New Actors for the Immunological Mechanims Involved in the materno-fetal tolerance

R. RAMHORST AND L. FAINBOIM

Current Womens Health Reviews

Bentham Science Publishers

Año: 2005 vol. 1 p. 15 - 20

1573-4048

Tolerance to the semi-allogeneic fetal graft by the maternal immune system is the consequence of a wide panel of mechanisms that may be interconnected. In the present work we will discuss new mechanisms that could contribute to the materno-fetal tolerance and possible immunological failures in patients with recurrent spontaneous abortions (RSA); including new markers for diagnosis and prognosis. Since, the presence of blocking factors (BF) of the maternal allogeneic response in sera of fertile women, was associated with a successful pregnancy, we identified and characterized new BF using the Mixed Lymphocyte Reaction (MLR) as in vitro model. In this context, Galectin-1 (a -galactoside-binding protein expressed at sites of T-cell activation and immune privilege) and RANTES (regulated on activated normal T cells, expressed and secreted) were able to immunosuppress the allogeneic response. This negative effect resulted in a significant increase of apoptosis of CD45R0+ cells and was accompanied by caspase activation and Bcl-2 down regulation. Moreover, in order to identify reliable markers for RSA diagnosis, we studied activation markers like CD69 (an early activation marker), SLAM (signaling lymphocytic activation molecule) and Th1/Th2 cytokine expression in the pre-implantatory endometrium and peripheral blood from fertile and RSA women. Finally we evaluated the effectiveness of the alloimmunization, with paternal leukocyte, as a treatment for RSA patients and we studied the immunomodulation of RANTES, CD3+CD69+ T cells and CD3+SLAM+ cells in RSA patients under allotreatment, like potential markers for successful treatment for this pathology.