Immunomorphologic studies of human decidua-associated lymphoid cells in normal early pregnancy.

Abstract

Human decidual lymphocytes from early, normal pregnancy were characterized in situ with respect to ultrastructure and distribution of subsets. The ultrastructure of isolated decidual gamma delta T cells was also studied. CD45+ cells comprised 11 +/- 2% of all decidual cells. The majority were localized in large lymphoid cell clusters (LCC), near endometrial glands, or as intraepithelial lymphocytes (IEL) in glandular epithelium. The major cell populations in LCC were CD56+TCR-gamma delta+ cells, CD56+ cells, TCR-alpha beta+CD4+ cells, and TCR-alpha beta+CD8+ cells. All expressed activation markers (CD45RO, Kp43, and/or HML-1) and MHC class II Ag (HLA-DR, HLA-DP, and/or HLA-DQ). No B cells were found. Almost all IEL were activated TCR-gamma delta+ cells (CD56+ and CD56-). The glandular epithelial cells expressed heat shock protein 60 at the basolateral side facing the TCR-gamma delta+ IEL. Decidual lymphocytes displayed cytoplasmic processes, microvilli, characteristic cytoplasmic granules, and had intimate contact with neighboring cells. Lymphocytes in the outer rim of LCC and the stroma showed signs of cellular movement. Two main morphotypes of gamma delta T cells could be distinguished. One had single microvilli, membrane-bound granules, and nuclear inclusions. The other had many microvilli, nonmembrane-bound granules and cytoplasmic multivesicular bodies. Our data suggest that LCC are centers of immune reactivity where T and NK cells become activated. The activated cells may guard against infections and undue trophoblast invasion and/or be involved in modulating the local maternal immune system toward unresponsiveness against the semiallogeneic fetus.

Chlamydia trachomatis infection, immunity, and pregnancy outcome

“…28 Whether prior immunity to the chlamydial hsp60 and to hsp60 epitopes also expressed in human hsp60 affects pregnancy outcome has become a critically important question since many women with tubal factor infertility now seek to become pregnant via IVF. A negative influence of hsp60mediated immunity on pregnancy is a realistic possibility since the embryo 29 and epithelial cells in the maternal decidua 30 both express hsp60 during the early stages of pregnancy. In addition, a murine hybridoma specific for hsp60 was shown to also react with the surface of human trophoblast, 31 suggesting hsp60 expression by these cells.…”

Immune Sensitization to the 60 kD Heat Shock Protein and Pregnancy Outcome

“…[8][9][10] In addition, heat shock proteins are specifically expressed in the human endometrium throughout the menstrual cycle and during the postovulatory implantation phase. 11 Hsp60 expression in the human decidua at 7-11 weeks gestation has been identified, 12,13 thus rep-resenting a potential target tissue for cross-reacting antibodies and a source of hsp60 capable of reactivating hsp60-sensitized lymphocytes. A murine hybridoma specific for mammalian hsp60 was shown to react with the surface of murine and human trophoblast, suggesting surface hsp60 expression by these cells as well.…”

Immunity to heat shock proteins and pregnancy outcome

“…Heat shock proteins, including hsp60, are also expressed during the early stages of pregnancy in both the embryo 2 and maternal decidua. 3 Termination of the pregnancy at this early stage may expose complexes of hsp60 and paternal antigens to the immune system, resulting in induction of hsp60-directed autoimmunity. Women with breast cancer frequently develop autoantibodies to heat shock proteins due to exposure of heat shock protein-tumor antigen complexes to the immune system.…”