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Models and Methods to Evaluate Transport of Drug Delivery Systems Across Cellular Barriers
Published on: October 17, 2013
Settings and mechanisms for trans-cellular diapedesis.
Peter T Sage1, Christopher V Carman
1Beth Israel Deaconess Medical Center, Department of Medicine, Harvard Medical School, Boston, MA 02215, USA.
Frontiers in Bioscience (Landmark Edition)
|June 2, 2009
Summary
Leukocyte diapedesis, or cell crossing of endothelial barriers, occurs via paracellular and transcellular routes. Recent in vitro data support the transcellular pathway, prompting a reevaluation of its in vivo significance.
Area of Science:
- Immunology
- Cell Biology
- Vascular Biology
Background:
- Immune cell function relies on leukocyte trafficking and diapedesis across endothelial barriers.
- Two migratory pathways, paracellular and transcellular, have been proposed for diapedesis.
- The transcellular pathway lacked in vitro validation, hindering its acceptance.
Purpose of the Study:
- To reevaluate the physiological roles and mechanisms of the transcellular diapedesis pathway.
- To integrate emerging in vitro findings with existing in vivo observations.
- To provide a comprehensive framework for understanding transcellular diapedesis.
Main Methods:
- Review and synthesis of existing in vivo literature on leukocyte diapedesis.
- Integration of recent in vitro studies demonstrating transcellular migration.
- Comparative analysis of paracellular versus transcellular pathways in various physiological and inflammatory settings.
Main Results:
- In vitro studies now provide unambiguous evidence for transcellular diapedesis.
- A substantial body of in vivo evidence supports significant utilization of the transcellular pathway.
- The transcellular route is observed in both constitutive trafficking (bone marrow, lymphoid organs) and inflammatory extravasation.
Conclusions:
- The transcellular route of leukocyte diapedesis is a physiologically relevant pathway.
- Renewed interest in transcellular diapedesis is supported by both in vitro and in vivo data.
- Understanding the transcellular pathway is crucial for comprehending immune cell trafficking and inflammatory responses.
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