Immunoregulatory activity, biochemistry, and phylogeny of ovine uterine serpin.
OBJECTIVE
During pregnancy, the endometrium of the ewe secretes a progesterone-induced member of the serpin superfamily of serine proteinase inhibitors called ovine uterine serpin (OvUS) that has immunosuppressive properties.


METHODS
Review of the literature.


CONCLUSIONS
OvUS inhibits a wide variety of immune responses, including mixed lymphocyte reaction, mitogen-stimulated lymphocyte proliferation, and T cell-dependent antibody production. Recent data have suggested that OvUS functions by inhibiting protein kinase C and interleukin-2-mediated events. OvUS and similar genes present in cattle and pigs diverged from other serpins prior to the divergence of artiodactyls. Since this time, the serpins have apparently undergone adaptive evolution that has led to a conformational state and biological functions distinct from prototypical serpins. Thus, it is likely that these proteins have an important role in the reproductive biology of Artiodactyla. Several lines of evidence suggest that, in sheep, OvUS functions to mediate the immunosuppressive effects of progesterone and prevent immunological rejection of the fetal allograft.
Peltier
M R
MR
Department of Pathobiology, University of Florida, Gainesville 32611-0806, USA. PeltierM@mail.vetmed.ufl.edu
Hansen
P J
PJ
D000818:Animals; D005075:Biological Evolution; D005260:Female; D007108:Immune Tolerance; D008431:Maternal-Fetal Exchange / Q000276:immunology; D008954:Models, Biological; D010802:Phylogeny; D011247:Pregnancy; D011487:Protein Conformation; D015843:Serpins / Q000737:chemistry* / Q000235:genetics / Q000276:immunology*; D012756:Sheep
D015843:Serpins