Single-Cell Transcriptomics of Human Saliva Immune Cells

This study investigated human saliva of 3 healthy subjects aiming to investigate oral neutrophil heterogeneity. Neutrophils are the most abundant white blood cells in the human body responsible for fighting viral, bacterial, and fungi infections. Because saliva is a fluid accessible through non-invasive techniques, it is an optimal source of cells and molecule surveillance in health and disease. While neutrophils are abundant in saliva, scientific advancements in neutrophil biology have been hampered likely due to their short life span, inability to divide once terminally differentiated, sensitivity to physical stress, and low RNA content. Here, we devise a protocol aiming to understand neutrophil heterogeneity by improving isolation methods, single-cell RNA 38 extraction, sequencing, and bioinformatics pipelines.