Autologous blood extracellular vesicles and specific CD4 T-cell co-activation.

Extracellular vesicles (EVs), which are generated by cell membrane budding in diverse cells, are present in variable numbers in the blood. An immunoregulatory role has been demonstrated principally for heterologous EVs, but the function of the EVs present naturally in blood remains unknown. We hypothesize that these autologous EVs might also modulate the phenotype and function of immune system cells, especially CD4 T lymphocytes (TLs), as previously described for heterologous EVs.