How do corticosteroids affect the immune system?

Corticosteroids primarily suppress the immune response through several mechanisms, making this the correct choice. These drugs inhibit various components of the immune system, which leads to a reduction in inflammation and an overall dampening of immune activity. Specifically, corticosteroids decrease the production of inflammatory cytokines, inhibit the function of T cells and B cells, and suppress the activity of phagocytes. This immunosuppressive effect is beneficial in treating autoimmune diseases, allergies, and other conditions where an overactive immune response poses a problem.

The other options do not accurately reflect the effects of corticosteroids on the immune system. For example, stimulating lymphocyte production would enhance immune activity, which is contrary to what corticosteroids do. Similarly, enhancing cytokine production would increase inflammation and immune response, which is not aligned with the immunosuppressive effects of corticosteroids. Lastly, while corticosteroids may influence macrophage function, they do not activate macrophages; instead, they usually lead to a reduction in their pro-inflammatory activity. Thus, the correct understanding of corticosteroids' role in modulating the immune response is crucial for applying this knowledge in clinical scenarios.