Cloning and characterization of the guinea pig C5a anaphylatoxin receptor: interspecies diversity among the C5a receptors.

Cloning and functional expression of the canine anaphylatoxin C5a receptor. Evidence for high interspecies variability.

A cDNA clone, DTJP03, encoding an orphan receptor, was isolated from a canine thyroid library, and found to exhibit 68.6% amino-acid identity with the recently described human C5a receptor. This relatively low similarity first suggested that DTJP03 encoded either a C5a receptor subtype, or the presumably related C3a receptor. Binding studies performed on membranes from COS-7 cells expressing th...

P183: Key Function of Complement System in Interactions between Pain and Nociceptors, C5a, and C3a

A part of the immune system that improves (complements) the ability of antibodies and phagocytic cells to clear microorganisms and injured cells from an organism, attacks the pathogen's cell membrane, and encourages inflammation called complement system. It is main part of immune system. Over thirty proteins and protein pieces compose the complement system, including cell membrane receptors, an...

Cutting Edge: Human Anaphylatoxin C4a Is a Potent Agonist of the Guinea Pig But Not the Human C3a Receptor

Human anaphylatoxin C4a is a potent agonist of the guinea pig but not the human C3a receptor.

The interaction of human anaphylatoxin C4a with the guinea pig (gp) and human (hu) C3a receptors (C3aR) was analyzed using human rC4a, which exhibited C4a-specific activity on guinea pig platelets. A gpC3aR of 475 residues with a large second extracellular loop and a peptide sequence approximately 60% identical to the huC3aR was isolated from a genomic DNA library and found to be expressed in g...

Structure and characterization of a high affinity C5a monoclonal antibody that blocks binding to C5aR1 and C5aR2 receptors

C5a is a potent anaphylatoxin that modulates inflammation through the C5aR1 and C5aR2 receptors. The molecular interactions between C5a-C5aR1 receptor are well defined, whereas C5a-C5aR2 receptor interactions are poorly understood. Here, we describe the generation of a human antibody, MEDI7814, that neutralizes C5a and C5adesArg binding to the C5aR1 and C5aR2 receptors, without affecting comple...