Your browser doesn't support javascript.
loading
Mostrar: 20 | 50 | 100
Resultados 1 - 15 de 15
Filtrar
Mais filtros










Base de dados
Intervalo de ano de publicação
1.
Exp Neurol ; 210(2): 286-94, 2008 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-18201702

RESUMO

Therapies aimed at depleting or blocking the migration of polymorphonuclear leukocytes (PMN or neutrophils) are partially successful in the treatment of neuroinflammatory conditions and in attenuating pain following peripheral nerve injury or subcutaneous inflammation. However, the functional effects of PMN on peripheral sensory neurons such as dorsal root ganglia (DRG) neurons are largely unknown. We hypothesized that PMN are detrimental to neuronal viability in culture and increase neuronal activity and excitability. We demonstrate that isolated peripheral PMN are initially in a relatively resting state but undergo internal oxidative burst and activation by an unknown mechanism within 10 min of co-culture with dissociated DRG cells. Co-culture for 24 h decreases neuronal count at a threshold<0.4:1 PMN:DRG cell ratio and increases the number of injured and apoptotic neurons. Within 3 min of PMN addition, fluorometric calcium imaging reveals intracellular calcium transients in small size (<25 microm diam) and large size (>25 microm diam) neurons, as well as in capsaicin-sensitive neurons. Furthermore, small size isolectin B4-labeled neurons undergo hyperexcitability manifested as decreased current threshold and increased firing frequency. Although co-culture of PMN and DRG cells does not perfectly model neuroinflammatory conditions in vivo, these findings suggest that activated PMN can potentially aggravate neuronal injury and cause functional changes to peripheral sensory neurons. Distinguishing the beneficial from the detrimental effects of PMN on neurons may aid in the development of more effective drug therapies for neurological disorders involving neuroinflammation, including painful neuropathies.


Assuntos
Gânglios Espinais/citologia , Neurônios/fisiologia , Neutrófilos/fisiologia , Anestésicos Locais/farmacologia , Animais , Anexina A5/metabolismo , Cálcio/metabolismo , Contagem de Células , Células Cultivadas , Técnicas de Cocultura/métodos , Relação Dose-Resposta à Radiação , Estimulação Elétrica/métodos , Proteína Glial Fibrilar Ácida/metabolismo , Lidocaína/farmacologia , Masculino , Potenciais da Membrana/efeitos dos fármacos , Potenciais da Membrana/fisiologia , Potenciais da Membrana/efeitos da radiação , Neurônios/efeitos dos fármacos , Neutrófilos/efeitos dos fármacos , Técnicas de Patch-Clamp/métodos , Fosfopiruvato Hidratase/metabolismo , Ratos , Ratos Sprague-Dawley , Espécies Reativas de Oxigênio/metabolismo , Fator de Necrose Tumoral alfa/farmacologia
2.
J Neuroimmunol ; 184(1-2): 164-71, 2007 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-17275921

RESUMO

To test whether neutrophils (PMN) target lumbar dorsal root ganglia (DRG) following axonal injury leading to neuropathic pain, we visualized PMN infiltration in DRG tissue sections and estimated PMN count by flow cytometry following sciatic chronic constriction injury (CCI). Seven days after CCI, results show PMN within DRG where their count increased by three fold ipsilateral to injury compared to contralateral or sham, concomitant with peak neuropathic pain behavior. Superoxide burst in PMN isolated from rats d7 after CCI was elevated by 170% +/-18 compared to naïve and MCP-1 mRNA expression in DRG increased by 8.9+/-2.9 fold, but that of MIP-2, CINC-1, and RANTES did not change. We conclude that CCI causes PMN invasion of the DRG whereby the functional implication of their close proximity to neuronal axon and soma remains unknown.


Assuntos
Gânglios Espinais/patologia , Neutrófilos/fisiologia , Neuropatia Ciática/patologia , Neuropatia Ciática/fisiopatologia , Animais , Quimiocina CCL2/genética , Quimiocina CCL2/metabolismo , Constrição , Lateralidade Funcional , Regulação da Expressão Gênica/fisiologia , Região Lombossacral , Masculino , Medição da Dor/métodos , RNA Mensageiro/metabolismo , Ratos , Reação em Cadeia da Polimerase Via Transcriptase Reversa , Fatores de Tempo
3.
Am J Pathol ; 159(6): 2281-91, 2001 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-11733377

RESUMO

The combination of tumor necrosis factor (TNF)-alpha plus interferon (IFN)-gamma has been shown previously to promote redistribution of platelet/endothelial cell adhesion molecule-1 (PECAM-1) (CD31), junctional adhesion molecule (JAM), and VE-cadherin away from lateral junctions of human umbilical vein endothelial cell monolayers. In parallel, neutrophil transmigration was significantly reduced. Because PECAM-1 and JAM have been implicated in leukocyte transmigration, the observed redistribution by cytokine activation was presumed to represent the mechanism causing decreased transmigration under static conditions. The current results confirm that culture of human umbilical vein endothelial cells with TNF-alpha plus IFN-gamma caused a decrease in surface-expressed and junctional-localized JAM and PECAM-1, but did not cause decreased leukocyte transmigration in an in vitro flow assay. Furthermore, blocking monoclonal antibody to PECAM-1 still significantly reduced monocyte transmigration, demonstrating that it retains a functional role even though its levels were reduced and redistributed away from junctions, whereas a panel of monoclonal antibodies to JAM failed to reduce leukocyte transmigration. Given the alterations in junction protein location, permeability function was assessed. IFN-gamma alone or TNF-alpha plus IFN-gamma significantly increased permeability, but TNF-alpha alone did not, suggesting lack of correlation between transmigration and loss of permeability. In conclusion, cytokine activation induced loss and redistribution of PECAM-1 and JAM away from lateral junctions, but per se does not negatively regulate either neutrophil or monocyte transmigration under flow.


Assuntos
Moléculas de Adesão Celular/biossíntese , Endotélio Vascular/efeitos dos fármacos , Interferon gama/farmacologia , Leucócitos/efeitos dos fármacos , Molécula-1 de Adesão Celular Endotelial a Plaquetas/biossíntese , Fator de Necrose Tumoral alfa/farmacologia , Adesão Celular/efeitos dos fármacos , Permeabilidade da Membrana Celular/efeitos dos fármacos , Movimento Celular/efeitos dos fármacos , Células Cultivadas , Endotélio Vascular/citologia , Endotélio Vascular/metabolismo , Citometria de Fluxo , Humanos , Junções Intercelulares/efeitos dos fármacos , Junções Intercelulares/metabolismo , Leucócitos/citologia , Monócitos/citologia , Monócitos/efeitos dos fármacos , Fluxo Pulsátil
4.
J Immunol ; 167(4): 2323-30, 2001 Aug 15.
Artigo em Inglês | MEDLINE | ID: mdl-11490021

RESUMO

Vascular endothelial-cadherin (VE-cadherin) is a component of the adherens junctions of endothelial cells whose role in endothelial transmigration of leukocytes has been controversial. Using a VE-cadherin/green fluorescent protein fusion construct (VEcadGFP) that mimics the native molecule, we visualized alterations in endothelial junctional structure in real time during transmigration of human neutrophils and monocytes in an in vitro flow model. We observed abundant transmigration occurring exclusively at the cell borders (paracellularly). Surprisingly, transmigration occurred both through de novo formation of transient gaps in VEcadGFP junctional distribution, and also through preexisting gaps. De novo gaps 4-6 microm in size were formed after a leukocyte arrived at a junction, whereas preexisting gaps were present even before the leukocyte had interacted with the endothelial cells contributing to a junction. Gaps rapidly resealed within 5 min after leukocyte transmigration. Migrating leukocytes appeared to push aside VEcadGFP in the plane of the junction, and this displaced material subsequently diffused back to refill the junction. To our knowledge, this is the first example where molecular events at the lateral junction have been tracked in real time during transmigration.


Assuntos
Caderinas/metabolismo , Movimento Celular , Endotélio Vascular/citologia , Endotélio Vascular/fisiologia , Aumento da Imagem/métodos , Leucócitos/fisiologia , Microscopia de Fluorescência/métodos , Transativadores , Antígenos CD , Caderinas/biossíntese , Caderinas/genética , Comunicação Celular/genética , Linhagem Celular , Permeabilidade da Membrana Celular/genética , Movimento Celular/genética , Proteínas do Citoesqueleto/metabolismo , Desmoplaquinas , Cultura em Câmaras de Difusão/métodos , Endotélio Vascular/metabolismo , Vetores Genéticos/biossíntese , Vetores Genéticos/fisiologia , Proteínas de Fluorescência Verde , Hemorreologia , Humanos , Aumento da Imagem/instrumentação , Junções Intercelulares/metabolismo , Cinética , Leucócitos/citologia , Leucócitos/metabolismo , Proteínas Luminescentes/biossíntese , Proteínas Luminescentes/genética , Proteínas Luminescentes/metabolismo , Microscopia de Fluorescência/instrumentação , Monócitos/citologia , Monócitos/metabolismo , Monócitos/fisiologia , Neutrófilos/citologia , Neutrófilos/metabolismo , Neutrófilos/fisiologia , Transfecção , beta Catenina
6.
Gastroenterology ; 118(2): 289-98, 2000 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-10648457

RESUMO

BACKGROUND & AIMS: The development of intestinal intraepithelial lymphocytes (IELs) requires the movement of lymphocytes into the epithelial compartment (i.e., IEL homing). The rules governing and the biologic consequences of IEL homing are poorly understood. The aims of this study were to examine the adhesion molecules involved in IEL homing and the phenotypic alteration of lymphocytes as a consequence of homing. METHODS: We previously developed an in vitro IEL homing model consisting of human IEL cell lines and a polarized monolayer of human intestinal epithelial T84 cells. Homing capacity of lymphocytes was assessed by measuring their migration into epithelial monolayers, and phenotypic analysis was performed by flow cytometry. RESULTS: In this model, approximately 30% of lymphocytes moved into the epithelial monolayer, regardless of the lymphocyte concentration. Flow cytometric screening of adhesion molecules revealed that homed lymphocytes expressed high levels of integrin alphaXbeta2 and alphaEbeta7 and low levels of alpha4beta7 compared with non-homed lymphocytes. In addition, subpopulations sorted as alphaXbeta2(high) or alphaEbeta7(high) independently showed greater homing capacities. After homing, alphaEbeta7 and intercellular adhesion molecule 1 (ICAM-1) on homed lymphocytes were significantly up-regulated, which was consistent with their high expression observed on freshly isolated human IELs. The up-regulation of alphaEbeta7 (but not ICAM-1) was completely dependent on epithelial-derived transforming growth factor beta1 (TGF-beta1). The expression of alphaXbeta2 was observed on a small population of freshly isolated human IELs, and was markedly induced by stimulation. Also, epithelial-derived TGF-beta1 down-regulated the alphaXbeta2 expression (an event likely to occur after homing). CONCLUSIONS: Our findings indicate a relationship between IEL alphaXbeta2 and alphaEbeta7 expression and homing into intestinal epithelia. We also show that phenotypic alteration of IELs is induced by close interaction with intestinal epithelia as a consequence of homing.


Assuntos
Integrinas , Mucosa Intestinal/imunologia , Linfócitos/imunologia , Glicoproteínas de Membrana/biossíntese , Glicoproteínas de Membrana/genética , Linhagem Celular , Quimiotaxia , Citometria de Fluxo , Regulação da Expressão Gênica , Humanos , Integrina alfaXbeta2 , Molécula 1 de Adesão Intercelular/genética , Ativação Linfocitária , Linfócitos/fisiologia , Fator de Crescimento Transformador beta/farmacologia
7.
Am J Physiol ; 275(3): G584-91, 1998 09.
Artigo em Inglês | MEDLINE | ID: mdl-9724272

RESUMO

Intraepithelial lymphocytes (IEL) are a phenotypically distinct population of lymphocytes that reside in mucosal epithelia, below the intercellular tight junctions. Although adhesive functions of this population have been previously studied, relatively little is known about IEL migration from the microvasculature into the epithelium. We demonstrated that cultured human IEL were capable of migration into polarized epithelial cells in vitro, where they assumed a subjunctional position, identical to that observed in vivo. The migration was rapid and efficient and was directionally polarized, such that IEL migrated into epithelial monolayers from the basolateral, but not the apical, aspect. After a 4-h period of residence, up to one-half of the IEL then exited the monolayer basolaterally. Migration was partially inhibited by pertussis toxin, suggesting a potential mechanism for IEL migration by chemokine receptor-mediated signaling. The conditions and ligand pairs used in IEL migration were different from those for neutrophils, another cell type known to migrate through epithelia. This system may serve as a model for microenvironmental homing of IEL into the epithelium.


Assuntos
Mucosa Intestinal/fisiologia , Linfócitos/fisiologia , Neutrófilos/fisiologia , Linfócitos T CD8-Positivos/imunologia , Linfócitos T CD8-Positivos/microbiologia , Linfócitos T CD8-Positivos/fisiologia , Linhagem Celular , Movimento Celular , Polaridade Celular , Quimiotaxia de Leucócito/efeitos dos fármacos , Quimiotaxia de Leucócito/fisiologia , Humanos , Integrinas/biossíntese , Integrinas/fisiologia , Mucosa Intestinal/imunologia , Cinética , N-Formilmetionina Leucil-Fenilalanina/farmacologia , Proteínas Recombinantes/biossíntese , Salmonella typhimurium/patogenicidade , Salmonella typhimurium/fisiologia , Fatores de Tempo , Transfecção
8.
J Cell Biol ; 140(1): 197-210, 1998 Jan 12.
Artigo em Inglês | MEDLINE | ID: mdl-9425167

RESUMO

The cadherins are a family of homophilic adhesion molecules that play a vital role in the formation of cellular junctions and in tissue morphogenesis. Members of the integrin family are also involved in cell to cell adhesion, but bind heterophilically to immunoglobulin superfamily molecules such as intracellular adhesion molecule (ICAM)-1, vascular cell adhesion molecule (VCAM)-1, or mucosal addressin cell adhesion molecule (MadCAM)-1. Recently, an interaction between epithelial (E-) cadherin and the mucosal lymphocyte integrin, alphaEbeta7, has been proposed. Here, we demonstrate that a human E-cadherin-Fc fusion protein binds directly to soluble recombinant alphaEbeta7, and to alphaEbeta7 solubilized from intraepithelial T lymphocytes. Furthermore, intraepithelial lymphocytes or transfected JY' cells expressing the alphaEbeta7 integrin adhere strongly to purified E-cadherin-Fc coated on plastic, and the adhesion can be inhibited by antibodies to alphaEbeta7 or E-cadherin. The binding of alphaEbeta7 integrin to cadherins is selective since cell adhesion to P-cadherin-Fc through alphaEbeta7 requires >100-fold more fusion protein than to E-cadherin-Fc. Although the structure of the alphaE-chain is unique among integrins, the avidity of alphaEbeta7 for E-cadherin can be regulated by divalent cations or phorbol myristate acetate. Cross-linking of the T cell receptor complex on intraepithelial lymphocytes increases the avidity of alphaEbeta7 for E-cadherin, and may provide a mechanism for the adherence and activation of lymphocytes within the epithelium in the presence of specific foreign antigen. Thus, despite its dissimilarity to known integrin ligands, the specific molecular interaction demonstrated here indicates that E-cadherin is a direct counter receptor for the alphaEbeta7 integrin.


Assuntos
Caderinas/fisiologia , Integrinas/fisiologia , Sequência de Aminoácidos , Animais , Anticorpos Monoclonais , Caderinas/biossíntese , Caderinas/química , Adesão Celular , Linhagem Celular , Vetores Genéticos , Humanos , Fragmentos Fc das Imunoglobulinas/química , Imunoglobulina G/química , Integrinas/biossíntese , Mucosa Intestinal , Cinética , Camundongos , Modelos Moleculares , Reação em Cadeia da Polimerase , Ligação Proteica , Proteínas Recombinantes de Fusão/metabolismo , Linfócitos T/imunologia , Linfócitos T/fisiologia , Transfecção
9.
Semin Immunol ; 7(5): 335-42, 1995 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-8580465

RESUMO

Lymphocytes recirculate extensively throughout the body and then localize in tissues and lymphoid organs. This is accomplished by an array of adhesion molecules on lymphocytes and counter-receptors on the vascular endothelium, extracellular matrix and the epithelium. Recent studies have identified several of the specific molecular interactions that mediate lymphocyte trafficking. Lymphocytes expressing alpha 4 beta 7 home to the intestine through recognition of the mucosal addressin cell adhesion molecule-1 (MAdCAM-1) expressed on Peyer's patch high endothelial venules. T cells in nearly all mucosal epithelial sites express the alpha E beta 7 integrin which has been shown to mediate lymphocyte binding to epithelial cell E-cadherin. Thus, members of the B7 subfamily of integrins, alpha E beta 7 and alpha 4 beta 7, and their counter-receptors, are believed to play key roles in directing lymphocyte traffic to and retention in mucosal organs.


Assuntos
Adesão Celular/imunologia , Movimento Celular/imunologia , Cadeias beta de Integrinas , Integrinas , Mucosa Intestinal , Linfócitos , Animais
10.
Nature ; 372(6502): 190-3, 1994 Nov 10.
Artigo em Inglês | MEDLINE | ID: mdl-7969453

RESUMO

In contrast to sessile cell types, lymphocytes migrate through the vasculature to become diffusely distributed in tissues or organized in lymphoid structures. A complex array of adhesion molecules including selectins, integrins and their counter-receptors mediate lymphocyte homing and migration into tissues and may be constitutively expressed or induced. However, the molecules that mediate the tissue-specific retention of lymphocytes within the parenchyma have not been identified. Along the epithelium at the basolateral surface of enterocytes, intestinal intraepithelial lymphocytes are found. These T cells of the mucosal immune system serve as a model for the tissue-specific compartmentalization of lymphocytes. We investigated whether the localization of these intestinal intraepithelial lymphocytes could be mediated by specific interactions between adhesion molecules expressed selectively on this subpopulation of T cells and tissue-restricted adhesion molecules on epithelial cells. Here we show that heterotypic adhesive interactions between epithelial cells and intraepithelial lymphocytes in vitro are mediated by E-cadherin and the alpha E beta 7 integrin.


Assuntos
Caderinas/fisiologia , Adesão Celular/fisiologia , Integrinas/fisiologia , Mucosa Intestinal/citologia , Mucosa Intestinal/imunologia , Linfócitos T/fisiologia , Animais , Linhagem Celular , Humanos , Células L , Camundongos , Proteínas Recombinantes/farmacologia
11.
Immunity ; 1(5): 393-403, 1994 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-7882170

RESUMO

Intraepithelial T lymphocytes possess a (TGF beta)-inducible integrin complex that consists of the beta 7 integrin chain in association with a novel alpha chain, murine alpha M290. Using antibodies directed against the murine alpha M290 chain, IL-3-dependent murine bone marrow-derived mast cells demonstrated positive staining after induction with TGF beta. Sequence information from the human intraepithelial T lymphocyte-alpha E gene sequence was used to clone the murine homolog from a TGF beta-induced T cell library. The murine alpha E homolog gene encodes a protein recognized by antibodies to alpha M290. Expression of this gene by bone marrow-derived mast cells was found to be induced by TGF beta or IgE-mediated cross-linking of Fc epsilon R1. Furthermore, exposure of murine TK-1 cells to supernatants from activated mast cells induces the expression of the alpha M290 gene, indicating that a mast cell mediator(s) can act in a paracrine manner to induce expression of this integrin complex by other cells.


Assuntos
Integrinas/química , Integrinas/genética , Mastócitos/fisiologia , Sequência de Aminoácidos , Animais , Sequência de Bases , Degranulação Celular , Expressão Gênica , Humanos , Imunoglobulina E/farmacologia , Mastócitos/imunologia , Camundongos , Camundongos Endogâmicos BALB C , Dados de Sequência Molecular , Estrutura Molecular , Proteínas/análise
12.
J Biol Chem ; 269(8): 6016-25, 1994 Feb 25.
Artigo em Inglês | MEDLINE | ID: mdl-8119947

RESUMO

The human mucosal lymphocyte-1 (HML-1) antigen is expressed on a subclass of T-lymphocytes known as intra-epithelial lymphocytes which are located between mucosal epithelial cells. The HML-1 complex is known to mediate adhesion of intra-epithelial T-lymphocytes to epithelial cell monolayers in vitro. We and others have shown that the HML-1 antigen is an integrin composed of the beta 7 subunit in association with a novel alpha subunit, alpha E. Here we report the cloning of the alpha E cDNA and its primary amino acid sequence. alpha E contained an inserted or I domain and was more homologous to the other I domain containing integrins than to the cleaved group of integrin alpha subunits. However, alpha E contained a unique extra domain of 55 amino acids located just NH2-terminal to the I domain without counterpart in other integrins. This extra domain contained a stretch of 18 consecutive charged residues and included a proteolytic cleavage site. Thus alpha E is the only I domain containing integrin alpha subunit that is also cleaved, and the cleavage site is distinct from that of members of the cleaved group of integrin alpha subunits. These structural features mark alpha E as an unusual member of the integrin family. High levels of alpha E and beta 7 mRNA were restricted to mucosal lymphocytes supporting the hypothesis that alpha E beta 7 plays a role in the localization or site-specific functions of intra-epithelial T-lymphocytes.


Assuntos
Antígenos CD/genética , Cadeias alfa de Integrinas , Integrinas/genética , RNA Mensageiro/metabolismo , Subpopulações de Linfócitos T/metabolismo , Sequência de Aminoácidos , Antígenos CD/metabolismo , Sequência de Bases , Clonagem Molecular , DNA Complementar , Humanos , Integrinas/metabolismo , Dados de Sequência Molecular , Mucosa/imunologia , Análise de Sequência de DNA , Homologia de Sequência de Aminoácidos
13.
J Biol Chem ; 267(30): 21924-7, 1992 Oct 25.
Artigo em Inglês | MEDLINE | ID: mdl-1400503

RESUMO

In this report we demonstrate that a transcriptional regulatory element for one gene lies within a second, seemingly unrelated gene. Specifically, the 3' portion of the murine sex-limited protein (slp) gene, located within the class III region of the major histocompatibility complex, contains an element that regulates expression of the linked steroid 21-hydroxylase gene. A 4.2-kilobase (kb) major histocompatibility complex region, located between -2.2 and -6.4 kb upstream of 21OH-A, is required for expression of a chloramphenicol acetyltransferase reporter gene in transgenic mice. Two short regions of DNA, located between -5.3 and -6.0 kb, stimulate chloramphenicol acetyltransferase expression in Y1 adrenocortical tumor cells, and both of these active regions lie within the slp gene. A 21-base pair sequence, which is required for activity of the most 3' region, does not contain any of over 100 previously identified transcriptional regulatory elements. This juxtaposition of structural and regulatory elements of otherwise unrelated genes suggests a mechanism by which the evolutionarily conserved genetic linkage of 21OH-A and slp (or the homologous complement component C4) might provide a selective advantage. Analogous genetic arrangements may explain other examples of conserved linkage of disparate genes.


Assuntos
Glândulas Suprarrenais/enzimologia , Proteínas Sanguíneas/genética , Regulação Enzimológica da Expressão Gênica , Sequências Reguladoras de Ácido Nucleico , Esteroide 21-Hidroxilase/genética , Animais , Sequência de Bases , Cloranfenicol O-Acetiltransferase/genética , Complemento C4 , DNA , Camundongos , Camundongos Transgênicos , Dados de Sequência Molecular , Transcrição Gênica , Transfecção
14.
Proc Natl Acad Sci U S A ; 89(5): 1924-8, 1992 Mar 01.
Artigo em Inglês | MEDLINE | ID: mdl-1542691

RESUMO

The heterodimeric protein complex recognized by the human mucosal lymphocyte 1 (HML-1) monoclonal antibody is expressed on 95% of intraepithelial lymphocytes but on only 1-2% of peripheral blood lymphocytes [Cerf-Bensusson, N., Jarry, A., Brousse, N., Lisowska-Grospierre, B., Guy-Grand, D. & Griscelli, C. (1987) Eur. J. Immunol. 17, 1279-1285]. We purified the smaller HML-1 subunit (105 kDa under nonreducing conditions) from hairy-cell leukemia cells and determined the N-terminal amino acid sequence of this chain. The 17 residues determined were identical to the deduced amino acid sequence encoded by an integrin beta 7 cDNA clone [Yuan, Q., Jiang, W.-M., Krissansen, G.W. & Watson, J.D. (1990) Int. Immunol. 2, 1097-1108]. Biochemical analysis of the larger HML-1 subunit (175 kDa under nonreducing conditions) suggested that it was a distinct member of the cleaved group of integrin alpha chains, which we designated alpha E. The beta 7 chain also was associated with the integrin alpha 4 subunit, suggesting that the HML-1 antigen (alpha E beta 7) and alpha 4 beta 7 constitute a beta 7 integrin family on mucosal lymphocytes. Interestingly, regulation of the expression of the HML-1 antigen was reciprocal to that of lymphocyte function-associated molecule 1 in the presence of transforming growth factor beta 1. We suggest that these beta 7 integrins may play a specific role in mucosal localization or adhesion and that the expression of the HML-1 antigen might be regulated by transforming growth factor beta 1 produced at or near epithelial tissues.


Assuntos
Antígenos de Neoplasias/química , Cadeias beta de Integrinas , Integrinas/química , Mucosa Intestinal/citologia , Linfócitos T/química , Sequência de Aminoácidos , Animais , Anticorpos Monoclonais/imunologia , Antígenos de Neoplasias/imunologia , Antígenos de Neoplasias/metabolismo , Humanos , Integrinas/imunologia , Integrinas/metabolismo , Substâncias Macromoleculares , Camundongos , Dados de Sequência Molecular , Peso Molecular , Precursores de Proteínas/metabolismo , Linfócitos T/citologia , Fator de Crescimento Transformador beta/metabolismo
SELEÇÃO DE REFERÊNCIAS
DETALHE DA PESQUISA
...