Abstract
IgE antigen complexes induce increased specific T cell proliferation and increased specific IgG production. Immediately after immunization, CD23+ B cells capture IgE antigen complexes, transport them to the spleen where, via unknown mechanisms, dendritic cells capture the antigen and present it to T cells. CD23, the low affinity IgE receptor, binds IgE antigen complexes and internalizes them. In this study, we show that these complexes are processed onto B-cell derived exosomes (bexosomes) in a CD23 dependent manner. The bexosomes carry CD23, IgE and MHC II and stimulate antigen specific T-cell proliferation in vitro. When IgE antigen complex stimulated bexosomes are incubated with dendritic cells, dendritic cells induce specific T-cell proliferation in vivo, similar to IgE antigen complexes. This suggests that bexosomes can provide the essential transfer mechanism for IgE antigen complexes from B cells to dendritic cells.
Highlights
Antibody, in complex with its antigen, provides the immune system with a feedback response against the complexed antigen
Combining antigen presentation properties of CD23 with the observed immunostimulation led to the hypothesis that antigen presentation by CD23+ B cells was responsible for these activities
Cells and were being transferred to dendritic cells (DCs). This led to the obvious question, what is the mechanism of this transfer? Henningson et al [4] suggested two possibilities; trogocytosis by DCs or exosomal mediated transfer from B cells to DCs
Summary
In complex with its antigen, provides the immune system with a feedback response against the complexed antigen. Culture of bexosomes with bone marrow derived DCs (BMDC), followed by isolation and injection of DCs did directly enhance in vivo antigen specific T cell proliferation.
Sign-in/Register to view highlights & summary Sign-in/Register to access full text options 
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a call
