Immune stimuli shape the small non-coding transcriptome of extracellular vesicles released by dendritic cells

Area of Science:

• Cell Biology
• Molecular Biology
• Immunology

Background:

• Extracellular vesicles (EVs) are key mediators of intercellular communication.
• EV molecular cargo, including RNA, reflects cellular states and holds biomarker potential.
• EV-associated RNA research has primarily focused on microRNAs, neglecting other small non-coding RNAs.

Purpose of the Study:

• To investigate how immune stimuli affect the release of various small non-coding RNAs via EVs from dendritic cells.
• To determine if changes in cellular RNA are mirrored in EV-associated RNA.
• To explore the broader spectrum of EV-RNAs beyond microRNAs for potential gene-regulatory functions.

Main Methods:

• Primary dendritic cells were subjected to immune-activating or -suppressing stimuli.
• Highly pure EV populations were isolated, ensuring absence of ribonucleoprotein particles.
• Small RNA transcriptomes of EVs were analyzed using RNA sequencing and RT-qPCR.

Main Results:

• Immune stimuli induced specific changes in EV-associated miRNA, snoRNA, and Y-RNA content.
• Transfer RNA (tRNA) and small nuclear RNA (snRNA) levels in EVs were less affected by immune stimuli.
• Changes in EV-RNA content did not always correlate with changes in cellular RNA, questioning the 'snapshot' model.

Conclusions:

• EVs convey genetic messages through multiple classes of small non-coding RNAs, not just microRNAs.
• Cell stimulation influences the association of various RNA classes with EVs.
• These findings pave the way for understanding the functional and biomarker potential of diverse EV-RNAs.