Which secreted molecules play a vital role in granuloma formation?

Granuloma formation is a complex immunological response typically associated with chronic inflammation and is often seen in conditions such as tuberculosis and sarcoidosis. The correct answer highlights important secreted molecules that play critical roles in this process.

Several key factors contribute to the formation of granulomas, and among them are cytokines and proteins such as interferon-gamma (IFNγ) and tumor necrosis factor-alpha (TNFα). These molecules are crucial for orchestrating the immune response by activating macrophages, which then differentiate into the epithelioid cells that are characteristic of granulomas. TNFα, in particular, is essential for the maintenance of granuloma integrity and the inflammatory response, while IFNγ is vital for macrophage activation and inducing a robust immune response.

Additionally, molecules like angiotensin-converting enzyme (ACE) and 1,25-dihydroxy vitamin D are implicated in the regulation of this inflammatory process. ACE is notably elevated in sarcoidosis and may contribute to granuloma formation, while vitamin D is known to modulate immune responses. Osteopontin, another molecule mentioned, promotes granuloma stability and influences macrophage function.

In contrast, while cytokines such as IL-1 and IL-