Longitudinal saliva omics responses to immune perturbation: a case study

Area of Science:

• Longitudinal multi-omics analysis of human saliva.
• Investigating non-invasive diagnostic potential of saliva.
• Profiling salivary extracellular vesicles and their RNA content.

Background:

• Saliva omics holds promise for non-invasive diagnostics, particularly for vulnerable populations.
• Previous studies have explored saliva's diagnostic capabilities, but longitudinal multi-omics data is limited.
• Understanding dynamic changes in saliva composition is crucial for developing effective diagnostic markers.

Observation:

• Hourly and daily saliva sampling (100 timepoints) was performed over three periods, including a 24-hour baseline and post-vaccination monitoring.
• Total saliva transcriptome, proteome, and small RNA (mRNA, miRNA, piRNA, bacterial RNA) from extracellular vesicles were profiled.
• Paired analysis of 24-hour periods removed daily variation, enabling precise detection of vaccination responses.

Findings:

• Over 18,000 omics longitudinal series exhibited statistically significant temporal trends.
• Vaccination activated immune pathways like interferon and cytokine signaling, and MHC antigen presentation.
• Salivary messenger RNA (mRNA) demonstrated higher specificity and timeliness in reflecting vaccination responses compared to other omics modalities.

Implications:

• Saliva omics provides a consistent and sensitive method for non-invasive personalized health monitoring.
• This approach can be utilized for real-time diagnostics of immune system activation and response.
• The findings support the development of saliva-based diagnostics for various clinical applications, including vaccine efficacy assessment.