A MAJOR HISTOCOMPATIBILITY COMPLEX CLASS I-LIKE FC RECEPTOR CLONED FROM HUMAN PLACENTA - POSSIBLE ROLE IN TRANSFER OF IMMUNOGLOBULIN-G FROMMOTHER TO FETUS
Cm. Story et al., A MAJOR HISTOCOMPATIBILITY COMPLEX CLASS I-LIKE FC RECEPTOR CLONED FROM HUMAN PLACENTA - POSSIBLE ROLE IN TRANSFER OF IMMUNOGLOBULIN-G FROMMOTHER TO FETUS, The Journal of experimental medicine, 180(6), 1994, pp. 2377-2381
The acquisition of maternal antibodies is critical for immunologic def
ense of the newborn. In humans, maternal IgG is actively transported a
cross the placenta. The receptor responsible for this transport has no
t been identified definitively. We report the isolation from a placent
al cDNA library of clones encoding the or-chain of an immunoglobulin G
(IgG)-Fc receptor (hTcRn) that resembles a class I major histocompati
bility complex antigen. The DNA and predicted amino resembles a class
I histocompatibility complex antigen. The DNA and predicted amino acid
sequences are very similar to those of the neonatal rat and mouse int
estinal Fc receptors, rFcRn and mFcRn. These receptors mediate transpo
rt of maternal IgG from milk to the bloodstream of the suckling rat or
mouse. Like rat and mouse FcRn, hFcRn binds IgG preferentially at low
PH, which may imply that IgG binds hFcRn in an acidic intracellular c
mpartment during transport across the placenta.