HISTOLOGY AND HISTOPATHOLOGY

Cellular and Molecular Biology

 

Review

Dendritic cell migration and lymphocyte homing imprinting

Eduardo J. Villablanca1,2,3, Vincenzo Russo1 and J. Rodrigo Mora3

1Cancer Gene Therapy Unit, Scientific Institute H. San Raffaele, 2International Ph.D. Program in Molecular Medicine, University “Vita-Salute” San Raffaele, Milan, Italy and 3Gastrointestinal Unit, Massachusetts General Hospital, Harvard Medical School, Boston, USA.

Offprint requests to: J. Rodrigo Mora, Gastrointestinal Unit, Massachusetts General Hospital, Harvard Medical School, Boston, MA 02114, USA. email: j_rodrigo_mora@hms.harvard.edu


Summary. For an effective adaptive immune response to occur, dendritic cells (DC), which are the most efficient antigen-presenting cells, must be able to sample the peripheral microenvironment and migrate towards secondary lymphoid organs (SLO) where they activate naïve lymphocytes. Upon activation, lymphocytes proliferate and acquire the capacity to migrate to extralymphoid compartments. Although the molecular mechanisms controlling lymphocyte homing to lymphoid and to some extralymphoid tissues have been described in significant detail, it is much less clear how DC migration is controlled. Do DC obey similar adhesion cues that lymphocytes do, or do they have their own “zip codes”? This is relevant from a therapeutic standpoint because effective DC-based vaccines should be able to reach the appropriate tissues in order to generate protective immune responses. Here, we discuss some of the mechanisms used by DC to reach their target tissues. Once DC arrive at their destination, they are exposed to the tissue microenvironment, which likely modulates their functional properties in a tissue-specific fashion. This local DC “education” is probably responsible among other things; for the acquisition of tissue-specific homing imprinting capacity by which DC instruct lymphocytes to migrate to specific tissues. Finally, we discuss how dysregulation of these signals may play a key role in disease. Histol Histopathol 23, 897-910 (2008)

Key words: Dendritic cells, Homing, Gut, Skin

DOI: 10.14670/HH-23.897