The pericyte and stromal cell marker CD248 (endosialin) is required for efficient lymph node expansion

CD248 is a cell surface receptor that specifically identifies fibroblasts and pericytes during development and in association with cancer and inflammation. However, its function is poorly defined and its role in lymphoid organs unstudied. Here we used (4-hydroxy-3-nitrophenyl)acetyl chicken gamma globulin (NP-CGG) immunisation and mice lacking CD248 to study whether CD248 modulates popliteal lymph node (pLN) expansion and subsequent immune responses. We have found that CD248 is required for complete pLN expansion but not to co-ordinate compartmentalisation of B and T cells or antibody production following NP-CGG immunisation. In vitro, we show that CD248 expression in human MG63 stromal cells and mouse embryonic fibroblasts (MEFs) leads to a pro-proliferative and pro-migratory phenotype. This correlates with a proliferating CD248-positive population observed in vivo during pLN expansion. Taken together these data highlight a role for CD248 in secondary lymphoid organ (SLO) remodelling during adaptive immune responses.