One type of receptor (FcγRI) grabs onto single antibodies really tightly, while other receptors only grab well when many antibodies are stuck together on a germ.
Scientific Claim
FcγRI has the highest affinity for monomeric IgG1 and IgG4, while low-affinity FcγRs (FcγRIIA, FcγRIIIA, FcγRIIB) preferentially bind IgG immune complexes under physiological conditions.
Original Statement
“FcγRI (also termed CD64) has the greatest affinity for IgG molecules, while FcγRs IIA/B/C (CD32) and FcγRIIIA/B (CD16) have lower affinities for IgG (40). ... Bruhns et al. found that, as monomers, IgG1, and IgG4 exclusively bound to FcγRI, whereas monomeric IgG2 failed to bind any of the FcγRs. Monomeric IgG3 also bound to FcγRI and additionally to FcγRIIIA. ... IgG-ICs are able to differentially engage an array of FcγRs and preferentially cross-link low affinity receptors FcγRIIA, IIIA, and IIB, which under serum conditions are considered the main effector FcγRs on immune cells.”
Evidence Quality Assessment
Claim Status
appropriately stated
Study Design Support
Design supports claim
Appropriate Language Strength
definitive
Can make definitive causal claims
Assessment Explanation
The claim reflects quantitative binding data from in vitro biochemical assays cited in the review. Definitive language is justified as these are direct molecular interaction measurements.
Evidence from Studies
Supporting (0)
Contradicting (1)
The study talks about how certain immune receptors grab onto antibody-coated germs, but it doesn’t say which ones grab single antibodies best or which ones prefer clumps of antibodies, so we can’t tell if the claim is right or wrong.