Structural peculiarities of vascular dendritic cell tubulovesicular system in human atherosclerotic aorta

The principal function of vascular dendritic cells has been suggested to be antigen processing/presentation but how this might occur is not clear. To find out whether the organisation of vascular dendritic cells might allow them to internalise antigens, we used electron microscopy to examine their fine cytoarchitectonics. Tubular and vesicular structures were observed to form continuous nets through which extracellular molecules might gain access to lysosomes. This suggests that vascular dendritic cells might be able to degrade antigens using the same mechanisms as occur in macrophages. We also speculate that antigen processing might be different between type I vascular dendritic cells which possess a hypertrophied tubulovesicular system and type II vascular dendritic cells where the tubulovesicular system is less prominent. The present work indicates that the tubulovesicular system is functionally associated with the extracellular space. This connection with the extracellular space through the system of cisterns and vesicles can allow the transport of different substances entering the cistern nets.