Identification of two macrophage populations by flow cytometry monitoring of oxidative burst and phagocytic functions

Area of Science:

• Immunology
• Cell Biology
• Biochemistry

Background:

• Trehalose dimycolate elicits distinct phagocytic cell populations in mouse peritoneal exudates.
• Flow cytometry is a powerful tool for analyzing cellular heterogeneity.
• Fluorescent probes enable the discrimination and characterization of specific cell types.

Purpose of the Study:

• To differentiate phagocytic and non-phagocytic cells from trehalose dimycolate-elicited mouse peritoneal cells.
• To identify and characterize activated phagocytic cell populations within this context.
• To establish a flow cytometry-based method for analyzing these cellular populations.

Main Methods:

• Utilizing flow cytofluorometry with two fluorescent probes excited at 488 nm.
• Employing liposomes with a diethylenetriaminepentaacetate daunorubicin conjugate (emission max: 590 nm) for phagocyte/non-phagocyte discrimination.
• Assessing cell-associated fluorescence of the dichlorofluorescein diacetate oxidation product (emission max: 520 nm) to detect activated phagocytes.

Main Results:

• Two distinct phagocytic cell populations were identified in mouse peritoneal cells.
• Liposomes effectively distinguished phagocytic from non-phagocytic cells.
• A subpopulation of activated phagocytes was revealed by dichlorofluorescein diacetate fluorescence.

Conclusions:

• Flow cytometry with specific fluorescent probes can successfully differentiate phagocytic cell populations.
• The method allows for the identification of activated phagocytes within elicited peritoneal cell populations.
• This approach provides insights into cellular responses to trehalose dimycolate.