Natural killer and natural cytotoxic cells are present at the maternal‐fetal interface during murine pregnancy

Abstract

Summary NK cell activity has been detected in the early murine decidua, and hypothesized to be mediated by granulated metrial gland (GMG) cells. The possibility that natural cytotoxic (NC) cells are also present in the decidua has not been investigated. In this study mAb to NK cells (anti‐NK‐1.1) and NC cells (anti‐NC‐1.1) were used to characterize the decidual cells of days 8–14 pregnant (CBAxC57BL/6) Fl mice. Flow cytometric and immunohistological analyses showed predominantly NK‐1.1+ and NC‐1.1+ large and granular single nucleated decidual cells with abundant cytoplasm. A ‘bright’ and a ‘dim’ subset were identified for both NK‐1.1+ and NC‐1.1+ cells. The NC‐1.1dim and NK‐1.1dim cells increased in number and size as pregnancy progressed. When tested in 51Cr‐release assays, the decidual cells showed significant levels of both NK and NC activities which increased with progression of pregnancy. The NK and NC activities were partially inhibited (47 and 34%) by preincubation of the decidual cells with anti‐NC‐1.1 and complement (C), or anti‐NC‐1.1 alone. Results indicate that natural cell‐mediated cytotoxicity in the decidua is in part, at least, mediated by NK‐1.1+ and NC‐l.l+ cells, and that the NK‐1.1dim and NC‐1.1dim cells are very likely to be GMG cells. This is the first report of NC cells in the mouse uterus.

A Study of Natural Cytotoxic (NC) Activity in the Metrial Glands of Rats and Mice

“…Natural cytotoxic cells are defined by their ability to lyse Wehi 164 cells, a mouse fibrosarcoma cell line [17], although the recognition molecules which initiate this activity remain to be established. Earlier results from our own laboratory of NK cytotoxic activity in metrial gland cell suspensions [12,13] do not accord with the findings of Clarke et al [16]. However, we report here on our studies of NC activity in cell suspensions which contain GMG cells prepared from mouse metrial glands, and also from rat metrial glands which have not previously been assessed for NC cell cytotoxic activity.…”

Experimental genital mycoplasmosis: time of infection influences pregnancy outcome

“…Mitogenic response is decreased during pregnancy. Natural killer cell activity decreases as estrogen levels rise; therefore, this protective mechanism would be predicted to be at its lowest efficiency during pregnancy (6,8,19). Finally, local secretion of Igs is influenced by estrogen levels.…”

“…The placenta is rapidly developing more intimate contact between the maternal and fetal circulations to support this growth (9). Development of the metrial gland and maximal numbers of pregnancy-associated granulated metrial gland cells also occur around gd 14 (6,8,12,19).…”

Natural cytotoxic and antibody‐dependent cellular cytotoxic activity of cells in the decidua basales and metrial glands of pseudopregnant rats with deciduomata

“…In vitro characterization of the type of cytotoxic activity expressed by cells from the uterine wall of pregnant mice 4 and rats 5 revealed they were cytotoxic to Wehi 164 fibrosarcoma cells (the targets for natural cytotoxic (NC) activity); the effector cells were identified as GMG cells 5 . In addition, cells isolated from metrial glands of pregnant rats were shown to express antibody‐dependent cellular cytotoxic (ADCC) activity 6 .…”