Semaphorins guide the entry of dendritic cells into the lymphatics by activating myosin II
Semaphorins guide the entry of dendritic cells into the lymphatics by activating myosin II
Takamatsu, H. et al. Nat. Immuno. 11, 594–600 (2010)
Speaker: Yen-Wei Wu (吳彥緯) Time: 15:10~16:00, Dec. 22, 2010
Commentator: Shin, Jyh-Wei, Ph.D.(辛致煒老師) Place: Room 601
Abstract:
Semaphorins not only involved in determining the direction and migration of neurons during neurogenesis, but also promoting the activation of B cells, T cells, DCs and macrophages with costimulatory molecule–like activities. Plexins were receptors for semaphorins families.In Plxna1-/- mice, T cell priming is found to be deficient. In this study, the role of semaphorins on the DC migration is further studied . When Plxna1-/- bone marrow derived dentridic cells (BMDCs) transferred into wild type mice, the BMDCs migration to draining lymph node was impaired. However, the ability of Plxna1-/- BMDCs to uptake antigens, sense chemokines and transmigration from tissues to afferent lymphatics were no differences between wild type and Plxna1-/-BMDCs, except the transmigration across the lymphatics. The Plxna1-/- BMDCs had impaired transmigration ability at chemokines contained environment. Semaphorins including Sema3A, Sema6C and Sema6D, are related to Plxna1 signal. Sema3A produced by the lymphatics and acts on the rear side of DCs, and induces actomyosin contraction via myosin Ⅱactivity. The Sema3A combined with chemokines can enhance transmigration of DCs. The results show that Sema3A from lymphatic endothelial cells induced actomyosin contraction in DCs during plexin-A1-mediated transmigration. It demonstrates a new function of Semaphorins in DCs trafficking by a previously unknown mechanism that induce actomysin contraction as those cells pass through narrow gaps.
References:
1. Alvarez, D., Vollmann, E.H. & von Andrian, U.H. Mechanisms and consequences of dendritic cell migration. Immunity 29, 325–342 (2008).
2. MartIn-Fontecha, A. et al. Regulation of dendritic cell migration to the draining lymph node: impact on T lymphocyte traffic and priming. J. Exp. Med. 198, 615–621 (2003).