Implication des hormones de croissance et du système CD95/CD95-ligand dans la tolérance fœto-placentaire
We attempted here to contribute to the study of 2 hypothesis concerning mechanisms implicated in the foeto-tolerance phenomenon. The first hypothesis concerned the potential effects of the replacement of the pituitary growth hormone (hGH-N) by the placental growth hormone (hPGH) on the maternal immune system. We mainly performed a preliminary study of these effects in the man and in the non-pregnant woman in order to transpose the obtained results to the pregnant woman. We have also analyzed the expression of the hGH-N receptor, which can be bound by both hGH-N and hPGH, on the surface of a wide variety of cell types and sub-types, activated or not, which had never been done in a single study before. We showed notably that, among the stydied cell types, the expression of hGH-N-R was mainly performed by activated T cells, by activated or non-activated B cells and by monocytes. Lowly differentiated cells could express more hGH-N-R, which is supported by published data suggesting that immature cells (hematopoietic bone marrow and thymus) are particularly sensitive to hGH-N. However, the activation of lymphoid cells, mainly T lymphocytes, by mitogens increases the expression of hGH-N-R. The comparative study of the effects of hGH-N and hPGH on cells from the human immune system had never been performed before. Our tests performed by the introduction of growth hormones at physiological concentrations in the culture medium of lymphoif cells indicates that their effect on the cell proliferation is equivalent.
Life sciences, Anatomy (cytology, histology, embryology...) & physiology, Sciences du vivant, Anatomie (cytologie, histologie, embryologie...) & physiologie
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