Reduced phagocytic activity of polymorphonuclear leukocytes in alpha(1,3) fucosyltransferase VII-deficient mice

Deficiencies in adhesion molecules or their counter-receptors in humans may have severe consequences as exemplified by leukocyte adhesion deficiency ( LAD) I or II syndromes. Because such diseases occur with great rarity, anim al models are valuable for studying the role of particular adhesion molecul es and their natural ligands in immunity. We studied selected immune parame ters and general health in mice with a defect in the sialyl-Lewis X antigen (selectin ligand) caused by disruption of the gene encoding alpha(1,3)fuco syltransferase VII (Fuc-TVII). Leukocytes from Fuc-TVII -/- and control mic e were tested for adherence to cellophane membranes or polymer particles in vivo and phagocytic activity in vitro. While no difference in adherence wa s found, the number of neutrophil granulocytes in exudate induced by intrap eritoneal injection of polymer beads was reduced in knock-out mice. Moreove r, the phagocytic activity in Fuc-TVII -/- mice was significantly reduced. These animals have splenomegaly due to increased hematopoiesis and reduced weight but do not exhibit clinical signs of immunodeficiency. In conclusion , the lack of Fuc-TVII activity leads to several morphological and function al abnormalities without an impact on survival rate.