Preferred Label : Lectin Induced Complement Pathway;
Alternative definition : BIOCARTA: The complement cascade of proteolytic factors involved in cellular lysis
can be initiated by several different factors, including antibody-dependent and antibody-independent
recognition of infectious organisms. In the lectin-induced complement cascade, carbohydrates
on the surface of microbial cells activate the complement cascade by binding to mannan-binding
lectin (also called the mannan-binding protein, Mbl/Mbp). Mbp is an acute phase serum
protein whose expression is induced by microbial infection. The binding of Mbl to
microbial ligands activates the Mbl associated serine proteases Masp1 and Masp2, triggering
the cleavage of C2 and C4 to create C4bC2a, a C3 convertase that cleaves large numbers
of C3. Masp1 and Masp2 are similar to the C1 protease in the classical complement
pathway. Once formed the C3 convertase cleaves and activates the remaining complement
factors leading ultimately to formation of a pore in the bacterial membrane by the
membrane attack complex (MAC) that lyses the bacterial cell. The lectin-induced pathway
also appears to play an important role of the activation of phagocytotic cells by
infection. Although the initiating event activating the complement cascade is distinct
in the lectin-induced pathway, from the C3 convertase onward the lectin induced complement
pathway is the same as the classical complement pathway. Since antibodies are not
required in the lectin-induced pathway, this aspect of the immune response is part
of the innate immune response. The importance of this pathway to the immune response
has been demonstrated by the identification of children and adults with little or
no Mbl who lacked normal phagocytotic responses and are highly susceptible to infection.
(This definition may be outdated - see the DesignNote.);
NCIt note : The BIOCARTA Definition (ALT_DEFINITION) for this pathway concept was provided by
BioCarta. This property was not created by, nor is it maintained by the NCI Thesaurus
staff. Additionally, BioCarta is no longer updating its pathway data; thus, the BIOCARTA
Definition might be outdated or inaccurate. Please see the Terms and Conditions for
Use at http://www.biocarta.com/.;
Biocarta ID : h_lectinPathway;
Origin ID : C39138;
UMLS CUI : C1517754;
Semantic type(s)
- has_gene_product_element
- pathway_has_gene_element
