Absence of IL-4 would most likely reduce the production or presence of which cell type?

Absence of IL-4 would most likely reduce the production or presence of which cell type?

• A. Neutrophils
• B. Erythrocytes
• C. Platelets
• D. Eosinophils

Answer: (D)

IL-4 drives Th2-type responses and supports pathways that lead to eosinophil involvement in allergic inflammation. When IL-4 is absent, the Th2 milieu weakens, reducing signals that recruit and activate eosinophils, so their presence declines. Neutrophils rely more on other signals like IL-8, while red blood cells and platelets are controlled by other factors (erythropoietin and thrombopoietin), not IL-4. Thus, eosinophils are the cell type most affected by the absence of IL-4.

IL-4 drives Th2-type responses and supports pathways that lead to eosinophil involvement in allergic inflammation. When IL-4 is absent, the Th2 milieu weakens, reducing signals that recruit and activate eosinophils, so their presence declines. Neutrophils rely more on other signals like IL-8, while red blood cells and platelets are controlled by other factors (erythropoietin and thrombopoietin), not IL-4. Thus, eosinophils are the cell type most affected by the absence of IL-4.