What happens to C3bBb formed on a human cell surface?

C3bBb is a crucial component of the alternative pathway of the complement system, serving as a C3 convertase that plays a significant role in the immune response. When C3bBb is formed on a human cell surface, it is subject to regulation to prevent excessive complement activation that could lead to damage to host tissues.

Regulatory membrane proteins, such as Factor H and Decay Accelerating Factor (DAF), are important in controlling the activity of C3bBb on human cells. These proteins work to prevent the unintended effects of the complement system on self-cells, which could otherwise lead to autoimmune reactions or tissue damage. They facilitate the decay of the C3 convertase activity, thereby ensuring that complement activation remains regulated and that it does not cause harm to healthy human tissues.

By being rapidly disrupted by regulatory membrane proteins, the normal functioning and homeostasis of the immune system are maintained, emphasizing the importance of these regulatory mechanisms in preventing autoimmunity and protecting host cells.