Expression of the inhibitory CD200 receptor is associated with alternative macrophage activation

Classical macrophage activation is inhibited by the CD200
receptor (CD200R). Here, we show that CD200R expression
was specifically induced on human in vitro polarized macrophages
of the alternatively activated M2a subtype, generated
by incubation with IL-4 or IL-13. In mice, peritoneal M2
macrophages, elicited during infection with the parasites
Taenia crassiceps or Trypanosoma brucei brucei , expressed increased
CD200R levels compared to those derived from uninfected
mice. However, in vitro stimulation of mouse peritoneal
macrophages and T. crassiceps infection in IL-4-/- and
IL-4R-/- mice showed that, in contrast to humans, induction
of CD200R in mice was not IL-4 or IL-13 dependent. Our data
identify CD200R as a suitable marker for alternatively activated
macrophages in humans and corroborate observations
of distinct species- and/or site-specific mechanisms
regulating macrophage polarization in mouse and man.

Trefwoorden:IL-4, Immune inhibition, macrophage polarization, parasite infection, type 2 responses