Activated T cells recruit exosomes secreted by dendritic cells via LFA-1.
Dendritic cells (DCs) are known to secrete exosomes that transfer membrane proteins, like major histocompatibility complex class II, to other DCs. Intercellular transfer of membrane proteins is also observed during cognate interactions between DCs and CD4(+) T cells. The acquired proteins are functional and play a role in regulation of immune responses. How membrane protein transfer is achieved and regulated is unclear. Here we show that T cells can recruit major histocompatibility complex class II-containing DC exosomes secreted in the extracellular milieu during cognate DC-T-cell interactions. Recruitment of these exosomes required T-cell activation and was dependent on leukocyte function-associated antigen-1 (LFA-1) rather than on T-cell receptor specificity. Indeed, inducing a high-affinity state of LFA-1 on resting T cells was sufficient to provoke exosome binding. These results imply that DC exosomes secreted in the extracellular milieu during cognate T-cell-DC interactions are targeted to T cells activated in that microenvironment.
Nolte-'t Hoen
Esther N M
EN
Faculty of Veterinary Medicine, Department of Biochemistry & Cell Biology, Utrecht University, Utrecht, The Netherlands.
Buschow
Sonja I
SI
Anderton
Stephen M
SM
Stoorvogel
Willem
W
Wauben
Marca H M
MH
D000818:Animals; D015496:CD4-Positive T-Lymphocytes / Q000276:immunology / Q000378:metabolism*; D002417:Cattle; D002450:Cell Communication / Q000276:immunology; D002478:Cells, Cultured; D003713:Dendritic Cells / Q000378:metabolism*; D055354:Exosomes / Q000378:metabolism*; D016158:Genes, p53 / Q000502:physiology; D018799:Intercellular Adhesion Molecule-1 / Q000378:metabolism; D008213:Lymphocyte Activation / Q000502:physiology*; D016169:Lymphocyte Function-Associated Antigen-1 / Q000378:metabolism / Q000502:physiology*; D051379:Mice; D008810:Mice, Inbred C57BL; D018345:Mice, Knockout; D011485:Protein Binding
D016169:Lymphocyte Function-Associated Antigen-1; D018799:Intercellular Adhesion Molecule-1