The effect of rhG-CSF on the conformation of LFA-1 on CD4+ T cells in hemopoietic stem cell transplantation

Abstract

Recombinant human granulocyte colony-stimulating factor (rhG-CSF) modulates donor T cell function in hemopoietic stem cell transplantation. The effects of rhG-CSF on the activation of CD4+ T cells have been poorly investigated. We investigated whether rhG-CSF mobilization influenced the activation and proliferation capacity of CD4+ T cells. Cell treatment with phorbol 12-myristate 13-acetate (PMA) plus ionomycin or the CD3 mAb OKT3 plus intercellular cell adhesion molecule-1 (ICAM-1) at 37°C for 6 h induced a dramatic increase in CD25, CD69 and MEM148 epitope exposure. rhG-CSF mobilization decreased CD25, CD69 and MEM148 epitope expression on activated CD4+ T cells compared with cells before mobilization. The transcription factor Jun activation domain-binding protein 1 (JAB1) plays a role in the activation of CD4+ T cells, and the rhG-CSF mobilization changed the level of nuclear JAB1 protein. rhG-CSF mobilization also decreased the adhesion of CD4+ T cells to ICAM-1, but had no effect on the levels of donor CD4+CD25+ regulatory T cells. Overall, these data suggest the rhG-CSF mobilization can influence CD4+ T cell activation through LFA-1/ICAM-1 costimulatory signaling in HSC transplantation.