Immunological Acceptance of the Conceptus

Type :

Research papers

Pages :

3 pages

Format :

.doc

Published date :

11/26/2007

Category :

Science & technology

Sub category :

Medical studies

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Summary :

Introduction
Current status of research
Immunocompetency of the trophoblasts
Trophoblast hla class i expression
HLA-I gene expression
Uterine large granular lymphocytes (LGLs)1
HLA-G expression in human trophoblasts
HLA expression in the human embryo
Implantation and integrin switching
Trophoblast attachment in decidua: Oncofetal fibronectin
Conclusion
Bibliography

Abstract

Over the last half century, many attempts to explain the survival of the semiallogenic fetal graft have been proposed. One of the earliest explanations was based on the theory of antigenic immaturity of the embryo-fetus. This was disproved by Billingham (1964) who showed that transplantation (HLA) antigens are demonstrable very early in embryonic life. The trophoblasts are the only cells of the conceptus in direct contact with maternal tissues or blood and these tissues are genetically identical with fetal tissues. Another explanation was based on diminished immunological responsiveness of the pregnant woman. There is, however, no evidence for this to be other than an ancillary factor. In a third explanation, the uterus (decidua) is proposed as an immunologically privileged tissue site. Clearly, transplantation immunity can be evoked and expressed in the uterus as in other tissues. Therefore, the acceptance and the survival of the conceptus in the maternal uterus must be attributed to an immunological peculiarity of the trophoblasts, not the decidua.