MNPmApp: An image analysis tool to quantify mononuclear phagocyte distribution in mucosal tissues

Area of Science:

• Immunology
• Cell Biology
• Computational Biology

Background:

• Mononuclear phagocytes (MNPs), including dendritic cells and macrophages, are crucial for mucosal immunity.
• Their strategic positioning at the epithelial interface influences immune responses to pathogens.
• Understanding MNP distribution and spatial relationships is key to inferring cellular interactions in health and disease.

Purpose of the Study:

• To develop and validate a MATLAB-based platform, MNP mapping application (MNPmApp), for high-throughput analysis of MNP density and distribution in gastrointestinal mucosa.
• To assess the spatial distribution patterns of MNPs using Monte Carlo modeling.
• To investigate the impact of H. pylori infection on MNP distribution in the gastric mucosa.

Main Methods:

• Development of a MATLAB-based tissue cytometry platform (MNPmApp) for analyzing digital multicolor fluorescence microscopy images.
• High-throughput quantification of MNP density and distribution in human gastric mucosa.
• Integration of Monte Carlo modeling to assess the randomness of MNP distribution and spatial relationships.

Main Results:

• MNPmApp demonstrated high specificity (98%) and sensitivity (76-85%) for identifying HLA-DR+ and CD11c+ MNPs.
• Monte Carlo modeling indicated significantly non-random MNP-MNP spacing, while MNP-epithelial distances were random.
• H. pylori infection did not significantly alter MNP numbers or distribution in the gastric lamina propria.

Conclusions:

• MNPmApp is a reliable and user-friendly tool for unbiased quantitation of MNPs and their distribution in mucosal tissues.
• MNP distribution within the gastric mucosa is non-random, suggesting specific cellular interactions.
• H. pylori infection does not appear to disrupt the fundamental distribution of key MNPs in the gastric lamina propria.