Monoclonal antibodies against endometrial protein PP14 and their use for purification and radioimmunoassay of PP14.

Monoclonal antibodies against placental protein 14 (PP14) were generated in mice. One of these (code 105DH1F1) was used for the purification of PP14 from mid-trimester amniotic fluid. The method is a simple one-step procedure, whereby monoclonal antibodies are bound to a solid phase and used for affinity immunoadsorption. 1.2 mg of PP14 was recovered from 25 ml of amniotic fluid. Using this purified PP14 and another monoclonal antibody (code 105AH7G3) a highly specific radioimmunoassay was developed. When the urine of pregnant women (7-10 weeks gestation) was tested little PP14 could be found at the detection level of 10 micrograms/l. The serum patterns of chorionic gonadotropin and PP14 were very similar in pregnancy. This study suggests that, unlike hCG, little PP14 is secreted into maternal urine. The purification method is gentle and allows quick purification of large amounts of PP14 for studies of its biological action(s).