A 58-year-old Indian man with a 6-month history of recurrent oral erosions and painful blisters on the trunk and flexural areas is referred to dermatology. He reports that the lesions started in his mouth and gradually spread to the skin. Oral examination reveals extensive erosions on the buccal mucosa and soft palate. Skin biopsy from an active blister shows acantholysis with suprabasal clefting. Serum testing reveals high-titre circulating IgG antibodies against desmoglein 3. Which of the following statements about the pathogenesis of this condition is correct?