What is the function of TH1 cells in Leishmania pathogenesis?

What is the function of TH1 cells in Leishmania pathogenesis?

• A. Migrate to skin and promote antimicrobial defenses of macrophages
• B. Produce antibodies
• C. Recruit eosinophils
• D. Suppress inflammation

Answer: (A)

TH1 cells drive a cell-mediated immune response that is key to controlling Leishmania, which resides inside macrophages. They migrate to the site of infection in the skin and secrete cytokines such as IFN-γ (and TNF-α) that activate macrophages. Once activated, macrophages ramp up antimicrobial mechanisms, including production of nitric oxide via inducible nitric oxide synthase, and generate reactive species that kill intracellular Leishmania. This activation of macrophages is the main way TH1 cells help clear the parasite, making the response protective in cutaneous leishmaniasis.

TH1 cells drive a cell-mediated immune response that is key to controlling Leishmania, which resides inside macrophages. They migrate to the site of infection in the skin and secrete cytokines such as IFN-γ (and TNF-α) that activate macrophages. Once activated, macrophages ramp up antimicrobial mechanisms, including production of nitric oxide via inducible nitric oxide synthase, and generate reactive species that kill intracellular Leishmania. This activation of macrophages is the main way TH1 cells help clear the parasite, making the response protective in cutaneous leishmaniasis.