Tropical Medicine Commons^™

Pseudoviruses, A Safer Toolbox For Vaccine Development Against Enveloped Viruses, Syamala R Thimmiraju, Jason T Kimata, Jeroen Pollet

Faculty, Staff and Students Publications

Introduction: Pseudoviruses are recombinant, replication-incompetent, viral particles designed to mimic the surface characteristics of native enveloped viruses. They are a safer, and cost-effective research alternative to live viruses. With the potential emergence of the next major infectious disease, more vaccine scientists must become familiar with the pseudovirus platform as a vaccine development tool to mitigate future outbreaks.

Areas covered: This review aims at vaccine developers to provide a basic understanding of pseudoviruses, list their production methods, and discuss their utility to assess vaccine efficacy against enveloped viral pathogens. We further illustrate their usefulness as wet-lab simulators for emerging mutant variants, …

Generation And Characterization Of In Vitro Transcribed Mrna, Cristina Poveda, Yi-Lin Chen, Ulrich Strych

Faculty, Staff and Students Publications

Here we describe the in vitro preparation of mRNA from DNA templates, including setting up the transcription reaction, mRNA capping, and mRNA labeling. We then describe methods used for mRNA characterization, including UV and fluorescence spectrophotometry, as well as gel electrophoresis. Moreover, characterization of the in vitro transcribed RNA using the Bioanalyzer instrument is described, allowing a higher resolution analysis of the target molecules. For the in vitro testing of the mRNA molecules, we include protocols for the transfection of various primary cell cultures and the confirmation of translation by intracellular staining and western blotting.

Crystal Structure Of Trichinella Spiralis Calreticulin And The Structural Basis Of Its Complement Evasion Mechanism Involving C1q, Zhihui Jia, Wen Yu, Jingmo Li, Mingming Zhang, Bin Zhan, Liming Yan, Zhenhua Ming, Yuli Cheng, Xiaolin Tian, Shuai Shao, Jingjing Huang, Xinping Zhu

Faculty, Staff and Students Publications

Helminths produce calreticulin (CRT) to immunomodulate the host immune system as a survival strategy. However, the structure of helminth-derived CRT and the structural basis of the immune evasion process remains unclarified. Previous study found that the tissue-dwelling helminth Trichinella spiralis produces calreticulin (TsCRT), which binds C1q to inhibit activation of the complement classical pathway. Here, we used x-ray crystallography to resolve the structure of truncated TsCRT (TsCRTΔ), the first structure of helminth-derived CRT. TsCRTΔ was observed to share the same binding region on C1q with IgG based on the structure and molecular docking, which explains the inhibitory effect of TsCRT …

Optimizing Immunogenicity And Product Presentation Of A Sars-Cov-2 Subunit Vaccine Composition: Effects Of Delivery Route, Heterologous Regimens With Self-Amplifying Rna Vaccines, And Lyophilization, William R Lykins, Jeroen Pollet, Jessica A White, Brian Keegan, Leroy Versteeg, Ulrich Strych, Wen-Hsiang Chen, Raodoh Mohamath, Gabi Ramer-Denisoff, Sierra Reed, Christina Renshaw, Samuel Beaver, Alana Gerhardt, Emily A Voigt, Mark A Tomai, Robert Sitrin, Robert K M Choy, Frederick J Cassels, Peter J Hotez, Maria Elena Bottazzi, Christopher B Fox

Faculty, Staff and Students Publications

INTRODUCTION: Dozens of vaccines have been approved or authorized internationally in response to the ongoing SARS-CoV-2 pandemic, covering a range of modalities and routes of delivery. For example, mucosal delivery of vaccines via the intranasal (i.n.) route has been shown to improve protective mucosal responses in comparison to intramuscular (i.m.) delivery. As we gain knowledge of the limitations of existing vaccines, it is of interest to understand if changes in product presentation or combinations of multiple vaccine modalities can further improve immunological outcomes.

METHODS: We investigated a commercial-stage SARS-CoV-2 receptor binding domain (RBD) antigen adjuvanted with a clinical-stage TLR-7/8 agonist …

Early Cellular And Molecular Signatures Correlate With Severity Of West Nile Virus Infection, Ho-Joon Lee, Yujiao Zhao, Ira Fleming, Sameet Mehta, Xiaomei Wang, Brent Vander Wyk, Shannon E Ronca, Heather Kang, Chih-Hung Chou, Benoit Fatou, Kinga K Smolen, Ofer Levy, Clary B Clish, Ramnik J Xavier, Hanno Steen, David A Hafler, J Christopher Love, Alex K Shalek, Leying Guan, Kristy O Murray, Steven H Kleinstein, Ruth R Montgomery

Faculty, Staff and Students Publications

Infection with West Nile virus (WNV) drives a wide range of responses, from asymptomatic to flu-like symptoms/fever or severe cases of encephalitis and death. To identify cellular and molecular signatures distinguishing WNV severity, we employed systems profiling of peripheral blood from asymptomatic and severely ill individuals infected with WNV. We interrogated immune responses longitudinally from acute infection through convalescence employing single-cell protein and transcriptional profiling complemented with matched serum proteomics and metabolomics as well as multi-omics analysis. At the acute time point, we detected both elevation of pro-inflammatory markers in innate immune cell types and reduction of regulatory T cell …

Therapeutic Effect Of Echinococcus Granulosus Cyst Fluid On Bacterial Sepsis In Mice, Shuying Wang, Donghui Jiang, Feifei Huang, Yayun Qian, Meitao Qi, Huihui Li, Xiaoli Wang, Zhi Wang, Kaigui Wang, Yin Wang, Pengfei Du, Bin Zhan, Rui Zhou, Liang Chu, Xiaodi Yang

Faculty, Staff and Students Publications

BACKGROUND: The primary pathophysiological process of sepsis is to stimulate a massive release of inflammatory mediators to trigger systemic inflammatory response syndrome (SIRS), the major cause of multi-organ dysfunction and death. Like other helminths, Echinococcus granulosus induces host immunomodulation. We sought to determine whether E. granulosus cyst fluid (EgCF) displays a therapeutic effect on sepsis-induced inflammation and tissue damage in a mouse model.

METHODS: The anti-inflammatory effects of EgCF were determined by in vitro culture with bone marrow-derived macrophages (BMDMs) and in vivo treatment of BALB/C mice with cecal ligation and puncture (CLP)-induced sepsis. The macrophage phenotypes were determined by …

Exploration Of The Implementation Of An Integrated Electronic Laboratory Information Management System On Quality Diagnostics Service Indicators At A County Level Public Hospital In Western Kenya., Kelly Allen

Capstone Collection

Underinvestment in pathology and laboratory capacity caused by low visibility in research and in prioritization by public health leaders results in limited effective healthcare coverage and an estimated 1.1 million premature deaths annually in Low-and-Middle-Income Countries. Kenya’s public health laboratories provide a median 41% of the Essential Diagnostic List to their patients and in Kisumu County, as much as 44.2% of the population has little to no access to essential diagnostics. The government of Kisumu implemented the county Health Laboratory Strategic Plan 2018-2022 to address this public health challenge. Little information exists on the effectiveness of these initiatives and the …

Autogenous Reproduction By Ornithodoros Turicata (Ixodida: Argasidae) Females And Vertical Transmission Of The Tick-Borne Pathogen Borrelia Turicatae (Spirochaetales: Borreliaceae), Serhii Filatov, Aparna Krishnavajhala, Job E Lopez

Faculty, Staff and Students Publications

Ornithodoros turicata is a vector of relapsing fever spirochetes in North America and transmits Borrelia turicatae to a variety of vertebrate hosts. The remarkably long lifespan of O. turicata and its ability to maintain spirochetes horizontally (between life stages) and vertically (to progeny) promote the perpetuation of B. turicatae in nature. Nevertheless, the reproductive biology of O. turicata is poorly understood. In this report, we collected ticks from a park within a neighborhood of Austin, TX. They were reared to adulthood, and male ticks were individually housed with females. We observed autogenous reproduction, which is the ability to produce eggs …

Neglected Tropical Disease Vaccines: Hookworm, Leishmaniasis, And Schistosomiasis, Peter J Hotez, Maria Elena Bottazzi, Paul M Kaye, Bruce Y Lee, Karl Philipp Puchner

Faculty, Staff and Students Publications

No abstract provided.

The Impact Of Vaccine-Linked Chemotherapy On Liver Health In A Mouse Model Of Chronic Trypanosoma Cruzi Infection, Duc Minh Nguyen, Cristina Poveda, Jeroen Pollet, Fabian Gusovsky, Maria Elena Bottazzi, Peter J Hotez, Kathryn Marie Jones

Faculty, Staff and Students Publications

BACKGROUND: Chagas disease, chronic infection with Trypanosoma cruzi, mainly manifests as cardiac disease. However, the liver is important for both controlling parasite burdens and metabolizing drugs. Notably, high doses of anti-parasitic drug benznidazole (BNZ) causes liver damage. We previously showed that combining low dose BNZ with a prototype therapeutic vaccine is a dose sparing strategy that effectively reduced T. cruzi induced cardiac damage. However, the impact of this treatment on liver health is unknown. Therefore, we evaluated several markers of liver health after treatment with low dose BNZ plus the vaccine therapy in comparison to a curative dose of BNZ. …

Localized Cardiac Small Molecule Trajectories And Persistent Chemical Sequelae In Experimental Chagas Disease, Zongyuan Liu, Rebecca Ulrich Vonbargen, April L Kendricks, Kate Wheeler, Ana Carolina Leão, Krithivasan Sankaranarayanan, Danya A Dean, Shelley S Kane, Ekram Hossain, Jeroen Pollet, Maria Elena Bottazzi, Peter J Hotez, Kathryn M Jones, Laura-Isobel Mccall

Faculty, Staff and Students Publications

Post-infectious conditions present major health burdens but remain poorly understood. In Chagas disease (CD), caused by Trypanosoma cruzi parasites, antiparasitic agents that successfully clear T. cruzi do not always improve clinical outcomes. In this study, we reveal differential small molecule trajectories between cardiac regions during chronic T. cruzi infection, matching with characteristic CD apical aneurysm sites. Incomplete, region-specific, cardiac small molecule restoration is observed in animals treated with the antiparasitic benznidazole. In contrast, superior restoration of the cardiac small molecule profile is observed for a combination treatment of reduced-dose benznidazole plus an immunotherapy, even with less parasite burden reduction. Overall, …

Excretory/Secretory Products From Trichinella Spiralis Adult Worms Ameliorate Myocardial Infarction By Inducing M2 Macrophage Polarization In A Mouse Model, Lingqin Wu, Wenhui Yin, Jutai Wen, Shuying Wang, Huihui Li, Xiaoli Wang, Weixiao Zhang, Shuyao Duan, Qiuyu Zhu, Erhe Gao, Shili Wu, Bin Zhan, Rui Zhou, Xiaodi Yang

Faculty, Staff and Students Publications

BACKGROUND: Ischemia-induced inflammatory response is the main pathological mechanism of myocardial infarction (MI)-caused heart tissue injury. It has been known that helminths and worm-derived proteins are capable of modulating host immune response to suppress excessive inflammation as a survival strategy. Excretory/secretory products from Trichinella spiralis adult worms (Ts-AES) have been shown to ameliorate inflammation-related diseases. In this study, Ts-AES were used to treat mice with MI to determine its therapeutic effect on reducing MI-induced heart inflammation and the immunological mechanism involved in the treatment.

METHODS: The MI model was established by the ligation of the left anterior descending coronary artery, …

Socio-Economic Factors And Its Influence On The Association Between Temperature And Dengue Incidence In 61 Provinces Of The Philippines, 2010–2019, Xerxes Seposo, Sary Valenzuela, Geminn Louis Apostol

Ateneo School of Medicine and Public Health Publications

Background

Temperature has a significant impact on dengue incidence, however, changes on the temperature-dengue relationship across axes of socio-economic vulnerability is not well described. This study sought to determine the association between dengue and temperature in multiple locations in the Philippines and explore the effect modification by socio-economic factors.

Method

Nationwide dengue cases per province from 2010 to 2019 and data on temperature were obtained from the Philippines’ Department of Health–Epidemiological Bureau and ERA5-land, respectively. A generalized additive mixed model (GAMM) with a distributed lag non-linear model was utilized to examine the association between temperature and dengue inci-dence. We further …

The New Era Of Long-Acting Antiretroviral Therapy: When And Why To Make The Switch, Melanie C Goebel, Emmanuel Guajardo, Thomas P Giordano, Shital M Patel

Faculty, Staff and Students Publications

Purpose of review: Despite the availability of safe and effective oral combination antiretroviral therapy, barriers to maintaining viral suppression remain a challenge to ending the HIV epidemic. Long-acting injectable antiretroviral therapy was developed as an alternative to daily oral therapy. This review summarizes the current literature on the efficacy of long-acting cabotegravir plus rilpivirine for the treatment of HIV-1, reasons to switch to injectable therapy, and barriers to switching.

Recent findings: Long-acting cabotegravir plus rilpivirine is safe and effective in maintaining HIV-1 virologic suppression. Ideal candidates for switching to long-acting cabotegravir plus rilpivirine are virologically suppressed on oral regimens with …

A Recombinant Protein Xbb15 Rbd/Alum/Cpg Vaccine Elicits High Neutralizing Antibody Titers Against Omicron Subvariants Of Sars-Cov-2, Syamala Rani Thimmiraju, Rakesh Adhikari, Maria Jose Villar, Jungsoon Lee, Zhuyun Liu, Rakhi Kundu, Yi-Lin Chen, Suman Sharma, Karm Ghei, Brian Keegan, Leroy Versteeg, Portia M Gillespie, Allan Ciciriello, Nelufa Y Islam, Cristina Poveda, Nestor Uzcategui, Wen-Hsiang Chen, Jason T Kimata, Bin Zhan, Ulrich Strych, Maria Elena Bottazzi, Peter J Hotez, Jeroen Pollet

Faculty, Staff and Students Publications

(1) Background: We previously reported the development of a recombinant protein SARS-CoV-2 vaccine, consisting of the receptor-binding domain (RBD) of the SARS-CoV-2 spike protein, adjuvanted with aluminum hydroxide (alum) and CpG oligonucleotides. In mice and non-human primates, our wild-type (WT) RBD vaccine induced high neutralizing antibody titers against the WT isolate of the virus, and, with partners in India and Indonesia, it was later developed into two closely resembling human vaccines, Corbevax and Indovac. Here, we describe the development and characterization of a next-generation vaccine adapted to the recently emerging XBB variants of SARS-CoV-2. (2) Methods: We conducted preclinical studies …

Blockade Of Interferon Signaling Decreases Gut Barrier Integrity And Promotes Severe West Nile Virus Disease, Shih-Ching Lin, Fang R Zhao, Hana Janova, Adrian Gervais, Summer Rucknagel, Kristy O Murray, Jean-Laurent Casanova, Michael S Diamond

Faculty, Staff and Students Publications

The determinants of severe disease caused by West Nile virus (WNV) and why only ~1% of individuals progress to encephalitis remain poorly understood. Here, we use human and mouse enteroids, and a mouse model of pathogenesis, to explore the capacity of WNV to directly infect gastrointestinal (GI) tract cells and contribute to disease severity. At baseline, WNV poorly infects human and mouse enteroid cultures and enterocytes in mice. However, when STAT1 or type I interferon (IFN) responses are absent, GI tract cells become infected, and this is associated with augmented GI tract and blood-brain barrier (BBB) permeability, accumulation of gut-derived …

Comparative Genomics Analysis Of Three Conserved Plasmid Families In The Western Hemisphere Soft Tick-Borne Relapsing Fever Borreliae Provides Insight Into Variation In Genome Structure And Antigenic Variation Systems, Alexander R Kneubehl, Job E Lopez

Faculty, Staff and Students Publications

Borrelia spirochetes, causative agents of Lyme disease and relapsing fever (RF), have uniquely complex genomes, consisting of a linear chromosome and both circular and linear plasmids. The plasmids harbor genes important for the vector-host life cycle of these tick-borne bacteria. The role of plasmids from Lyme disease causing spirochetes is more refined compared to RF Borrelia because of limited plasmid-resolved genome assemblies for the latter. We recently addressed this limitation and found that three linear plasmid families (F6, F27, and F28) were syntenic across all the RF Borrelia species that we examined. Given this conservation, we further investigated the three …

Description Of A New Pavlovskyella Species (Acari: Argasidae) From Chile, Sebastián Muñoz-Leal, José M Venzal, Alexander R Kneubehl, Job E Lopez, Thiago F Martins, Marcelo B Labruna

Faculty, Staff and Students Publications

Soft ticks (Argasidae) of the Pavlovskyella Pospelova-Shtrom subgenus are important vectors of relapsing fever spirochetes, which are agents of disease globally. South American representatives of the Pavlovskyella subgenus include 3 species: Ornithodoros (Pavlovskyella) brasiliensis Aragão, Ornithodoros (Pavlovskyella) furcosus Neumann, and Ornithodoros (Pavlovskyella) rostratus Aragão. Here, we describe a fourth species based on morphological and mitogenomic evidence of ticks collected in burrows of unknown hosts in central Chile. The larva of the new species separates from other South American soft ticks by the following combination of characters: 13 pairs of dorsolateral setae, dorsal plate hexagonal, hypostome blunt with denticles from apex …

New Records Of Ornithodoros Turicata (Ixodida: Argasidae) In Rural And Urban Sites In The Mexican States Of Aguascalientes And Zacatecas Indicate The Potential For Tick-Borne Relapsing Fever, Edwin Vázquez-Guerrero, José Luis González-Quiroz, María Lilia Domínguez-López, Alexander R Kneubehl, Aparna Krishnavajhala, Michael W Curtis, Alejandro Ponce-Mendoza, Paulina Estrada-De Los Santos, Job E Lopez, J Antonio Ibarra

Faculty, Staff and Students Publications

Soft ticks from the Ornithodoros genus are vectors of relapsing fever (RF) spirochetes around the world. In Mexico, they were originally described in the 19th century. However, few recent surveillance studies have been conducted in Mexico, and regions where RF spirochetes circulate remain vague. Here, the presence of soft ticks in populated areas was assessed in two sites from the Mexican states of Aguascalientes and Zacatecas. Argasidae ticks were collected, identified by morphology and mitochondrial 16S rDNA gene sequencing, and tested for RF borreliae. The specimens in both sites were identified as Ornithodoros turicata but no RF spirochetes were detected. …

Development Of Chimeric Protein As A Multivalent Vaccine For Human Kinetoplastid Infections: Chagas Disease And Leishmaniasis, Marianna De Carvalho Clímaco, Luiza Almeida De Figueiredo, Rayane Cristina Lucas, Guilherme Rafael Gomide Pinheiro, Luísa Mourão Dias Magalhães, Ana Laura Grossi De Oliveira, Raquel Martins Almeida, Fernando Sérgio Barbosa, Daniella Castanheira Bartholomeu, Lilian Lacerda Bueno, Tiago Antonio Mendes, Bin Zhan, Kathryn Marie Jones, Peter Hotez, Maria Elena Bottazzi, Fabrício Marcus Silva Oliveira, Ricardo Toshio Fujiwara

Faculty, Staff and Students Publications

Leishmania spp. and Trypanosoma cruzi are parasitic kinetoplastids of great medical and epidemiological importance since they are responsible for thousands of deaths and disability-adjusted life-years annually, especially in low- and middle-income countries. Despite efforts to minimize their impact, current prevention measures have failed to fully control their spread. There are still no vaccines available. Taking into account the genetic similarity within the Class Kinetoplastida, we selected CD8+ T cell epitopes preserved among Leishmania spp. and T. cruzi to construct a multivalent and broad-spectrum chimeric polyprotein vaccine. In addition to inducing specific IgG production, immunization with the vaccine was able to …