A highly efficacious lymphocyte chemoattractant, stromal cell-derived factor 1 (SDF-1)

Area of Science:

• Immunology
• Cell Biology
• Molecular Biology

Background:

• Chemotactic factors, specifically chemokines, are known to attract lymphocytes to inflammatory sites.
• Existing chemokines demonstrate limited efficacy in attracting maximal percentages of lymphocytes.
• A need exists for more potent lymphocyte chemoattractants for research and therapeutic applications.

Purpose of the Study:

• To identify and characterize novel, highly efficacious lymphocyte chemotactic activities.
• To investigate the potential role of identified factors in immune surveillance and cell extravasation.

Main Methods:

• Analysis of supernatants from murine bone marrow stroma cell line MS-5 for chemotactic activity.
• Purification of the active chemotactic factor using biochemical techniques.
• In vitro and in vivo assays to assess lymphocyte and monocyte attraction by the purified factor.
• Assessment of intracellular actin polymerization in lymphocytes upon exposure to the factor.

Main Results:

• A highly efficacious lymphocyte chemotactic activity was identified in MS-5 cell supernatants, attracting 10-fold more lymphocytes than known chemoattractants.
• Purification identified this activity as stromal cell-derived factor 1 (SDF-1).
• SDF-1 demonstrated potent chemoattraction for lymphocytes and monocytes in vitro and in vivo, but not neutrophils.
• SDF-1 induced intracellular actin polymerization in lymphocytes, suggesting a mechanism for motility.

Conclusions:

• Stromal cell-derived factor 1 (SDF-1) is a highly efficacious and potent chemoattractant for lymphocytes and monocytes.
• SDF-1's ability to induce actin polymerization supports its role in cell motility.
• Constitutive expression of SDF-1 suggests a role in immune surveillance and basal extravasation, rather than solely in inflammation.