Research output: Contribution to Journal/Magazine › Journal article › peer-review
Research output: Contribution to Journal/Magazine › Journal article › peer-review
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TY - JOUR
T1 - CYTOTROPHOBLAST CELLS - A BARRIER TO MATERNOFETAL TRANSMISSION OF PASSIVE-IMMUNITY
AU - BRIGHT, N A
AU - OCKLEFORD, C D
PY - 1995/9
Y1 - 1995/9
N2 - The human fetus receives passive immunity via the chorioallantoic placenta in the form of maternal immunoglobulin G (IgG) class antibodies. This provides protection against pathogens at a time when the fetus is immunologically naive. We localized endogenous human IgG using confocal laser scanning fluorescence microscopy and immunoelectron microscopy of frozen sections of chorionic villi from early and late gestation. With confocal microscopy we also investigated the distribution of a receptor for IgG (Fc gamma RIII; CD16) that is typically expressed on the surface of human leukocytes. Endogenous IgG was present in the syncytiotrophoblast that surrounds chorionic villi but underlying cytotrophoblast cells were devoid of endogenous antibody. Fc gamma RIII immunoreactivity was confined to the syncytiotrophoblast and was also absent from cytotrophoblast cells. We propose that cytotrophoblast cells represent a barrier to the transmission of maternally derived IgG across the human placenta. This accounts for the paradox that there are low levels of transport in the first trimester when the syncytiotrophoblast is known to express receptors for IgG. Cytotrophoblast cells form an almost complete epithelial layer underlying the syncytiotrophoblast at this stage of gestation, but this becomes discontinuous as the placenta matures, thus removing the cellular impediment to IgG transmission.
AB - The human fetus receives passive immunity via the chorioallantoic placenta in the form of maternal immunoglobulin G (IgG) class antibodies. This provides protection against pathogens at a time when the fetus is immunologically naive. We localized endogenous human IgG using confocal laser scanning fluorescence microscopy and immunoelectron microscopy of frozen sections of chorionic villi from early and late gestation. With confocal microscopy we also investigated the distribution of a receptor for IgG (Fc gamma RIII; CD16) that is typically expressed on the surface of human leukocytes. Endogenous IgG was present in the syncytiotrophoblast that surrounds chorionic villi but underlying cytotrophoblast cells were devoid of endogenous antibody. Fc gamma RIII immunoreactivity was confined to the syncytiotrophoblast and was also absent from cytotrophoblast cells. We propose that cytotrophoblast cells represent a barrier to the transmission of maternally derived IgG across the human placenta. This accounts for the paradox that there are low levels of transport in the first trimester when the syncytiotrophoblast is known to express receptors for IgG. Cytotrophoblast cells form an almost complete epithelial layer underlying the syncytiotrophoblast at this stage of gestation, but this becomes discontinuous as the placenta matures, thus removing the cellular impediment to IgG transmission.
KW - HUMAN PLACENTA
KW - CYTOTROPHOBLAST CELLS
KW - IMMUNOGLOBULIN G
KW - IMMUNOCYTOCHEMISTRY
KW - IMMUNOELECTRON MICROSCOPY
KW - FC RECEPTORS
KW - PASSIVE IMMUNITY
KW - ULTRATHIN FROZEN-SECTIONS
KW - HUMAN-PLACENTA
KW - IMMUNOGLOBULIN-G
KW - IGG SUBCLASSES
KW - LOCALIZATION
KW - RECEPTORS
U2 - 10.1177/43.9.7642966
DO - 10.1177/43.9.7642966
M3 - Journal article
VL - 43
SP - 933
EP - 944
JO - Journal of Histochemistry and Cytochemistry
JF - Journal of Histochemistry and Cytochemistry
SN - 0022-1554
IS - 9
ER -