Cell type specific gene expression profiling reveals a role for complement component C3 in neutrophil responses to...

Area of Science:

• Immunology
• Developmental Biology
• Genetics

Background:

• Tissue damage triggers leukocyte recruitment and transcriptional changes vital for wound healing.
• Cell-type specific transcriptional alterations impacting leukocyte function and tissue repair remain poorly understood.

Purpose of the Study:

• To identify cell-type specific transcriptional changes in neutrophils, macrophages, and epithelial cells during wound healing using translating ribosome affinity purification and RNA sequencing (TRAP-seq).
• To investigate the role of the identified complement pathway component, c3a.1, in neutrophil function and zebrafish response to injury and infection.

Main Methods:

• Utilized translating ribosome affinity purification and RNA sequencing (TRAP-seq) in larval zebrafish to profile gene expression in specific cell types post-wounding.
• Generated c3a.1 knockout (c3a.1^-/-) zebrafish larvae to assess the functional impact of this gene on immune responses.

Main Results:

• TRAP-seq identified significant upregulation of the complement pathway, specifically c3a.1, in neutrophils after wounding.
• c3a.1^-/- zebrafish exhibited delayed neutrophil migration to wounds and impaired recruitment to bacterial infections.
• c3a.1 deficiency led to reduced survival rates during bacterial infections, indicating a neutrophil-mediated effect.

Conclusions:

• TRAP-seq is a powerful method for dissecting cell-type specific gene expression changes influencing immune cell behavior.
• The complement component c3a.1 plays a critical role in neutrophil-mediated innate immunity, wound healing, and host defense against infection in zebrafish.