Cytokine-induced leukocyte rolling in mouse cremaster muscle arterioles in P-selectin dependent.

Leukocyte rolling and adhesion are generally observed in venules but rarely observed in arterioles. With the use of intravital microscopy, we found that a 4-h treatment with interleukin-1beta (IL-1beta) and tumor necrosis factor-alpha (TNF-alpha) dose dependently induced leukocyte rolling and adhesion in arterioles of the mouse cremaster muscle. The rolling response lasted more than 24 h and was completely inhibited by treatment with the sulfated polysaccharide fucoidin. Moreover, we found that costimulation with IL-1beta and TNF-alpha for 4 h synergistically increased arteriolar leukocyte rolling, i.e., threshold doses of IL-1beta and TNF-alpha together caused a more than 10-fold increase of rolling in arterioles compared with the sum of the individual responses. This rolling interaction was abolished by treatment with a monoclonal antibody directed against P-selectin (RB40.34), but it apparently was unaffected by a monoclonal antibody against L-selectin (MEL-14). Taken together, our functional data show that IL-1beta and TNF-alpha separately induce and synergistically increase P-selectin-dependent leukocyte rolling and firm adhesion in mouse cremaster arterioles.