Enhancement of polymorphonuclear leukocyte (PMN) function by OK-432

Area of Science:

• Immunology
• Microbiology

Background:

• Polymorphonuclear leukocytes (PMN) are crucial immune cells.
• OK-432 is a streptococcal preparation with immunomodulatory potential.

Purpose of the Study:

• To investigate the effects of OK-432 on human PMN function.
• To determine if OK-432 influences cytokine production by leukocytes.

Main Methods:

• Human PMN and peripheral blood mononuclear cells (PBMC) were cultured with OK-432.
• Assays included reactive oxygen species generation, chemiluminescence, nitroblue tetrazolium reduction, myeloperoxidase activity, and cytokine quantification (IL-1β, IL-6, TNF-α, GM-CSF, IFN-γ).
• Cellular activities like candidacidal activity and antibody-dependent cell-mediated cytotoxicity were assessed.

Main Results:

• OK-432 enhanced O2- generation and chemiluminescence in PMN stimulated with phorbol myristate acetate (PMA) or formyl-metionyl-leucil-phenylalanine (FMLP).
• PMN O2- generation was also promoted by PBMC supernatants from OK-432-treated cells.
• OK-432 significantly increased the production of IL-1β, IL-6, TNF-α, GM-CSF, and IFN-γ by leukocytes in a dose-dependent manner.
• Enhanced candidacidal activity and antibody-dependent cell-mediated cytotoxicity were observed.

Conclusions:

• OK-432 directly enhances PMN function, including reactive oxygen species generation and cytotoxic activities.
• OK-432 promotes the production of key cytokines and growth factors by leukocytes.
• These immunomodulatory effects suggest potential therapeutic benefits of OK-432 for immunosuppressed patients.