Tropical Medicine Commons^™

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. …

A Serological Assay To Detect And Differentiate Rodent Exposure To Soft Tick And Hard Tick Relapsing Fever Infections In The United States, Christina M Parise, Ying Bai, Kevin S Brandt, Shelby L Ford, Sarah Maes, Adam J Replogle, Alexander R Kneubehl, Job E Lopez, Rebecca J Eisen, Andrias Hojgaard

Faculty, Staff and Students Publications

Human cases of relapsing fever (RF) in North America are caused primarily by Borrelia hermsii and Borrelia turicatae, which are spread by argasid (soft) ticks, and by Borrelia miyamotoi, which is transmitted by ixodid (hard) ticks. In some regions of the United States, the ranges of the hard and soft tick RF species are known to overlap; in many areas, recorded ranges of RF spirochetes overlap with Lyme disease (LD) group Borrelia spirochetes. Identification of RF clusters or cases detected in unusual geographic localities might prompt public health agencies to investigate environmental exposures, enabling prevention of additional cases through locally …

Tonb-Dependent Receptor Protein Displayed On Spores Of Bacillus Subtilis Stimulates Protective Immune Responses Against Acinetobacter Baumannii, Nor-Aziyah Matrahim, Kathryn Marie Jones, Brian P Keegan, Ulrich Strych, Bin Zhan, Hai-Yen Lee, Sazaly Abubakar

Faculty, Staff and Students Publications

The emergence of antibiotic-resistant Acinetobacter baumannii strains with limited treatment options has become a significant global health concern. Efforts to develop vaccines against the bacteria have centred on several potential protein targets, including the TonB-dependent receptors (TBDRs). In the present study, TBDRs from A. baumannii were displayed on the surface of Bacillus subtilis spores. The immunogenicity of the recombinant spores was evaluated in orally vaccinated mice. None of the immunized mice demonstrated signs of illness and were observed to be healthy throughout the study. Sera and the intestinal secretions from the recombinant spores-treated mice demonstrated mucosal and humoral antibody responses …

Covid-19 Vaccines And The Pandemic: Lessons Learnt For Other Neglected Diseases And Future Threats, Peter J Hotez, Sarah Gilbert, Melanie Saville, Lois Privor-Dumm, Salim Abdool-Karim, Didi Thompson, Jean-Louis Excler, Jerome H Kim

Faculty, Staff and Students Publications

Through the experiences gained by accelerating new vaccines for both Ebola virus infection and COVID-19 in a public health emergency, vaccine development has benefited from a 'multiple shots on goal' approach to new vaccine targets. This approach embraces simultaneous development of candidates with differing technologies, including, when feasible, vesicular stomatitis virus or adenovirus vectors, messenger RNA (mRNA), whole inactivated virus, nanoparticle and recombinant protein technologies, which led to multiple effective COVID-19 vaccines. The challenge of COVID-19 vaccine inequity, as COVID-19 spread globally, created a situation where cutting-edge mRNA technologies were preferentially supplied by multinational pharmaceutical companies to high-income countries while …

Reconstructive Surgery For The Neglected Tropical Diseases: Global Gaps And Future Directions, Kala T Pham, Peter J Hotez, Kristy L Hamilton

Faculty, Staff and Students Publications

BACKGROUND: Several neglected tropical diseases (NTDs) are highly disfiguring, particularly those in resource-poor countries that lack access to basic surgery. There has been a push to integrate surgery into treatment programs for NTDs. In this article, we provide an overview of the major disfiguring NTDs and discuss the processes and barriers that impede access to reconstructive surgical treatments or their integration into health systems.

METHODS: A review of the literature was conducted using the online database PubMed, from 2008 to 2021 with the specific diseases listed as NTDs either on the World Health Organization or the

RESULT: Success in the …

A Randomized Phase I/Ii Safety And Immunogenicity Study Of The Montanide-Adjuvanted Sars-Cov-2 Spike Protein-Rbd-Fc Vaccine, Aks-452, Eline A Feitsma, Yester F Janssen, Hendrikus H Boersma, Yannick Van Sleen, Debbie Van Baarle, David G Alleva, Thomas M Lancaster, Thillainaygam Sathiyaseelan, Sylaja Murikipudi, Andrea R Delpero, Melanie M Scully, Ramya Ragupathy, Sravya Kotha, Jeffrey R Haworth, Nishit J Shah, Vidhya Rao, Shashikant Nagre, Shannon E Ronca, Freedom M Green, Ari Aminetzah, Frans Sollie, Schelto Kruijff, Maarten Brom, Gooitzen M Van Dam, Todd C Zion

Faculty, Staff and Students Publications

BACKGROUND: Previous interim data from a phase I study of AKS-452, a subunit vaccine comprising an Fc fusion of the respiratory syndrome coronavirus 2 (SARS-CoV-2) spike protein receptor binding domain (SP/RBD) emulsified in the water-in-oil adjuvant, Montanide™ ISA 720, suggested a good safety and immunogenicity profile in healthy adults. This phase I study was completed and two dosing regimens were further evaluated in this phase II study.

METHODS: This phase II randomized, open-labelled, parallel group study was conducted at a single site in The Netherlands with 52 healthy adults (18 - 72 years) receiving AKS-452 subcutaneously at one 90 µg …

Interleukins, Chemokines, And Tumor Necrosis Factor Superfamily Ligands In The Pathogenesis Of West Nile Virus Infection, Emna Benzarti, Kristy O Murray, Shannon E Ronca

Faculty, Staff and Students Publications

West Nile virus (WNV) is a mosquito-borne pathogen that can lead to encephalitis and death in susceptible hosts. Cytokines play a critical role in inflammation and immunity in response to WNV infection. Murine models provide evidence that some cytokines offer protection against acute WNV infection and assist with viral clearance, while others play a multifaceted role WNV neuropathogenesis and immune-mediated tissue damage. This article aims to provide an up-to-date review of cytokine expression patterns in human and experimental animal models of WNV infections. Here, we outline the interleukins, chemokines, and tumor necrosis factor superfamily ligands associated with WNV infection and …

Human Schistosomiasis Vaccines As Next Generation Control Tools, Peter J Hotez, Maria Elena Bottazzi

Faculty, Staff and Students Publications

No abstract provided.

Case Report: Exposure To Relapsing Fever Group Borreliae In Patients With Undifferentiated Febrile Illness In Mexico, Edwin Vázquez-Guerrero, Guadalupe Gordillo-Pérez, Nora Ríos-Sarabia, Job E Lopez, J Antonio Ibarra

Faculty, Staff and Students Publications

Relapsing fever (RF) borreliosis is a neglected disease in Mexico. A retrospective serological survey using diagnostic antigens GlpQ and BipA from Borrelia turicatae was performed to evaluate human exposure to RF borreliae. Seventy serum samples were used from a cohort of patients with undifferentiated febrile illness in Mexico. Four samples were positive to GlpQ and three to BipA. Results indicate that RF borreliae continue to circulate in regions of Mexico and pose a risk to human health.

Sars-Cov-2 Variants Offer A Second Chance To Fix Vaccine Inequities, Peter J Hotez

Faculty, Staff and Students Publications

Global COVID-19 vaccine equity remains aspirational for much of the world. But the emergence of rapidly evolving SARS-CoV-2 variants provides new opportunities to correct past public policies, support local vaccine production and combat rising anti-vaccine aggression.

Sars-Cov-2 Seroprevalence In Children Worldwide: A Systematic Review And Meta-Analysis, Reza Naeimi, Mahdi Sepidarkish, Abolfazl Mollalo, Hamid Parsa, Sanaz Mahjour, Fatemeh Safarpour, Mustafa Almukhtar, Amal Mechaal, Hiam Chemaitelly, Behnam Sartip, Elika Marhoommirzabak, Ali Ardekani, Peter J Hotez, Robin B Gasser, Ali Rostami

Faculty, Staff and Students Publications

BACKGROUND: The higher hospitalisation rates of those aged 0-19 years (referred to herein as 'children') observed since the emergence of the immune-evasive SARS-CoV-2 Omicron variant and subvariants, along with the persisting vaccination disparities highlighted a need for in-depth knowledge of SARS-CoV-2 sero-epidemiology in children. Here, we conducted this systematic review to assess SARS-CoV-2 seroprevalence and determinants in children worldwide.

METHODS: In this systematic review and meta-analysis study, we searched international and preprinted scientific databases from December 1, 2019 to July 10, 2022. Pooled seroprevalences were estimated according to World Health Organization (WHO) regions (at 95% confidence intervals, CIs) using random-effects …

A Data-Driven Approach To Construct A Molecular Map Of Trypanosoma Cruzi To Identify Drugs And Vaccine Targets, Swarsat Kaushik Nath, Preeti Pankajakshan, Trapti Sharma, Priya Kumari, Sweety Shinde, Nikita Garg, Kartavya Mathur, Nevidita Arambam, Divyank Harjani, Manpriya Raj, Garwit Kwatra, Sayantan Venkatesh, Alakto Choudhoury, Saima Bano, Prashansa Tayal, Mahek Sharan, Ruchika Arora, Ulrich Strych, Peter J Hotez, Maria Elena Bottazzi, Kamal Rawal

Faculty, Staff and Students Publications

Chagas disease (CD) is endemic in large parts of Central and South America, as well as in Texas and the southern regions of the United States. Successful parasites, such as the causative agent of CD, Trypanosoma cruzi have adapted to specific hosts during their phylogenesis. In this work, we have assembled an interactive network of the complex relations that occur between molecules within T. cruzi. An expert curation strategy was combined with a text-mining approach to screen 10,234 full-length research articles and over 200,000 abstracts relevant to T. cruzi. We obtained a scale-free network consisting of 1055 nodes …

Echinococcus Multilocularis Calreticulin Interferes With C1q-Mediated Complement Activation, Siqi Xian, Lujuan Chen, Yan Yan, Jianfang Chen, Guixia Yu, Yuxiao Shao, Bin Zhan, Yanhai Wang, Limei Zhao

Faculty, Staff and Students Publications

As a zoonotic disease caused by Echinococcus multilocularis larvae, alveolar echinococcosis (AE) is one of the most severe forms of parasitic infection. Over a long evolutional process E. multilocularis has developed complex strategies to escape host immune attack and survive within a host. However, the mechanisms underlying immune evasion remain unclear. Here we investigated the binding activity of E. multilocularis calreticulin (EmCRT), a highly conserved Ca2+-binding protein, to human complement C1q and its ability to inhibit classical complement activation. ELISA, Far Western blotting and immunoprecipitation results demonstrated that both recombinant and natural EmCRTs bound to human C1q, …

Vaccine-Linked Chemotherapy Improves Cardiac Structure And Function In A Mouse Model Of Chronic Chagas Disease, Kathryn M Jones, Elise N Mangin, Corey L Reynolds, Liliana E Villanueva, Julio Vladimir Cruz, Leroy Versteeg, Brian Keegan, April Kendricks, Jeroen Pollet, Fabian Gusovsky, Maria Elena Bottazzi, Peter J Hotez

Faculty, Staff and Students Publications

INTRODUCTION: Chagas disease, caused by chronic infection with the protozoan parasite Trypanosoma cruzi, affects 6-7 million people worldwide. The major clinical manifestation of Chagas disease is chronic Chagasic cardiomyopathy (CCC), which encompasses a spectrum of symptoms including arrhythmias, hypertrophy, dilated cardiomyopathy, heart failure, and sudden death. Current treatment is limited to two antiparasitic drugs, benznidazole (BNZ) and nifurtimox, but both have limited efficacy to halt the progression of CCC. We developed a vaccine-linked chemotherapy strategy using our vaccine consisting of recombinant Tc24-C4 protein and a TLR-4 agonist adjuvant in a stable squalene emulsion, in combination with low dose benznidazole treatment. …

Heterologous Mrna-Protein Vaccination With Tc24 Induces A Robust Cellular Immune Response Against Trypanosoma Cruzi, Characterized By An Increased Level Of Polyfunctional Cd8+ T-Cells, Cristina Poveda, Ana Carolina Leão, Chiara Mancino, Francesca Taraballi, Yi-Lin Chen, Rakesh Adhikari, Maria Jose Villar, Rakhi Kundu, Duc M Nguyen, Leroy Versteeg, Ulrich Strych, Peter J Hotez, Maria Elena Bottazzi, Jeroen Pollet, Kathryn M Jones

Faculty, Staff and Students Publications

Tc24 is a Trypanosoma cruzi-derived flagellar protein that, when formulated with a TLR-4 agonist adjuvant, induces a balanced immune response in mice, elevating IgG2a antibody titers and IFN-γ levels. Furthermore, vaccination with the recombinant Tc24 protein can reduce parasite levels and improve survival during acute infection. Although some mRNA vaccines have been proven to elicit a stronger immune response than some protein vaccines, they have not been used against T. cruzi. This work evaluates the immunogenicity of a heterologous prime/boost vaccination regimen using protein and mRNA-based Tc24 vaccines. Mice (C57BL/6) were vaccinated twice subcutaneously, three weeks apart, with …

Prevalence Of Trypanosoma Cruzi, The Etiologic Agent Of Chagas Disease, Infection In Texas Skunks (Mammalia: Mephitidae), Bonnie E Gulas-Wroblewski, Rodion Gorchakov, Rebecca B Kairis, Robert C Dowler, Kristy O Murray

Faculty, Staff and Students Publications

Background:

Chagas disease is one of the world's most neglected tropical diseases, infecting over six million people across the Americas. The hemoparasite Trypanosoma cruzi is the etiological agent for the disease, circulating in domestic, peridomestic, and sylvatic transmission cycles that are maintained by triatomine vectors and a diversity of wild and synanthropic hosts. Public health and wildlife management interventions targeting the interruption of T. cruzi transmission rely on an understanding of the dynamics driving the ecology of this zoonotic pathogen. One wildlife host that purportedly plays a role in the transmission of Chagas disease within the southern United States is …

Immunomodulatory Proteins From Hookworms Reduce Cardiac Inflammation And Modulate Regulatory Responses In A Mouse Model Of Chronic Trypanosoma Cruzi Infection, Kathryn M Jones, Bin Zhan, Keenan J Ernste, Maria Jose Villar, Nalini Bisht, Duc Nguyen, Li-Yen Chang, Cristina Poveda, Gonteria J Robinson, Akshar J Trivedi, Colby J Hofferek, William K Decker, Vanaja Konduri

Faculty, Staff and Students Publications

Introduction

Hookworms are parasitic helminths that secrete a variety of proteins that induce anti-inflammatory immune responses, stimulating increased CD4+Foxp3+ regulatory T cells and IL-10 production. Hookworm-derived recombinant proteins AIP-1 and AIP-2 have been shown to reduce inflammation in mouse models of inflammatory bowel disease and inflammatory airway disease by inducing CD4+Foxp3+ cells and IL-10 production. In contrast, chronic infection with the protozoal parasite Trypanosoma cruzi, the causative agent of Chagas disease, leads to chronic inflammation in tissues. Persistence of the parasites in tissues drives chronic low-grade inflammation, with increased infiltration of inflammatory cells into the heart, accompanied by increased …

Analysis Of Variable Major Protein Antigenic Variation In The Relapsing Fever Spirochete, Borrelia Miyamotoi, In Response To Polyclonal Antibody Selection Pressure, Robert D Gilmore, Brittany A Armstrong, Kevin S Brandt, Taylor J Van Gundy, Andrias Hojgaard, Job E Lopez, Alexander R Kneubehl

Faculty, Staff and Students Publications

Borrelia miyamotoi is a tick-transmitted spirochete that is genetically grouped with relapsing fever Borrelia and possesses multiple archived pseudogenes that encode variable major proteins (Vmps). Vmps are divided into two groups based on molecular size; variable large proteins (Vlps) and variable small proteins (Vsps). Relapsing fever Borrelia undergo Vmp gene conversion at a single expression locus to generate new serotypes by antigenic switching which is the basis for immune evasion that causes relapsing fever in patients. This study focused on B. miyamotoi vmp expression when spirochetes were subjected to antibody killing selection pressure. We incubated a low passage parent …

Case Report: Molecular Diagnosis Of Cystoisospora Belli In A Severely Immunocompromised Patient With Hiv And Kaposi Sarcoma, Roumen Borilov Iordanov, Lauren M Leining, Meng Wu, Galant Chan, Andrew R Dinardo, Rojelio Mejia

Faculty, Staff and Students Publications

Diarrhea in an immunocompromised patient has a broad infectious differential. Diagnosis is difficult despite advances in diagnostic modalities. We report a case of a 45-year-old Nigerian woman who immigrated to the United States 2 years ago. She presented to the hospital with gastrointestinal bleeding, newly diagnosed HIV, and disseminated Kaposi sarcoma. During hospitalization, the patient had an onset of watery diarrhea and high eosinophilia. Subsequent stool analysis using multi-parallel real-time quantitative polymerase chain reaction for 13 parasites was positive for Cystoisospora belli. The patient was treated with trimethoprim-sulfamethoxazole, but had relapsed disease when her antibiotics were stopped prematurely. After restarting …