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Secretion of plasminogen activator by human polymorphonuclear leukocytes. Modulation by glucocorticoids and other

A Granelli-Piperno, J D Vassalli, E Reich

    The Journal of Experimental Medicine
    |December 1, 1977
    PubMed

    Insights

    Human neutrophils (PMNs) secrete plasminogen activator, a process regulated by inflammation-affecting agents and distinct from other lytic enzyme release, suggesting a role in cell migration.

    Area of Science:

    • Immunology
    • Cell Biology
    • Biochemistry

    Background:

    • Human polymorphonuclear neutrophils (PMNs) are key immune cells involved in inflammatory responses.
    • The secretion of specific enzymes by PMNs plays a crucial role in their function and interaction with tissues.
    • Plasminogen activator is an enzyme secreted by various cells, involved in fibrinolysis and extracellular matrix remodeling.

    Purpose of the Study:

    • To investigate the regulation of plasminogen activator secretion by human PMNs.
    • To compare the regulatory mechanisms of plasminogen activator production with those of other granule-bound enzymes, such as elastase.
    • To explore the potential role of plasminogen activator secretion in PMN inflammatory responses and cell migration.

    Main Methods:

    • Purification of human PMNs.
    • Stimulation of PMN secretion using Concanavalin A (Con A) and phorbol 12-myristate 13-acetate (PMA) at varying concentrations.
    • Inhibition studies using glucocorticoids, cyclic adenosine monophosphate (cAMP), actinomycin D, and cycloheximide.
    • Assay of plasminogen activator and elastase release.

    Main Results:

    • Plasminogen activator secretion by PMNs is stimulated by Con A and low concentrations of PMA.
    • Glucocorticoids, cAMP, actinomycin D, and cycloheximide inhibit plasminogen activator production.
    • Release of granule-bound elastase requires higher PMA concentrations and is unaffected by the inhibitors that block plasminogen activator production.

    Conclusions:

    • PMN plasminogen activator production is distinctly regulated by agents influencing inflammation, separate from other lytic enzymes like elastase.
    • The specific control mechanisms suggest a unique role for plasminogen activator in the PMN response pattern.
    • Findings support the hypothesis that plasminogen activator secretion correlates with cell migration in vivo, similar to observations in macrophages.

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