Semimature stage: a checkpoint in a dendritic cell maturation program that allows for functional reversion after signal-regulatory protein-alpha ligation and maturation signals

J Immunol. 2006 Dec 15;177(12):8550-9. doi: 10.4049/jimmunol.177.12.8550.

Abstract

CD47 on live cells actively engages signal-regulatory protein-alpha (SIRP-alpha) on phagocytes and delivers a negative signal that prevents their elimination. We evaluated the biological consequences of SIRP-alpha ligation on the dendritic cell (DC) response to maturation signals and the potential interplay with the IL-10/IL-10R inhibitory pathway. At first, CD47/SIRP-alpha allowed the generation of mature migratory DCs not producing IL-12, IFN-gamma-inducible protein-10, and CCL19. Rather, they secreted neutrophils attracting chemokine CXCL5 and IL-1beta, reflecting a partial block in functional DC maturation. Afterward, semimature DCs functionally regressed in an IL-10-independent fashion toward cells that retrieved the cardinal features of immature DCs: re-expression of CCR5, loss of DC-lysosome-associated membrane protein, high endocytosis, and impaired allostimulatory functions. The global gene expression profile of IL-10 and SIRP-alpha-ligated DC demonstrated two distinct molecular pathways. IL-10R and SIRP-alpha expression were reciprocally down-regulated by CD47 and IL-10, respectively. These results emphasize that the SIRP-alpha pathway might be part of the molecular machinery used by the DC to dampen or resolve an inflammatory response in an IL-10-independent manner.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Antigens, Differentiation / genetics
  • Antigens, Differentiation / physiology*
  • CD47 Antigen / physiology
  • Cell Differentiation*
  • Dendritic Cells / cytology*
  • Dendritic Cells / physiology*
  • Gene Expression Profiling
  • Gene Expression Regulation
  • Humans
  • Inflammation / metabolism
  • Interleukin-10 / genetics
  • Receptors, Immunologic / genetics
  • Receptors, Immunologic / physiology*
  • Receptors, Interleukin-10 / genetics
  • Receptors, Interleukin-10 / physiology
  • Signal Transduction*

Substances

  • Antigens, Differentiation
  • CD47 Antigen
  • Receptors, Immunologic
  • Receptors, Interleukin-10
  • SIRPA protein, human
  • Interleukin-10