Interleukin-27 directly induces differentiation in hematopoietic stem cells

Area of Science:

• Immunology
• Hematopoiesis
• Cytokine signaling

Background:

• Interleukin-27 (IL-27) is an IL-6 family cytokine involved in immune responses.
• IL-27 acts on T cells, B cells, and macrophages via gp130 and WSX-1 receptors.
• The role of IL-27 in hematopoietic stem cells (HSCs) was previously unknown.

Purpose of the Study:

• To investigate the effect of IL-27 on hematopoietic stem cells (HSCs).
• To determine if IL-27 influences HSC differentiation and hematopoiesis in vitro and in vivo.

Main Methods:

• Cultured mouse CD34(-)KSL cells (enriched HSCs) with IL-27 and stem cell factor (SCF).
• Generated transgenic mice expressing IL-27 to study in vivo effects.
• Analyzed human CD34(+) cells for IL-27 responsiveness.

Main Results:

• IL-27, with SCF, directly supported early HSC differentiation and progenitor expansion in vitro.
• IL-27 maintained some long-term HSC repopulating activity.
• In vivo, IL-27 induced enhanced myelopoiesis, impaired B lymphopoiesis, and extramedullary hematopoiesis.
• IL-27 demonstrated similar effects on human CD34(+) cells.

Conclusions:

• IL-27 directly regulates hematopoietic stem cells (HSCs).
• IL-27 influences both myeloid and lymphoid hematopoietic lineages.
• IL-27 is identified as a key cytokine in HSC regulation.