AP BIOLOGY

THE HUMAN IMMUNE SYSTEM

IMMUNE RESPONSE

Question [CLICK ON ANY CHOICE TO KNOW THE RIGHT ANSWER]
Chemotaxis is facilitated by what complement component?
A
C5a
B
C3b
C
C5
D
C5b
Explanation: 

Detailed explanation-1: -Plasma membrane binding and subsequent shedding of DBP are essential to function as a chemotactic cofactor for C5a [76]. This function of DBP is specific as DBP cannot augment other C5a-mediated leukocyte functions (oxidant generation and degranulation) [77].

Detailed explanation-2: -Chemotaxis: C5a and C5a des Arg Although C5a is the primary complement chemoattractant, other complement proteins also act as chemotactic factors for specific cell types. C3a induces chemotaxis of basophils, eosinophils, and mast cells while C1q is a chemoattractant for dendritic cells.

Detailed explanation-3: -C3a and C5a are chemotactic factors for human mesenchymal stem cells, which cause prolonged ERK1/2 phosphorylation. J Immunol. 2009 Mar 15; 182(6):3827-36.

Detailed explanation-4: -C5b binds to the surface of foreign particles. C5b triggers the assembly of complement components C6 to C9 into MAC, which destroys foreign particles [1, 2]. Molecularly targeted therapies with antibodies are yielding dramatic results in the treatment of rheumatoid arthritis (RA) and malignancies.

There is 1 question to complete.