Strain specific variation in IFN-gamma inducible lymphocyte adhesion to rat brain endothelial cells

We have examined the interferon-gamma (LFN-gamma) induced increase in lymph ocyte adhesion to rat brain endothelial cells (BEC) in the experimental all ergic encephalomyelitis (EAE) susceptible LEW and resistant PVG strain. A s ignificant increase in adhesion of mitogen activated lymphocytes could be d emonstrated by stimulating LEW BEC with 50 U/ml IFN-gamma for 24 h. In cont rast the same treatment failed to induce a significant increase in lymphocy te adhesion in the PVG strain. Flow cytometric analysis of lymphocyte integ rin expression indicated a marked increase in the number of cells expressin g both LFA-1 and VLA-4 following mitogen activation and was similar between the LEW and PVG strain. Depletion of LFA-1 and VLA-4 positive lymphocytes resulted in an equivalent inhibition, of adhesion to BBB-EnC indicating tha t the adherent population was comprised predominantly of the VLA-4 +/LFA-1 + phenotype, We conclude that this strain variation in the IFN-gamma activa tion of BEC may be related to the disease phenotypes of these strains. (C) 1998 Elsevier Science B.V. All rights reserved.