isolation-processing-and-analysis-of-murine-gingival-cells

Isolation, Processing and Analysis of Murine Gingival Cells

We have developed a technique to precisely isolate and process murine gingival tissue for flow cytometry and molecular studies. The gingiva is a unique ...

Hebrew University - Hadassah Medical Center

Excessive bone resorption is frequently associated with chronic infections and inflammatory diseases. Whereas T cells were demonstrated to facilitate osteoclastogenesis in such diseases, the role of dendritic cells, the most potent activators of naive T cells, remains unclear. Using a model involving inflammation-driven alveolar bone loss attributable to infection, we showed that in vivo ablation of Langerhans cells (LCs) resulted in enhanced bone loss. An increased infiltration of B and T lymphocytes into the tissue surrounding the bone was observed in LC-ablated mice, including receptor activator of NF-ÎºB ligand (RANKL)-expressing CD4(+) T cells with known capabilities of altering bone homeostasis. In addition, the absence of LCs significantly reduced the numbers of CD4(+)Foxp3(+) T-regulatory cells in the tissue. Further investigation revealed that LCs were not directly involved in presenting antigens to T cells. Nevertheless, despite their low numbers in the tissue, the absence of LCs resulted in an elevated activation of CD4(+) but not CD8(+) T cells. This activation involved elevated production of IFN-Î³ but not IL-17 or IL-10 cytokines. Our data, thus, reveal a protective immunoregulatory role for LCs in inflammation-induced alveolar bone resorption, by inhibiting IFN-Î³ secretion and excessive activation of RANKL(+)CD4(+) T cells with a capability of promoting osteoclastogenesis.

Langerhans cells down-regulate inflammation-driven alveolar bone loss.

R&eacute;sorption osseuse excessive est souvent associ&eacute;e &agrave; des infections chroniques et de maladies inflammatoires. Alors que les cellules T ont &eacute;t&eacute; d&eacute;montr&eacute;s pour faciliter osteoclastogenesis dans ces maladies, le r&ocirc;le des cellules dendritiques, les plus puissants activateurs des cellules na&iuml;ves T, demeure incertain. En utilisant un mod&egrave;le impliquant une perte osseuse alv&eacute;olaire ax&eacute;e sur l&#39;inflammation attribuable &agrave; l&#39;infection, nous avons montr&eacute; que l&#39;ablation in vivo de Langerhans (LCs) des cellules a entra&icirc;n&eacute; une perte osseuse accrue. Une infiltration d&#39;une augmentation des lymphocytes B et T dans les tissus autour de l&#39;OS a &eacute;t&eacute; observ&eacute;e chez les souris LC-ablation, y compris activateur du r&eacute;cepteur du ligand de NF-&kappa;B (RANKL)-exprimant CD4 + T avec capacit&eacute;s connues de modifier les cellules osseuses hom&eacute;ostasie. En outre, l&#39;absence de LCs a consid&eacute;rablement r&eacute;duit le nombre de cellules CD4(+)Foxp3(+) T r&eacute;gulateurs dans le tissu. Une enqu&ecirc;te plus pouss&eacute;e a r&eacute;v&eacute;l&eacute; que LCs n&#39;&eacute;taient pas directement impliqu&eacute;s dans la pr&eacute;sentation des antig&egrave;nes aux cellules T. N&eacute;anmoins, malgr&eacute; leur faible nombre dans le tissu, l&#39;absence de LCs a entra&icirc;n&eacute; une activation &eacute;lev&eacute;e de CD4 + mais pas les cellules T CD8. Cette activation a impliqu&eacute; une production &eacute;lev&eacute;e d&#39;IFN-&gamma; mais pas les cytokines IL-17 ou d&#39;IL-10. Nos donn&eacute;es, donc, de r&eacute;v&eacute;ler un r&ocirc;le protecteur immunor&eacute;gulatrices pour LCs dans la r&eacute;sorption de l&#39;os alv&eacute;olaire induite par l&#39;inflammation, en inhibant la s&eacute;cr&eacute;tion de l&#39;IFN-&gamma; et d&#39;activation excessive des cellules RANKL(+)CD4(+) T avec une capacit&eacute; de promotion osteoclastogenesis.

Les cellules de Langerhans bas-r&eacute;glementent la perte osseuse alv&eacute;olaire ax&eacute;e sur l&#39;inflammation.

Riassorbimento osseo eccessivo &egrave; frequentemente associato a infezioni croniche e malattie infiammatorie. Considerando che le cellule T sono state dimostrate per facilitare l&#39;osteoclastogenesis di tali malattie, il ruolo delle cellule dendritiche, i pi&ugrave; potenti attivatori delle cellule T na&iuml;ve, rimane poco chiaro. Utilizzando un modello che comportano la perdita di osso alveolare infiammazione-driven attribuibile all&#39;infezione, abbiamo dimostrato che in vivo ablazione di Langerhans cellule (LCs) ha provocato la perdita ossea avanzata. Un&#39;aumentata infiltrazione dei linfociti B e T nel tessuto che circonda l&#39;osso &egrave; stata osservata nei topi LC-ablazione, tra cui attivatore del recettore del ligand NF-&kappa;B (RANKL)-esprimendo CD4(+) T cellule con capacit&agrave; nota di alterazione ossea omeostasi. Inoltre, l&#39;assenza di LCs notevolmente ridotto il numero di cellule CD4(+)Foxp3(+) T-regolamentazione nel tessuto. Ulteriori indagini hanno rivelato che LCs non sono stati direttamente coinvolti nella presentazione degli antigeni ai linfociti T. Tuttavia, nonostante il loro numero ridotto nel tessuto, l&#39;assenza di LCs provocato un&#39;elevata attivazione di CD4(+) ma non le cellule cellule T. Questa attivazione coinvolto elevata produzione di IFN-&gamma;, ma non le citochine IL-17 o IL-10. I nostri dati, quindi, rivelano un ruolo protettivo immunoregulatory per LCs nel riassorbimento dell&#39;osso alveolare infiammazione indotta, inibendo la secrezione di IFN-&gamma; ed eccessiva attivazione delle cellule T RANKL(+)CD4(+) con una capacit&agrave; di promuovere la osteoclastogenesis.

Hadas Segev

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