Surrounding the axon is a myelin sheath, which is actually just insulation.

轴突周围是髓鞘，实际上只是绝缘层。

Once activated, the B-cells make antibodies that mark the auto antigens and the macrophages use those antibody markers to bind to and strip the myelin sheath off of the peripheral neurons.

一旦被激活，B细胞产生识别抗体与自身抗原结合，而巨噬细胞识别、结合抗原抗体复合物，清除周围神经元上的髓鞘。

To be clear, these bacteria and viruses don't directly damage the myelin sheath, instead it's thought that they have antigens on their surface that looks similar to the lipid in the myelin sheath.

需要说明的是，这些细菌或病毒并不直接损伤髓鞘，相反，它们的表面抗原类似于髓鞘的脂质。

As a result, immune cells mistakenly attack and destroy the myelin sheath and this is called molecular mimicry, because from the perspective of the immune cells a host substance is mimicking a foreign protein.

因此，免疫细胞会错误地攻击、损伤髓鞘；由于自身物质和细胞外来蛋白具有相似抗原表位而导致免疫细胞攻击自身，被称为分子模拟。