A 28-year-old male presents to the emergency department with acute onset weakness and tingling in both legs progressing to the arms over 2 days. He reports a viral illness 3 weeks prior. On examination, he has flaccid paralysis of lower limbs with absent deep tendon reflexes. Nerve conduction studies show prolonged distal latencies and conduction block. CSF analysis reveals elevated protein with normal cell count. Which of the following best explains the pathophysiology of the conduction block observed in this patient's peripheral nerves?