IMMUNE SUPPRESSION AND TH1 TH2 BALANCE IN PREGNANCY REVISITED - A (VERY) PERSONAL TRIBUTE TO WEGMANN,TOM/

PROBLEM: The paradigm of local suppression necessary to understand the survival of the fetal allograft is often compared with the host-tumor relationship. METHODS: We investigated two components of local immune suppression: placenta-induced immunosuppression, which is mediated at least in part by a soluble factor of low molecular weight that can in duce anergy in lymphocytes, and interleukin-10 (IL-10). RESULTS: We sh ow that enhancement of IL-10 production in the decidua and placenta af ter alloimmunization requires the presence of Asialo GM1+ cells. Place nta-induced immunosuppression is linked with defects in phosphorylatio n of some components of the T cell receptor. CONCLUSION: NK cells coul d be in fact regulatory cells pushing maternal immune response toward a Th2 profile, beneficial for fetal survival, or toward a Th1 type of immune response, which acts in synergy. Modulation of TcR may represen t a new mechanism for maternal-fetal tolerance.