Didehydroroflamycoin pentaene macrolide family from Streptomyces durmitorensis MS405(T): production optimization and antimicrobial activity

AimsThe aim of this study was to improve production of pentaene 32,33-didehydroroflamycoin (DDHR) in Streptomyces durmitorensis MS405 strain to obtain quantities sufficient for in depth analysis of antimicrobial properties. Methods and ResultsThrough classical medium optimization conditions for stable growth, DDHR production within 7days of incubation was established. Yields of 215mgl(-1) were achieved in shake flask experiments in complex medium with mannitol as the primary carbon source. DDHR had poor antibacterial activity with minimal inhibitory concentrations (MIC) of 400gml(-1) for Staphylococcus aureus and Bacillus subtilis, while MIC of 70gml(-1) was determined for Candida albicans. Using flow cytometry and fluorescent microscopy, it was demonstrated that DDHR induced membrane damage in C.albicans followed by cell death. Combination studies with known antifungal nystatin showed that DDHR is a promising agent for the development of novel antimycotic treatments potentially less toxic for human cells. ConclusionsPentaene didehydroroflamycoin has no antibacterial activity but can be further developed for the application in antifungal therapy. Significance and Impact of the StudyThis study is the first report on the stable and production in high yields of a novel pentaene family that acts on Candida cell membranes and can be used in combination with known antifungals. Polyenes are still antifungal antibiotics of choice, and therefore, isolation and production of new lead structures are highly significant

Supplementary data for article: Stanković, N.; Šenerović, L.; Bojic-Trbojevic, Z.; Vuckovic, I.; Vicovac, L.; Vasiljevic, B.; Nikodinović-Runić, J. Didehydroroflamycoin Pentaene Macrolide Family from Streptomyces Durmitorensis MS405(T): Production Optimization and Antimicrobial Activity. Journal of Applied Microbiology 2013, 115 (6), 1297–1306. https://doi.org/10.1111/jam.12326

Supporting information for: [https://doi.org/10.1111/jam.12326]Related to published version: [http://cherry.chem.bg.ac.rs/handle/123456789/1438]Related to accepted version: [http://cherry.chem.bg.ac.rs/handle/123456789/3486

Placental syncytiotrophoblast constitutes a major barrier to vertical transmission of Listeria monocytogenes.

Listeria monocytogenes is an important cause of maternal-fetal infections and serves as a model organism to study these important but poorly understood events. L. monocytogenes can infect non-phagocytic cells by two means: direct invasion and cell-to-cell spread. The relative contribution of each method to placental infection is controversial, as is the anatomical site of invasion. Here, we report for the first time the use of first trimester placental organ cultures to quantitatively analyze L. monocytogenes infection of the human placenta. Contrary to previous reports, we found that the syncytiotrophoblast, which constitutes most of the placental surface and is bathed in maternal blood, was highly resistant to L. monocytogenes infection by either internalin-mediated invasion or cell-to-cell spread. Instead, extravillous cytotrophoblasts-which anchor the placenta in the decidua (uterine lining) and abundantly express E-cadherin-served as the primary portal of entry for L. monocytogenes from both extracellular and intracellular compartments. Subsequent bacterial dissemination to the villous stroma, where fetal capillaries are found, was hampered by further cellular and histological barriers. Our study suggests the placenta has evolved multiple mechanisms to resist pathogen infection, especially from maternal blood. These findings provide a novel explanation why almost all placental pathogens have intracellular life cycles: they may need maternal cells to reach the decidua and infect the placenta

Expression of CD82 in Human Trophoblast and Its Role in Trophoblast Invasion

BACKGROUND: Well-controlled trophoblast invasion at maternal-fetal interface is a critical event for the normal development of placenta. CD82 is a member of transmembrane 4 superfamily, which showed important role in inhibiting tumor cell invasion and migration. We surmised that CD82 are participates in trophoblast differentiation during placenta development. METHODOLOGY/PRINCIPAL FINDINGS: CD82 was found to be strongly expressed in human first trimester placental villous and extravillous trophoblast cells as well as in trophoblast cell lines. To investigate whether CD82 plays a role in trophoblast invasion and migration, we further utilized human villous explants culture model on matrigel and invasion/migration assay of trophoblast cell line HTR8/SVneo. CD82 siRNA significantly promoted outgrowth of villous explants in vitro (P<0.01), as well as invasion and migration of HTR8/SVneo cells (P<0.05), whereas the trophoblast proliferation was not affected. The enhanced effect of CD82 siRNA on invasion and migration of trophoblast cells was found associated with increased gelatinolytic activities of matrix metalloproteinase MMP9 while over-expression of CD82 markedly decreased trphoblast cell invasion and migration as well as MMP9 activities. CONCLUSIONS/SIGNIFICANCE: These findings suggest that CD82 is an important negative regulator at maternal-fetal interface during early pregnancy, inhibiting human trophoblast invasion and migration

Placental Galectins Are Key Players in Regulating the Maternal Adaptive Immune Response

Galectins are potent immunomodulators that regulate maternal immune responses in pregnancy and prevent the rejection of the semi-allogeneic fetus that also occurs in miscarriages. We previously identified a gene cluster on Chromosome 19 that expresses a subfamily of galectins, including galectin-13 (Gal-13) and galectin-14 (Gal-14), which emerged in anthropoid primates. These galectins are expressed only by the placenta and induce the apoptosis of activated T lymphocytes, possibly contributing to a shifted maternal immune balance in pregnancy. The placental expression of Gal-13 and Gal-14 is decreased in preeclampsia, a life-threatening obstetrical syndrome partly attributed to maternal anti-fetal rejection. This study is aimed at revealing the effects of Gal-13 and Gal-14 on T cell functions and comparing the expression of these galectins in placentas from healthy pregnancies and miscarriages. First-trimester placentas were collected from miscarriages and elective termination of pregnancies, tissue microarrays were constructed, and then the expression of Gal-13 and Gal-14 was analyzed by immunohistochemistry and immunoscoring. Recombinant Gal-13 and Gal-14 were expressed and purified, and their effects were investigated on primary peripheral blood T cells. The binding of Gal-13 and Gal-14 to T cells and the effects of these galectins on apoptosis, activation marker (CD25, CD71, CD95, HLA-DR) expression and cytokine (IL-1 beta, IL-6, IL-8, IL-10, IFN gamma) production of T cells were examined by flow cytometry. Gal-13 and Gal-14 are primarily expressed by the syncytiotrophoblast at the maternal-fetal interface in the first trimester, and their placental expression is decreased in miscarriages compared to first-trimester controls. Recombinant Gal-13 and Gal-14 bind to T cells in a population- and activation-dependent manner. Gal-13 and Gal-14 induce apoptosis of Th and Tc cell populations, regardless of their activation status. Out of the investigated activation markers, Gal-14 decreases the cell surface expression of CD71, Gal-13 increases the expression of CD25, and both galectins increase the expression of CD95 on T cells. Non-activated T cells produce larger amounts of IL-8 in the presence of Gal-13 or Gal-14. In conclusion, these results show that Gal-13 and Gal-14 already provide an immunoprivileged environment at the maternal-fetal interface during early pregnancy, and their reduced expression is related to miscarriages

Expression of prolactin receptors in the human extra villous cytotrophoblast cell line HTR-8/SVNEO

Prolactin is a pituitary hormone that is widely produced at extrapitutitary locations. One of the first described sites of its production is the decidualized endometrium, suggesting that it could be potentially significant for local processes such as immunomodulation, embryo implantation, and survival. In this study, expression of prolactin receptor protein is investigated by immunocytochemistry and Western blot in the HTR-8/SVneo cell line, often used as a model of first-tri­mester trophoblast. The obtained data enabled us to identify both long and intermediate forms of prolactin receptors, which were shown to be significant in PRL signaling in other tissues