Follicular dendritic cells control engulfment of apoptotic bodies by secreting Mfge8

J Kranich, NJ Krautler, E Heinen… - The Journal of …, 2008 - rupress.org
J Kranich, NJ Krautler, E Heinen, M Polymenidou, C Bridel, A Schildknecht, C Huber…
The Journal of experimental medicine, 2008rupress.org
The secreted phosphatidylserine-binding protein milk fat globule epidermal growth factor 8
(Mfge8) mediates engulfment of apoptotic germinal center B cells by tingible-body
macrophages (TBMφs). Impairment of this process can contribute to autoimmunity. We show
that Mfge8 is identical to the mouse follicular dendritic cell (FDC) marker FDC-M1. In bone-
marrow chimeras between wild-type and Mfge8−/− mice, all splenic Mfge8 was derived from
FDCs rather than TBMφs. However, Mfge8−/− TBMφs acquired and displayed Mfge8 only …
The secreted phosphatidylserine-binding protein milk fat globule epidermal growth factor 8 (Mfge8) mediates engulfment of apoptotic germinal center B cells by tingible-body macrophages (TBMφs). Impairment of this process can contribute to autoimmunity. We show that Mfge8 is identical to the mouse follicular dendritic cell (FDC) marker FDC-M1. In bone-marrow chimeras between wild-type and Mfge8−/− mice, all splenic Mfge8 was derived from FDCs rather than TBMφs. However, Mfge8−/− TBMφs acquired and displayed Mfge8 only when embedded in Mfge8+/+ stroma, or when situated in lymph nodes draining exogenous recombinant Mfge8. These findings indicate a licensing role for FDCs in TBMφ-mediated removal of excess B cells. Lymphotoxin-deficient mice lacked FDCs and splenic Mfge8, and suffer from autoimmunity similar to Mfge8−/− mice. Hence, FDCs facilitate TBMφ-mediated corpse removal, and their malfunction may be involved in autoimmunity.
rupress.org