A DUAL LAMININ COLLAGEN RECEPTOR ACTS IN PERIPHERAL-NERVE REGENERATION

A regeneration chamber was created in vivo by suturing a synthetic tube sealed at its distal end onto the proximal stump of a severed rat sciatic nerve. Nerves regenerated into tubes coated with laminin at a rate of 0.33 mm/day after a lag of about 2 days. At 25 days, regenerating nerves had extended 23% farther into laminin-coated tubes as compared with uncoated ones. Monoclonal antibody 3A3, which functionally interferes with a dual laminin/collagen receptor, inhibited nerve regeneration into laminin-coated tubes by 32%. In contrast, monoclonal antibody JG22, which inhibits chicken matrix receptors, had no significant effect on regeneration. Immunohistochemical studies of teased adult rat sciatic nerves indicate that 3A3 bound to Schwann cells and possibly to axons. In other studies, the heterodimeric, laminin/collagen receptor recognized by 3A3 has been shown to be a member of the integrin superfamily of adhesive receptors. These data provide evidence that an integrin receptor functions in nerve regeneration in vivo.