Human Trophoblast‐Specific Surface Antigens Identified Using Monoclonal Antibodies*

Abstract

ABSTRAW Mouse monoclonal antibodies have been produced against syncytiotrophoblast plasma membrane preparations isolated from term human placentas. Of 20 positive clones, two antibodies (H309, H318) were directed against the Cy2 domain of IgG, one (H312) was directed against albumin, and another (H303) was directed against a further normal human serum component (not transferrin). One monoclonal antibody (H310) recognized an antigenic epitope restricted to trophoblast and lymphocytes: this antibody did not inhibit mitogenic or allogeneic stimulation of lymphocytes. Two monoclonal antibodies (H315 and H317) reacted with trophoblast-specific antigenic determinants. The H315 antigen was present on first trimester syncytiotrophoblast, unlike the H317 antigen. (Am J Reprod Immunol. 1981; 1:246-254.)

Expression of human placental‐type alkaline phosphatase in primary breast cancer

“…EIA with H317 has consistently detected low concentration of PI-ALP in non-malignant cervix and lung (McLaughlin et al, in preparation), although H317 does not localize PI-ALP in any of these normal tissues in either immunofluorescence or immunoperoxidase studies (Johnson et al, 1981;McDicken, unpublished observations). As the amounts of PI-ALP in the normal tissue extracts are of the same order as extracts of breast and ovarian carcinoma tissue, the development of H317 for imaging analysis may sometime be precluded.…”

“…The H317 mAb is reactive with the foetal trophoblast of villous placenta, placental bed and extraembryonic membranes, and is unreactive with other non-malignant human tissues (Johnson et al, 1981;Johnson and Mollay, 1983). This mAb has been shown to specifically recognise PI-ALP in extraembryonic tissues, as well as at least some tumour-associated forms of PI-ALP, and to be unreactive with the non-placental isoenzymes of alkaline phosphatase (ALP) (McLaughlin et al, 1982(McLaughlin et al, ,1983.…”

Human Trophoblast Glycoproteins Defined by Monoclonal Antibody 1D2

“…The solid phase enzyme immunoas say of McLaughlin et al [1983] was used to assess the placental alkaline phosphatase ac tivity of 1D2 antigen. mAb 1D2, an anti-PLAP mAb H317 [Johnson et al, 1981;McLaughlin et al, 1983] and a control mAb (for example mAb 312 in fig. 1) were immo bilised on ELISA plates on an equal concen- tration of immunoglobulin basis, a source of PLAP added and the mAb-bound antigen quantitated by colourimetric reaction with the alkaline phosphatase substrate pNPP ( fig.…”

“…Although reactive with DOC-solubilised StMPM in immunodol, mAb 1D2 was unreactive with any of human transferrin, ferritin, IgG, albumin, hPL, hCG and calmodulin when used as antigen. Syncytiotrophoblast expresses high concen trations of placental alkaline phosphate en zymatic activity [Truman and Ford, 1984], and several StMPM-reactive mAbs have been reported to be directed against PLAP [Johnson et al, 1981;Travers and Bodmer, 1984]. The solid phase enzyme immunoas say of McLaughlin et al [1983] was used to assess the placental alkaline phosphatase ac tivity of 1D2 antigen.…”

Detection of placental-type alkaline phosphatase in ovarian cancer

“…The H317 hybridoma had been produced after immunization with isolated plasma membrane preparations from syncytiotrophoblast microvilli of normal human term placentae (Johnson et al, 1981;Johnson & Molloy, 1983). This mAb is specific for the heat-stable, L-phenylalanine-inhibitable, PLAP isoenzyme and is unreactive with other AP isoenzymes from normal human tissues (McLaughlin et al, 1982(McLaughlin et al, , 1984a A sensitive solid-phase EIA using the H317 mAb, described in detail previously (McLaughlin et al, , 1984a, was used to determine active PLAP in sera collected prior to laparotomy and in fresh tumour tissue extracts.…”