Project description:Shiga toxins (Stxs) are bacterial cytotoxins produced by the enteric pathogens Shigella dysenteriae serotype 1 and some serotypes of Escherichia coli that cause bacillary dysentery and hemorrhagic colitis, respectively. To date, approaches to studying the capacity of Stxs to alter gene expression in intoxicated cells have been limited to individual genes. However, it is known that many of the signaling pathways activated by Stxs regulate the expression of multiple genes in mammalian cells. To expand the scope of analysis of gene expression and to better understand the underlying mechanisms for the various effects of Stxs on cell functions, we carried out comparative microarray analyses to characterize the global transcriptional response of human macrophage-like THP-1 cells to Shiga toxin type 1 (Stx1) and LPS. Data were analyzed using a rigorous combinatorial approach with three separate statistical algorithms. Thirty-six genes met the criteria of up-regulated expression in response to Stx1 treatment with 14 genes uniquely up-regulated by Stx1. Microarray data were validated by real time RT-PCR for genes encoding Egr-1 (transcriptional regulator), COX-2 (inflammation), and DUSP1, 5 and 10 (regulation of MAPK signaling). Stx1-mediated signaling through ERK1/2 and Egr-1 appears to be involved in the increased expression of the proinflammatory mediator TNF-Î±. Activation of COX-2 expression is associated with the increased production of proinflammatory and vasoactive eicosanoids. However, the capacity of Stx1 to increase the expression of genes encoding phosphatases suggests that mechanisms to dampen the macrophage proinflammatory response may be built into host response to the toxins. Three separate experiments were performed for each of three treatment types: 3 untreated controls, 3 Stx-1 treated cell (400 ng/ml for 6h), 3 LPS-stimulated cells (200 ng/ml for 6h). Total RNA was isolated, processexc, and hybridized to a total of 9 Affymetrix human HG U133 arrays.

Project description:HIV-1 infections of women are mainly acquired through female reproductive tract where cervical and vaginal epithelial cells are the first line of defense. Although HIV-1 does not directly infect epithelial cells, HIV-1 obligatorily interacts with and crosses over epithelial layer to infect susceptible target cells, mainly CD4+ T cells, in the lamina propria to initiate an infection. However, the mechanism and ramification of the interaction of HIV-1 and epithelial cells in vaginal transmission of HIV-1 remain to be elucidated. We hypothesized that cervical epithelial cells are not a passive barrier, but actively respond to HIV-1 to change mucosal milieu and facilitate HIV-1 transmission. We tested this hypothesis by studying the responses of cervical epithelial cells to HIV-1 through profiling genome-wide transcription. We found 1) cervical epithelial cells actively respond to HIV-1. Five hundred forty-three transcripts/genes in cervical epithelial cells were significantly altered in expression at four hours post exposure to HIV-1, of which many relate to important signaling pathways, such as innate immune responses, pattern recognition receptors, apoptosis, biosynthesis, and energy production, 2) HIV-1 increases the expression of CXC Chemokines (IL-8, CXCL1 and CXCL3) in cervical epithelial cells. IL-8 and CXCL1 are potent chemotactic for multinuclear neutrophils (MNP), monocytes and a minority of lymphocytes, and CXCL3 is predominant chemotactic for monocytes, 3) HIV-1 increases the expression of key inflammatory enzymes-COX-1 and COX-2. COX-1 is responsible for the production of prostaglandins that are important for homeostatic functions, and COX-2 is a key enzyme to convert arachidonic acid to prostaglandins, key inflammatory mediators, and 4) the increased expression of IL-8 and COX-2 revealed using microarray analysis was mapped into the endocervical epithelial cells of macaques inoculated with inactivated SIV in vivo. Our date lead to a role model of epithelial cells in HIV-1 vaginal transmission, that is the axis of HIV-1, epithelial cells, proinflammatory molecules (IL-8, CXCL1, CXCL3, COX-1 and COX-2), cell recruitment (MNP, monocytes and T cells), and inflammation. This model implies that moderating epithelial proinflammatory response to HIV-1 may be utilized in prevention of HIV vaginal transmission. Human endocervical epithelial cell line, CRL-2615, was inoculated with HIV-1 ME1 and collected 4hrs post exposure. Biologically duplicated mRNAs were prepared after exposure.

Project description:HIV-1 infections of women are mainly acquired through female reproductive tract where cervical and vaginal epithelial cells are the first line of defense. Although HIV-1 does not directly infect epithelial cells, HIV-1 obligatorily interacts with and crosses over epithelial layer to infect susceptible target cells, mainly CD4+ T cells, in the lamina propria to initiate an infection. However, the mechanism and ramification of the interaction of HIV-1 and epithelial cells in vaginal transmission of HIV-1 remain to be elucidated. We hypothesized that cervical epithelial cells are not a passive barrier, but actively respond to HIV-1 to change mucosal milieu and facilitate HIV-1 transmission. We tested this hypothesis by studying the responses of cervical epithelial cells to HIV-1 through profiling genome-wide transcription. We found 1) cervical epithelial cells actively respond to HIV-1. Five hundred forty-three transcripts/genes in cervical epithelial cells were significantly altered in expression at four hours post exposure to HIV-1, of which many relate to important signaling pathways, such as innate immune responses, pattern recognition receptors, apoptosis, biosynthesis, and energy production, 2) HIV-1 increases the expression of CXC Chemokines (IL-8, CXCL1 and CXCL3) in cervical epithelial cells. IL-8 and CXCL1 are potent chemotactic for multinuclear neutrophils (MNP), monocytes and a minority of lymphocytes, and CXCL3 is predominant chemotactic for monocytes, 3) HIV-1 increases the expression of key inflammatory enzymes-COX-1 and COX-2. COX-1 is responsible for the production of prostaglandins that are important for homeostatic functions, and COX-2 is a key enzyme to convert arachidonic acid to prostaglandins, key inflammatory mediators, and 4) the increased expression of IL-8 and COX-2 revealed using microarray analysis was mapped into the endocervical epithelial cells of macaques inoculated with inactivated SIV in vivo. Our date lead to a role model of epithelial cells in HIV-1 vaginal transmission, that is the axis of HIV-1, epithelial cells, proinflammatory molecules (IL-8, CXCL1, CXCL3, COX-1 and COX-2), cell recruitment (MNP, monocytes and T cells), and inflammation. This model implies that moderating epithelial proinflammatory response to HIV-1 may be utilized in prevention of HIV vaginal transmission.

Dataset Information

Global transcriptional response of macrophage-like THP-1 cells

Dataset's files

Similar Datasets

OmicsDI is part of the ELIXIR infrastructure

Tweets