Immunological studies of mouse decidual cells. I. Membrane markers of decidual cells in the days after implantation

The mechanisms by which the mammalian embryo is protected from allograft rejection by the mother remain unclear at present although several hypotheses have been brought forward (1-3). Recent advances seem to favor the lack of detectable transplantation antigens on the postimplantation trophoblast (4, 5) and of blocking antibodies (6). On the other hand, the decidua in the pregnant uterus may provide a locally privileged environment to the embryo (7, 8). For example, extracts from artificially induced decidua have been shown recently to possess immunosuppressive properties (9). Little is known of the exact role or origin of the decidua that develops and surrounds the postimplantation embryo in the pregnant uterus (10). Most decidual cells seem to be derived from uterine stroma cells that resemble embryonic fibroblasts (11, 12), but morphological data have suggested that some of the cells present in mouse and rat decidua may be lymphocytes or derived from lymphocytes (13, 14). Moreover, recent data show that immunoglobulincontaining cells are present in the mouse decidua shortly aider implantation (15) as well as in the rat metrial gland at a later stage (16). We report here the results of an attempt to define immunologically the cells of the mouse decidua in the days after implantation. It is shown that, in addition to H-2 antigens, Thy-1 antigen can be detected on a sizable fraction of decidual cells and that an apparently increasing number of cells bearing receptors for the Fc portion of immunoglobulin G can be detected in the decidua as pregnancy proceeds from day 6 to day 8

Serological Crossreactivity Between H-Y (Male) Antigens of Mouse and Man

Antisera to H-Y (male-specific) antigen were prepared by immunizing female mice with spleen cells from males of the same inbred strain. These antisera were used in mixed hemadsorption and cytotoxicity tests with cells of rats, guinea pigs, rabbits, and humans. The results showed that the H-Y components of all four species are antigenically related to H-Y of the mouse