Research

The Vu Laboratory is dedicated to study swine viruses

The Vu Laboratory is interested in translational research that helps promote animal health and well-being. The overarching goal of is to develop effective intervention strategies to control viral diseases in animals. Currently, the lab is devoted to study three major swine viruses: porcine reproductive and respiratory syndrome virus (PRRSV), swine influenza virus (SIV) and African swine fever virus (ASFV). The research topics include: (i) characterization of host immune responses to natural infection or vaccination, (ii) identification of viral proteins and/or epitopes capable of eliciting protective immunity and (iii) rationale design of safe and efficacy vaccine immunogens.

African Swine Fever Research

African swine fever virus (ASFV) is a devastating viral disease of swine with mortality rates that can approach 100%. The disease has spread to many swine producing countries including Central and Eastern Europe and Asia, causing large economic losses, and affecting global food security. For instance, outbreaks of ASF in China have reduced its swine inventory by 41.4% within one year. Currently, there are no effective vaccines or treatments available for ASF. The control of ASF mainly relies on biosecurity and compulsory depopulation of affected herds. The primary goal of my research on ASF is to identify immunogenic viral proteins that are essential for eliciting protective immune responses in pigs as this knowledge is vital for the rationale design of an efficacious ASF vaccine. It has been observed that a small percentage of pigs survive ASFV infection under field conditions and that these survivors are resistant to re-infection with homologous ASFV strains. Importantly, pigs immunized with a live-attenuated vaccine (LAV) for ASF develop solid homologous protective immunity. On the other hand, pigs vaccinated with experimental inactivated ASF vaccines fail to develop protective immunity even though they were seroconverted. My central hypothesis is that the minority of pigs surviving infection with highly virulent ASFV in the field as well as pigs immunized with an ASF LAV develop a different antibody profile than those vaccinated with an inactivated ASF vaccine.

PRRS Research

Porcine reproductive and respiratory syndrome virus (PRRSV) is a major swine viral pathogen that is affecting swine production worldwide. The virus causes two major clinical forms: reproductive failure (abortions) when infecting pregnant sows and respiratory diseases (pneumonia) when infecting young pigs. It is estimated that PRRSV costs the U.S. swine industry over $1 billion annually.
The goal of my lab is to develop a new generation of PRRSV vaccine capable of conferring a broad spectrum of heterologous protection and featuring an optimal serologic marker. Specifically, I aim to generate a new PRRSV vaccine that not only confers broad heterologous protection but also permits tracking the circulation of wild-type PRRSV in vaccinated herds, thus, making the vaccine more efficacious in eradication of the virus. I use two complementary approaches to achieve this goal. On one hand, I use bioinformatics and molecular virology to engineer the viral strain to enhance the levels of protection. On the other hand, I focus on studying the mechanisms of protection against PRRSV infection, as this knowledge is of critical for the optimal design of an effective PRRS vaccine.

Swine Influenza Research

Swine influenza virus (SIV) is widespread worldwide, causing tremendous financial losses to swine producers. Notably, SIV can also infect humans, posing a significant public health concern. Direct transmission of SIV from pig to humans is documented, with the 2009 H1N1 pandemic being an example. SIV vaccines have been commonly used to control SIV in the United States. However, the efficacy of these vaccines is far from satisfactory as they fail to confer optimal levels of heterologous protection, mainly due to the genetic diversity of the viral genome. The overarching goal of my research on SIV is to develop a novel intervention strategy to effectively control influenza viruses in pigs. I pursue this goal by using two different approaches: (i) I employ bioinformatics to design vaccine immunogens with the broadest levels of antigenic coverage for the SIV circulating in the U.S. and use these immunogens to vaccine pigs, and (ii) Development of novel platform for rapid and sustainable induction of protective immunity against animal influenza viruses.

Research Methods

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Traditional Cloning Basics

Traditional cloning relies on recombinant DNA methods that begin with preparing a vector to receive an insert DNA by digesting each with restriction enzymes. The digested fragments are then spliced together by an enzyme called ligase, in a process known as ligation, to form a new vector capable of expressing a gene of interest. This may be the simplest and oldest technique for traditional cloning and laid the foundation for researchers to develop novel cloning methods such as TA cloning, TOPO cloning, PCR cloning, ligation-independent cloning, and gene assembly that exploit unique characteristics of other modifying enzymes.

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Western blot

Western blot (WB) is a technique that separates a mixture of proteins via size exclusion electrophoresis. The target protein is identified using an antibody specific for the target and is visualized as a band via chemiluminescent or fluorescent detection.

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Flow Cytometry

Flow cytometry identifies cellular characteristics and expression of proteins in a heterogeneous cell population by flowing one cell at a time past a laser beam.

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Immunocytochemistry/Immunofluorescence

Immunocytochemistry/Immunofluorescence (ICC/IF) identifies cells from samples that are no longer in their natural state. Antibodies are used to microscopically visualize cellular structures.

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Immunohistochemistry

Immunohistochemistry (IHC) identifies structures in whole tissue samples. A mixture of antibodies and stains are used to microscopically visualize the cells.

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ELISA

Enzyme-linked immunosorbent assay (ELISA) identifies protein concentrations using antibodies and a plate with multiple sample wells. Visualization is performed using colorimetric or fluorescent enzymatic substrates and is represented graphically.

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Luciferase-immunoprecipitation system (LIPS)
Luciferase Immunoprecipitation System (LIPS) assay is a rapid, simple, and sensitive test to detect antibody response to respiratory syncytial virus.

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Cell Culture

Cell culture refers to the removal of cells from an animal or plant and their subsequent growth in a favorable artificial environment. The cells may be removed from the tissue directly and disaggregated by enzymatic or mechanical means before cultivation, or they may be derived from a cell line or cell strain that has already been established.

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Transfection

Transfection is the process of introducing nucleic acids into eukaryotic cells by nonviral methods. Using various chemical or physical methods, this gene transfer technology enables the study of gene function and protein expression in a cellular environment.