Letter | Published:

Targeted recycling of PECAM from endothelial surface-connected compartments during diapedesis


Leukocytes enter sites of inflammation by squeezing through the borders between endothelial cells that line postcapillary venules at that site. This rapid process, called transendothelial migration (TEM) or diapedesis, is completed within 90 s after a leukocyte arrests on the endothelial surface1,2,3,4. In this time, the leukocyte moves in ameboid fashion across the endothelial borders, which remain tightly apposed to it during transit. It is not known how the endothelial cell changes its borders rapidly and reversibly to accommodate the migrating leukocyte. Here we show that there is a membrane network just below the plasmalemma at the cell borders that is connected at intervals to the junctional surface. PECAM-1, an integral membrane protein with an essential role in TEM5,6,7, is found in this compartment and constitutively recycles evenly along endothelial cell borders. During TEM, however, recycling PECAM is targeted to segments of the junction across which monocytes are in the act of migration. In addition, blockade of TEM with antibodies against PECAM specifically blocks the recruitment of this membrane to the zones of leukocyte migration, without affecting the constitutive membrane trafficking.

Access optionsAccess options

Rent or Buy article

Get time limited or full article access on ReadCube.


All prices are NET prices.


  1. 1

    Butcher, E. C. Leukocyte-endothelial cell recognition: three (or more) steps to specificity and diversity. Cell 67, 1033–1036 (1991)

  2. 2

    Springer, T. A. Traffic signals for lymphocyte recirculation and leukocyte emigration: the multistep paradigm. Cell 76, 301–314 (1994)

  3. 3

    Muller, W. A. & Randolph, G. J. Migration of leukocytes across endothelium and beyond: molecules involved in the transmigration and fate of monocytes. J. Leukoc. Biol. 66, 698–704 (1999)

  4. 4

    Muller, W. A. Leukocyte–endothelial cell interactions in the inflammatory response. Lab. Invest. 82, 521–534 (2002)

  5. 5

    Muller, W. A., Weigl, S. A., Deng, X. & Phillips, D. M. PECAM-1 is required for transendothelial migration of leukocytes. J. Exp. Med. 178, 449–460 (1993)

  6. 6

    Berman, M. E., Xie, Y. & Muller, W. A. Roles of platelet/endothelial cell adhesion molecule-1 (PECAM-1, CD31) in natural killer cell transendothelial migration and β2 integrin activation. J. Immunol. 156, 1515–1524 (1996)

  7. 7

    Liao, F., Ali, J., Greene, T. & Muller, W. A. Soluble domain 1 of platelet-endothelial cell adhesion molecule (PECAM) is sufficient to block transendothelial migration in vitro and in vivo. J. Exp. Med. 185, 1349–1357 (1997)

  8. 8

    Schenkel, A. R., Mamdouh, Z., Chen, X., Liebman, R. M. & Muller, W. A. CD99 plays a major role in the migration of monocytes through endothelial junctions. Nature Immunol. 3, 143–150 (2002)

  9. 9

    Yamashiro, D. J. & Maxfield, F. R. Kinetics of endosome acidification in mutant and wild-type chinese hamster ovary cells. J. Cell Biol. 105, 2713–2721 (1987)

  10. 10

    Liao, F., Huynh, H. K., Eiroa, A., Greene, T., Polizzi, E. & Muller, W. A. Migration of monocytes across endothelium and passage through extracellular matrix involve separate molecular domains of PECAM-1. J. Exp. Med. 182, 1337–1343 (1995)

  11. 11

    Feng, D., Nagy, J. A., Hipp, J., Dvorak, H. F. & Dvorak, A. M. Vesiculo-vacuolar organelles and the regulation of venule permeability to macromolecules by vascular permeability factor, histamine, and serotonin. J. Exp. Med. 183, 1981–1986 (1996)

  12. 12

    Vasile, E., Qu, H., Dvorak, H. F. & Dvorak, A. M. Caveolae and vesiculo-vacuolar organelles in bovine capillary endothelial cells cultured with VPF/VEGF on floating Matrigel-collagen gels. J. Histochem. Cytochem. 47, 159–167 (1999)

  13. 13

    Schmidt, A., Hannah, M. J. & Huttner, W. B. Synaptic-like microvesicles of neuroendocrine cells orginate from a novel compartment that is continuous with the plasma membrane and devoid of transferrin receptor. J. Cell Biol. 137, 445–458 (1997)

  14. 14

    Feng, D., Nagy, J. A., Pyne, K., Dvorak, H. F. & Dvorak, A. M. Neutrophils emigrate from venules by a transendothelial cell pathway in response to fMLP. J. Exp. Med. 187, 903–915 (1998)

  15. 15

    Bamforth, S., Lightman, S. & Greenwood, J. Ultrastructural analysis of interleukin-1β-induced leukocyte recruitment to the rat retina. Investig. Ophtalmol. Vis. Sci. 38, 25–35 (1997)

  16. 16

    Hammersen, F. & Hammersen, E. The ultrastructure of endothelial gap formation and leukocyte emigration. Prog. Appl. Microcirc. 12, 1–34 (1987)

  17. 17

    Allport, J. R., Muller, W. A. & Luscinskas, F. W. Monocytes induce reversible focal changes in vascular endothelial cadherin complex during transendothelial migration under flow. J. Cell Biol. 148, 203–216 (2000)

  18. 18

    Shaw, S. K., Bamba, P. S., Perkins, B. N. & Luscinskas, F. W. Real-time imaging of vascular endothelial-cadherin during transmigration across endothelium. J. Immunol. 167, 2323–2330 (2001)

  19. 19

    Muller, W. A., Ratti, C. M., McDonnell, S. L. & Cohn, Z. A. A human endothelial cell-restricted, externally disposed plasmalemmal protein enriched in intercellular junctions. J. Exp. Med. 170, 399–414 (1989)

  20. 20

    Muller, W. A. & Weigl, S. Monocyte-selective transendothelial migration: Dissection of the binding and transmigration phases by an in vitro assay. J. Exp. Med. 176, 819–828 (1992)

  21. 21

    Ali, J., Liao, F., Martens, E. & Muller, W. A. Vascular endothelial cadherin (VE-Cadherin): cloning and role in endothelial cell–cell adhesion. Microcirculation 4, 267–277 (1997)

Download references


We thank R. Liebman for technical assistance; P. Newman for the P1.1 antibody; and P. Brennwald, T. McGraw and T. Ryan for discussions and comments on the manuscript. Supported by NIH grants (to W.A.M. and F.R.M.), a Charles H. Revson Foundation Fellowship (to Z.M.), and an Atorvastatin Research Award from Pfizer/Parke Davis (to L.P.).

Author information

Correspondence to William A. Muller.

Ethics declarations

Competing interests

The authors declare that they have no competing financial interests.

Supplementary information

Supplementary Figure 1S (JPG 82 kb)

Supplementary Figure 2S (JPG 88 kb)

Supplementary Figure 3S (JPG 12 kb)

Supplementary Figure 4S (JPG 42 kb)

Supplementary Figure 5S (PDF 479 kb)

Supplementary Table 1, Materials, Methods, Analysis and Figure Legends (DOC 46 kb)

Rights and permissions

Reprints and Permissions

About this article

Further reading

Figure 1: PECAM-rich membrane is rapidly internalized from the cell border into a subjunctional reticulum.
Figure 2: PECAM-bearing membrane enters a reticulum of surface-connected compartments.
Figure 3: Quantification of PECAM recycling.
Figure 4: Recycling PECAM is involved in transendothelial migration.


By submitting a comment you agree to abide by our Terms and Community Guidelines. If you find something abusive or that does not comply with our terms or guidelines please flag it as inappropriate.