Identification of a unique form of p53 in human cord blood associated with the development of maternal autoantibodies.
OBJECTIVE
The possible link between p53-reactive antibodies in multiparous women and exposure to a unique p53 protein during pregnancy was examined.


METHODS
p53-reactive antibodies were evaluated in sera from nulligravid and multiparous women and patients with ovarian cancer by Western immunoblot. Furthermore, the presence of p53 protein was assayed in cord blood by enzyme-linked immunosorbent assay. Cord blood-derived p53 was compared structurally by protein fingerprinting and functionally by gel mobility shift assay to other isolates of p53.


RESULTS
Antibodies reactive with wild-type p53 were observed in 92% of multiparous women and 42% were reactive with one tumor-derived p53 protein. p53 protein was detected in 27 of 154 samples of cord blood. Structural analysis indicated that the fetal p53 resembled the UL-1 p53. Functionally, the fetal and UL-1 protein failed to bind DNA.


CONCLUSIONS
Fetal p53 protein seems to be distinct from wild-type p53, characterized by enhanced stability, structural differences and inability to bind DNA, analogous to alternatively spliced variants. Exposure to fetal p53 protein may form the basis for immunologic protection against cancer induced by multiparity.
Yashar
C M
CM
Department of Obstetrics and Gynecology, University of Louisville School of Medicine, KY, USA.
Gerçel-Taylor
C
C
Gibb
R K
RK
Weeks
J W
JW
Taylor
D D
DD
D000911:Antibodies, Monoclonal; D001323:Autoantibodies / Q000097:blood*; D005260:Female; D005312:Fetal Blood / Q000737:chemistry* / Q000276:immunology*; D005333:Fetus / Q000276:immunology; D006801:Humans; D007114:Immunization; D007231:Infant, Newborn; D008431:Maternal-Fetal Exchange / Q000276:immunology*; D009154:Mutation; D010051:Ovarian Neoplasms / Q000209:etiology / Q000276:immunology / Q000517:prevention & control; D010298:Parity / Q000276:immunology; D010920:Placenta / Q000276:immunology; D011247:Pregnancy; D016159:Tumor Suppressor Protein p53 / Q000097:blood* / Q000235:genetics / Q000276:immunology*
D000911:Antibodies, Monoclonal; D001323:Autoantibodies; D016159:Tumor Suppressor Protein p53