PK1/EG-VEGF induces monocyte differentiation and activation

Area of Science:

• Immunology
• Cell Biology
• Endocrinology

Background:

• Macrophages are key sentinels in innate immunity.
• They express proinflammatory cytokines and antigen-presenting molecules.
• Prokineticin-1 (PK1) is also known as endocrine gland-derived vascular endothelial growth factor.

Purpose of the Study:

• To identify novel functions of PK1.
• To investigate PK1's role in macrophage biology.
• To determine PK1's effect on monocyte differentiation and function.

Main Methods:

• Screening of murine tissue sections and cells for PK1 binding sites.
• Induction of differentiation in murine and human bone marrow cells using PK1.
• Analysis of human peripheral blood monocyte responses to PK1, including morphological changes and gene expression.
• Assessment of cytokine production (IL-12, TNF-alpha, IL-10) by PK1-treated monocytes stimulated with lipopolysaccharide.

Main Results:

• Macrophages were identified as an in vivo cellular target for PK1.
• PK1 induced differentiation of bone marrow cells into the monocyte/macrophage lineage.
• PK1 altered monocyte surface marker expression (down-regulating B7-1, CD14, CCR5, CXCR4).
• PK1-treated monocytes showed enhanced IL-12 and TNF-alpha production and reduced IL-10 production upon LPS stimulation.
• PK1 generated a distinct monocyte-derived population primed for pro-inflammatory cytokine release.

Conclusions:

• PK1 plays a novel role in regulating macrophage differentiation and function.
• PK1 promotes a pro-inflammatory monocyte phenotype.
• PK1-induced monocytes favor a T helper cell type 1 immune response.