Requirement of HMGB1 for stromal cell-derived factor-1/CXCL12-dependent migration of macrophages and dendritic cells.
HMGB1 finely tunes the function of DCs, thus influencing their maturation program and eventually the establishment of adaptive, T cell-dependent immune responses. Moreover, it promotes the up-regulation of receptors for lymph node chemokines, regulates the remodeling of the cytoskeleton of migrating cells, and sustains their journey to secondary lymphoid organs via a RAGE-dependent pathway. The inflammatory properties of HMGB1 depend at least partially on the ability to complex with soluble moieties, including nucleic acids, microbial products, and cytokines. Here, we show that bone marrow-derived mouse DCs release HMGB1 during CXCL12-dependent migration in vitro. Macrophages share this property, suggesting that it may be a general feature of CXCL12-responsive leukocytes. The chemotactic response to rCXCL12 of DCs and macrophages abates in the presence of the HMGB1 antagonist BoxA. HMGB1 secreted from DCs and macrophages binds to CXCL12 in the fluid phase and protects the chemokine conformation and function in a reducing environment. Altogether, our data indicate that HMGB1 release is required for CXCL12 ability to attract myeloid-derived cells and reveal a functional interaction between the two molecules that possibly contributes to the regulation of leukocyte recruitment and motility.
Innate Immunity and Tissue Remodeling Unit, H. San Raffaele Scientific Institute, Milano 20132, Italy.
Lara
L
Campana
Lidia
L
Bosurgi
Marco E
ME
Bianchi
Angelo A
AA
Manfredi
Patrizia
P
Rovere-Querini
D000818:Animals; D001854:Bone Marrow Cells / Q000166:cytology; D002465:Cell Movement / Q000276:immunology*; D002478:Cells, Cultured; D054377:Chemokine CXCL12 / Q000276:immunology / Q000502:physiology*; D002633:Chemotaxis / Q000276:immunology; D003713:Dendritic Cells / Q000276:immunology* / Q000378:metabolism; D005260:Female; D024243:HMGB1 Protein / Q000502:physiology*; D008264:Macrophages / Q000276:immunology* / Q000378:metabolism; D051379:Mice; D008810:Mice, Inbred C57BL; D017154:Stromal Cells / Q000276:immunology
D054377:Chemokine CXCL12; D024243:HMGB1 Protein