scholarly journals Assessment of Immunogenicity and Neutralisation Efficacy of Viral-Vectored Vaccines Against Chikungunya Virus

Viruses ◽  
2019 ◽  
Vol 11 (4) ◽  
pp. 322 ◽  
Author(s):  
César López-Camacho ◽  
Young Chan Kim ◽  
Joshua Blight ◽  
Marcos Lazaro Moreli ◽  
Eduardo Montoya-Diaz ◽  
...  
Keyword(s):  
Chikungunya Virus ◽  
Pacific Islands ◽  
High Capacity ◽  
Febrile Illness ◽  
Structural Proteins ◽  
Vaccine Platform ◽  
Cell Responses ◽  
Efficacious Vaccine

Chikungunya virus (CHIKV) has caused extensive outbreaks in several countries within the Americas, Asia, Oceanic/Pacific Islands, and Europe. In humans, CHIKV infections cause a debilitating disease with acute febrile illness and long-term polyarthralgia. Acute and chronic symptoms impose a major economic burden to health systems and contribute to poverty in affected countries. An efficacious vaccine would be an important step towards decreasing the disease burden caused by CHIKV infection. Despite no licensed vaccine is yet available for CHIKV, there is strong evidence of effective asymptomatic viral clearance due to neutralising antibodies against the viral structural proteins. We have designed viral-vectored vaccines to express the structural proteins of CHIKV, using the replication-deficient chimpanzee adenoviral platform, ChAdOx1. Expression of the CHIKV antigens results in the formation of chikungunya virus-like particles. Our vaccines induce high frequencies of anti-chikungunya specific T-cell responses as well as high titres of anti-CHIKV E2 antibodies with high capacity for in vitro neutralisation. Our results indicate the potential for further clinical development of the ChAdOx1 vaccine platform in CHIKV vaccinology.

scholarly journals Infectious RNA vaccine protects mice against chikungunya virus infection

2020 ◽  
Vol 10 (1) ◽  
Author(s):  
Inga Szurgot ◽  
Karl Ljungberg ◽  
Beate M. Kümmerer ◽  
Peter Liljeström
Keyword(s):  
Chikungunya Virus ◽  
Neutralizing Antibody ◽  
Antibody Responses ◽  
High Dose ◽  
Vaccine Platform ◽  
Encoding Gene ◽  
Rna Replicon ◽  
Nsp3 Gene

AbstractWe describe a novel vaccine platform that can generate protective immunity to chikungunya virus (CHIKV) in C57BL/6J mice after a single immunization by employing an infectious RNA (iRNA), which upon introduction into a host cell launches an infectious attenuated virus. We and others have previously reported that an engineered deletion of 183 nucleotides in the nsP3 gene attenuates chikungunya virus (CHIKV) and reduces in vivo viral replication and viremia after challenge in mice, macaques and man. Here, we demonstrated that in vitro transfection of iRNA carrying the nsP3 deletion generated infectious viruses, and after intramuscular injection, the iRNA induced robust antibody responses in mice. The iRNA was superior at eliciting binding and neutralizing antibody responses as compared to a DNA vaccine encoding the same RNA (iDNA) or a non-propagating RNA replicon (RREP) lacking the capsid encoding gene. Subsequent challenge with a high dose of CHIKV demonstrated that the antibody responses induced by this vaccine candidate protected animals from viremia. The iRNA approach constitutes a novel vaccine platform with the potential to impact the spread of CHIKV. Moreover, we believe that this approach is likely applicable also to other positive-strand viruses.

scholarly journals Autonomously Replicating RNAs of Bungowannah Pestivirus: ERNS Is Not Essential for the Generation of Infectious Particles

2020 ◽  
Vol 94 (14) ◽  
Author(s):  
Anja Dalmann ◽  
Ilona Reimann ◽  
Kerstin Wernike ◽  
Martin Beer
Keyword(s):  
Virus Assembly ◽  
Host Cells ◽  
Structural Proteins ◽  
Progeny Virus ◽  
Human Populations ◽  
Structural Protein ◽  
Vaccine Platform ◽  
Susceptible Host ◽  
Infectious Progeny Virus

ABSTRACT Autonomously replicating subgenomic Bungowannah virus (BuPV) RNAs (BuPV replicons) with deletions of the genome regions encoding the structural proteins C, ERNS, E1, and E2 were constructed on the basis of an infectious cDNA clone of BuPV. Nanoluciferase (Nluc) insertion was used to compare the replication efficiencies of all constructs after electroporation of in vitro-transcribed RNA from the different clones. Deletion of C, E1, E2, or the complete structural protein genome region (C-ERNS-E1-E2) prevented the production of infectious progeny virus, whereas deletion of ERNS still allowed the generation of infectious particles. However, those ΔERNS viral particles were defective in virus assembly and/or egress and could not be further propagated for more than three additional passages in porcine SK-6 cells. These “defective-in-third-cycle” BuPV ΔERNS mutants were subsequently used to express the classical swine fever virus envelope protein E2, the N-terminal domain of the Schmallenberg virus Gc protein, and the receptor binding domain of the Middle East respiratory syndrome coronavirus spike protein. The constructs could be efficiently complemented and further passaged in SK-6 cells constitutively expressing the BuPV ERNS protein. Importantly, BuPVs are able to infect a wide variety of target cell lines, allowing expression in a very wide host spectrum. Therefore, we suggest that packaged BuPV ΔERNS replicon particles have potential as broad-spectrum viral vectors. IMPORTANCE The proteins NPRO and ERNS are unique for the genus Pestivirus, but only NPRO has been demonstrated to be nonessential for in vitro growth. While this was also speculated for ERNS, it has always been previously shown that pestivirus replicons with deletions of the structural proteins ERNS, E1, or E2 did not produce any infectious progeny virus in susceptible host cells. Here, we demonstrated for the first time that BuPV ERNS is dispensable for the generation of infectious virus particles but still important for efficient passaging. The ERNS-defective BuPV particles showed clearly limited growth in cell culture but were capable of several rounds of infection, expression of foreign genes, and highly efficient trans-complementation to rescue virus replicon particles (VRPs). The noncytopathic characteristics and the absence of preexisting immunity to BuPV in human populations and livestock also provide a significant benefit for a possible use, e.g., as a vector vaccine platform.

scholarly journals Long-Term Transgene Expression in Proliferating Cells Mediated by Episomally Maintained High-Capacity Adenovirus Vectors

2004 ◽  
Vol 78 (1) ◽  
pp. 9-22 ◽  
Author(s):  
Florian Kreppel ◽  
Stefan Kochanek
Keyword(s):  
Transgene Expression ◽  
High Capacity ◽  
Target Cells ◽  
Resting Cells ◽  
Proliferating Cells ◽  
Daughter Cells ◽  
Adenovirus Vectors

ABSTRACT High-capacity “gutless” adenovirus vectors (HC-AdV) mediate long-term transgene expression in resting cells in vitro and in vivo because of low toxicity and immunogenicity. However, in proliferating cells, expression is transient since HC-AdV genomes do not possess elements that allow for replication and segregation of the replicated genomes to daughter cells. We developed a binary HC-AdV system that, under certain conditions, allows for significantly prolonged episomal maintenance of HC-AdV genomes in proliferating tissue culture cells, resulting in sustained transgene expression. After transduction of target cells the linear HC-AdV genomes were circularized by the DNA recombinase FLPe, which was expressed from the second HC-AdV. The oriP/EBNA-1 replication system derived from Epstein-Barr virus, as well as the human replication origin from the lamin B2 locus, were used as cis elements to test for replication of the 28-kb circular vector genomes with or without selective pressure. Depending on the system, up to 98% of the circularized genomes were replicated and segregated to daughter cells, as demonstrated by Southern assays and as confirmed by monitoring EGFP transgene expression. Surprisingly, in the absence of FLPe recombinase, a small but significant number of HC-AdV genomes spontaneously circularized after transduction of target cells. These circles, found to contain end-to-end joined adenovirus termini, replicated with increased efficiency compared to vectors circularized by FLPe. After further improvements, this HC-AdV system might be suitable for gene therapy applications requiring long-term transgene expression.

scholarly journals Virus-Specific CD4+ and CD8+ Cytotoxic T-Cell Responses and Long-Term T-Cell Memory in Individuals Vaccinated against Polio

2005 ◽  
Vol 79 (10) ◽  
pp. 5988-5995 ◽  
Author(s):  
Rahnuma Wahid ◽  
Martin J. Cannon ◽  
Marie Chow
Keyword(s):  
T Cells ◽  
T Cell ◽  
T Cell Responses ◽  
Neutralizing Antibody ◽  
T Cell Response ◽  
Cytotoxic T Cell ◽  
Cell Responses ◽  
Cytotoxic T Cell Responses

ABSTRACT The presence of poliovirus (PV)-specific CD4+ T cells in individuals vaccinated against polio has been shown, but CD8+ T-cell responses have not been described. Here, we functionally characterize the CD4+ T-cell response and show for the first time that dendritic cells and macrophages can stimulate PV-specific CD8+ T-cell responses in vitro from vaccinees. Both CD4+ T and CD8+ T cells secrete gamma interferon in response to PV antigens and are cytotoxic via the perforin/granzyme B-mediated pathway. Furthermore, the T cells also recognize and kill Sabin 1 vaccine-infected targets. The macrophage-stimulated CD4+ T and CD8+ T cells most likely represent memory T cells that persist for long periods in vaccinated individuals. Thus, immunity to PV vaccination involves not only an effective neutralizing antibody titer but also long-term CD4+ and CD8+ cytotoxic T-cell responses.

scholarly journals Cytotoxic CD4+ T-cells specific for EBV capsid antigen BORF1 are maintained in long-term latently infected healthy donors

2021 ◽  
Vol 17 (12) ◽  
pp. e1010137
Author(s):  
Alexander C. Dowell ◽  
Tracey A. Haigh ◽  
Gordon B. Ryan ◽  
James E. Turner ◽  
Heather M. Long ◽  
...  
Keyword(s):  
T Cells ◽  
T Cell ◽  
Granzyme B ◽  
T Cell Responses ◽  
Cd4 T Cell ◽  
Structural Proteins ◽  
Cell Responses ◽  
Ebv Infection ◽  
Cell Clones

Epstein Barr Virus (EBV) infects more than 95% of the population whereupon it establishes a latent infection of B-cells that persists for life under immune control. Primary EBV infection can cause infectious mononucleosis (IM) and long-term viral carriage is associated with several malignancies and certain autoimmune diseases. Current efforts developing EBV prophylactic vaccination have focussed on neutralising antibodies. An alternative strategy, that could enhance the efficacy of such vaccines or be used alone, is to generate T-cell responses capable of recognising and eliminating newly EBV-infected cells before the virus initiates its growth transformation program. T-cell responses against the EBV structural proteins, brought into the newly infected cell by the incoming virion, are prime candidates for such responses. Here we show the structural EBV capsid proteins BcLF1, BDLF1 and BORF1 are frequent targets of T-cell responses in EBV infected people, identify new CD8+ and CD4+ T-cell epitopes and map their HLA restricting alleles. Using T-cell clones we demonstrate that CD4+ but not CD8+ T-cell clones specific for the capsid proteins can recognise newly EBV-infected B-cells and control B-cell outgrowth via cytotoxicity. Using MHC-II tetramers we show a CD4+ T-cell response to an epitope within the BORF1 capsid protein epitope is present during acute EBV infection and in long-term viral carriage. In common with other EBV-specific CD4+ T-cell responses the BORF1-specific CD4+ T-cells in IM patients expressed perforin and granzyme-B. Unexpectedly, perforin and granzyme-B expression was sustained over time even when the donor had entered the long-term infected state. These data further our understanding of EBV structural proteins as targets of T-cell responses and how CD4+ T-cell responses to EBV change from acute disease into convalescence. They also identify new targets for prophylactic EBV vaccine development.

scholarly journals Modified Vaccinia Virus Ankara as a Viral Vector for Vaccine Candidates against Chikungunya Virus

Biomedicines ◽  
2021 ◽  
Vol 9 (9) ◽  
pp. 1122
Author(s):  
Juan García-Arriaza ◽  
Mariano Esteban ◽  
Daniel López
Keyword(s):  
Vaccinia Virus ◽  
Chikungunya Virus ◽  
Vaccine Development ◽  
Viral Vector ◽  
Severe Disease ◽  
Febrile Illness ◽  
Structural Proteins ◽  
Effective Vaccine ◽  
Vaccine Candidates ◽  
Modified Vaccinia Virus Ankara

There is a need to develop a highly effective vaccine against the emerging chikungunya virus (CHIKV), a mosquito-borne Alphavirus that causes severe disease in humans consisting of acute febrile illness, followed by chronic debilitating polyarthralgia and polyarthritis. In this review, we provide a brief history of the development of the first poxvirus vaccines that led to smallpox eradication and its implications for further vaccine development. As an example, we summarize the development of vaccine candidates based on the modified vaccinia virus Ankara (MVA) vector expressing different CHIKV structural proteins, paying special attention to MVA-CHIKV expressing all of the CHIKV structural proteins: C, E3, E2, 6K and E1. We review the characterization of innate and adaptive immune responses induced in mice and nonhuman primates by the MVA-CHIKV vaccine candidate and examine its efficacy in animal models, with promising preclinical findings needed prior to the approval of human clinical trials.

scholarly journals In silico study on anti-Chikungunya virus activity of hesperetin

PeerJ ◽  
2016 ◽  
Vol 4 ◽  
pp. e2602 ◽  
Author(s):  
Adrian Oo ◽  
Pouya Hassandarvish ◽  
Sek Peng Chin ◽  
Vannajan Sanghiran Lee ◽  
Sazaly Abu Bakar ◽  
...  
Keyword(s):  
Molecular Docking ◽  
Chikungunya Virus ◽  
Md Simulations ◽  
Inhibitory Effect ◽  
Structural Proteins ◽  
In Vitro Screening ◽  
Intracellular Replication ◽  
Lipinski’S Rule ◽  
Lipinski’S Rule Of Five

BackgroundThe re-emerging,Aedes spp.transmitted Chikungunya virus (CHIKV) has recently caused large outbreaks in a wide geographical distribution of the world including countries in Europe and America. Though fatalities associated with this self-remitting disease were rarely reported, quality of patients’ lives have been severely diminished by polyarthralgia recurrence. Neither effective antiviral treatment nor vaccines are available for CHIKV. Our previous in vitro screening showed that hesperetin, a bioflavonoid exhibits inhibitory effect on the virus intracellular replication. Here, we present a study using the computational approach to identify possible target proteins for future mechanistic studies of hesperetin.Methods3D structures of CHIKV nsP2 (3TRK) and nsP3 (3GPG) were retrieved from Protein Data Bank (PDB), whereas nsP1, nsP4 and cellular factor SPK2 were modeled using Iterative Threading Assembly Refinement (I-TASSER) server based on respective amino acids sequence. We performed molecular docking on hesperetin against all four CHIKV non-structural proteins and SPK2. Proteins preparation and subsequent molecular docking were performed using Discovery Studio 2.5 and AutoDock Vina 1.5.6. The Lipinski’s values of the ligand were computed and compared with the available data from PubChem. Two non-structural proteins with crystal structures 3GPG and 3TRK in complexed with hesperetin, demonstrated favorable free energy of binding from the docking study, were further explored using molecular dynamics (MD) simulations.ResultsWe observed that hesperetin interacts with different types of proteins involving hydrogen bonds, pi-pi effects, pi-cation bonding and pi-sigma interactions with varying binding energies. Among all five tested proteins, our compound has the highest binding affinity with 3GPG at −8.5 kcal/mol. The ligand used in this study also matches the Lipinski’s rule of five in addition to exhibiting closely similar properties with that of in PubChem. The docking simulation was performed to obtain a first guess of the binding structure of hesperetin complex and subsequently analysed by MD simulations to assess the reliability of the docking results. Root mean square deviation (RMSD) of the simulated systems from MD simulations indicated that the hesperetin complex remains stable within the simulation timescale.DiscussionThe ligand’s tendencies of binding to the important proteins for CHIKV replication were consistent with our previous in vitro screening which showed its efficacy in blocking the virus intracellular replication. NsP3 serves as the highest potential target protein for the compound’s inhibitory effect, while it is interesting to highlight the possibility of interrupting CHIKV replication via interaction with host cellular factor. By complying the Lipinski’s rule of five, hesperetin exhibits drug-like properties which projects its potential as a therapeutic option for CHIKV infection.

scholarly journals Inefficient Placental Virus Replication and Absence of Neonatal Cell-Specific Immunity Upon Sars-CoV-2 Infection During Pregnancy

2021 ◽  
Vol 12 ◽  
Author(s):  
Ann-Christin Tallarek ◽  
Christopher Urbschat ◽  
Luis Fonseca Brito ◽  
Stephanie Stanelle-Bertram ◽  
Susanne Krasemann ◽  
...  
Keyword(s):  
Pregnant Women ◽  
Vertical Transmission ◽  
Virus Replication ◽  
Ex Vivo ◽  
Acute Infection ◽  
Cell Responses ◽  
Viral Expression ◽  
Risk Of Progression

Pregnant women have been carefully observed during the COVID-19 pandemic, as the pregnancy-specific immune adaptation is known to increase the risk for infections. Recent evidence indicates that even though most pregnant have a mild or asymptomatic course, a severe course of COVID-19 and a higher risk of progression to diseases have also been described, along with a heightened risk for pregnancy complications. Yet, vertical transmission of the virus is rare and the possibility of placental SARS-CoV-2 infection as a prerequisite for vertical transmission requires further studies. We here assessed the severity of COVID-19 and onset of neonatal infections in an observational study of women infected with SARS-CoV-2 during pregnancy. Our placental analyses showed a paucity of SARS-CoV-2 viral expression ex vivo in term placentae under acute infection. No viral placental expression was detectable in convalescent pregnant women. Inoculation of placental explants generated from placentas of non-infected women at birth with SARS-CoV-2 in vitro revealed inefficient SARS-CoV-2 replication in different types of placental tissues, which provides a rationale for the low ex vivo viral expression. We further detected specific SARS-CoV-2 T cell responses in pregnant women within a few days upon infection, which was undetectable in cord blood. Our present findings confirm that vertical transmission of SARS-CoV-2 is rare, likely due to the inefficient virus replication in placental tissues. Despite the predominantly benign course of infection in most mothers and negligible risk of vertical transmission, continuous vigilance on the consequences of COVID-19 during pregnancy is required, since the maternal immune activation in response to the SARS-CoV2 infection may have long-term consequences for children’s health.

scholarly journals Fc-null anti-PD-1 monoclonal antibodies deliver optimal checkpoint blockade in diverse immune environments

2022 ◽  
Vol 10 (1) ◽  
pp. e003735
Author(s):  
Julia Moreno-Vicente ◽  
Jane E Willoughby ◽  
Martin C Taylor ◽  
Steven G Booth ◽  
Vikki L English ◽  
...  
Keyword(s):  
T Cells ◽  
Monoclonal Antibodies ◽  
T Cell ◽  
Cd8 T Cells ◽  
T Cell Responses ◽  
Therapeutic Activity ◽  
Cell Responses

BackgroundDespite extensive clinical use, the mechanisms that lead to therapeutic resistance to anti-programmed cell-death (PD)-1 monoclonal antibodies (mAbs) remain elusive. Here, we sought to determine how interactions between the Fc region of anti-PD-1 mAbs and Fcγ receptors (FcγRs) affect therapeutic activity and how these are impacted by the immune environment.MethodsMouse and human anti-PD-1 mAbs with different Fc binding profiles were generated and characterized in vitro. The ability of these mAbs to elicit T-cell responses in vivo was first assessed in a vaccination setting using the model antigen ovalbumin. The antitumor activity of anti-PD-1 mAbs was investigated in the context of immune ‘hot’ MC38 versus ‘cold’ neuroblastoma tumor models, and flow cytometry performed to assess immune infiltration.ResultsEngagement of activating FcγRs by anti-PD-1 mAbs led to depletion of activated CD8 T cells in vitro and in vivo, abrogating therapeutic activity. Importantly, the extent of this Fc-mediated modulation was determined by the surrounding immune environment. Low FcγR-engaging mouse anti-PD-1 isotypes, which are frequently used as surrogates for human mAbs, were unable to expand ovalbumin-reactive CD8 T cells, in contrast to Fc-null mAbs. These results were recapitulated in mice expressing human FcγRs, in which clinically relevant hIgG4 anti-PD-1 led to reduced endogenous expansion of CD8 T cells compared with its engineered Fc-null counterpart. In the context of an immunologically ‘hot’ tumor however, both low-engaging and Fc-null mAbs induced long-term antitumor immunity in MC38-bearing mice. Finally, a similar anti-PD-1 isotype hierarchy was demonstrated in the less responsive ‘cold’ 9464D neuroblastoma model, where the most effective mAbs were able to delay tumor growth but could not induce long-term protection.ConclusionsOur data collectively support a critical role for Fc:FcγR interactions in inhibiting immune responses to both mouse and human anti-PD-1 mAbs, and highlight the context-dependent effect that anti-PD-1 mAb isotypes can have on T-cell responses. We propose that engineering of Fc-null anti-PD-1 mAbs would prevent FcγR-mediated resistance in vivo and allow maximal T-cell stimulation independent of the immunological environment.

scholarly journals PROTEOME-WIDE ANALYSIS OF CD8+ T CELL RESPONSES TO EBV REVEALS DIFFERENCES BETWEEN PRIMARY AND PERSISTENT INFECTION

2018 ◽  
Author(s):  
Calum Forrest ◽  
Andrew D. Hislop ◽  
Alan B Rickinson ◽  
Jianmin Zuo
Keyword(s):  
T Cell ◽  
Human Herpesvirus ◽  
T Cell Responses ◽  
Cd8 T Cell ◽  
Lytic Replication ◽  
Lytic Cycle ◽  
Specific Response ◽  
Cell Responses

ABSTRACT (286 words)Human herpesviruses are antigenically rich agents that induce strong CD8+T cell responses in primary infection yet persist for life, continually challenging T cell memory through recurrent lytic replication and potentially influencing the spectrum of antigen-specific responses. Here we describe the first lytic proteome-wide analysis of CD8+ T cell responses to the Epstein-Barr gamma1-herpesvirus (EBV), and the first such proteome-wide analysis of primary versus memory CD8 responses to any human herpesvirus. Primary effector preparations were generated directly from activated CD8+ T cells in the blood of infectious mononucleosis (IM) patients by in vitro mitogenic expansion. For memory preparations, EBV-specific cells in the blood of long-term virus carriers were first re-stimulated in vitro by autologous dendritic cells loaded with a lysate of lytically-infected cells, then expanded as for IM cells. Preparations from 7 donors of each type were screened against each of 70 EBV lytic cycle proteins in combination with the donor’s individual HLA class I alleles. Multiple reactivities against immediate early (IE), early (E) and late (L) lytic cycle proteins, including many hitherto unrecognised targets, were detected in both contexts. Interestingly however, the two donor cohorts showed a different balance between IE, E and L reactivities. Primary responses targeted IE and a small group of E proteins preferentially, seemingly in line with their better presentation on the infected cell surface before later-expressed viral evasins take full hold. By contrast, target choice equilibrates in virus carriage with responses to key IE and E antigens still present but with responses to a select subset of L proteins now often prominent. We infer that, for EBV at least, long-term virus carriage with its low level virus replication and lytic antigen release is associated with a re-shaping of the virus-specific response.

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