PRODUCTION OF A MONOCLONAL-ANTIBODY TO AN ANTIGEN PRESENT ON BOTH TROPHOBLASTS AND LEUKOCYTES

In the present study, we report the establishment of a monoclonal anti body (Mab) designated F10 that recognized an antigen commonly shared b y human trophoblasts and leucocytes, F10 MAb was obtained using cell m embrane components from a trophoblast cell line HT as immunogen, Based on immunochemical studies, the F10 reactive antigen (F10-Ag) could be located on both villous and nonvillous trophoblasts from early and te rm placental tissues and on all trophoblastic cell lines, In addition, flow cytometry revealed that most (>95 %) peripheral blood lymphocyte s, monocytes, as well as polymorphonuclear leukocytes (PMN) were posit ively stained with F10 MAb, Immunoblotting with Fill MAb identified tw o protein bands with apparent molecular mass of 62 and 56 kDa. Further more, the antigens were glycoproteins and were glycosylated via the O- linkage, Scatchard plot analyses of the binding data between I-125-lab eled MAb F10 IgG and HT cells revealed a single class of F10 binding s ites with an apparent dissociation constant (K-d) of 10.54 +/- 2.03 pM and maximum binding-site (B-max) value of 2.1 +/- 0.11 x 10(6) sites per cell, We suggest that F10 may be useful for the identification of a novel epitope that is commonly shared by all trophoblasts and leukoc ytes and such an epitope may be potentially active in maternal-fetal i nteractions.