Impaired susceptibility of human trophoblast to MHC nonrestricted killer cells: implication in the maternal-fetal relationship.
Mammalian pregnancy has frequently been termed "Nature's allograft," and there is developing evidence that the placental trophoblast cells in their key position at the maternal fetal interface are responsible for escape mechanisms to the maternal immune system. In this paper, we show impaired susceptibility of human trophoblastic tumor cells to major histocompatibility complex (MHC) nonrestricted cytotoxicity systems such as natural killer (NK) cells and lymphokine-activated killer (LAK) cells. LAK cells were induced by the culture of peripheral blood mononuclear lymphocytes (PBL) in recombinant interleukin-2 (rIL-2). Among 21 cultured cell lines derived from various tissues and organs tested, five choriocarcinoma-derived cell lines gave decreased levels of LAK lysis. Cold-target inhibition study and trinitrophenyl (TNP) modification experiment clearly indicated that the impaired sensitivity of trophoblast cells to LAK lysis is due to the decrease of a common target molecule recognized by LAK effector cells. It is suggested that the impaired susceptibilty of trophoblast to MHC nonrestricted killer cells should be functional for the survival of the semiallogeneic fetus.
Saji
F
F
Department of Obstetrics and Gynecology, Osaka University Medical School, Japan.
Kameda
T
T
Koyama
M
M
Matsuzaki
N
N
Negoro
T
T
Tanizawa
O
O
D003602:Cytotoxicity, Immunologic; D005260:Female; D006801:Humans; D007108:Immune Tolerance; D007376:Interleukin-2 / Q000494:pharmacology; D007694:Killer Cells, Natural / Q000187:drug effects / Q000276:immunology*; D011247:Pregnancy / Q000276:immunology*; D011994:Recombinant Proteins / Q000494:pharmacology; D014327:Trophoblasts / Q000276:immunology*
D007376:Interleukin-2; D011994:Recombinant Proteins