth of neuroblastomas, nude mice were injected with IGFBP-6-expressing or control IGR-N-91 human neuroblastoma cells and the resulting xenografts examined. Expression of IGFBP-3, IGFBP-4 and type 1 and type 2 IGF receptor messengers was similar in control tumours and equal-sized IGFBP-6-expressing tumours that had developed. IGF-II was more strongly expressed in control tumours, and IGFBP-6-expressing tumours contained less IGFBP-2 than controls. In both populations, there was a significant positive correlation between IGF-II and IGFBP-2 expression. In small IGFBP-6-expressing xenografts where tumour development had apparently been arrested, haematoxylin--eosin and TUNEL staining revealed numerous apoptotic cells. In situ hybridization indicated homogeneous distribution of the IGFBP-6 signal in test tumours. In cell culture, IGFBP-6-expressing cells expressed similar amounts of IGFBP-2, IGF-II and N-myc mRNAs as control cells; but media conditioned by IGFBP-6-expressing cells contained less intact IGFBP-2 protein, with no increase in its proteolytic fragment. In media treated with plasminogen, in which IGFBP-2 was proteolysed, IGFBP-6 was increased. With its especially strong affinity for IGF-II and its resistance to proteolysis, IGFBP-6 would act by sequestering IGF-II, hence inhibiting its mitogenic and anti-apoptotic effects. In excess, IGFBP-6 would displace IGF-II from IGFBP-2 whose potentiation of IGF-II action would cease and whose susceptibility to degradation would be increased. This study therefore shows that IGFBP-6 plays a role in neuroblastoma cell growth in vivo and in vitro and that stable overexpression of IGFBP-6 leads to alteration of the initial balance between the IGFBPs.
Asunto(s)
Proteína 6 de Unión a Factor de Crecimiento Similar a la Insulina/fisiología , Neuroblastoma/metabolismo , Somatomedinas/metabolismo , Animales , Apoptosis/genética , División Celular/genética , Femenino , Expresión Génica , Humanos , Hibridación in Situ/métodos , Proteína 2 de Unión a Factor de Crecimiento Similar a la Insulina/genética , Proteína 3 de Unión a Factor de Crecimiento Similar a la Insulina/genética , Proteína 6 de Unión a Factor de Crecimiento Similar a la Insulina/genética , Factor II del Crecimiento Similar a la Insulina/genética , Ratones , Ratones Desnudos , Trasplante de Neoplasias , Proteínas Proto-Oncogénicas c-myc/genética , ARN Mensajero/análisis , Trasplante HeterólogoRESUMEN
The case of a patient in whom multiple nonosteogenic fibromas developed is reported. This condition is very unusual and must be differentiated not only from the multiple lesions that occur in association with well-known entities but also from some occasionally multifocal bone tumors. The lesion is characterized by proliferations of spindle cells disposed in storiform patterns, with numerous scattered multinucleated giant cells. Ultrastructural study revealed that the basic cell of this lesion had fine structural features of both fibroblast and myofibroblast cells.
Asunto(s)
Neoplasias Óseas/patología , Fibroma/patología , Adolescente , Neoplasias Óseas/diagnóstico por imagen , Niño , Femenino , Fémur , Fibroma/diagnóstico por imagen , Humanos , Radiografía , TibiaRESUMEN
Sarcoidosis is a chronic granulomatous disease that may be considered to be a human model for the delayed-type hypersensitivity reaction. The expression of cytokine genes in organs displaying sarcoid granulomas was analyzed by in situ hybridization with several cytokine probes using biopsies from 11 sarcoid lymph nodes. We detected cells expressing interleukin-1 beta (IL-1 beta), tumor necrosis factor-alpha (TNF-alpha), IL-6, IL-2, and interferon-gamma (IFN-gamma) genes in all lymph nodes. The major finding of this study was that cytokine genes are independently expressed. Of the monokine genes, the IL-1 beta gene was preferentially expressed. The distribution of cells containing IL-1 beta mRNA was characterized by their amalgamation in clusters inside sarcoid granulomas. Cells expressing the TNF-alpha gene were located exclusively inside granulomas and were always scattered. Cells expressing the IL-6 gene or the IL-1 alpha gene were found scattered inside sarcoid granulomas and in the residual lymphoid tissue. The number of cells expressing the IL-1 beta gene was significantly higher than that of cells expressing TNF-alpha gene (P = .001), IL-6 gene (P = .007), or IL-1 alpha gene (P less than .001). Of the cells expressing lymphokine genes, those expressing the IFN-gamma gene were 31.9 (+/- 7.6) times more frequent than those expressing the IL-2 gene (P less than .001). Cells containing IFN-gamma mRNA were detected mainly inside sarcoid granulomas, whereas cells containing IL-2 mRNA were randomly distributed. These results show that each monokine gene or lymphokine gene can be independently expressed in vivo. The high expression level of the IL-1 beta gene and the IFN-gamma gene inside granulomas may be specific to delayed-type hypersensitivity immune reactions.
Asunto(s)
Citocinas/biosíntesis , Expresión Génica , Enfermedades Linfáticas/metabolismo , Sarcoidosis/metabolismo , Citocinas/genética , Humanos , Interferón gamma/biosíntesis , Interferón gamma/genética , Interleucina-1/biosíntesis , Interleucina-1/genética , Enfermedades Linfáticas/genética , Hibridación de Ácido Nucleico , ARN Mensajero/análisis , Sarcoidosis/genéticaRESUMEN
We describe the clinical and pathologic features of a case of pediatric multicentric Kaposi's sarcoma (KS) associated with allograft transplantation in a human immunodeficiency virus (HIV)-negative child. A lethal polyadenopathic and visceral KS occurred in a 5-year-old Caribbean boy who had undergone an allogenic renal transplantation for diffuse mesangial sclerosis with end-stage renal failure 4 months previously. The HIV-1 and HIV-2 serologies were negative. Despite its rarity, KS must be considered as a differential diagnosis in posttransplantation polyadenopathic or multisystemic syndromes in children.