Where are complement proteins produced?

Where are complement proteins produced?

• A. In the thymus
• B. In the spleen
• C. In the liver
• D. In the bone marrow

Answer: (C)

Complement proteins circulate in the blood as inactive precursors and are activated in a cascade to help clear pathogens. The liver is the main source for these proteins; hepatocytes produce most of them and release them into the plasma. This makes liver health central to a functional complement system. The thymus is where T cells mature, the spleen acts as a secondary lymphoid organ filtering blood and mounting immune responses, and the bone marrow produces blood cells. While some cells in various tissues can make small amounts of certain complement components, the liver is the primary production site.

Complement proteins circulate in the blood as inactive precursors and are activated in a cascade to help clear pathogens. The liver is the main source for these proteins; hepatocytes produce most of them and release them into the plasma. This makes liver health central to a functional complement system. The thymus is where T cells mature, the spleen acts as a secondary lymphoid organ filtering blood and mounting immune responses, and the bone marrow produces blood cells. While some cells in various tissues can make small amounts of certain complement components, the liver is the primary production site.