Which of the following inflammatory mediators is NOT found in the Alternate Pathway?

The Alternate Pathway of the complement system is crucial in the immune response, particularly in enhancing inflammation. It primarily involves the activation of complement proteins that lead to a cascade of reactions aimed at defending against pathogens. In this pathway, proteins such as C3, C5, and others play significant roles in mediating inflammation and opsonization.

C2b is not part of the Alternate Pathway; it is a fragment derived from C2 when it is cleaved by C1 in the Classical Pathway, which is a different activation pathway of the complement system. The Alternate Pathway does not utilize C2 at all, as it operates independently of C1 and does not involve this particular component.

On the other hand, C4a, C3a, and C5a are all fragments generated during the complement activation process that can be associated with the inflammatory response. C4a is a product of C4 cleavage, although associated with Classical Pathway activation, it does relate to inflammation. C3a and C5a are potent anaphylatoxins that recruit inflammatory cells and increase vascular permeability. Their presence in the Alternative Pathway makes them relevant in discussions concerning inflammation mediated by this system.

Thus, the correct answer is C2