scholarly journals Characterization of Reverse Genetics-Derived Cold-Adapted Master Donor Virus A/Leningrad/134/17/57 (H2N2) and Reassortants with H5N1 Surface Genes in a Mouse Model

2014 ◽  
Vol 21 (5) ◽  
pp. 722-731 ◽  
Author(s):  
Irina Isakova-Sivak ◽  
Li-Mei Chen ◽  
Melissa Bourgeois ◽  
Yumiko Matsuoka ◽  
J. Theo M. Voeten ◽  
...  
Keyword(s):  
Mouse Model ◽  
Reverse Genetics ◽  
Protective Efficacy ◽  
Influenza Pandemic ◽  
Lethal Dose ◽  
Challenge Inoculation ◽  
Cold Adapted ◽  
Antibody Titers ◽  
Inactivated Vaccines ◽  
Clade 1

ABSTRACTLive attenuated influenza vaccines (LAIV) offer significant advantages over subunit or split inactivated vaccines to mitigate an eventual influenza pandemic, including simpler manufacturing processes and more cross-protective immune responses. Using an established reverse genetics (rg) system for wild-type (wt) A/Leningrad/134/1957 and cold-adapted (ca) A/Leningrad/134/17/1957 (Len17) master donor virus (MDV), we produced and characterized three rg H5N1 reassortant viruses carrying modified HA and intact NA genes from either A/Vietnam/1203/2004 (H5N1, VN1203, clade 1) or A/Egypt/321/2007 (H5N1, EG321, clade 2) virus. A mouse model of infection was used to determine the infectivity and tissue tropism of the parentalwtviruses compared to thecamaster donor viruses as well as the H5N1 reassortants. Allcaviruses showed reduced replication in lungs and enhanced replication in nasal epithelium. In addition, the H5N1 HA and NA enhanced replication in lungs unless it was restricted by the internal genes of thecaMDV. Mice inoculated twice 4 weeks apart with the H5N1 reassortant LAIV candidate viruses developed serum hemagglutination inhibition HI and IgA antibody titers to the homologous and heterologous viruses consistent with protective immunity. These animals remained healthy after challenge inoculation with a lethal dose with homologous or heterologouswtH5N1 highly pathogenic avian influenza (HPAI) viruses. The profiles of viral replication in respiratory tissues and the immunogenicity and protective efficacy characteristics of the twocaH5N1 candidate LAIV viruses warrant further development into a vaccine for human use.

scholarly journals Generation and Characterization of a Mouse-Adapted Makona Variant of Ebola Virus

Viruses ◽  
2019 ◽  
Vol 11 (11) ◽  
pp. 987 ◽  
Author(s):  
Mable Chan ◽  
Anders Leung ◽  
Bryan D. Griffin ◽  
Robert Vendramelli ◽  
Nikesh Tailor ◽  
...  
Keyword(s):  
Mouse Model ◽  
Reverse Genetics ◽  
Ebola Virus ◽  
Lethal Dose ◽  
West African ◽  
Zoonotic Pathogen ◽  
Immunocompetent Mice ◽  
Pro Inflammatory Cytokines ◽  
Prior Adaptation

Ebola virus (EBOV) is a zoonotic pathogen that poses a significant threat to public health, causing sporadic yet devastating outbreaks that have the potential to spread worldwide, as demonstrated during the 2013–2016 West African outbreak. Mouse models of infection are important tools for the development of therapeutics and vaccines. Exposure of immunocompetent mice to clinical isolates of EBOV is nonlethal; consequently, EBOV requires prior adaptation in mice to cause lethal disease. Until now, the only immunocompetent EBOV mouse model was based on the Mayinga variant, which was isolated in 1976. Here, we generated a novel mouse-adapted (MA)-EBOV based on the 2014 Makona isolate by inserting EBOV/Mayinga-MA mutations into the EBOV/Makona genome, followed by serial passaging of the rescued virus in suckling mice. The resulting EBOV/Makona-MA causes lethal disease in adult immunocompetent mice within 6 to 9 days and has a lethal dose (LD50) of 0.004 plaque forming units (PFU). Two additional mutations emerged after mouse-adaptation in the viral nucleoprotein (NP) and membrane-associated protein VP24. Using reverse genetics, we found the VP24 mutation to be critical for EBOV/Makona-MA virulence. EBOV/Makona-MA infected mice that presented with viremia, high viral burden in organs, increased release of pro-inflammatory cytokines/chemokines, and lymphopenia. Our mouse model will help advance pre-clinical development of countermeasures against contemporary EBOV variants.

scholarly journals Evaluation of the cell culture based and the mouse brain derived inactivated vaccines against Crimean-Congo hemorrhagic fever virus in transiently immune-suppressed (IS) mouse model

2020 ◽  
Vol 14 (11) ◽  
pp. e0008834
Author(s):  
Shaikh Terkis Islam Pavel ◽  
Hazel Yetiskin ◽  
Ahmet Kalkan ◽  
Aykut Ozdarendeli
Keyword(s):  
Cell Culture ◽  
Mouse Model ◽  
Mouse Brain ◽  
Protective Efficacy ◽  
Hemorrhagic Fever ◽  
Fever Virus ◽  
Crimean Congo Hemorrhagic Fever ◽  
The Balkans ◽  
Hemorrhagic Fever Virus ◽  
Inactivated Vaccines

Crimean-Congo hemorrhagic fever virus (CCHFV) is a tick-borne virus in the Nairoviridae family within the Bunyavirales order of viruses. Crimean-Congo hemorrhagic fever (CCHF) is the most widespread among tick-borne human viral diseases. It is endemic in many areas of Africa, Asia, the Middle East, in the Balkans, Russia and countries of the former Soviet Union. The confirmed CCHF cases were seen in Spain in 2016 to signify expansion of the virus into new geographical areas. CCHFV causes a viral human disease characterized by sudden onset of fever, headache, abdominal pain, nausea, hypotension, hemorrhage, and hepatic dysfunction with fatality rates up to 30%. Currently, there are no spesific treatments or licensed vaccines available for CCHFV. The absence of a susceptible animal model for CCHFV infection was severely hindered work on the development of vaccines. However, several animal models of CCHFV infection have been recently developed and used to assess vaccine efficacy. In this study, we have used the transiently immune-suppressed (IS) mouse model that MAb-5A3 was used to block IFN-I signaling in immune intact, wild-type mice at the time of CCHFV infection to evaluate the immune response and efficacy of the cell culture based and the mouse brain derived inactivated vaccines against CCHFV. Both vaccine preparations have provided complete protection but the cell culture based vaccine more effectively induced to CCFHV spesific antibodies and T cell responses. This is the first comparison of the cell culture based and the mouse brain derived vaccines for assessing the protective efficacy and the immunogenicity in the IS mouse CCHFV model.

scholarly journals Evaluation of recombinant protein superoxide dismutase of Haemophilus parasuis strain SH0165 as vaccine candidate in a mouse model

2017 ◽  
Vol 63 (4) ◽  
pp. 312-320 ◽  
Author(s):  
Ling Guo ◽  
Lei Xu ◽  
Tao Wu ◽  
Shulin Fu ◽  
Yinsheng Qiu ◽  
...  
Keyword(s):  
Immune Response ◽  
Superoxide Dismutase ◽  
Mouse Model ◽  
Inflammatory Diseases ◽  
Protective Efficacy ◽  
Lethal Dose ◽  
Haemophilus Parasuis ◽  
Humoral Immune ◽  
Novel Approach ◽  
Ifn Γ

Haemophilus parasuis can cause a severe membrane inflammation disorder. It has been documented that superoxide dismutase (SOD) is a potential target to treat systemic inflammatory diseases. Therefore, we constructed an experimental H. parasuis subunit vaccine SOD and determined the protective efficacy of SOD using a lethal dose challenge against H. parasuis serovar 4 strain MD0322 and serovar 5 strain SH0165 in a mouse model. The results demonstrated that SOD could induce a strong humoral immune response in mice and provide significant immunoprotection efficacy against a lethal dose of H. parasuis serovar 4 strain MD0322 or serovar 5 strain SH0165 challenge. IgG subtype analysis indicated SOD protein could trigger a bias toward a Th1-type immune response and induce the proliferation of splenocytes and secretion of IL-2 and IFN-γ of splenocytes. In addition, serum in mice from the SOD-immunized group could inhibit the growth of strain MD0322 and strain SH0165 in the whole-blood killing bacteria assay. This is the first report that immunization of mice with SOD protein could provide protective effect against a lethal dose of H. parasuis serovar 4 and serovar 5 challenge in mice, which may provide a novel approach against heterogeneous serovar infection of H. parasuis in future.

scholarly journals Efficacy of Coxsackievirus A5 Vaccine Candidates in an Actively Immunized Mouse Model

2021 ◽  
Author(s):  
Wei-Ping Jin ◽  
Jia Lu ◽  
Xiao-Yu Zhang ◽  
Jie Wu ◽  
Zhen-Ni Wei ◽  
...  
Keyword(s):  
Animal Model ◽  
Mouse Model ◽  
Neutralizing Antibodies ◽  
Large Scale ◽  
Vaccine Candidate ◽  
Protective Efficacy ◽  
Lethal Dose ◽  
Enterovirus 71 ◽  
Vaccine Candidates ◽  
Enterovirus Serotypes

Coxsackievirus A5 (CV-A5) has recently emerged as a main hand, foot and mouth disease (HFMD) pathogen. Following a large-scale vaccination campaign against enterovirus 71 (EV-71) in China, the number of HFMD-associated cases with EV-71 was reduced, especially severe and fatal cases. However, the total number of HFMD cases remains high, as HFMD is also caused by other enterovirus serotypes. A multivalent HFMD vaccine containing 4 or 6 antigens of enterovirus serotypes is urgently needed. A formaldehyde-inactivated CV-A5 vaccine derived from Vero cells was used to inoculate newborn Kunming mice on days 3 and 10. The mice were challenged on day 14 with a mouse-adapted CV-A5 strain at a lethal dose, which was lethal for 14-day-old suckling mice. Within 14 days post-challenge, groups of mice immunized with three formulations, empty particles (EPs), full particles (FPs) and a mixture of the EP and FP vaccine candidates, all survived, while 100% of the mock-immunized mice died. Neutralizing antibodies (NtAbs) were detected in the sera of immunized mice, and the NtAb levels were correlated with the survival rate of the challenged mice. The virus loads in organs were reduced, and pathological changes and viral protein expression were weak or not observed in the immunized mice compared with those in alum-inoculated control mice. Another interesting finding was the identification of CV-A5 dense particles (DPs), facilitating morphogenesis study. These results demonstrated that the Vero cell-adapted CV-A5 strain is a promising vaccine candidate and could be used as a multivalent HFMD vaccine component in the future. IMPORTANCE The vaccine candidate strain CV-A5 was produced with a high infectivity titer and a high viral particle yield. Three particle forms, empty particles (EPs), full particles (FPs) and dense particles (DPs), were obtained and characterized after purification. The immunogenicities of EP, FP, and EP+FP were evaluated in mice. Mouse-adapted CV-A5 was generated as a challenge strain to infect 14-day-old mice. An active immunization challenge mouse model was established to evaluate the efficacy of the inactivated vaccine candidate. This animal model mimics vaccination, similar immune responses of the vaccinated. The animal model also tests protective efficacy in response to the vaccine against the disease. This work is important for the preparation of multivalent vaccines against HFMD caused by different emerging strains.

scholarly journals Immune Protective Efficacy of China’s Traditional Inactivated and Attenuated Vaccines against the Prevalent Strains of Pasteurella multocida in Mice

Vaccines ◽  
2021 ◽  
Vol 9 (10) ◽  
pp. 1155
Author(s):  
Li-Jun Guan ◽  
Ji-Jian Song ◽  
Yun Xue ◽  
Xia Ai ◽  
Zhi-Jun Liu ◽  
...  
Keyword(s):  
Mouse Model ◽  
Protective Effect ◽  
Aluminum Hydroxide ◽  
Pasteurella Multocida ◽  
Protective Efficacy ◽  
Cross Protection ◽  
Immune Protection ◽  
Capsular Type ◽  
Protection Effect ◽  
Antibody Titers

Capsular type A and D strains of Pasteurella multocida are the main epidemic serogroups in pigs in China. In this study, we preliminarily evaluated the immune protective efficacy of the two traditional vaccines, an inactivated C44-1 aluminum-hydroxide-gel-adjuvanted (Alh–C44-1) vaccine and a live EO630 vaccine, against currently circulating strains of P. multocida in a mouse model. Mice immunized twice with conventional vaccines generated higher antibody titers, and significantly higher levels of IgG were observed in the mice inoculated with the inactivated Alh–C44-1 vaccine on day 35 (p < 0.05) than those with the live EO630 vaccine. The mice immune protection test showed that the vaccination groups had a 57% or 71% protection effect against the serogroup B strain, but had no protective effect against epidemic strains. In conclusion, our study found that the widely used traditional P. multocida vaccines in China provide good protection against homologous strains, but could not provide cross-protection against heterologous strains in a mouse model.

scholarly journals Immunogenicity and protective efficacy of enterotoxigenic Escherichia coli (ETEC) total RNA against ETEC challenge in a mouse model

2020 ◽  
Vol 10 (1) ◽  
Author(s):  
Mandi Liu ◽  
Yue Zhang ◽  
Di Zhang ◽  
Yun Bai ◽  
Guomei Liu ◽  
...  
Keyword(s):  
Escherichia Coli ◽  
Mouse Model ◽  
Immune Responses ◽  
Protective Efficacy ◽  
Enterotoxigenic Escherichia Coli ◽  
Economic Losses ◽  
Th2 Response ◽  
Total Rna ◽  
Etec Infection

AbstractEnterotoxigenic Escherichia coli (ETEC), an essential cause of post-weaning diarrhea (PWD) in piglets, leads to significant economic losses to the pig industry. The present study aims to identify the role of ETEC total RNA in eliciting immune responses to protect animals against ETEC infection. The results showed that the total RNA isolated from pig-derived ETEC K88ac strain effectively stimulated the IL-1β secretion of porcine intestinal epithelial cells (IPEC-J2). The mouse model immunized with ETEC total RNA via intramuscular injection (IM) or oral route (OR) was used to evaluate the protective efficiency of the ETEC total RNA. The results suggested that 70 μg ETEC total RNA administered by either route significantly promoted the production of the serum IL-1β and K88ac specific immunoglobulins (IgG, IgM, and IgA). Besides, the ETEC RNA administration augmented strong mucosal immunity by elevating K88ac specific IgA level in the intestinal fluid. Intramuscularly administered RNA induced a Th1/Th2 shift toward a Th2 response, while the orally administered RNA did not. The ETEC total RNA efficiently protected the animals against the ETEC challenge either by itself or as an adjuvant. The histology characterization of the small intestines also suggested the ETEC RNA administration protected the small intestinal structure against the ETEC infection. Particularly of note was that the immunity level and protective efficacy caused by ETEC RNA were dose-dependent. These findings will help understand the role of bacterial RNA in eliciting immune responses, and benefit the development of RNA-based vaccines or adjuvants.

scholarly journals Porcine Reproductive and Respiratory Syndrome Virus: Immune Escape and Application of Reverse Genetics in Attenuated Live Vaccine Development

Vaccines ◽  
2021 ◽  
Vol 9 (5) ◽  
pp. 480
Author(s):  
Honglei Wang ◽  
Yangyang Xu ◽  
Wenhai Feng
Keyword(s):  
Immune Responses ◽  
Reverse Genetics ◽  
Vaccine Development ◽  
Immune Escape ◽  
Rna Virus ◽  
Economic Losses ◽  
Respiratory Syndrome Virus ◽  
Live Vaccines ◽  
Host Immune Responses ◽  
Inactivated Vaccines

Porcine reproductive and respiratory syndrome virus (PRRSV), an RNA virus widely prevalent in pigs, results in significant economic losses worldwide. PRRSV can escape from the host immune response in several processes. Vaccines, including modified live vaccines and inactivated vaccines, are the best available countermeasures against PRRSV infection. However, challenges still exist as the vaccines are not able to induce broad protection. The reason lies in several facts, mainly the variability of PRRSV and the complexity of the interaction between PRRSV and host immune responses, and overcoming these obstacles will require more exploration. Many novel strategies have been proposed to construct more effective vaccines against this evolving and smart virus. In this review, we will describe the mechanisms of how PRRSV induces weak and delayed immune responses, the current vaccines of PRRSV, and the strategies to develop modified live vaccines using reverse genetics systems.

scholarly journals Prediction of vaccine efficacy of the Delta variant

2021 ◽  
Author(s):  
Xinhua Chen ◽  
Andrew S. Azman ◽  
Wanying Lu ◽  
Ruijia Sun ◽  
Nan Zheng ◽  
...  
Keyword(s):  
Vaccine Efficacy ◽  
Protective Efficacy ◽  
Adenovirus Vector ◽  
Neutralizing Antibody ◽  
Effective Vaccine ◽  
Public Health Decision ◽  
Additional Tool ◽  
Health Decision Making ◽  
Health Decision ◽  
Antibody Titers

AbstractThe emergence of SARS-CoV-2 variants have raised concerns over the protective efficacy of the current generation of vaccines, and it remains unclear to what extent, if any, different variants impact the efficacy and effectiveness of various SARS-CoV-2 vaccines. We systematically searched for studies of SARS-CoV-2 vaccine efficacy and effectiveness, as well as neutralization data for variants, and used a previously published statistical model to predict vaccine efficacy against variants. Overall, we estimate the efficacy of mRNA-1273 and ChAdOx1 nCoV-19 against infection caused by the Delta variant to be 25-50% lower than that of prototype strains. The predicted efficacy against symptomatic illness of the mRNA vaccines BNT162b2 and mRNA-1273 are 95.1% (UI: 88.4-98.1%) and 80.8% (60.7-92.3%), respectively, which are higher than that of adenovirus-vector vaccines Ad26.COV2.S (44.8%, UI: 29.8-60.1%) and ChAdOx1 nCoV-19 (41.1%, 19.8-62.8%). Taken together, these results suggest that the development of more effective vaccine strategies against the Delta variant may be needed. Finally, the use of neutralizing antibody titers to predict efficacy against variants provides an additional tool for public health decision making, as new variants continue to emerge.

scholarly journals Identification of the Genome Segments of Bluetongue Virus Type 26/Type 1 Reassortants Influencing Horizontal Transmission in a Mouse Model

Viruses ◽  
2021 ◽  
Vol 13 (11) ◽  
pp. 2208
Author(s):  
Houssam Attoui ◽  
Baptiste Monsion ◽  
Bernard Klonjkowski ◽  
Stéphan Zientara ◽  
Peter P. C. Mertens ◽  
...  
Keyword(s):  
Mouse Model ◽  
Bluetongue Virus ◽  
Reverse Genetics ◽  
Horizontal Transmission ◽  
Clinical Signs ◽  
Small Ruminants ◽  
Minor Role ◽  
Individual Genome ◽  
A Minor ◽  
Reassortant Viruses

Bluetongue virus serotypes 1 to 24 are transmitted primarily by infected Culicoides midges, in which they also replicate. However, “atypical” BTV serotypes (BTV-25, -26, -27 and -28) have recently been identified that do not infect and replicate in adult Culicoides, or a Culicoides derived cell line (KC cells). These atypical viruses are transmitted horizontally by direct contact between infected and susceptible hosts (primarily small ruminants) causing only mild clinical signs, although the exact transmission mechanisms involved have yet to be determined. We used reverse genetics to generate a strain of BTV-1 (BTV-1 RGC7) which is less virulent, infecting IFNAR(−/−) mice without killing them. Reassortant viruses were also engineered, using the BTV-1 RGC7 genetic backbone, containing individual genome segments derived from BTV-26. These reassortant viruses were used to explore the genetic control of horizontal transmission (HT) in the IFNAR(−/−) mouse model. Previous studies showed that genome segments 1, 2 and 3 restrict infection of Culicoides cells, along with a minor role for segment 7. The current study demonstrates that genome segments 2, 5 and 10 of BTV-26 (coding for proteins VP2, NS1 and NS3/NS3a/NS5, respectively) are individually sufficient to promote HT.

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