Flow Cytometry Analyses of Meningioma Immune Cell Composition Using a Short, Optimized Digestion Protocol

Area of Science:

• Neuro-oncology
• Immunology
• Cell Biology

Background:

• Meningioma treatment faces challenges like post-surgical complications and cognitive issues.
• Immunological approaches offer potential but require understanding of tumor-infiltrating immune cells.
• Characterizing these cells is crucial for developing targeted, non-surgical therapies with fewer side effects.

Purpose of the Study:

• To optimize a rapid protocol for digesting meningioma tissues into viable single-cell suspensions.
• To identify and characterize the infiltrating immune cell populations within meningioma.

Main Methods:

• A modified commercial kit for skin dissociation was used to process resected meningioma tissues.
• Flow cytometry was employed to analyze the composition of tumor-infiltrating immune cells.

Main Results:

• The optimized protocol yielded viable single-cell suspensions rich in immune cells, primarily CD14+ macrophages and CD3+ T cells.
• Minor populations of CD56+ NK cells and CD19+ B cells were also identified.
• Tumor-associated macrophages frequently expressed TIM-3, indicating an immunosuppressive phenotype, with some co-expressing CD83.

Conclusions:

• A protocol was successfully optimized for generating viable immune cell suspensions from meningioma.
• The study identified infiltrating antigen-presenting cells with immunosuppressive properties and lymphocytes.
• This rapid protocol enables advanced analyses like single-cell RNA sequencing and flow cytometry on live, dissociated cells.