Anti-tubulin antibodies in a sensorimotor neuropathy patient alter tubulin polymerization

The effect of anti-tubulin antibodies present in the serum of a patient with a progressive sensorimotor neuropathy on microtubule assembly was examined. The patient's serum was reactive on immunoblots with a single band of proteins of 55-kDa from homogenates of neural tissues. Tubulin was identified as the quantitatively major component of these 55-kDa proteins. Polymerization of tubulin in vitro was significantly enhanced by the patient's serum. A monoclonal antibody to nerve-specific class III beta-tubulin precisely duplicated the immunoreactive profile of the patient's serum, while an antibody to class (I + II) beta-tubulins also reacted with tubulins in non-neural tissues. The results indicate for the first time that human antisera reactive with nerve specific beta-tubulin can alter tubulin polymerization-depolymerization dynamics.