What occurs during an autoimmune reaction?

During an autoimmune reaction, the immune system begins to mistakenly recognize the body's own tissues as foreign, leading it to attack and damage those tissues. This misdirected immune response results in inflammation and destruction of the cells, which can manifest in various autoimmune diseases such as rheumatoid arthritis, lupus, and multiple sclerosis.

In contrast, the other options describe processes that do not accurately represent an autoimmune reaction. Tolerating one’s own tissues is a normal immune function that prevents such reactions. Enhancing healthy cells does not pertain to an autoimmune response, as the focus is on rejection rather than support. Finally, developing antibodies against non-harmful substances relates to allergies or intolerances rather than an autoimmune reaction, which specifically involves the body turning against its own components.