Activated T cells recruit exosomes secreted by dendritic cells via LFA-1

ENM Nolte-'t Hoen, SI Buschow… - Blood, The Journal …, 2009 - ashpublications.org
ENM Nolte-'t Hoen, SI Buschow, SM Anderton, W Stoorvogel, MHM Wauben
Blood, The Journal of the American Society of Hematology, 2009ashpublications.org
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 …
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.
ashpublications.org