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Intimate Attachment Of Escherichia Coli O157:H7 To Urinary Bladder Epithelium In The Gnotobiotic Piglet Model, Rodney A. Moxley, Tom W. Bargar, Stephen D. Kachman, Diane R. Baker, David H. Francis

School of Veterinary and Biomedical Sciences: Faculty Publications

Enterohemorrhagic Escherichia coli (EHEC), a pathogenic subset of Shiga toxin-producing E. coli (STEC), is an important cause of hemorrhagic colitis and hemolytic–uremic syndrome (HUS), and a rare cause of urinary tract infections (UTIs) with associated HUS. EHEC strains attach intimately to intestinal epithelium with formation of actin pedestals (attaching-effacing (A/E) lesions); however, the mechanism of EHEC attachment to the uroepithelium is unknown. We conducted a retrospective study on archived urinary bladder specimens from gnotobiotic piglets that naturally developed cystitis associated with EHEC O157:H7 infection following oral inoculation and fecal shedding. Paraffin-embedded bladder tissues from three piglets with cystitis and immunohistochemical …

Triggers Of Inflammatory Heart Disease, Ninaad Lasrado, Bharathi Yalaka, Jay Reddy

School of Veterinary and Biomedical Sciences: Faculty Publications

Inflammatory heart disease (IHD) is a group of diseases that includes pericarditis, myocarditis, and endocarditis. Although males appear to be more commonly affected than females, IHD can be seen in any age group. While the disease can be self-limiting leading to full recovery, affected individuals can develop chronic disease, suggesting that identification of primary triggers is critical for successful therapies. Adding to this complexity, however, is the fact that IHD can be triggered by a variety of infectious and non-infectious causes that can also occur as secondary events to primary insults. In this review, we discuss the immunological insights into …

Current Status Of Zika Virus Vaccines: Successes And Challenges, Aryamav Pattnaik, Bikash R. Sahoo, Asit K. Pattnaik

School of Veterinary and Biomedical Sciences: Faculty Publications

The recently emerged Zika virus (ZIKV) spread to the Americas, causing a spectrum of congenital diseases including microcephaly in newborn and Guillain-Barré syndrome (GBS) in adults. The unprecedented nature of the epidemic and serious diseases associated with the viral infections prompted the global research community to understand the immunopathogenic mechanisms of the virus and rapidly develop safe and efficacious vaccines. This has led to a number of ZIKV vaccine candidates that have shown significant promise in human clinical trials. These candidates include nucleic acid vaccines, inactivated vaccines, viral-vectored vaccines, and attenuated vaccines. Additionally, a number of vaccine candidates have been …

Rapid Differentiation Of Moraxella Bovoculi Genotypes 1 And 2 Using Maldi-Tof Mass Spectrometry Profiles, Matthew M. Hille, Aaron M. Dickey, Kara Robbins, Michael L. Clawson, John Dustin Loy

School of Veterinary and Biomedical Sciences: Faculty Publications

Moraxella bovoculi is the most frequently isolated bacteria from the eyes of cattle with Infectious Bovine Keratoconjunctivitis (IBK), also known as bovine pinkeye. Two distinct genotypes of M. bovoculi, genotype 1 and genotype 2, were characterized after whole genome sequencing showed a large degree of single nucleotide polymorphism (SNP) diversity within the species. To date, both genotypes have been isolated from the eyes of cattle without clinical signs of IBK while only genotype 1 strains have been isolated from the eyes of cattle with clinical signs of IBK. We used 38 known genotype 1 strains and 26 known genotype …

Essential Concepts And Learning Outcomes For Cell And Molecular Biology, Laura L. Newcomb Phd, Mike Chao Phd, Dan Nickerson Phd, Paul Orwin Phd, Jeremy Dodsworth Phd, David Rhoads Phd

Q2S Enhancing Pedagogy

In the new, transformed Biology BS program for conversion from quarter to semester, multiple faculty will teach varied courses under the “Cell and Molecular” requirement for our program. Our old program required multiple core courses, leading to bottlenecks as students could not get seats in needed classes. We have designed our new program to provide students with options under core categories, providing students more flexibility which should improve time to graduation. Students must take at least ONE of the courses, although students who chose to focus on Cell and Molecular Biology should be able to learn new material in ALL …

Identification Of Imiquimod As A Potential Combination For Anti-Cd47 Antibodies In Cancer Therapy, Nicole Brittaney Pang

Scripps Senior Theses

The avenues of targeted immunotherapy offers a promise of less toxic treatment options for those battling different forms of cancer. Specifically, the process of hijacking a patient’s own immune system to fight cancer from within versus using external treatments like chemotherapy which is extremely damaging to the patient. One such avenue includes the usage of monoclonal antibodies as an effective modality for immunotherapy. Cluster of Differentiation 47 (CD47), also known as the ‘don’t eat me signal’, aids in cell proliferation and evasion of phagocytosis and has been found to be a target for stopping tumorigenesis. Previous research has been successful …

Blood Substitution Therapy Rescues The Brain Of Mice From Ischemic Damage, Xuefang Ren, Heng Hu, Imran Farooqi, James W. Simpkins

Faculty & Staff Scholarship

Acute stroke causes complex, pathological, and systemic responses that have not been treatable by any single medication. In this study, using a murine transient middle cerebral artery occlusion stroke model, a novel therapeutic strategy is proposed, where blood replacement (BR) robustly reduces infarctions and improves neurological deficits in mice. Our analyses of immune cell subsets suggest that BR therapy substantially decreases neutrophils in blood following a stroke. Electrochemiluminescence detection demonstrates that BR therapy reduces cytokine storm in plasma and ELISA demonstrates reduced levels of matrix metalloproteinase-9 (MMP-9) in the plasma and brains at different time points post-stroke. Further, we have …

Genomic-Based Identification Of Environmental And Clinical Listeria Monocytogenes Strains Associated With An Abortion Outbreak In Beef Heifers, Katherine J. Whitman, James L. Bono, Michael L. Clawson, John D. Loy, Joseph M. Bosilevac, Terrance M. Arthur, Jeff D. Ondrak

School of Veterinary and Biomedical Sciences: Faculty Publications

Background: In a beef cattle facility an outbreak of abortions occurred over a 36-day period and included samples from two aborted (non-viable) fetuses and 21 post-abortion clinical cases. There are numerous etiologies, including clinical listeriosis. At the species level, Listeria monocytogenes is ubiquitous in cattle production environments, including soil, feed, and occasionally water sources, and is a common enteric resident of cattle and other mammals. There are four genetically distinct lineages of L. monocytogenes (I-IV), with most lineage III and IV isolates obtained from ruminants. Definitive diagnosis of L. monocytogenes as a causative agent in disease outbreaks relies upon case …

The Role Of Notch1, Il-6 And Mir-146a In Inflammation And Infection In Crohn's Disease Non-Responders To Anti-Tnf-Alpha Therapy, Esra'a Keewan

Electronic Theses and Dissertations, 2020-2023

Despite the extensive research on Notch signaling involvement in inflammation, its role in macrophage response in autoimmune diseases and defense mechanisms against bacterial infection such as Mycobacterium avium paratuberculosis (MAP) remains unknown. In this study, we investigated the molecular role of Notch-1 signaling and its downstream modulation in the macrophage response during infection and disease treatment. We demonstrated that MAP infection significantly upregulated Notch-1 and IL-6, which hijacked myeloid cell leukemia sequence-1 (MCL)-1 dependent inhibition of apoptosis and caused chronic MAP persistence and significantly led to successive inflammation. Blocking Notch signaling with gamma-secretase inhibitor (DAPT) decreased MAP survival and burden, …

Augmenting Guadecitabine To Promote Anticancer Immunity In Murine Breast Cancer, Timothy M. Smith Jr.

Theses and Dissertations

In immune-competent individuals, tumor growth occurs due to a failure of the immune system to recognize and destroy malignant cells. Immune surveillance can be curtailed by the presence of immunosuppressive cells such as myeloid-derived suppressor cells (MDSCs) and T-regulatory cells (Tregs) which both serve to dampen antitumor immunity. These studies utilize a metronomic low-dose therapeutic approach to examine the effects of anticancer drugs against murine breast cancer and the effects on the immune cell compartments. The focus of these studies revolve around the drug guadecitabine (guad), a second-generation DNA methyl-transferase inhibitor (DNMTi). DNMTi’s have been shown to dysregulate the methylation …

Hiv-1 Subtypes And Drug Resistance Mutations Among Female Sex Workers Varied In Different Cities And Regions Of The Democratic Republic Of Congo, Eun Hee Kwon, Godefroid M. A. Musema, Jessica Boelter, Sydney Townsend, Desire Tshala-Katumbay, Patrick K. Kayembe, John T. West, Charles Wood

Nebraska Center for Virology: Faculty Publications

Background Complex mosaic structures of HIV-1 were found in the Democratic Republic of Congo (DRC). Currently, there is limited information on the circulating HIV-1 strains, the distribution of these strains and antiretroviral (ART) resistant viruses in different regions of the country, and the HIV-1 strains harbored by the high-risk groups like female sex workers (FSW) reported to be the source of recombinant and ART resistant viruses.

Methods Dried Blood Spots (DBS), collected from 325 infected FSWs in ten cities from 2012 DRC HIV/STI Integrated Biological and Behavioral Surveillance Survey, were tested for HIV-1 genotypes and antiretroviral resistance mutations. Regional segregation …

How The Cervical Microbiota Contributes To Cervical Cancer Risk In Sub-Saharan Africa, Cameron Klein, Crispin Kahesa, Julius Mwalselage, John T. West, Charles Wood, Peter C. Angeletti

Nebraska Center for Virology: Faculty Publications

Despite ongoing efforts, sub-Saharan Africa faces a higher cervical cancer burden than anywhere else in the world. Besides HPV infection, definitive factors of cervical cancer are still unclear. Particular states of the cervicovaginal microbiota and viral infections are associated with increased cervical cancer risk. Notably, HIV infection, which is prevalent in sub-Saharan Africa, greatly increases risk of cervicovaginal dysbiosis and cervical cancer. To better understand and address cervical cancer in sub-Saharan Africa, a better knowledge of the regional cervicovaginal microbiome is required This review establishes current knowledge of HPV, HIV, cervicovaginal infections, and the cervicovaginal microbiota in sub-Saharan Africa. Because …

The Kaposi’S Sarcoma-Associated Herpesvirus (Kshv) Gh/Gl Complex Is The Predominant Neutralizing Antigenic Determinant In Kshv-Infected Individuals, Yasaman Mortazavi, Salum J. Lidenge, Tara Tran, John T. West, Charles Wood, For Yue Tso

Nebraska Center for Virology: Faculty Publications

Kaposi’s sarcoma-associated herpesvirus (KSHV) is the etiological agent of Kaposi’s sarcoma (KS), one of the most prevalent cancers of people living with HIV/AIDS in sub-Saharan Africa. The seroprevalence for KSHV is high in the region, and no prophylactic vaccine against the virus is available. In this study, we characterized the antigenic targets of KSHV-specific neutralizing antibodies (nAbs) in asymptomatic KSHV-infected individuals and KS patients with high nAbs titers. We quantified the extent to which various KSHV envelope glycoproteins (gB, ORF28, ORF68, gH, gL, gM, gN and gpK8.1) adsorbed/removed KSHV-specific nAbs from the plasma of infected individuals. Our study revealed that …

Mycoplasma Co-Infection Is Associated With Cervical Cancer Risk, Cameron Klein, Kandali Samwel, Crispin Kahesa, Julius Mwaiselage, John T. West, Charles Wood, Peter C. Angeletti

Nebraska Center for Virology: Faculty Publications

Tanzania faces one of the highest cervical cancer burdens in the world. Recent work has suggested that the bacterial family Mycoplasmataceae is associated with higher levels of human papillomavirus (HPV), human immunodeficiency virus (HIV), and pre-cancerous cervical lesions. Mycoplasmataceae infection in Tanzania is not well understood, especially when considering the differences between sexually transmitted species of Mycoplasmataceae. To establish the prevalence of common Mycoplasmataceae cervical infections and evaluate their relationship with risk factors for cervical cancer, 1160 Tanzanian women responded to an epidemiological questionnaire and were tested for HIV, HPV, cervical lesions, Mycoplasma genitalium, Mycoplasma hominis, Ureaplasma spp., and Lactobacillus …

Epstein Barr Virus-Immortalizedｂlymphocytes Exacerbate Experimental Autoimmune Encephalomyelitis In Xenograft Mice, Pascal Polepole, Alison Bartenslager, Yutong Liu, Thomas M. Petro, Samodha C. Fernando, Luwen Zhang

Nebraska Center for Virology: Faculty Publications

Multiple sclerosis (MS) is the most common autoimmune disorder affecting the central nervous system. Epstein-Barr virus (EBV) is a causative agent for infectious mononucleosis (IM) that is associated with MS pathogenesis. However, the exact mechanism by which EBV, specifically in IM, increases the risk for MS remains unknown. EBV immortalizes primary B lymphocytes in vitro and causes excessive B lymphocyte proliferation in IM in vivo. In asymptomatic carriers, EBV-infected B lymphocytes still proliferate to certain degrees, the process of which is tightly controlled by the host immune systems. Experimental autoimmune encephalomyelitis (EAE) mimics key features of MS in humans and …

A Decade In Review: A Systematic Review Of Universal Influenza Vaccines In Clinical Trials During The 2010 Decade, Brigette N. Corder, Brianna L. Bullard, Gregory Poland, Eric A. Weaver

Nebraska Center for Virology: Faculty Publications

On average, there are 3–5 million severe cases of influenza virus infections globally each year. Seasonal influenza vaccines provide limited protection against divergent influenza strains. Therefore, the development of a universal influenza vaccine is a top priority for the NIH. Here, we report a comprehensive summary of all universal influenza vaccines that were tested in clinical trials during the 2010–2019 decade. Of the 1597 studies found, 69 eligible clinical trials, which investigated 27 vaccines, were included in this review. Information from each trial was compiled for vaccine target, vaccine platform, adjuvant inclusion, clinical trial phase, and results. As we look …

Species D Adenoviruses As Oncolytic Viral Vectors, Brianna L. Bullard, Brigette N. Corder, Eric A. Weaver

Nebraska Center for Virology: Faculty Publications

Oncolytic adenoviruses (Ad) have shown promising results in the therapeutic treatment of cancer. Ad type 5 (Ad5) is the most extensively utilized Ad type. However, several limitations exist to using Ad5 as an oncolytic virus, including high levels of anti-Ad5 neutralizing antibodies in the population, binding of the Ad5 hexon to blood coagulation factor X leading to liver sequestration and toxicity, and reduced expression of the primary receptor CAR on many tumors. Here, we use in vitro methods to explore the oncolytic potential of four alternative Ad types (Ad26, 28, 45, and 48) belonging to the species D Ad subgroup …

Recommendations For Measuring Hiv Reservoir Size In Cure- Directed Clinical Trials., Luis J. Montaner, Qingsheng Li

Nebraska Center for Virology: Faculty Publications

Therapeutic strategies are being clinically tested either to eradicate the latent HIV reservoir or to achieve virologic control in the absence of antiretroviral therapy (ART). Attaining this goal will require a consensus on how best to measure the levels of persistently-infected cells with the potential to cause viral rebound upon ART cessation to assess the results of cure-directed strategies in vivo. Current measurements assess different aspects of the HIV provirus and its functionality, and produce divergent results. Here, we provide the collective insight and position from the BEAT-HIV Martin Delaney Collaboratory on which viral measurements to prioritize in HIV cure-directed …

Uterine Torsion Dystocia Complicated By Perosomus Elumbis In An Angus Calf Associated With A Consanguineous Mating, Alyssa B. Helms, Riley E. Thompson, Sam Lawton, Jessica L. Petersen, Allison Watson, Mee-Ja Sula, David J. Steffen, Brian K. Whitlock

School of Veterinary and Biomedical Sciences: Faculty Publications

A six-year-old multiparous Angus cow was presented for dystocia. Vaginal and rectal examinations revealed an approximately 360° counterclockwise uterine torsion. The torsion was corrected by rolling the cow counterclockwise (three episodes) with the aid of a plank coupled with manual detorsion via the vagina. The placement of obstetric chains followed by manual traction ultimately delivered a stillborn male calf with evidence of vertebral aplasia, arthrogryposis, and abdominal organ herniation. Patient history and subsequent parentage verification revealed that the calf was the result of a consanguineous (mother to son) mating. Tissue samples from the affected calf and blood samples from the …

Identification Of Immunogenic Epitopes That Permit The Detection Of Antigen-Specific T Cell Responses In Multiple Serotypes Of Group B Coxsackievirus Infections, Ninaad Lasrado, Arunakumar Gangaplara, Rajkumar Arumugam, Chandirasegara Massilamany, Sayli Pokal, Yuzhen Zhou, Shi-Hua Xiang, David Steffen, Jay Reddy

School of Veterinary and Biomedical Sciences: Faculty Publications

Coxsackievirus group B (CVB) contains six serotypes that can affect various organs. Some of these organ-specific diseases such as myocarditis and pancreatitis can be caused by more than one serotype. Thus, development of immunological tools common to multiple serotypes is desired. This is especially critical for analyzing antigen-specific T cell responses at a single cell level. To this end, we made efforts to identify the immunogenic epitopes of CVB3 leading us to localize three T cell epitopes within the viral protein 1 (VP1) namely, VP1 681–700, VP1 721–740 and VP1 771–790. First, we confirmed their immunogenicity in the immunization settings. …

First Records Of Established Populations Of Ixodes Scapularis (Acari: Ixodidae) Collected From Three Nebraska Counties, Lindsey E. Nielsen, Roberto Cortinas, Paul D. Fey, Peter C. Iwen, David H. Nielsen

School of Veterinary and Biomedical Sciences: Faculty Publications

Reported cases of Lyme disease in Nebraska have been assumed to be imported from other endemic areas. Previous surveillance efforts provided no evidence of established populations as only individual specimens of Ixodes scapularis (Say) had been collected. In the winter of 2018, adult I. scapularis were found on a dog at Two Rivers State Recreation Area, Douglas County, prompting tick collection at the site and nearby natural areas. In May 2019, all life stages of host-seeking I. scapularis were collected using dragging and flagging techniques in sites located near the Platte River in Douglas, Sarpy, and Saunders counties. This is …

Methods Of Treating Or Preventing Zika Virus Infection, Shi-Hua Xiang, Nicholas Palermo, Asit K. Pattnaik, Aryamay Pattnaik

School of Veterinary and Biomedical Sciences: Faculty Publications

This document relates to methods and materials for treating a mammal having a Zika virus (ZIKV) infection. For example, a composition including one or more non-nucleoside RNA polymerase inhibitors can be administered to a mammal having, or at risk of developing, a ZIKV infection to treat the mammal.

Recent Advances In The Diagnosis Of Classical Swine Fever And Future Perspectives, Lihua Wang, Rachel Madera, Yuzhen Li, D. Scott Mcvey, Jishu Shi

School of Veterinary and Biomedical Sciences: Faculty Publications

Classical swine fever (CSF) is a highly contagious viral disease of pigs, including wild boar. It is regarded as one of the major problems in the pig industry as it is still endemic in many regions of the world and has the potential to cause devastating epidemics, particularly in countries free of the disease. Rapid and reliable diagnosis is of utmost importance in the control of CSF. Since clinical presentations of CSF are highly variable and may be confused with other viral diseases in pigs, laboratory diagnosis is indispensable for an unambiguous diagnosis. On an international level, well-established diagnostic tests …

Evaluation Of A Baculovirus-Expressed Vp2 Subunit Vaccine For The Protection Of White-Tailed Deer (Odocoileus Virginianus) From Epizootic Hemorrhagic Disease, Sun Young Sunwoo, Leela E. Noronha, Igor Morozov, Jessie D. Trujilo, In Joong Kim, Erin E. Schirtzinger, Bonto Faburary, Barbara S. Drolet, Kinga Urbaniak, D. Scott Mcvey, David A. Meekins, Mitchell V. Palmer, Velmurugan Balaraman, William C. Wilson, Juergen A. Richt

School of Veterinary and Biomedical Sciences: Faculty Publications

Epizootic hemorrhagic disease virus (EHDV) is an arthropod-transmitted RNA virus and the causative agent of epizootic hemorrhagic disease (EHD) in wild and domestic ruminants. In North America, white-tailed deer (WTD) experience the highest EHD-related morbidity and mortality, although clinical disease is reported in cattle during severe epizootics. No commercially licensed EHDV vaccine is available in North America. The objective of this study was to develop and evaluate a subunit vaccine candidate to control EHD in WTD. Recombinant VP2 (rVP2) outer capsid proteins of EHDV serotypes 2 (EHDV-2) and 6 (EHDV-6) were produced in a baculovirus-expression system. Mice and cattle vaccinated …

Amphiphilic Cyclobutenes And Cylobutanes, Wantanee Sittiwong, Patrick H. Dussault, Raul G. Barletta, Robert Powers

School of Veterinary and Biomedical Sciences: Faculty Publications

This disclosure relates to amphiphilic compounds containing a cyclobutene or cyclobutane moiety. In some embodiments, the compounds are useful for treating infection by Mycobacterium such as Mycobacterium tuberculosis. Cyclobutene containing compounds are also useful as monomers in the preparation of amphiphilic polymers.

Non-Neuroinvasivevirusesand Uses Thereof, Gregory A. Smith, Patricia J. Sollars, Gary E. Pickard, Ekaterina E. Heldwein

School of Veterinary and Biomedical Sciences: Faculty Publications

Provided herein are compositions and methods for vaccination and research applications. In particular, provided herein are non-neuroinvasive herpesviruses and alpha herpesviruses and uses thereof.

Mitochondrial Metabolism In Astrocytes Regulates Brain Bioenergetics, Neurotransmission And Redox Balance, Jordan Rose, Christian Brian, Aglaia Pappa, Mihalis I. Panayiotidi, Rodrigo Franco

School of Veterinary and Biomedical Sciences: Faculty Publications

In the brain, mitochondrial metabolism has been largely associated with energy production, and its dysfunction is linked to neuronal cell loss. However, the functional role of mitochondria in glial cells has been poorly studied. Recent reports have demonstrated unequivocally that astrocytes do not require mitochondria to meet their bioenergetics demands. Then, the question remaining is, what is the functional role of mitochondria in astrocytes? In this work, we review current evidence demonstrating that mitochondrial central carbon metabolism in astrocytes regulates overall brain bioenergetics, neurotransmitter homeostasis and redox balance. Emphasis is placed in detailing carbon source utilization (glucose and fatty acids), …

Mechanisms Of Sex Hormones In Autoimmunity: Focus On Eae, Ninaad Lasrado, Ting Jia, Chandirasegaran Massilamany, Rodrigo Franco, Zsolt Illes, Jay Reddy

School of Veterinary and Biomedical Sciences: Faculty Publications

Sex-related differences in the occurrence of autoimmune diseases is well documented, with females showing a greater propensity to develop these diseases than their male counterparts. Sex hormones, namely dihydrotestosterone and estrogens, have been shown to ameliorate the severity of inflammatory diseases. Immunologically, the beneficial effects of sex hormones have been ascribed to the suppression of effector lymphocyte responses accompanied by immune deviation from pro-inflammatory to anti-inflammatory cytokine production. In this review, we present our view of the mechanisms of sex hormones that contribute to their ability to suppress autoimmune responses with an emphasis on the pathogenesis of experimental autoimmune encephalomyelitis.

Evidence For Anti-Viral Effects Of Complete Freund’S Adjuvant In The Mouse Model Of Enterovirus Infection, Arunakumar Gangaplara, Chandirasegaran Massilamany, Ninaad Lasrado, David J. Steffen, Jay Reddy

School of Veterinary and Biomedical Sciences: Faculty Publications

Group B coxsackieviruses (CVBs) belonging to the genus, Enterovirus and contain six serotypes that induce various diseases, whose occurrence may involve the mediation of more than one serotype. We recently identified immunogenic epitopes within coxsackieviruses B3 (CVB3) viral protein 1 that induce anti-viral T cell responses in mouse models of CVB infections. In our investigations to determine the protective responses of the viral epitopes, we unexpectedly noted that animals immunized with complete Freund’s adjuvant (CFA) alone and later challenged with CVB3 were completely protected against myocarditis. Similarly, the pancreatitis-inducing ability of CVB3 was remarkably reduced to only 10% in the …

Porcine Reproductive And Respiratory Syndrome Virus Reverse Genetics And The Major Applications, Jayeshbhai Chaudhari, Hiep Vu

School of Veterinary and Biomedical Sciences: Faculty Publications

Porcine reproductive and respiratory syndrome virus (PRRSV) is a positive sense, single-stranded RNA virus that is known to infect only pigs. The virus emerged in the late 1980s and became endemic in most swine producing countries, causing substantial economic losses to the swine industry. The first reverse genetics system for PRRSV was reported in 1998. Since then, several infectious cDNA clones for PRRSV have been constructed. The availability of these infectious cDNA clones has facilitated the genetic modifications of the viral genome at precise locations. Common approaches to manipulate the viral genome include site-directed mutagenesis, deletion of viral genes or …