G-CSF enhances the adhesion of encephalitogenic T cells to extracellular matrix components: a possible mechanism for exacerbation of multiple sclerosis.

Autologous stem cell transplantation is being considered as treatment of severe refractory autoimmune disorders, including MS. Stem cell mobilization is achieved with granulocyte-colony stimulating factor (G-CSF), however, G-CSF administration resulted in cases of worsened clinical MS status. We studied autoreactive T-cell properties, which can promote CNS inflammation in MS. We show that G-CSF enhances MS autoreactive T cell line adhesion to the ECM proteins collagen IV and fibronectin as effectively as the proinflammatory IFNgamma and TNFalpha, known to exacerbate MS symptoms. We propose a link between clinical worsening of MS symptoms induced by G-CSF and the hyperstimulation of T cell adhesion to ECM elicited by G-CSF.