Myelin ingestion alters macrophage antigen-presenting function in vitro and in vivo

During MS, phagocytosing myelin-containing macrophages arise and lie in close proximity to T cells. To date, it has not been addressed whether these myelinladen macrophages have the capacity to present antigens to T cells and whether this contributes to inflammation in disease. We demonstrate that in vitro-generated human and mouse myelin-laden macrophages expressed MHC class I and II and costimulatory molecules and are thus well equipped for antigen presentation.uman myelin-laden macrophages exhibited normal endocytosis of particulate and soluble antigens. In addition, human myelin-laden macrophages elicited active T cell proliferation of nai{dotless}̈ve as well as memory T cells. Furthermore, mouse myelin-laden macrophages induced primary antigen-specific CD4+T cell proliferation in vivo but transiently diminished IFN-γ release. Functionally, MOG peptide-loaded myelin-laden mouse macrophages modestly but significantly reduced the severity of MOG peptide-induced EAE. These data show that myelin uptake results in the induction of a population of macrophages that retains antigen-presenting capacity and limits autoimmune-mediated disease.

• View at Publisher
• View at Pubmed
• View at Scopus
• View at Web of Science