Three main pathways can activate the complement system: classical, lectin, and alternative (Fig. 1). The classical pathway (CP) uses C1 and is triggered by antigen–antibody immune complexes.

The classical complement pathway typically requires antigen-antibody complexes for activation (specific immune response), whereas the alternative pathway can be activated by spontaneous complement …

This occurs through three pathways; the classical pathway, activated by antigen-antibody reaction, the alternative pathway, activated on microbial cell surfaces, and the mannose-binding lectin pathway, …

Mar 20, 2022 · The products of complement activation become covalently attached to microbial cell surfaces, to antibodies bound to microbes and to other antigens, and to apoptotic bodies. …

Aug 7, 2025 · What triggers complement activation? Complement can be activated via the classical (antibody-antigen), lectin (carbohydrate pattern), or alternative (pathogen surface) pathways.

Complement can be activated via three different pathways (Figure 1), which can each cause the activation of C3, cleaving it into a large fragment, C3b, that acts as an opsonin, and a small fragment …

Mar 19, 2025 · The complement system consists of plasma proteins of the activating cascades and membrane regulators and receptors. The plasma proteins interact via three major cascades: the …

Sep 5, 2023 · Complement activation proceeds through a finely regulated cascade of proteolytic reactions that initially engages soluble pattern-recognition molecules and leads to the assembly of …

Jun 2, 2015 · Here, we discuss the recent advances describing the molecular and structural basis of activation and regulation of the complement pathways and their implication on physiology and …

There are 3 complement pathways that make up the complement system: the classical complement pathway, the lectin pathway, and the alternative complement pathway. The pathways differ in the …