Serum exosomes in pregnancy-associated immune modulation and neuroprotection during CNS autoimmunity

Jessica L Williams1, NaTosha N Gatson, Kristen M Smith

  • 1The Ohio State University, Department of Microbial Infection and Immunity, 208 Bricker Hall, 190 North Oval Mall, Columbus, OH 43210, USA.

In multiple sclerosis (MS) and experimental autoimmune encephalomyelitis (EAE), relapses are markedly reduced during pregnancy. Exosomes are lipid-bound vesicles and are more abundant in the serum during pregnancy. Using murine EAE, we demonstrate that serum exosomes suppress T cell activation, promote the maturation of oligodendrocyte precursor cells (OPC), and pregnancy exosomes facilitate OPC migration into active CNS lesions. However, exosomes derived from both pregnant and non-pregnant mice reduced the severity of established EAE. Thus, during pregnancy, serum exosomes modulate the immune and central nervous systems and contribute to pregnancy-associated suppression of EAE.