A 27-year-old woman presents to the clinic because she is concerned about a red rash over her cheeks. The rash is more intense on sun exposure, and a recent trial of a mild topical steroid did not make any difference. She also reports new symptoms of joint discomfort in her hands and knees that seem to be worse in the morning. Her past medical history is negative and she is not taking any medications. On physical examination, the vital signs are normal, there are some oral ulcers on the buccal mucosa, a small patch of hair loss, and a raised nontender rash over her cheeks. Laboratory investigations are significant for a positive ANA, low complements, and 3+ proteinuria. Which of the following is the most likely mechanism for the renal damage in this condition?