Page 194 - Veterinary Immunology, 10th Edition

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FIG. 7.4 Species differences in the major acute-phase proteins
produced by the domestic mammals.

Soluble Pattern-Recognition Receptors

Pentraxins are P-type lectins that act as soluble PRRs. Two of the

most important are C-reactive protein and serum amyloid P. C-
reactive protein (CRP) is the major acute-phase protein produced in
primates, rabbits, hamsters, and dogs, and is important in pigs.
CRP has a pentameric structure (five 20-kDa units arranged in a

circle) with two faces. One face binds phosphocholine, a common
side chain found in all cell membranes and many bacteria and
protozoa. The other face binds to the antibody receptors FcγRI and
FcγRIIa on neutrophils. CRP thus acts as an opsonin and promotes

the phagocytosis and removal of damaged, dying, or dead cells in
addition to microorganisms. CRP can bind to bacterial
polysaccharides and glycolipids and to necrotic cells, where it
activates complement C1q. (Its name derives from its ability to bind

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