Increased blood vessel density in decidua parietalis is associated with spontaneous human first trimester abortion.

Spontaneous pregnancy loss affects 15-18% of couples, and a number of potential causes are being discussed. The purpose of the present study was to assess if angiogenic disorders in the decidua of early human pregnancy could be related to spontaneous abortions. First trimester human decidua from elective terminations of normally progressing pregnancies and from missed abortions were investigated immunohistochemically. We quantified vessel density in decidua from normal pregnancies and from abortions by von Willebrand factor (vWF), platelet endothelial cell adhesion molecule (PECAM-1) and CD34 staining. Decidual blood vessel expression of alphavbeta3 integrin was also investigated. Significant increase (P < 0.02) in vessel density was observed in decidua parietalis of abortions, compared to decidua basalis. This increase was detected on slides stained for vWF and CD34, but not for PECAM-1. We observed a 15% increase analysing with vWF and a 77% increase with CD34 staining. alphavbeta3 integrin expression was not significantly different, neither in decidua parietalis from abortion, nor parietalis from normal pregnancies. Our data suggest that the increased vascularization in decidua parietalis from abortions could reflect complex disorders, such as specific cytokine expressions and hypoxia phenomena during the development of the decidua.     

Differential distribution of NK cells in decidua basalis compared with decidua parietalis after uncomplicated human term pregnancy

As pregnancy progresses, a characteristic decline in the percentage of CD56bright CD16- uterine natural killer (NK) cells occurs. Studies of term decidua, however, have focused only on leukocytes derived from decidua basalis, the site of implantation. The decidua parietalis, lining the remainder of the uterine cavity is another important region of the maternal-fetal interface that forms contact with fetal tissue at the end of the first trimester. The aim of this study was to evaluate possible differences in expression of CD16 and CD56 on leukocytes from normal term decidua basalis and decidua parietalis. Decidua basalis and parietalis samples were obtained from 30 placentas collected after elective cesarean section. Percentages of leukocyte subpopulations and NK cell subsets within the CD45+ cell fraction were determined by flow cytometry. In six decidual samples, concurrent immunohistochemical staining was performed. Higher percentages of CD56dim CD16+ NK cells and CD56- CD16+ cells were found in decidua basalis in comparison to decidua parietalis. In contrast, the percentage of CD56bright CD16- uterine NK cells was significantly higher in decidua parietalis. Immunohistochemical quantification supported flow cytometric results. We conclude that significant differences exist with respect to the distribution of NK cells in term decidua basalis and parietalis. Future functional studies may improve our understanding of their role at the maternal-fetal interface.     

Different immunoregulatory components at the decidua basalis of oocyte donation pregnancies

Oocyte donation (OD) pregnancies are characterized by more fetal-maternal human leukocyte antigen (HLA) mismatches compared with naturally conceived (NC) and in vitro fertilization (IVF) pregnancies. The maternal immune system has to cope with greater immunogenetic dissimilarity, but involved immunoregulation remains poorly understood. We examined whether the amount of regulatory T cells (Tregs) and immunoregulatory cytokines in decidua basalis of OD pregnancies differs from NC and IVF pregnancies. The cohort included 25 OD, 11 IVF and 16 NC placentas, maternal peripheral blood, and umbilical cord blood of uncomplicated pregnancies. Placenta slides were stained for FOXP3, IL-10, IL-6, gal-1, TGF-β and Flt-1. Semi-quantitative (FOXP3+ Tregs) and computerized analysis (cytokines) were executed. The blood samples were typed for HLA class I and II to calculate fetal-maternal HLA mismatches. The percentage of Tregs was significantly higher in pregnancies with 4–6 HLA class I mismatches (n = 17), compared to 0–3 mismatches (n = 35; p = 0.04). Cytokine analysis showed significant differences between OD, IVF and NC pregnancies. Flt-1 was significantly lower in pregnancies with 4–6 HLA class I mismatches (p = 0.004), and in pregnancies with 6–10 HLA mismatches in total (p = 0.024). This study suggests that immunoregulation at the fetal-maternal interface in OD pregnancies with more fetal-maternal HLA mismatches is altered.     

Scanning electron microscopy of the decidual stalk and decidua basalis in the mouse

Summary Placentas either in situ or mechanically separated from their uterine beds were surveyed by scanning electron microscopy to determine the changing relationship of the placenta to its uterine bed with special reference to alteration in the decidua basalis accompanying parturition.At 13 days gestation the placenta is connected to the uterus by a short, broad decidual stalk which becomes longer and more constricted by term. The stalk is covered by a layer of squamous epithelium. Mechanical separation of the placenta and uterus in early gestation reveals that the entire decidua basalis of the decidual stalk is composed of large coarse fibers. As gestation progresses, a relatively smooth acellular capsule forms around the base of the placenta. However, the center of the decidua basalis, the core of the stalk, continues to be composed of large coarse fibers throughout gestation and appears to be the only region penetrated by maternal vessels.     

Immunohistochemical localization of progesterone receptor in human decidua of early pregnancy.

Rat monoclonal antibodies to human progesterone receptor were used for immunolocalization studies in human decidua of early pregnancy. Frozen sections of 42 specimens of decidua were stained by the peroxidase-antiperoxidase method (PAP). Progesterone receptor was localized exclusively in the nuclei of decidual and myometrial cells with no specific staining in the cytoplasm. In the decidualized endometrium, stroma were always positively stained. Smooth muscle, pericyte and endothelial cells of blood vessels were extensively stained. Glandular epithelia showed variation in staining, which was positive in the basal but very weak or negative in the superficial layer of the decidua. No specific staining could be detected in the control sections. Of special interest was the positive staining of the endothelium of decidual blood vessels, a finding which has not been reported previously. The cells of the inner lining of vessels that stained with the antiprogesterone receptor antibodies were also Factor VIII positive, thus confirming the endothelial nature of these cells. It is concluded from these results that endothelial cells from human first trimester decidua express progesterone receptors.     

Cytokine secretion patterns of NK cells and macrophages in early human pregnancy decidua and blood: implications for suppressor macrophages in decidua

PROBLEM: Local immune modulation has been shown to be of considerable importance for the maintenance of successful pregnancy. We have previously reported the secretion of interferon-gamma (IFN-gamma), interleukin-4 (IL-4) and IL-10 in human decidua from early normal pregnancy. The aim of this study was to investigate the cellular source of cytokine secretion in the decidua, and compare this to secretion patterns in peripheral blood. METHOD OF STUDY: Decidual tissue and peripheral blood was collected from 20 women undergoing surgical abortion during first trimester pregnancy. Monocytes/macrophages and NK cells were enriched by immunomagnetic cell separation and cytokine secretion was detected by enzyme-linked immunosorbent spot-forming cell assay. RESULTS: Decidual and peripheral monocytes/macrophages and NK cells spontaneously secrete IFN-gamma, IL-4 and IL-10. The number of IL-10 secreting cells was significantly higher in decidual macrophages compared with decidual non-monocytic cells as well as compared with blood monocytes/macrophages. These differences were not seen for IFN-gamma or IL-4. CONCLUSIONS: Our results indicate that decidual macrophages subserve important suppressive functions in the pregnant uterus.     

Immunolocalization of oestrogen and progesterone receptors in the human decidua in relation to prolactin production

The distribution of oestrogen and progesterone receptors withinthe decidualized stroma of the uterus was examined in earlyand term human pregnancy and the results related to the effectof oestradiol and progesterone on prolactin production by deciduain vitro. In early pregnancy progesterone receptors were presentin the nucleus of decidualized cells of both the capsularisand parietalis but not in glandular cells. In contrast at termprogesterone receptors were located within the cytoplasm ofdecidual cells. Oestrogen receptors were detected only in thenucleus and were present in greater amounts in decidua capsularisthan parietalis in early pregnancy, but were not detectablein term decidua. Both oestrogen and progesterone receptors werepresent in the nuclei of cells of arterioles within the decidua.In early pregnancy prolactin production decreased during in-vitroculture of decidua parietalis but was maintained in deciduacapsularis, associated with an increase in progesterone productionby the decidua capsularis. In term decidua, prolactin productionin vitro was only stimulated by a combination of oestradioland progesterone. These results suggest, firstly, that maintaineddecidualization and prolactin production by decidua capsularisduring treatment of women in early pregnancy with the anti-progestinmifepristone is not due to an absence of progesterone receptor;secondly, there is a shift in immunoreactive progesterone receptorin decidual cells from the nucleus in early pregnancy to thecytoplasm in term pregnancy. This may indicate an alterationin the action of progesterone around the time of parturition;and thirdly, in term decidua, progesterone, apparently actingthrough the cytoplasmic receptor, is active in increasing prolactinproduction in vitro only when combined with oestradiol.     

Linking molecular and cellular events in T-cell activation and synapse formation

The complex sequence of events in which T cells recognize foreign entities on other cells is not well understood. However, the development of new techniques and approaches in both the molecular and cellular aspects of this problem have provided significant insights into the mechanisms of T-cell recognition and synapse formation. In particular, we have a clearer picture of T-cell sensitivity, the role of co-stimulation in formation of the immunological synapse, and how TCR signaling acts to maintain synapse structure and potentiate the T cells over many hours of engagement. We also are aware of new complexities in the way T-cell receptor molecules bind peptide-MHC (pMHC) ligands and what that may mean for TCR scanning, cross-reactivity, and activation. Ultimately, we want to integrate these cellular aspects of T-cell recognition with key features of the molecular interactions that drive specific events.     

Stochasticity and spatial heterogeneity in T-cell activation

Summary: Stochastic and spatial aspects are becoming increasingly recognized as an important factor in T-cell activation. Activation occurs in an intrinsically noisy environment, requiring only a handful of agonist peptide-major histocompatibility complex molecules, thus making consideration of signal to noise of prime importance in understanding sensitivity and specificity. Furthermore, it is widely established that surface-bound ligands are more effective at activation than soluble forms, while surface patternation has highlighted the role of spatial relocation in activation. Here we consider the results of a number of models of T-cell activation, from a realistic model of kinetic segregation-induced T-cell receptor (TCR) triggering through to simple queuing theory models. These studies highlight the constraints on cell activation by a surface receptor that recruits kinases. Our analysis shows that TCR triggering based on trapping of bound TCRs in regions of close proximity that exclude large ectodomain-containing molecules, such as the phosphatases CD45 and CD148, can effectively reproduce known signaling characteristics and is a viable ‘signal transduction’ mechanism distinct from oligomerization and conformation-based mechanisms. A queuing theory analysis shows the interrelation between sensitivity and specificity, emphasizing that these are properties of individual cell functions and need not be, nor are likely to be, uniform across different functions. In fact, threshold-based mechanisms of detection are shown to be poor at ligand discrimination because, although they can be highly specific, that specificity is limited to a small range of peptide densities. Time integration mechanisms however are able to control noise effectively, while kinetic proofreading mechanisms endow them with good specificity properties. Thus, threshold mechanisms are likely to be important for rapidly detecting minimal signaling requirements, thus achieving efficient scanning of antigen-presenting cells. However, for good specificity, time integration on a scale of hours is required.     

V-chain preference of gamma/delta T-cell receptors in peripheral blood during term labor

PROBLEM: An altered function of the maternal immune system creates a favorable environment for the developing fetus during pregnancy. At term, new regulatory mechanisms are activated, to initiate labor. Earlier we showed that in peripheral blood of pregnant women gamma/delta T cells of cytotoxic phenotype are replaced by those of a non-cytotoxic phenotype. Here we studied the Vgamma and Vdelta chain usage of peripheral gamma/delta T cells from women in labor. METHOD OF STUDY: Vgamma and Vdelta chain expression on peripheral blood lymphocytes obtained at the 3rd trimester of pregnancy and during parturition were examined by immuncytochemistry and flow cytometry. RESULTS: Increased % of Vgamma9/Vdelta2 and decreased % of Vgamma4/Vdelta1 T cells were found in peripheral blood during labor, together with unaltered percentages of single Vgamma+ or Vdelta+ cells. The initially high Vgamma4/Vdelta1 to Vgamma9/Vdelta2 ratio decreased during labor. CONCLUSION: The initiation of labor is characterized by an altered V-chain usage of gamma/delta T cells.     

Accumulation of CD16-CD56+ natural killer cells with high affinity interleukin 2 receptors in human early pregnancy decidua.

Most human peripheral blood natural killer (NK) cells express the phenotype CD16+CD56+. However, a very minor subset of NK cells express CD16-CD56+, and these NK cells bear both interleukin 2 receptor (IL-2R)alpha (p55) and IL-2R beta (p75) (high affinity IL-2 receptors). In this report, we demonstrate that in human early pregnancy decidua--an interface between maternal immunocompetent cells and fetus (placenta)--abundant (approximately 83%) CD16-CD56+ NK cells with high affinity IL-2 receptors were present, and these cells responded to low amounts of IL-2 (4.5 pM). These CD16-CD56+ NK cells significantly expressed an early activation antigen, CD69, in vivo, whereas peripheral CD16-CD56+ NK cells did not express CD69. These findings suggest that CD16-CD56+ NK cells in early pregnancy decidua may be activated in vivo, and may play an important role in immunoregulation during early pregnancy. Also, decidual lymphocytes may be useful materials to study the mechanism of MHC-unrestricted cytotoxicity of this type of NK cells.     

Altered collagen II peptides inhibited T-cell activation in rheumatoid arthritis

It has been reported that collagen II (CII)-derived peptide induced T-cell activation via its amino acids responsible for T-cell receptor (TCR) recognition. In this study, three altered CII263-272 peptide ligands (APL) containing multiple substitutions of TCR contact residues were synthesized. Their roles in inhibition of T-cell activation were evaluated in peripheral blood lymphocytes (PBL) of rheumatoid arthritis (RA) in vitro. It was shown that 41% (25/61) of RA patients were responsive to the wild-type antigenic CII263-272. In contrast, marginal or silent T-cell responses to the three APLs were found, accompanied by inhibitory effects on secretion of Th1 type cytokines and expression of cell surface markers, CD69 and CD25. In addition, T-cell activation induced by the wild-type antigenic CII263-272 was inhibited by all the three APLs in a dose-dependent manner. It is demonstrated that APLs with substitutions of TCR contact residues are capable of down-regulating T-cell responses in PBLs of RA, suggesting that the CII-derived APLs are potentially therapeutic in RA.     

Role of monocytes in anti-CD3-induced T-cell DNA synthesis: Effect of chloroquine and monensin on anti-CD3-induced human T-cell activation

Anti-CD3 monoclonal antibody (MoAb) induces proliferation of freshly isolated peripheral blood T cells only in the presence of monocytes/macrophages and requires binding of the Fc portion of antibody to monocytes/macrophages. In this investigation, we examined whether monocytes process anti-CD3 similar to any soluble antigen and present to T cells in context with HLA-DR to induce maximal DNA synthesis. Adherent monocytes were pulsed with anti-CD3 MoAb in the presence or absence of the lysozomotropic agents chloroquine and monensin, which are known to inhibit processing of soluble antigens, washed extensively, and then incubated with autologous T cells in the absence of soluble anti-CD3, and³H-thymidine incorporation and CD25 expression were measured. Both monensin and chloroquine inhibited anti-CD3-pulsed monocyte-induced T-cell DNA synthesis and CD25 expression in a dose-dependent manner. This inhibitory effect was not due to any loss in cell viability or the effect on the expression of HLA-DR on monocytes. Paraformaldehyde-fixed monocytes pulsed with anti-CD3 MoAb induced significantly less DNA synthesis, HLA-DR expression, and CD25 antigen expression on autologous T cells as compared to responses induced by unfixed anti-CD3-pulsed monocytes. The treatment of anti-CD3-pulsed monocytes with frame-work-specific anti-HLA-DR MoAb inhibited their capacity to induce T-cell DNA synthesis. These data suggest that monocytes, in addition to serving as the matrix for cross-linking, also process anti-CD3 MoAb and present to the T cells in the context of HLA-DR antigens to induce optimal DNA synthesis.     

丙酸睾丸酮、米非司酮对早孕蜕膜、绒毛组织超微结构的影响

使用透射电镜观察丙酸睾丸酮（丙睾）、米非司酮、或两者合用对早孕蜕膜、绒毛组织超微结构的影响。结果表明：丙睾组出现蜕膜细胞缩小、结构不清、核固缩、合体滋养细胞核密度增高、核膜不清等严重改变。米非司酮组则见合体滋养层细胞内质网扩大、溶酶体增多、微绒毛减少、细胞核异染色质边聚；朗罕细胞线粒体肿胀、空泡变、细胞核异染色质边聚等严重损害改变。而两药合用组出现较其中任何一组更严重的损害作用（Ｐ＜０．０１）。揭示了丙睾和米非司酮有协同的抗早孕作用，对应用于临床抗早孕提高完全流产率、减少流产过程出血量及缩短流产后阴道出血时间提供了可靠的理论依据。     

Stability of neuronal number in the human nucleus basalis of Meynert with age

Numbers of neurons in the nucleus basalis of Meynert were estimated in seventeen non-demented patients who died of chronic hepatic or cardiopulmonary disease. Neurons were counted at the site of maximal neuronal density (SMND). This site was chosen by reviewing serial sections around the decussation of the anterior commissure and appeared to be comparable in different individuals. No correlation between numbers of neurons and age could be found. It appears that no uniform neuronal loss occurs in the nucleus basalis with age. Taken together with biochemical studies of cerebral cortical choline acetyltransferase activity, these findings suggest that there is no overall change in cholinergic input to cerebral cortex with age.     

Impaired T-cell activation in patients with systemic lupus erythematosus

Interleukin-2 (IL-2) production was studied in T lymphocytes from 32 patients with systemic lupus erythematosus (SLE) and 27 healthy volunteers. The IL-2 production by phytohemagglutinin (PHA)-stimulated cells from SLE patients was significantly depressed compared to control values, with a correlation between degree of depression and disease activity. The depressed IL-2 production by SLE T cells are largely reversed by the addition of either phorbol ester (PMA) or partially by a calcium ionophore. SLE T cells had significantly lower peak increases in intracellular free calcium ([Ca²⁺]_i) than controls after stimulation by PHA or by a monoclonal antibody against the CD3 antigen. This abnormality was found even in T cells from patients with mild disease activity or in those whose T cells produced normal amounts of IL-2. Calcium ionophore produced similar increases in [Ca²⁺]_i in SLE patients as in normals. These results suggest that a major component of the defect responsible for decreased IL-2 production by SLE lymphocytes is proximal to protein kinase C activation and may involve impaired signal transduction after activation of the antigen receptor complex.