Non-Primate Monocytes - CD14, CD16 - Ziegler-Heitbrock


S1PR5 is pivotal for the homeostasis of patrolling monocytes.


Patrolling Ly6C(-) monocytes are blood-circulating cells that play a role in inflammation and in the defense against pathogens. Here, we show that similar to natural killer (NK) cells, patrolling monocytes express high levels of S1PR5, a G-coupled receptor for sphingosine-1 phosphate. We found that S1pr5(-/-) mice lack peripheral Ly6C(-) monocytes but have a normal number of these cells in the bone marrow (BM). Various lines of evidence exclude a direct contribution of S1PR5 in the survival of Ly6C(-) monocytes at the periphery. Rather, our data support a role for S1PR5 in the egress of Ly6C(-) monocytes from the BM. In particular, we observed a reduced frequency of patrolling monocytes in BM sinusoids of S1PR5 KO mice. Unexpectedly, S1P was not a chemoattractant for patrolling monocytes and had no significant effect on their viability in vitro. Moreover, the disruption of S1P gradients in vivo did not alter Ly6C(-) monocyte trafficking and viability. These data suggest that S1PR5 regulates the trafficking of monocytes via a mechanism independent of S1P gradients.

Authors: Debien E, Mayol K, Biajoux V, Daussy C, De Aguero MG, Taillardet M, Dagany N, Brinza L, Henry T, Dubois B, Kaiserlian D, Marvel J, Balabanian K, Walzer T
Journal: Eur. J. Immunol.; 2013 Jun; 43(6) 1667-75. doi:10.1002/eji.201343312
Year: 2013
PubMed: PMID: 23519784 (Go to PubMed)