CD200S-positive granulated lymphoid cells in endometrium appear to be CD56-positive uterine NK cells.

The eutopic secretory phase endometrium in endometriosis overproduces and releases a soluble immunosuppressive CD200 molecule (CD200L) and is populated by stromal cells that contain a truncated CD200 (CD200S) that promotes a proinflammatory environment. The CD200S+ cell population persists when pregnancy occurs and are abundant in the early pregnancy decidua of women with missed abortion. In the present study, CD200S+, CD56+, and CD68+ cells were enumerated in formalin-fixed paraffin-embedded tissue sections from women with endometriosis and non-endometriosis controls. CD200S+ cells were more numerous than CD68+ macrophages and were similar in number and location to CD56bright endometrial NK cells. In some endometria, there was an additional population of CD200S- CD56+ NK cells. In ectopic endometrial peritoneal deposits and in ectopic myometrial deposits (adenomyosis), CD200S+ cells were less frequent, consistent with the known paucity of CD56+ NK cells in sites of ectopic deposits. CD200S+ cell frequency was greater in stroma surrounding the smaller ectopic cystic deposits. Dual immunofluorescent antibody staining confirmed CD200S+ cells were CD56+ NK cells. CD200S+ NK cell frequency may be greater in endometriosis patients' endometrium and may affect embryo survival in early pregnancy. In our opinion, regulation of alternative splicing that results in CD200S rather than CD200L may provide new diagnostic and therapeutic options for women with endometriosis.

EFFECT OF LACTOBACILLUS POSTBIOTICS ON ENTAMOEBA HISTOLYTICA TROPHOZOITES.

BACKGROUND: Amebiasis is an infectious disease caused by Entamoeba histolytica. It represents one of the three worldwide leading causes of death by parasites and a public health problem due to its frequency, morbidity, mortality, and easy dispersion. OBJECTIVE: The study was aimed to evaluate the in vitro effect of Lactobacillus spp. postbiotics on E. histolytica trophozoites (HM1-IMSS strain) and to determine morphometric changes in trophozoite membrane by atomic force microscopy (AFM). METHODS: Bioassays on trophozoites were conducted with lyophilized postbiotics at 0.1, 0.3, and 0.5 mg/mL concentrations, and trophozoite samples were obtained for AFM analysis. RESULTS: Results indicated postbiotic inhibitory activity; the highest percentage inhibition was 89.63% at 0.5 mg/mL. Trophozoites nanomechanical analysis showed 28.32% increase in ruggedness and 56% decrease in size with treatments compared to the control. CONCLUSION: Our study showed that the synergy of Lactobacillus postbiotics inhibited E. histolytica HM1-IMSS in vitro growth under axenic conditions, inducing morphometric alterations in trophozoites' cell membrane. These results would allow designing strategies or treatments aimed at E. histolytica control in the future.

Effect of lactobacillus postbiotics on entamoeba histolytica trophozoites

ABSTRACT Background Amebiasis is an infectious disease caused by Entamoeba histolytica. It represents one of the three worldwide leading causes of death by parasites and a public health problem due to its frequency, morbidity, mortality, and easy dispersion. Objective The study was aimed to evaluate the in vitro effect of Lactobacillus spp. postbiotics on E. histolytica trophozoites (HM1-IMSS strain) and to determine morphometric changes in trophozoite membrane by atomic force microscopy (AFM). Methods Bioassays on trophozoites were conducted with lyophilized postbiotics at 0.1, 0.3, and 0.5 mg/mL concentrations, and trophozoite samples were obtained for AFM analysis Results Results indicated postbiotic inhibitory activity; the highest percentage inhibition was 89.63% at 0.5 mg/mL. Trophozoites nanomechanical analysis showed 28.32% increase in ruggedness and 56% decrease in size with treatments compared to the control. Conclusion Our study showed that the synergy of Lactobacillus postbiotics inhibited E. histolytica HM1-IMSS in vitro growth under axenic conditions, inducing morphometric alterations in trophozoites’ cell membrane. These results would allow designing strategies or treatments aimed at E. histolytica control in the future.

Soluble CD200 in secretory phase endometriosis endometrial venules may explain endometriosis pathophysiology and provide a novel treatment target.

Retrograde menstruation is common and in about 10% of women, endometrial tissues implant at ectopic sites and grow as endometriosis (EM) deposits. To date, there has been no marker to identify which patients have an endometrium that will generate deposits. Both endometrial regulatory T cells (Tregs) and increased stromal cell indoleamine 2,3-dioxygenase (IDO) have been implicated, and may suppress rejection by peritoneal NK cells, neutrophils, and cytotoxic macrophages. CD200 is a tolerance signaling molecule which promotes Tregs, IDO-producing macrophages, and can directly inhibit cytolytic natural killer (NK) cells and neutrophils. To determine if CD200 might be overexpressed in the endometrium of women with endometriosis, a pilot study using quantitative immunohistochemistry was done using uterine sections and EM deposits from hysterectomy patients. Both CD200 and CD200R proteins were detectable in endometriosis (EM) deposits and in endometrial epithelium and stroma. CD200 increased slightly in secretory phase whole endometrium of EM patients, but strikingly increased soluble CD200 (sCD200) absent sCD200R within venules typified both endometriosis deposits and secretory phase endometrial stromal venules and lymphatics in EM endometria compared to secretory phase NE endometria (P = 0.000006). In our opinion, accumulation of sCD200 in secretory phase endometrial blood vessels may explain development of ectopic deposits and quantifying sCD200 in menstrual blood may cases and identify predisposition to EM. Animal model studies are required to determine if antagonizing CD200 could be therapeutic.

Trophoblast CD200 expression in successful human pregancies and missed abortions.

Presence of the CD200 immune check-point inhibitor at the feto-maternal interface is linked to prevention of spontaneous abortion in mice and humans. In human missed abortions (MA), absence of Th17-driven inflammation has been attributed to expression of villus trophoblast CD200 quantified using immunohistochemistry. While rapid aneuploidy (QF-PCR) testing linked low CD200 to pregnancy failure, data showing normal VT CD200 in first trimester normal pregnancy and in abortion of chromosomally abnormal embryos has not been demonstrated. The present report shows normal CD200 in a 7 week gestation termination with normal male QF-PCR and in a 10 week male trisomy 18 MA.

Changes in expression of the CD200 tolerance-signaling molecule and its receptor (CD200R) by villus trophoblasts during first trimester missed abortion and in chronic histiocytic intervillositis.

PROBLEM: Expression of CD200 at the feto-maternal interface is associated with successful murine and human pregnancy. CD200 binding to CD200 receptors on lymphomyeloid cells suppresses inflammation and induces Tregs. CD200 receptors are also expressed on mouse and human placental trophoblast cells. What is the expression of CD200 and CD200R in human missed abortions which have preserved Treg levels and in chronic histiocytic intervillositis (CHI) where maternal inflammatory cells cause IUGR? METHODS: Immunohistiochemistry for CD200, CD200R, and Ki67 using human placental sections from missed abortions, term placenta, and CHI. PCR testing was done for trisomy in missed abortion. RESULTS: CD200 and CD200R were expressed by human villus trophoblasts from 2 weeks post-implantation to term. Cytotrophoblast proliferation (Ki-67+ count) decreased at term. In first trimester missed abortion cases, CD200>CD200R villus trophoblasts accompanied missed abortion of non-trisomic male fetuses. CD200 and Ki67+ trophoblast proliferation was preserved in CHI with maternal inflammatory cell infiltration but CD200R was greatly decreased. CONCLUSION: Residual CD200 activity may prevent completion of abortions via induction of Treg cells. In CHI, infiltrating maternal effector T cells may block Treg induction. An autocrine role for CD200-CD200R interaction versus inhibition of soluble CD200 by soluble CD200R is discussed.

The CD200 tolerance-signaling molecule and its receptor, CD200R1, are expressed in human placental villus trophoblast and in peri-implant decidua by 5 weeks' gestation.

CD200 expression in murine trophoblast and decidua prevents semi-allogeneic and LPS-induced abortions by binding to CD200 receptor-bearing cells to suppress NK activity, induces IDO in macrophages, and promotes the generation of regulatory T cell subsets. CD200 and its receptor CD200R1 reported in 7-9 weeks' gestation human villus trophoblasts are reduced in spontaneous abortion syncytiotrophoblasts. By specific antibody staining, we find that both CD200 and CD200R1 are expressed even earlier, by 5 weeks' gestation, by villus trophoblasts and by decidual cells. Expression of CD200 was validated using two independent antibodies. CD200-CD200R1 signaling may be required for human pregnancy success.

The Receptor for the CD200 Tolerance-Signaling Molecule Associated with Successful Pregnancy is Expressed by Early-Stage Breast Cancer Cells in 80% of Patients and by Term Placental Trophoblasts.

PROBLEM: The CD200 tolerance-signaling molecule that is expressed by a wide variety of tissues, including placental trophoblast and epithelial tumor cells, lacks an intracytoplasmic tail and must act by binding to CD200 receptors that have a limited expression on lymphomyeloid cells. This binding can inhibit inflammation and NK cells, promote macrophage secretion of indoleamine-2,3 dioxygenase (IDO), and promote generation of Treg cells. Recently, CD200R1 was reported on human first trimester placental villous trophoblast cells. CD200R1 has not been described on malignant tumor cells. As malignant tumor cells exhibit a number of characteristics of trophoblast, is CD200R1 expressed? METHOD OF STUDY: Affinity-purified rabbit polyclonal antibodies to CD200 and CD200R1 were used to immunostain tissue blocks available from cases in a previous cross-sectional study of Stage 1-IIIA human breast cancer cases and term placental trophoblast. RESULTS: Affinity-purified anti-CD200R1 stained primary breast cancer cells and term placental villous trophoblasts. Tumor cells were also stained by anti-CD200 as in a previous study (correlation P = 0.0042), but CD200R1 and CD200 were not correlated. Presence or absence of strong CD200 expression in the tumor did not correlate with metastasis, and a similar result was obtained with CD200R1. CONCLUSIONS: This is the first report of CD200R1 expression by human epithelial tumor cells, and specifically, early-stage human breast cancer cells. It is also the first report of CD200R1 expression by term placental villous trophoblasts. The potential biological significance of CD200R1 expression in non-hematopoietic cells is discussed.

Ocular findings in pediatric deaths under 2 years of age (1994-2004).

Our purpose is to highlight novel ocular findings of 102 forensic pediatric cases under 2 years of age who die suddenly. Forensic information, grossing, and microscopic eye protocol was followed. The most common diagnosis was Sudden Infant Death Syndrome (SIDS) (57/102). Novel cytoid bodies were present in the retina of 72/102 cases and they were located predominantly 90% (65/72) at the anterior part of the retina (p < 0.001). Of the SIDS cases, 85% (47/57) showed the presence of cytoid bodies, and among all diagnosis, SIDS was the most associated with cytoid bodies (p = 0.003). A second observation was extramedullary hematopoiesis (EMH) identified in 35/102 cases and 22 of the 57 SIDS cases. The most frequent EMH location was the choroids (29/35). This study is the first to demonstrate the presence of cytoid bodies and extramedullary hematopoiesis in the retinas of SIDS cases and children who die suddenly from other causes.