The placental regulatory factor involved in the asymmetric IgG antibody synthesis responds to IL-6 features

Pregnancy success is attributed to the joint action of several Factors such as regulatory placental molecules and components of the mother's immune sy stem, among others. Asymmetrical glycosilated and functionally univalent Ig e antibodies are suggested to influence the immune balance between the moth er and foetus, playing a meaningful role on the foetal survival in the mate rnal uterus. Placental secretory factors might be responsible for the incre ase of these molecules during gestation. Since placental factors appeared t o be the inducers of these high Concanavaline A-affinity (Con-A) IgG molecu les our work was focused on the identification of such factors. The chromat ographic separation of placental culture supernatants (PCS) allowed the det ection of fractions capable of increasing the high Con-A affinity monoclona l antibody (Mab) ratio synthesised by a hybridoma. The presence of multimer ic placental forms of interleukin 6 (IL-6) could be identified in these fra ctions. Considering that IL-6 modulates protein glycosylation we decided to investigate its effect on the monoclonal IgG glycosylation. When placental IL-6 containing fractions or rIL-6h were added to hybridoma cultures, the proportion of asymmetric IgG antibodies increased substantially. (C) 2001 E lsevier Science Ireland Ltd. All rights reserved.