Chemiluminescence by polymorphonuclear leukocytes adhering to surfaces

Area of Science:

• Immunology
• Cell Biology
• Biochemistry

Background:

• Granulocyte stimulation initiates an oxidative metabolic response, measurable via Nitro Blue Tetrazolium reduction or chemiluminescence.
• Variations in chemiluminescence were noted in human granulocytes suspended without protein.

Purpose of the Study:

• To investigate the role of protein in human polymorphonuclear leukocyte suspensions.
• To understand the mechanism behind surface attachment-stimulated chemiluminescence.

Main Methods:

• Human polymorphonuclear leukocytes were suspended in Hanks balanced salt solution with and without protein (gelatin, serum, albumin, fetal calf serum).
• Cell counts and chemiluminescence were measured over time.
• Inhibition studies were performed using superoxide dismutase and sodium azide.

Main Results:

• Leukocytes decreased in number and adhered to surfaces in protein-free suspensions.
• Protein-containing suspensions maintained stable cell numbers.
• Protein-free suspensions exhibited surface attachment-stimulated chemiluminescence, inhibited by superoxide dismutase and sodium azide.
• This response was absent in granulocytes from chronic granulomatous disease patients.

Conclusions:

• Surface adherence of polymorphonuclear leukocytes induces superoxide- and myeloperoxidase-dependent oxidative metabolic reactions.
• Proteins like gelatin are essential in suspending media for accurate assessment of leukocyte metabolic responses to stimuli.