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Updated: Aug 11, 2026
Murine Model of CD40-activation of B cells
Published on: March 6, 2010
Association of murine CD31 with transmigrating lymphocytes following antigenic stimulation
S A Bogen1, H S Baldwin, S C Watkins
1Department of Pathology, Brigham and Women's Hospital, Boston, Massachusetts.
Insights
The study found that the CD31 molecule is highly expressed on lymphocytes moving across blood vessel walls. This suggests CD31 plays a key role in lymphocyte recruitment during immune responses.
Area of Science:
- Immunology
- Cell Biology
Background:
- CD31 is a molecule found on blood cells and vessel linings, belonging to the immunoglobulin superfamily.
- Its precise function remains largely unknown, though structural similarities suggest a role in cell adhesion.
Purpose of the Study:
- To characterize the cellular distribution and function of a murine CD31 homolog.
- To investigate the potential role of CD31 in lymphocyte trafficking.
Main Methods:
- Utilized immunoperoxidase and immunoelectron microscopy to analyze monoclonal antibody reactivity.
- Examined tissue from murine lymph nodes during an immune response.
Main Results:
- The murine CD31 homolog was found in high abundance on lymphocytes actively transmigrating through vascular endothelium.
- Immunoelectron microscopy revealed CD31 localization to lymphocyte-endothelial cell contact sites.
- Expression was particularly notable in lymph nodes during peak immune responses.
Conclusions:
- CD31 expression is concentrated on lymphocytes during transmigration across blood vessels.
- These findings indicate a novel role for CD31 in mediating lymphocyte recruitment and vascular diapedesis.
Abstract:
Human CD31 is a recently characterized molecule present on leukocytes, platelets, and endothelium. Its function is not known. Because it is a member of the immunoglobulin superfamily and structurally homologous to carcinoembryonic antigen, a putative intercellular adhesion molecule, it is believed that CD31 may function also as an adhesion molecule. In this report, we characterize the cellular reactivity of a monoclonal antibody to a murine protein that is homologous to CD31. To delineate the cellular reactivity of the murine CD31 homologue recognized by our monoclonal antibody, we used immunoperoxidase and immunoelectron microscopic techniques. The most striking finding was that the putative murine homolog of CD31 is expressed in particularly high amounts on endothelium-adherent lymphocytes transmigrating across sinusoidal or venular vascular boundaries. Such a distribution was apparent in draining murine lymph nodes during the peak of an immune response after immunization with a protein antigen in adjuvant, a situation in which there are many transmigrating lymphocytes. Immunoelectron microscopic analysis also shows that CD31 is predominantly distributed on portions of transmigrating lymphocytes that are in contact with or adjacent to areas of contact with endothelial cells. These findings suggest a previously undescribed role for CD31 in lymphocyte recruitment and transmigration.
