# Recombinant G-CSF-ApoAI Fusion Protein Is a Pleiotropic Factor

## TL;DR

A new fusion protein combining G-CSF and ApoAI shows enhanced immune and cell viability benefits, potentially useful for treating infected wounds.

## Contribution

A novel recombinant G-CSF-ApoAI fusion protein with pleiotropic effects was developed and characterized.

## Key findings

- The fusion protein retains G-CSF's granulocyte activity and enhances neutrophil differentiation and progenitor cell viability.
- It increases monocyte counts and reduces apoptosis by lowering caspase 3/7 expression.
- The protein accelerates inflammation phase transitions and boosts phagocytosis by 1.4-fold in an LPS model.

## Abstract

In this study, we report the development of a recombinant human G-CSF fused with apolipoprotein A-I. The chimeric protein was expressed in Pichia pastoris. Using human bone marrow cells, the fusion protein was shown to retain the granulocyte activity of authentic G-CSF, more effectively inducing the differentiation and maturation of segmented neutrophils and maintaining the viability of progenitor cells. Using human mononuclear cells and THP cells, the resulting protein demonstrated monocytic activity, manifested by an increase in both total and CD14+ cell counts. By maintaining cell viability, the chimeric protein reduced the number of cells expressing caspase 3/7. G-CSF-ApoAI demonstrated accelerated cytokine regulation, promoting a more rapid transition of inflammation phases, accompanied by increased phagocytosis of latex particles, compared with G-CSF, increasing phagocytosis by 1.4-fold in the LPS-induced inflammation model. This suggests that this new pleotropic factor may be useful for pathogen clearance in infected wounds.