@article{briggs_smith_piper_huitt_spears_quiles_ribeiro_thomas_brown_hernandez_2014, title={Live Attenuated Tetravalent Dengue Virus Host Range Vaccine Is Immunogenic in African Green Monkeys following a Single Vaccination}, volume={88}, ISSN={["1098-5514"]}, DOI={10.1128/jvi.00541-14}, abstractNote={ABSTRACT
          
            The causative agent of dengue fever, dengue virus (DENV), is transmitted by mosquitoes, and as distribution of these insects has expanded, so has dengue-related disease. DENV is a member of the
            Flaviviridae
            family and has 4 distinct serotypes (DENV-1, -2, -3, and -4). No lasting cross protection is afforded to heterologous serotypes following infection by any one of the individual serotypes. The presence of nonneutralizing antibodies to one serotype can facilitate the occurrence of more-severe dengue hemorrhagic fever through immune enhancement upon infection with a second serotype. For this reason, the development of a safe, tetravalent vaccine to produce a balanced immune response to all four serotypes is critical. We have developed a novel approach to produce safe and effective live-attenuated vaccines for DENV and other insect-borne viruses. Host range (HR) mutants of each DENV serotype were created by truncating transmembrane domain 1 of the E protein and selecting for strains of DENV that replicated well in insect cells but not mammalian cells. These vaccine strains were tested for immunogenicity in African green monkeys (AGMs). No vaccine-related adverse events occurred. The vaccine strains were confirmed to be attenuated
            in vivo
            by infectious center assay (ICA). Analysis by 50% plaque reduction neutralization test (PRNT
            50
            ) established that by day 62 postvaccination, 100% of animals seroconverted to DENV-1, -2, -3, and -4. Additionally, the DENV HR tetravalent vaccine (HR-Tet) showed a tetravalent anamnestic immune response in 100% (16/16) of AGMs after challenge with wild-type (WT) DENV strains.
          
          
            IMPORTANCE
            We have generated a live attenuated viral (LAV) vaccine capable of eliciting a strong immune response in African green monkeys (AGMs) in a single dose. This vaccine is delivered by injecting one of four attenuated serotypes into each limb of the animal. 100% of animals given the vaccine generated antibodies against all 4 serotypes, and this response was found to be balanced in nature. This is also one of the first studies of dengue in AGMs, and our study suggests that viremia and antibody response in AGMs may be similar to those seen in DENV infection in humans.
          }, number={12}, journal={JOURNAL OF VIROLOGY}, author={Briggs, Caitlin M. and Smith, Katherine M. and Piper, Amanda and Huitt, Emerson and Spears, Carla J. and Quiles, Michelle and Ribeiro, Mariana and Thomas, Malcolm E. and Brown, Dennis T. and Hernandez, Raquel}, year={2014}, month={Jun}, pages={6729–6742} }
 @article{piper_ribeiro_smith_briggs_huitt_nanda_spears_quiles_cullen_thomas_et al._2013, title={Chikungunya Virus Host Range E2 Transmembrane Deletion Mutants Induce Protective Immunity against Challenge in C57BL/6J Mice}, volume={87}, ISSN={["1098-5514"]}, DOI={10.1128/jvi.03357-12}, abstractNote={ABSTRACT
          
            A vaccine against Chikungunya virus (ChikV), a reemerging pathogenic arbovirus, has been made by attenuating wild-type (WT) virus via truncation of the transmembrane domain (TMD) of E2 and selecting for host range (HR) mutants. Mice are a standard model system for ChikV disease and display the same symptoms of the disease seen in humans. Groups of mice were inoculated with one of three ChikV HR mutants to determine the ability of each mutant strain to elicit neutralizing antibody and protective immunity upon virus challenge. One mutant, ChikV TM17-2, fulfilled the criteria for a good vaccine candidate. It displayed no reactogenicity at the site of injection, no tissue disease in the foot/ankle and quadriceps, and no evidence of viral persistence in foot/ankle tissues 21 days after infection. Upon challenge with a highly pathogenic strain of ChikV, the mutant blocked viral replication in all tissues tested. This study identified a ChikV HR mutant that grows to high levels in insect cells but was restricted in the ability to assemble virus in mammalian cells
            in vitro
            . The study demonstrates that these HR strains are attenuated in the mammalian host and warrant further development as live-attenuated vaccine strains.
          }, number={12}, journal={JOURNAL OF VIROLOGY}, author={Piper, Amanda and Ribeiro, Mariana and Smith, Katherine M. and Briggs, Caitlin M. and Huitt, Emerson and Nanda, Kavita and Spears, Carla J. and Quiles, Michelle and Cullen, John and Thomas, Malcolm E. and et al.}, year={2013}, month={Jun}, pages={6748–6757} }
 @article{vancini_kramer_ribeiro_hernandez_brown_2013, title={Flavivirus infection from mosquitoes in vitro reveals cell entry at the plasma membrane}, volume={435}, ISSN={["0042-6822"]}, DOI={10.1016/j.virol.2012.10.013}, abstractNote={Dengue and West Nile viruses are enveloped RNA viruses that belong to genus Flavivirus (family Flaviviridae) and are considered important mosquito-borne viral pathogenic agents worldwide. A potential target for intervention strategies is the virus cell entry mechanism. Previous studies of flavivirus entry have focused on the effects of biochemical and molecular inhibitors on viral entry leading to controversial conclusions suggesting that the process is dependent upon endocytosis and low pH mediated membrane fusion. In this study we analyzed the early events in the infection process by means of electron microscopy and immuno-gold labeling of viral particles during cell entry, and used as a new approach for infecting cells with viruses obtained directly from mosquitoes. The results show that Dengue and West Nile viruses may infect cells by a mechanism that involves direct penetration of the host cell plasma membrane as proposed for alphaviruses.}, number={2}, journal={VIROLOGY}, author={Vancini, Ricardo and Kramer, Laura D. and Ribeiro, Mariana and Hernandez, Raquel and Brown, Dennis}, year={2013}, month={Jan}, pages={406–414} }
 @article{smith_nanda_spears_ribeiro_vancini_piper_thomas_thomas_brown_hernandez_2011, title={Structural mutants of dengue virus 2 transmembrane domains exhibit host-range phenotype}, volume={8}, ISSN={["1743-422X"]}, DOI={10.1186/1743-422x-8-289}, abstractNote={There are over 700 known arboviruses and at least 80 immunologically distinct types that cause disease in humans. Arboviruses are transmitted among vertebrates by biting insects, chiefly mosquitoes and ticks. These viruses are widely distributed throughout the world, depending on the presence of appropriate hosts (birds, horses, domestic animals, humans) and vectors. Mosquito-borne arboviruses present some of the most important examples of emerging and resurgent diseases of global significance. A strategy has been developed by which host-range mutants of Dengue virus can be constructed by generating deletions in the transmembrane domain (TMD) of the E glycoprotein. The host-range mutants produced and selected favored growth in the insect hosts. Mouse trials were conducted to determine if these mutants could initiate an immune response in an in vivo system. The DV2 E protein TMD defined as amino acids 452SWTMKILIGVIITWIG467 was found to contain specific residues which were required for the production of this host-range phenotype. Deletion mutants were found to be stable in vitro for 4 sequential passages in both host cell lines. The host-range mutants elicited neutralizing antibody above that seen for wild-type virus in mice and warrant further testing in primates as potential vaccine candidates. Novel host-range mutants of DV2 were created that have preferential growth in insect cells and impaired infectivity in mammalian cells. This method for creating live, attenuated viral mutants that generate safe and effective immunity may be applied to many other insect-borne viral diseases for which no current effective therapies exist.}, journal={VIROLOGY JOURNAL}, author={Smith, Katherine M. and Nanda, Kavita and Spears, Carla J. and Ribeiro, Mariana and Vancini, Ricardo and Piper, Amanda and Thomas, Gwynneth S. and Thomas, Malcolm E. and Brown, Dennis T. and Hernandez, Raquel}, year={2011}, month={Jun} }
 @article{nanda_vancini_ribeiro_brown_hernandez_2009, title={A high capacity Alphavirus heterologous gene delivery system}, volume={390}, ISSN={["0042-6822"]}, DOI={10.1016/j.virol.2009.05.026}, abstractNote={A novel replication competent Sindbis virus based gene delivery vector has been developed for the introduction of genetic cargo into cell lines in vitro and potentially, animal models in vivo. This delivery system expands the previous uses of Sindbis virus as a gene delivery system in that no replicons are required and the resulting cargo containing virus particles are infectious. The heterologous vector is based on a morphological mutant in C, Ser180/Gly183 which produces larger than the normal size T = 4 virus particles of 70 nm in size. This mutant produced particles up to 205 nm in size equal to a triangulation number of 36. It was postulated that because the Ser180/Gly183 mutant was capable of assembling such large particles, that increasing the size of the RNA genome incorporated into this mutant capsid protein would favor the assembly of larger than T = 4 wild type sized virions. The first generation prototype larger vehicle, described here, carries a ~ 18 kb cDNA insert, however it is conceivable that RNA as large as 32 kb could be transcribed and packaged. The large variant produces a high virus titer of ~ 109 pfu/ml from either mammalian or insect cells in culture. Multiple passages of the virus show no loss of the inserted genetic material.}, number={2}, journal={VIROLOGY}, author={Nanda, Kavita and Vancini, Ricardo and Ribeiro, Mariana and Brown, Dennis T. and Hernandez, Raquel}, year={2009}, month={Aug}, pages={368–373} }