Immunological studies of human placentae. Lectin binding to villous stroma and to trophoblastic basement membrane.

It has been demonstrated immunohistologically using cryostat sections that the lectins PHA and Con A bind to human placentae. Both lectins stain trophoblastic basement membrane (TBM), perivascular tissue and stroma. No staining of trophoblasts was observed. It has been shown by blocking experiments that the lectin binding sites on placental TBM are glycoproteins, whereas experiments involving pretreatment of placental sections with anti-collagen antisera or highly purified bacterial collagenase have indicated that lectin binding to stromal and perivascular structures is collagen-associated. The possible relation of TBM lectin-binding sites to immune response gene products is briefly discussed.