Neutropenia is a principal complication of cancer treatment. We investigated the supportive effect of adipose tissue-derived mesenchymal stem cells (AD-MSCs) on the viability and function of neutrophils. Neutrophils were derived from HL-60 cells by dimethylformamide stimulation and cultured with or without AD-MSCs under serum-starved conditions to evaluate neutrophil survival, proliferation, and function. Serum starvation resulted in the apoptosis of neutrophils and decreased cell survival. The co-culture of neutrophils and AD-MSCs resulted in cell survival and inhibited neutrophil apoptosis under serum-starved conditions. The survival rate of neutrophils was prolonged up to 72 h, and the expression levels of interferon (IFN)-alpha, granulocyte colony-stimulating factor (G-CSF), granulocyte-macrophage colony-stimulating factor, and transforming growth factor (TGF)-beta in AD-MSCs were increased after co-culture with neutrophils. AD-MSCs promoted the viability of neutrophils by inhibiting apoptosis as well as enhancing respiratory burst, which could potentially be mediated by the increased expression of IFN-alpha, G-CSF, and TGF-beta. Thus, we conclude that the use of AD-MSCs may be a promising cell-based therapy for increasing immunity by accelerating neutrophil function. (C) 2012 Elsevier Inc. All rights reserved.