The Role of RCAS1 and oxytocinase in immune tolerance during pregnancy.
OBJECTIVE
To determine and compare the level of RCAS1 (receptor-binding cancer antigen expressed in SiSo cells) in placentas at term as well as oxytocinase/cystine amino peptidase (CAP) serum level a few days before labor in order to evaluate their possible role in the regulation of maternal immune response during pregnancy and in initiation of labor.


METHODS
We estimated the RCAS1 content in 44 placental tissue samples, using Western blot method. We also assessed CAP serum level by its enzymatic activity, using L-cystine-di-beta-naphthylamide as a synthetic substrate. The statistical analysis was performed using Shapiro-Wilk procedure. Student's t test was applied to compare the differences between parametric data. A value of p < 0.05 was considered significant.


RESULTS
RCAS1 was found in all placental tissue samples examined. The differences in the RCAS1 relative amount depended on the onset of labor, with the highest level in induced labor and the lowest in spontaneous labor. The differences were also observed in the CAP serum level with the highest level in pregnant women whose labor was induced.


CONCLUSIONS
We have observed a link between the expression of the two proteins examined and the onset of the labor. Therefore, we posit that RCAS1 and CAP may play a role in the downregulation of the maternal immune response during pregnancy and may participate in the initiation of the labor.
Wicherek
L
L
Department of Gynecology and Infertility of Jagiellonian University, Krakow, Poland. mowicher@cyf-kr.edu.pl
Dutsch-Wicherek
M
M
Mak
P
P
Klimek
M
M
D000951:Antigens, Neoplasm / Q000097:blood / Q000276:immunology* / Q000378:metabolism; D010122:Cystinyl Aminopeptidase / Q000097:blood / Q000276:immunology* / Q000378:metabolism; D015536:Down-Regulation / Q000276:immunology; D005260:Female; D006801:Humans; D007108:Immune Tolerance / Q000276:immunology*; D007747:Labor Stage, First / Q000276:immunology / Q000378:metabolism; D010920:Placenta / Q000201:enzymology* / Q000276:immunology; D011247:Pregnancy; D011263:Pregnancy Trimester, Third / Q000276:immunology* / Q000378:metabolism
D000951:Antigens, Neoplasm; C120762:EBAG9 protein, human; D010122:Cystinyl Aminopeptidase