Gestation age dependent transfer of @entity1 immunoglobulins across placenta in timed-pregnant XXXX .

@entity1 @entity7722 @entity840 @entity235
INTRODUCTION: When administered during pregnancy, antibodies and other biologic drugs that contain the Fc part of the IgG molecule can traverse the placenta. Although it is generally accepted that the @entity7722 receptor mediates this process, gaps remain in our understanding of underlying details in @entity1 and in common laboratory animal species. METHODS: We expanded our previous studies in timed-pregnant @entity840 to both measure the transport of human (h) IgG at earlier gestation ages in vivo and evaluate @entity7722 function in vitro using Surface Plasmon Resonance (SPR) and Madin-Darby @entity235 kidney cells (MDCK) that express @entity840 (gp) @entity7722 . RESULTS: In timed-pregnant @entity840 both the average concentration of hIgG in the fetus and its ratio to maternal hIgG concentration increase exponentially with gestation age. Thus, hIgG fetal:maternal concentration ratios increase from an average of 1% to 3%, 17%, and 76% on GD    26, 35, 46, and 54, respectively. In vitro, gpFcRn immobilized on a solid surface can bind hIgG and gpIgG preparations in a similar manner. All engineered @entity1 Fc isotype-specific constructs were internalized by MDCK-gpFcRn cells at significant levels. While not significant, their recycling and hIgG transcytosis by this cell line also trend higher than background controls. DISCUSSION: Pregnant @entity840 exhibit similarities with @entity1 in the degree and timing of transplacental transfer as well as the ability of their @entity7722 to bind and internalize hIgG in vitro. Further studies are needed to guide building appropriate systems for the evaluation of @entity7722 mediated function of @entity1 immunoglobulin therapies.
