ABSTRACT
The immune system of mammals has evolved different lines of attack to defend the organism against a wide range of potentially infectious pathogens by differentiating self from nonself. Various immunoregulatory proteins play imperative roles in shaping the immune response. To enable allograft (fetus) survival, the immune response allows total immune competence in pregnancy. Consequently, pregnancy reveals two distinctive immunological aspects and raise questions. First, how does a fetus living in a sterile environment develop the essential framework of the immune system? And
20.1 Introduction .......................................................................................................................... 311 20.2 NK Cells in Pregnancy ......................................................................................................... 312
20.2.1 Role of uNK Cells in Trophoblast Invasion .............................................................. 313 20.3 Cytokines in Pregnancy ........................................................................................................ 313
20.3.1 Th1/Th2 Shifts during Healthy Pregnancy: A Short-Lived Hypothesis .................. 314 20.3.2 IL-17 .......................................................................................................................... 315 20.3.3 IFN-γ ........................................................................................................................ 315
20.4 Preeclampsia ......................................................................................................................... 316 20.4.1 Immune System Activation in Preeclampsia ............................................................ 317
20.5 Summary .............................................................................................................................. 318 References ...................................................................................................................................... 318
second, how do fetal and maternal immunological factors work together at the maternal-fetal interface to tolerate the growth of the semiallogeneic fetus? The success or failure of pregnancy depends on cellular immune effectors and their proinammatory or anti-inammatory response. The immunological recognition of pregnancy is imperative for the maintenance of gestation and also for modulation of common disorders of pregnancy. Some small soluble proteins like cytokines act as immunomodulators and play a very signicant role in this process. Cytokines are small signaling proteins secreted by and acting on a wide array of cells. Through binding of specic receptors, tight regulation of biological processes via secretion and distribution of these potent mediators are achieved. These versatile pluripotent factors are key mediators of reactions ranging from autoimmune diseases, rejection of allografts, and hypersensitivity.
