Final answer:
Molecular mimicry is a potential cause of acquired autoimmunity, where immune responses are directed at self tissues due to structural similarities with pathogen antigens.
Step-by-step explanation:
A potential cause of acquired autoimmunity is molecular mimicry. This phenomenon occurs when antibodies and T-cell receptors (TCRs) bind to self antigens that are structurally similar to antigens from pathogens. For instance, an infection with Streptococcus pyogenes may produce antibodies that mistakenly target heart muscle due to a similarity between the surface structures of the bacterium and the heart tissue, potentially leading to autoimmune conditions like rheumatic fever.