Final answer:
Antibodies are unable to enter the intracellular space of cells, making intracellular parasites inaccessible to antibodies. Fc receptor-mediated internalization of antibodies occurs, but the antibodies remain confined within endocytic vesicles and are unable to attack intracellular parasites.
Step-by-step explanation:
Antibodies are unable to enter the intracellular space of cells, making intracellular parasites inaccessible to antibodies. However, there is a process called Fc receptor-mediated internalization of antibodies, in which antibodies are bound by Fc receptors on the surface of cells and taken up into endocytic vesicles. Unfortunately, these antibodies remain confined within the vesicles and are unable to attack intracellular parasites.