A 23-Year-Old Woman Was Given an Intradermal Injection of Purified

Multiple Choice

A 23-year-old woman was given an intradermal injection of purified protein derivative of tubercle bacilli (PPD) as part of the yearly testing for tuberculosis. A positive reaction was elicited. Which cells secrete the cytokines needed for the formation of granulomas at the site of injection?

A) Keratinocytes
B) Melanocytes
C) B lymphocytes
D) T_H1 cells
E) T_H2 cells