Browsing by Author "Hashimi, Marziah"

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Antiviral responses in a Jamaican fruit bat intestinal organoid model of SARS-CoV-2 infection
(Springer Science and Business Media LLC, 2023-10) Hashimi, Marziah; Sebrell, T. Andrew; Hedges, Jodi F.; Snyder, Deann; Lyon, Katrina N.; Byrum, Stephanie D.; Mackintosh, Samuel G.; Crowley, Dan; Cherne, Michelle D.; Skwarchuk, David; Robison, Amanda; Sidar, Barkan; Kunze, Anja; Loveday, Emma K.; Taylor, Matthew P.; Chang, Connie B.; Wilking, James N.; Walk, Seth T.; Schountz, Tony; Jutila, Mark A.; Bimczok, Diane
Bats are natural reservoirs for several zoonotic viruses, potentially due to an enhanced capacity to control viral infection. However, the mechanisms of antiviral responses in bats are poorly defined. Here we established a Jamaican fruit bat (JFB, Artibeus jamaicensis) intestinal organoid model of severe acute respiratory syndrome coronavirus-2 (SARS-CoV-2) infection. Upon infection with SARS-CoV-2, increased viral RNA and subgenomic RNA was detected, but no infectious virus was released, indicating that JFB organoids support only limited viral replication but not viral reproduction. SARS-CoV-2 replication was associated with significantly increased gene expression of type I interferons and inflammatory cytokines. Interestingly, SARS-CoV-2 also caused enhanced formation and growth of JFB organoids. Proteomics revealed an increase in inflammatory signaling, cell turnover, cell repair, and SARS-CoV-2 infection pathways. Collectively, our findings suggest that primary JFB intestinal epithelial cells mount successful antiviral interferon responses and that SARS-CoV-2 infection in JFB cells induces protective regenerative pathways.
Expression and purification of two CRISPR-CAS proteins, Csm3 and Csm5 from Mycobacterium tuberculosis
(Montana State University - Bozeman, College of Letters & Science, 2015) Hashimi, Marziah; Chairperson, Graduate Committee: C. Martin Lawrence
One third of the World's population is infected with tuberculosis (TB). TB disease is caused by bacterium called Mycobacterim tuberculosis, which is a facultative intracellular parasite that is transferred through the air from one person to another in close contact. A six month course of four antimicrobial drugs is the only current treatment for drug-sensitive TB. However, multi-drug resistance TB is difficult to treat. Phage therapy might be one answer as a treatment for multi-drug resistance TB. In order for phage therapy to have a chance against TB, the immune system of bacteria, known as CRISPR/Cas needs to be inhibited. Our lab has taken a structural and biochemical approach to try to understand the CRISPR/Cas system in M. tuberculosis. We have cloned, expressed, and purified individual Csm proteins from the H37Rv M. tuberculosis strain. Two Csm protein, Csm3 and Csm5 were successfully purified to homogeneity in yields suitable for structure and biochemical studies. While to date, each has failed to produce crystals, the ability to the express and purify each of these proteins will allow further biochemical characterization of Csm3 and Csm5.
A Novel Gastric Spheroid Co-culture Model Reveals Chemokine-Dependent Recruitment of Human Dendritic Cells to the Gastric Epithelium
(2019-03) Sebrell, Thomas A.; Hashimi, Marziah; Sidar, Barkan; Wilkinson, Royce A.; Kirpotina, Liliya; Quinn, Mark T.; Malkoc, Zeynep; Taylor, Paul J.; Wilking, James N.; Bimczok, Diane
Background & Aims Gastric dendritic cells (DCs) control the adaptive response to infection with Helicobacter pylori, a major risk factor for peptic ulcer disease and gastric cancer. We hypothesize that DC interactions with the gastric epithelium position gastric DCs for uptake of luminal H pylori and promote DC responses to epithelial-derived mediators. The aim of this study was to determine whether the gastric epithelium actively recruits DCs using a novel co-culture model of human gastric epithelial spheroids and monocyte-derived DCs. Methods Spheroid cultures of primary gastric epithelial cells were infected with H pylori by microinjection. Co-cultures were established by adding human monocyte-derived DCs to the spheroid cultures and were analyzed for DC recruitment and antigen uptake by confocal microscopy. Protein array, gene expression polymerase chain reaction array, and chemotaxis assays were used to identify epithelial-derived chemotactic factors that attract DCs. Data from the co-culture model were confirmed using human gastric tissue samples. Results Human monocyte-derived DCs co-cultured with gastric spheroids spontaneously migrated to the gastric epithelium, established tight interactions with the epithelial cells, and phagocytosed luminally applied H pylori. DC recruitment was increased upon H pylori infection of the spheroids and involved the activity of multiple chemokines including CXCL1, CXCL16, CXCL17, and CCL20. Enhanced chemokine expression and DC recruitment to the gastric epithelium also was observed in H pylori–infected human gastric tissue samples. Conclusions Our results indicate that the gastric epithelium actively recruits DCs for immunosurveillance and pathogen sampling through chemokine-dependent mechanisms, with increased recruitment upon active H pylori infection.
P38 MAPK signaling mediates retinoic acid‐induced CD103 expression in human dendritic
(2020-11) Roe, Mandi M.; Hashimi, Marziah; Swain, Steve; Woo, Krista M.; Bimczok, Diane
Retinoic acid (RA) is an active derivative of vitamin A and a key regulator of immune cell function. In dendritic cells (DCs), RA drives the expression of CD103 (integrin αE), a functionally relevant DC subset marker. In this study, we analyzed the cell type specificity and the molecular mechanisms involved in RA-induced CD103 expression. We show that RA treatment caused a significant up-regulation of CD103 in differentiated monocyte-derived DCs and blood DCs, but not in differentiated monocyte-derived macrophages or T cells. DC treatment with an RA receptor α (RARα) agonist led to an increase in CD103 expression similar to that in RA treatment, whereas RARA gene silencing with small interfering RNA blocked RA-induced up-regulation of CD103, pointing to a major role of RARα in the regulation of CD103 expression. To elucidate RA-induced signaling downstream of RARα, we used Western blot analysis of RA-treated DCs and showed a significant increase of p38 mitogen-activated protein kinase (MAPK) phosphorylation. In addition, DCs cultured with RA and a p38 MAPK inhibitor had a significantly reduced expression of CD103 compared with DCs cultured with RA only, indicating that p38 MAPK is involved in CD103 regulation. In summary, these findings suggest that the RA-induced expression of CD103 is specific to DCs, is mediated primarily through RARα and involves p38 MAPK signaling.
Severe Acute Respiratory Syndrome Coronavirus 2 Is Detected in the Gastrointestinal Tract of Asymptomatic Endoscopy Patients but Is Unlikely to Pose a Significant Risk to Healthcare Personnel
(Elsevier, 2022-06) Cherne, Michelle D.; Gentry, Andrew B.; Nemudraia, Anna; Nemudryi, Artem; Hedges, Jodi F.; Walk, Heather; Blackwell, Karlin; Snyder, Deann T.; Jerome, Maria; Madden, Wyatt; Hashimi, Marziah; Sebrell, T. Andrew; King, David B.; Plowright, Raina K.; Jutila, Mark A.; Wiedenheft, Blake; Bimczok, Diane
Background and aims. Recent evidence suggests that the gut is an additional target for severe acute respiratory syndrome coronavirus 2 (SARS CoV-2) infection. However, whether SARS-CoV-2 spreads via gastrointestinal secretions remains unclear. To determine the prevalence of gastrointestinal SARS-CoV-2 infection in asymptomatic subjects, we analyzed gastrointestinal biopsy and liquid samples from endoscopy patients for the presence of SARS-CoV-2. Methods. We enrolled 100 endoscopic patients without known SARS-CoV-2 infection (cohort A) and 12 patients with a previous COVID-19 diagnosis (cohort B) in a cohort study performed at a regional hospital. Gastrointestinal biopsies and fluids were screened for SARS-CoV-2 by polymerase chain reaction (PCR), immunohistochemistry, and virus isolation assay, and the stability of SARS CoV-2 in gastrointestinal liquids in vitro was analyzed. Results. SARS-CoV-2 ribonucleic acid was detected by PCR in the colonic tissue of 1/100 patients in cohort A. In cohort B, 3 colonic liquid samples tested positive for SARS-CoV-2 by PCR and viral nucleocapsid protein was detected in the epithelium of the respective biopsy samples. However, no infectious virions were recovered from any samples. In vitro exposure of SARS-CoV-2 to colonic liquid led to a 4-log-fold reduction of infectious SARS-CoV-2 within 1 hour (P ≤ .05). Conclusion. Overall, the persistent detection of SARS-CoV-2 in endoscopy samples after resolution of COVID-19 points to the gut as a long term reservoir for SARS-CoV-2. Since no infectious virions were recovered and SARS-CoV-2 was rapidly inactivated in the presence of colon liquids, it is unlikely that performing endoscopic procedures is associated with a significant infection risk due to undiagnosed asymptomatic or persistent gastrointestinal SARS-CoV-2 infections.
Using gastrointestestinal organoids to study infectious diseases in humans and bats
(Montana State University - Bozeman, College of Agriculture, 2021) Hashimi, Marziah; Chairperson, Graduate Committee: Diane Bimczok; This is a manuscript style paper that includes co-authored chapters.
The gastrointestinal epithelium plays a critical role in protecting the gastrointestinal mucosa from invading microorganism such as bacteria or a viruses. Helicobacter pylori (H. pylori) infection of human gastric epithelium causes gastric cancer, which is the third leading cause of cancer-related mortality worldwide. Dendritic cells (DCs)--which are antigen presenting cells--are responsible for the activation of T cells. However, the mechanism by which DCs are recruited to the gastric epithelium is still unknown. We hypothesized that the DCs are recruited to the gastric epithelium in a chemokine- dependent manner. For my thesis work, I utilized human primary gastric epithelial organoids cells to test this hypothesis and evaluate the recruitment of DCs to the epithelium under normal conditions and upon H. pylori infection. Using monocyte-derived DCs in a chemotaxis assay, I showed that these cells are recruited to H. pylori-infected organoid supernatant. I showed that this recruitment is chemokine- dependent, as it was significantly decreased when a chemokine receptor inhibitor was included in the chemotaxis assay. COVID-19 is caused by severe respiratory syndrome coronavirus-2 (SARS-CoV-2). In addition to respiratory symptoms, COVID-19 patients can also have diarrhea and vomiting, indicating that SARS-CoV-2 may infect the gastrointestinal tract. Bats are thought to be the natural reservoirs for SARS-CoV-2, however there is no known bat gastrointestinal model to study SARS-CoV-2 infection. In the second part of my thesis, I developed Jamaican fruit bat (JFB), Artibeus jamaicensis) gastrointestinal organoids (JFB organoids). I successfully developed organoids from JFB stomach, proximal and distal intestine. I showed via histology and gene expression that developed organoids do indeed recapitulate their corresponding tissues from which they were derived. I also tested whether the JFB distal intestinal organoids were susceptible to SARS-CoV-2 infection. While they do not support the active replication of SARS-CoV-2 infection, they did show antiviral and pro-inflammatory responses. My results also showed that SARS-CoV-2 does not induce programmed cell death in the organoids.