Your browser doesn't support javascript.
loading
Mostrar: 20 | 50 | 100
Resultados 1 - 5 de 5
Filtrar
Mais filtros

Base de dados
Tipo de documento
Intervalo de ano de publicação
1.
J Immunol ; 195(9): 4257-4263, 2015 Nov 01.
Artigo em Inglês | MEDLINE | ID: mdl-26378073

RESUMO

Adaptive immunity critically depends on the functional compartmentalization of secondary lymphoid organs. Mesenchymal stromal cells create and maintain specialized niches that support survival, activation, and expansion of T and B cells, and integrated analysis of lymphocytes and their niche has been instrumental in understanding adaptive immunity. Lymphoid organs are also home to type 3 innate lymphoid cells (ILC3), innate effector cells essential for barrier immunity. However, a specialized stromal niche for ILC3 has not been identified. A novel lineage-tracing approach now identifies a subset of murine fetal lymphoid tissue organizer cells that gives rise exclusively to adult marginal reticular cells. Moreover, both cell types are conserved from mice to humans and colocalize with ILC3 in secondary lymphoid tissues throughout life. In sum, we provide evidence that fetal stromal organizers give rise to adult marginal reticular cells and form a dedicated stromal niche for innate ILC3 in adaptive lymphoid organs.


Assuntos
Imunidade Inata/imunologia , Linfócitos/imunologia , Tecido Linfoide/imunologia , Nicho de Células-Tronco/imunologia , Células Estromais/imunologia , Animais , Linhagem da Célula/genética , Linhagem da Célula/imunologia , Quimiocinas/imunologia , Quimiocinas/metabolismo , Feminino , Feto/citologia , Citometria de Fluxo , Humanos , Molécula 1 de Adesão Intercelular/genética , Molécula 1 de Adesão Intercelular/imunologia , Molécula 1 de Adesão Intercelular/metabolismo , Linfonodos/citologia , Linfonodos/imunologia , Linfonodos/metabolismo , Linfócitos/metabolismo , Tecido Linfoide/citologia , Tecido Linfoide/metabolismo , Masculino , Células-Tronco Mesenquimais/citologia , Células-Tronco Mesenquimais/imunologia , Células-Tronco Mesenquimais/metabolismo , Camundongos Transgênicos , Microscopia Confocal , Ligante RANK/genética , Ligante RANK/imunologia , Ligante RANK/metabolismo , Reação em Cadeia da Polimerase Via Transcriptase Reversa , Nicho de Células-Tronco/genética , Células Estromais/citologia , Células Estromais/metabolismo , Molécula 1 de Adesão de Célula Vascular/genética , Molécula 1 de Adesão de Célula Vascular/imunologia , Molécula 1 de Adesão de Célula Vascular/metabolismo
2.
Blood ; 120(24): 4675-83, 2012 Dec 06.
Artigo em Inglês | MEDLINE | ID: mdl-22955921

RESUMO

Nonhematopoietic stromal cells of secondary lymphoid organs form important scaffold and fluid transport structures, such as lymph node (LN) trabeculae, lymph vessels, and conduits. Furthermore, through the production of chemokines and cytokines, these cells generate a particular microenvironment that determines lymphocyte positioning and supports lymphocyte homeostasis. IL-7 is an important stromal cell-derived cytokine that has been considered to be derived mainly from T-cell zone fibroblastic reticular cells. We show here that lymphatic endothelial cells (LECs) are a prominent source of IL-7 both in human and murine LNs. Using bacterial artificial chromosome transgenic IL-7-Cre mice, we found that fibroblastic reticular cells and LECs strongly up-regulated IL-7 expression during LN remodeling after viral infection and LN reconstruction after avascular transplantation. Furthermore, IL-7-producing stromal cells contributed to de novo formation of LyveI-positive lymphatic structures connecting reconstructed LNs with the surrounding tissue. Importantly, diphtheria toxin-mediated depletion of IL-7-producing stromal cells completely abolished LN reconstruction. Taken together, this study identifies LN LECs as a major source of IL-7 and shows that IL-7-producing stromal cells are critical for reconstruction and remodeling of the distinct LN microenvironment.


Assuntos
Células Endoteliais/metabolismo , Interleucina-7/metabolismo , Linfonodos/metabolismo , Células Estromais/metabolismo , Adulto , Animais , Linhagem Celular , Proliferação de Células , Células Cultivadas , Feminino , Fibroblastos/citologia , Fibroblastos/metabolismo , Expressão Gênica , Humanos , Imuno-Histoquímica , Interleucina-7/genética , Rim/metabolismo , Proteínas Luminescentes/genética , Proteínas Luminescentes/metabolismo , Linfonodos/embriologia , Linfonodos/transplante , Vasos Linfáticos/citologia , Vasos Linfáticos/metabolismo , Coriomeningite Linfocítica/genética , Coriomeningite Linfocítica/metabolismo , Masculino , Camundongos , Camundongos Endogâmicos C57BL , Camundongos Transgênicos , Microscopia Confocal , Reação em Cadeia da Polimerase Via Transcriptase Reversa
3.
J Immunol ; 182(9): 5439-45, 2009 May 01.
Artigo em Inglês | MEDLINE | ID: mdl-19380791

RESUMO

The formation of lymph nodes is a complex process crucially controlled through triggering of LTbetaR on mesenchymal cells by LTalpha(1)beta(2) expressing lymphoid tissue inducer (LTi) cells. This leads to the induction of chemokines to attract more hematopoietic cells and adhesion molecules to retain them. In this study, we show that the extravasation of the first hematopoietic cells at future lymph node locations occurs independently of LTalpha and that these cells, expressing TNF-related activation-induced cytokine (TRANCE), are the earliest LTi cells. By paracrine signaling the first expression of LTalpha(1)beta(2) is induced. Subsequent LTbetaR triggering on mesenchymal cells leads to their differentiation to stromal organizers, which now also start to express TRANCE, IL-7, as well as VEGF-C, in addition to the induced adhesion molecules and chemokines. Both TRANCE and IL-7 will further induce the expression of LTalpha(1)beta(2) on newly arrived immature LTi cells, resulting in more LTbetaR triggering, generating a positive feedback loop. Thus, LTbetaR triggering by LTi cells during lymph node development creates a local environment to which hematopoietic precursors are attracted and where they locally differentiate into fully mature, LTalpha(1)beta(2) expressing, LTi cells. Furthermore, the same signals may regulate lymphangiogenesis to the lymph node through induction of VEGF-C.


Assuntos
Proteínas Angiogênicas/biossíntese , Citocinas/biossíntese , Linfonodos/imunologia , Receptor beta de Linfotoxina/fisiologia , Transdução de Sinais/imunologia , Regulação para Cima/imunologia , Proteínas Angiogênicas/genética , Animais , Diferenciação Celular/imunologia , Movimento Celular/imunologia , Células Cultivadas , Citocinas/genética , Células-Tronco Hematopoéticas/imunologia , Células-Tronco Hematopoéticas/metabolismo , Linfonodos/citologia , Linfonodos/embriologia , Linfonodos/metabolismo , Tecido Linfoide/embriologia , Tecido Linfoide/imunologia , Tecido Linfoide/metabolismo , Heterotrímero de Linfotoxina alfa1 e beta2/biossíntese , Heterotrímero de Linfotoxina alfa1 e beta2/deficiência , Heterotrímero de Linfotoxina alfa1 e beta2/genética , Heterotrímero de Linfotoxina alfa1 e beta2/fisiologia , Camundongos , Camundongos Endogâmicos C57BL , Camundongos Knockout , Ligante RANK/biossíntese , Ligante RANK/genética , Células Estromais/imunologia , Células Estromais/metabolismo
4.
Front Immunol ; 3: 72, 2012.
Artigo em Inglês | MEDLINE | ID: mdl-22566953

RESUMO

Human RORC(+) lymphoid tissue inducer cells are part of a rapidly expanding family of innate lymphoid cells (ILC) that participate in innate and adaptive immune responses as well as in lymphoid tissue (re) modeling. The assessment of a potential role for innate lymphocyte-derived cytokines in human homeostasis and disease is hampered by a poor characterization of RORC(+) innate cell subsets and a lack of knowledge on the distribution of these cells in adults. Here we show that functionally distinct subsets of human RORC(+) innate lymphoid cells are enriched for secretion of IL-17a or IL-22. Both subsets have an activated phenotype and can be distinguished based on the presence or absence of the natural cytotoxicity receptor NKp44. NKp44(+) IL-22 producing cells are present in tonsils while NKp44(-) IL-17a producing cells are present in fetal developing lymph nodes. Development of human intestinal NKp44(+) ILC is a programmed event that is independent of bacterial colonization and these cells colonize the fetal intestine during the first trimester. In the adult intestine, NKp44(+) ILC are the main ILC subset producing IL-22. NKp44(-) ILC remain present throughout adulthood in peripheral non-inflamed lymph nodes as resting, non-cytokine producing cells. However, upon stimulation lymph node ILC can swiftly initiate cytokine transcription suggesting that secondary human lymphoid organs may function as a reservoir for innate lymphoid cells capable of participating in inflammatory responses.

5.
Semin Immunol ; 20(3): 164-70, 2008 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-18424165

RESUMO

In contrast to our understanding of murine lymphoid organogenesis, detailed knowledge on the mechanisms of human lymph node development is virtually lacking. This is mainly due to the obvious difficulties that accompany research using human fetal organs. In this review we will highlight current knowledge on human lymph node and Peyer's patch development and will temporally align observations made in humans with data available from murine studies. In the final paragraphs we will put this knowledge in the context of human malignancies in which interactions between lymphocytes and stroma, resembling those seen in lymphoid organs, are recapitulated.


Assuntos
Linfonodos/embriologia , Nódulos Linfáticos Agregados/embriologia , Animais , Neoplasias Hematológicas/patologia , Humanos , Sistema Imunitário/embriologia , Transdução de Sinais
SELEÇÃO DE REFERÊNCIAS
Detalhe da pesquisa