A 24-Year-Old Nurse Comes to the Office for His Annual

A 24-year-old nurse comes to the office for his annual wellness visit that includes tuberculosis screening.  The patient has no chronic medical conditions and does not have recent fever, cough, or other health changes.  He receives an intradermal injection of tuberculin on the inner surface of his forearm.  Two days later, he has a distinct area of induration 20 mm across at the injection site.  Which of the following interactions is essential to the development of this patient's skin reaction?

A) CD14 on epidermal macrophages with bacterial lipopolysaccharide
B) CD16 on natural killer cells with IgG bound to infected cells
C) CD18 on neutrophils with ICAM-1 on endothelial cells
D) CD28 on T lymphocytes with CD80 on epidermal dendritic cells
E) CTLA4 on T lymphocytes with CD80 on epidermal dendritic cells