THE
Argo
Official Quarterly Newsletter of the Department of Molecular Genetics & Microbiology at The University of New Mexico School of Medicine
Fall 2021 Volume 1, Issue 4
MGM Research Retreat: On September 30, MGM held its Annual Retreat and also announced awards for the best Works in Progress presentations for 2020-2021.
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Bryce Chackerian, PhD - guest editor
The Argo, MGM Quarterly Newsletter, Fall 2021
Welcome to the fall 2021 edition of The Argo, the official newsletter of the Department of Molecular Genetics and Microbiology (MGM) at The University of New Mexico School of Medicine.
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MGM in the News: Notable recent grants, papers, and achievements
AIM Core Newsletter: MGM is the home of a CoBRE P20 center. Check out all of the latest news from this important resource.
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Highlighting Diversity, Equity and Inclusion
Research Highlights: Read about the research endeavors of MGM graduate students and post-doctoral fellows
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MGM faculty, post-docs, students and staff braved a rare rainy day to share their research, play games, and enjoy good food at the MGM Research day.
2021 MGM Retreat
Julianne Peabody (Graduate Student, Chackerian Lab) and Dr. Bhaskar Saha (Post-doctoral fellow, Mandell Lab) are the recipients of the "best talk" award 2020-2021 MGM Works-In-Progress seminar series. Congratulations to both winners who will each receive $500 to support their research!
Dr. Mary Ann Osley was named a Distinguished Professor at UNM. This rank is awarded to UNM faculty who have demonstrated outstanding achievements and are nationally and internationally renowned as scholars. Congratulations Dr. Osley!
Dr. Kathryn Frietze was featured on KOB and KRQE news to discuss her laboratory's work developing vaccines targeting heroin and fentanyl and recent receipt of an NIH grant to fund these studies.
MGM in the News
Dr. Michael Mandell received his first R01 award entitled "Cellular Responses to Retroviral Capsid Recognition". Congratulations Dr. Mandell!
Dr. Bryce Chackerian was recently interviewed by The Atlantic in an article about the concept of sterilizing immunity and whether vaccines, including SARS-CoV-2 vaccines, can achieve this elusive goal.
Dr. Kiran Bhaskar's laboratory recently published a paper in Cell Reports describing a mechanism in which pathological tau triggers inflammation in the brain. This study was led by Dr. Shanya Jiang. More information on this work can be found here.
This issue of The Argo highlights research by MGM trainees.
Dr. Jesse Young (Ozbun Lab) Human papillomavirus (HPV) infections are transmitted through sexual or other close contact and are etiologically associated with epithelial warts, papillomas, and intraepithelial lesions that may progress to cancer. Indeed, 4.8% of the global cancer burden is linked to HPV infection. Highly effective vaccines protect against two to nine of the most medically important HPV genotypes; yet vaccine uptake is inadequate and/or cost prohibitive in many settings. With HPV-related cancer incidence expected to rise over the coming decades, there is a need for effective HPV microbicides. Herein we demonstrate the strong inhibitory activity of the heparin-neutralizing drug protamine sulfate (PS) against HPV infection. Pre-treatment of cells with PS greatly reduced infection regardless of HPV genotype or virus source. Vaginal application of PS prevented infection of the murine genital tract by HPV pseudovirions. Time-of-addition assays where PS was added to cells before infection, during infection, or after viral attachment demonstrated strong inhibitory activities on early infection steps. No effect on virus infection was found for cell lines deficient in heparan sulfate expression, suggesting that PS binds to heparan sulfate on the cell surface. Consistent with this, prophylactic PS exposure prevented viral attachment, including under low pH conditions akin to the human vaginal tract. Our findings suggest PS acts a dually to prevent HPV infection: prophylactic treatment prevents HPV attachment to host cells and post-attachment administration alters viral entry. Clinical trials are warranted to determine whether protamine-based products are effective as topical microbicides against genital HPVs.
Research Highlights from MGM Trainees
Dr. Young and Dr. El Abidine's work (see next page) was recently accepted into the journal, Antimicrobial Agents and Chemotherapy
Dr. Dandan Wu (Yang Lab) During the COVID-19 pandemic, we as immunologists tried to help out. TH17 cells and associated cytokine storm are considered to be a leading cause of mortality. We tested Fedratinib, an FDA approved JAK2 inhibitor on TH17 cell cytokine production and found that Fedratinib treatment decreased the expression of IL-17 and IL-22 by murine TH17 cells, and this suppressive effect was even more profound when IL-23 was added. Based on this, we proposed Fedratinib as a drug candidate for this disease [J. Microbiol. Immunol. Infect. 53(3): 368–370 (2020)]. Recently, we reanalyzed a published single-cell RNA-Seq dataset and found that bronchoalveolar lavage fluid (BALF) of patients with severe disease compared to those with mild disease contained decreased TH17-type cells (opposite to the blood profile), decreased IFNA1-expressing cells with lower expression of toll-like receptor 7 (TLR7) and TLR8, increased IgA-expressing B cells, and increased hyperactive epithelial cells (and/or macrophages) expressing matrix metalloproteinases (MMPs), hyaluronan synthase 2 (HAS2), and plasminogen activator inhibitor-1 (PAI-1), which may together contribute to the pulmonary pathology in severe COVID-19. We propose IFN-I (and TLR7/TLR8), affecting anti-viral immunity, and PAI-1, promoting coagulation, as potential biomarkers to predict the susceptibility to severe COVID-19. The results were published in Viruses 13(6): 957 (2021). Our current study demonstrate noncanonical activation of unfolded protein responses contribute to TH17 cell-mediated neutrophilic airway inflammation. In the future, we will continuously focus on TH17 cells in inflammation and autoimmunity.
Images showing the effects of protamine sulfate (PS) on HPV infection of HaCaT cells
Dr. Amira Zine El Abidine (Ozbun Lab) Human papillomavirus (HPVs) attach to heparan sulfate proteoglycans (HSPGs) present on the cellular plasma membrane. Current published data suggest that HSPGs are simply transient attachment factors for HPV infections. This is based on the finding that HPV pseudovirions (PsVs) exposed to the cellular proprotein convertase, furin, in cell lysates or in “furin-conditioned medium” (FCM) from furin over-expressing cells can infect HSPG-deficient cells. Furin is well known to cleave the N-terminus of the HPV minor capsid protein, L2, which facilitates the endosomal escape of L2-viral genome complexes during infectious entry. However, furin inhibition does not prevent HPV entry into keratinocytes, suggesting that furin has additional functions during HPV entry. As furin activates matrix metalloproteinases (MMPs), which trigger release of HSPG molecules (“shedding”), we hypothesize that FCM provides soluble HS/HSPG molecules to promote infectious uptake. We are testing this hypothesis by investigating the effects of FCM on wild-type and engineered HPV PsVs and tissue-derived HPV virions. We find that FCM treatment of HPV virions leads to robust infection of HSPG-deficient cells, consistent with previous reports. We determine that FCM contains ≈4-fold more soluble HS compared to normal cells, consistent with the role of furin in activating MMPs. FCM-mediated infection correlates with increased HPV binding to cells. Both cell binding and infectivity are reversed when cells or FCM-treated HPV particles are incubated with HS antagonists, suggesting that FCM provides soluble HS to virions and HPV infection remains HS-dependent. Confocal microscopy data indicate that HS/HSPG molecules remain with HPV virions during endocytosis, implying they may be required for infectious uptake. Interestingly, PsVs containing an L2 “furin pre-cleaved mutant” (FPC-L2) are unable to bind cells/ECM and are noninfectious; however, binding and infection are rescued upon FCM treatment. This suggests that FCM supports virus infection by providing soluble HS, regardless of L2 cleavage. Our data are inconsistent with the idea that furin promotes HSPG-independent infection. We propose a new model wherein furin promotes HS/HSPG decoration of HPV virions, which is essential for HPV infectious uptake.
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Stefan Klimaj (Kell Lab) Orthohantaviruses are negative-sense, single-stranded RNA viruses in the orderBunyavirales. Orthohantaviruses are endemic to reservoir rodent populations world-wide, which maintain a persistent, asymptomatic infection. Old World orthohantaviruses, such as Hantaan (HTNV) and Seoul viruses (SEOV), are capable of zoonotic transmission to human hosts through inhalation of infected-rodent excreta, with the most severe cases experiencing hemorrhagic fever with renal syndrome and a case-fatality rate that is near 5-15%. The disease pathology in human infection contrasts sharply with lack of pathogenesis in rodent reservoir hosts, where in the reservoir host symptom progression is marked by a mild innate immune response which subsides and results in a persistent asymptomatic infection. The mechanisms by which reservoir and non-reservoir hosts experience such contrasting disease pathogenesis outcomes is not well defined. My research project investigates the mechanisms by which SEOV interacts with host innate immune sensing of viral PAMPs (pathogen-associated molecular pattern) such as single or double stranded non-self RNAs which can be recognized through innate immune sensors such as toll-like receptors (TLRs) and RIG-I-like receptors (RLRs), and how SEOV antagonizes type 1 interferon responses that are induced by viral PAMP recognition through TLRs and RLRs to inhibit antiviral activity. My current research is defining how proteins encoded by the SEOV genome (nucleocapsid, GnGc glycoproteins, or the RNA-dependent RNA polymerase) interact with and antagonize reservoir host innate immune responses through protein-protein interactions and contrasting this with human innate immune responses. Further, I am investigating how RLR and TLR recognition of SEOV PAMPs differ, and how the subsequent IFN response is mediated by these differences in PAMP recognition between the reservoir and non-reservoir host models. Defining the contrasting mechanisms by which SEOV interacts with the two species will have implications for understanding the innate immune dysfunction seen in human pathologies and contribute to the understanding of disease treatment in clinical settings.
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Julianne Peabody (Chackerian Lab) The goal of my dissertation project is to utilize virus-like particle (VLP) technology to characterize antibody responses to natural infection by viral pathogens. VLPs are composed of viral structural proteins but are noninfectious. VLPs based on MS2, an RNA bacteriophage, have been engineered to tolerate peptide insertions at a surface-exposed site without disruption of protein folding. Large libraries of VLPs can be constructed which display random or defined peptide epitopes. Because these epitopes are displayed in a context already suitable for vaccine formulation, this system is ideal for affinity selection and vaccine discovery. Sin Nombre Virus (SNV) is a New World, rodent-borne hantavirus of the family Bunyaviridae, a family that includes a number of highly pathogenic viruses. Infection with SNV can result in cardiopulmonary syndrome (HCPS), with a case-fatality rate of 30-50%. Effective treatments are lacking for HCPS, and no vaccine has been developed. SARS-CoV-2 is a single-stranded RNA virus of the family Coronaviridae responsible for the COVID-19 pandemic. A better understanding of antibody-mediated immunity during natural infection could provide vital information on epitopes which provoke protective immunity against these pathogens. Dave Peabody constructed antigen fragment libraries composed of MS2 VLPs displaying overlapping peptides derived from the proteomes of SNV and SARS-CoV-2. MS2-based VLPs encapsidate their coding RNA, allowing their sequences to be recovered and determined. I acquired plasma samples with viral neutralizing activity taken from individuals at multiple time points following infection with either SARSCoV-2 or Sin Nombre Virus. Using IgG isolated from these samples, I selected for epitopes represented in the antigen fragment library which elicit an antibody response during natural infection. Following selection, I performed deep sequencing on the selectants. Comparison of the deep sequencing results revealed potential targets in antigenic regions of the virus. Production and analysis of VLPs displaying these targets in on-going, as are analyses of these VLPs as prospective vaccine candidates.
National Coming Out Day (October 11, 2021)
Celebrating
DRIVING THE MISSION: MGM Teaching Contributions
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We want to share your stories. Please contact bchackerian@salud.unm.edu so that The Argo can cover this news item in the next issue!
Keep sailing to the AIM Core Newsletter on the following pages.