scholarly journals DNA Vaccine Administered by Cationic Lipoplexes or by In Vivo Electroporation Induces Comparable Antibody Responses against SARS-CoV-2 in Mice

Vaccines ◽  
2021 ◽  
Vol 9 (8) ◽  
pp. 874
Author(s):  
Allegra Peletta ◽  
Eakachai Prompetchara ◽  
Kittipan Tharakhet ◽  
Papatsara Kaewpang ◽  
Supranee Buranapraditkun ◽  
...  
Keyword(s):  
Dna Vaccine ◽  
Neutralizing Antibody ◽  
T Cell Response ◽  
Antibody Responses ◽  
Effective Vaccine ◽  
Thin Film Layer ◽  
Plasmid Dna Vaccine ◽  
Film Layer

In view of addressing the global necessity of an effective vaccine in the SARS-CoV-2 pandemic, a plasmid DNA vaccine, expressing for the spike (S) protein and formulated in lipoplexes, was manufactured and tested for in vitro transfection and in vivo immunogenicity. Blank cationic liposomes of 130.9 ± 5.8 nm in size and with a zeta potential of +48 ± 12 mV were formulated using the thin-film layer rehydration method. Liposomes were complexed with pCMVkan-S at different N/P ratios. Ratios of 0.25:1 and 1:1 were selected according to their complex stability and controlled size compared to other ratios and tested in vitro for transfection studies and in vivo for immunogenicity. Both selected formulations showed enhanced neutralizing antibody responses compared to pCMVkan-S injected alone, as well as an increased T cell response. The titers observed were similar to those of intramuscular electroporation (IM-EP), which was set as an efficacy goal.

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 Effect of Preexisting Immunity on an Adenovirus Vaccine Vector: In Vitro Neutralization Assays Fail To Predict Inhibition by Antiviral Antibody In Vivo

2009 ◽  
Vol 83 (11) ◽  
pp. 5567-5573 ◽  
Author(s):  
Susan L. Pichla-Gollon ◽  
Shih-Wen Lin ◽  
Scott E. Hensley ◽  
Marcio O. Lasaro ◽  
Larissa Herkenhoff-Haut ◽  
...  
Keyword(s):  
Neutralizing Antibodies ◽  
Neutralizing Antibody ◽  
Human Adenovirus ◽  
T Cell Response ◽  
Fundamental Properties ◽  
High Prevalence ◽  
Antiviral Antibody ◽  
Adenovirus Vectors

ABSTRACT A major obstacle to the use of adenovirus vectors derived from common human serotypes, such as human adenovirus 5 (AdHu5), is the high prevalence of virus-neutralizing antibodies in the human population. We previously constructed a variant of chimpanzee adenovirus 68 (AdC68) that maintained the fundamental properties of the carrier but was serologically distinct from AdC68 and resisted neutralization by AdC68 antibodies. In the present study, we tested whether this modified vector, termed AdCDQ, could induce transgene product-specific CD8+ T cells in mice with preexisting neutralizing antibody to wild-type AdC68. Contrary to our expectation, the data show conclusively that antibodies that fail to neutralize the AdCDQ mutant vector in vitro nevertheless impair the vector's capacity to transduce cells and to stimulate a transgene product-specific CD8+ T-cell response in vivo. The results thus suggest that in vitro neutralization assays may not reliably predict the effects of virus-specific antibodies on adenovirus vectors in vivo.

scholarly journals Characterization of an attenuated SARS-CoV-2 variant with a deletion at the S1/S2 junction of the spike protein

2021 ◽  
Vol 12 (1) ◽  
Author(s):  
Pui Wang ◽  
Siu-Ying Lau ◽  
Shaofeng Deng ◽  
Pin Chen ◽  
Bobo Wing-Yee Mok ◽  
...  
Keyword(s):  
Neutralizing Antibody ◽  
T Cell Response ◽  
Spike Protein ◽  
Wild Type Virus ◽  
Wild Type ◽  
Cleavage Motif ◽  
Sterilizing Immunity

AbstractSARS-CoV-2 is of zoonotic origin and contains a PRRA polybasic cleavage motif which is considered critical for efficient infection and transmission in humans. We previously reported on a panel of attenuated SARS-CoV-2 variants with deletions at the S1/S2 junction of the spike protein. Here, we characterize pathogenicity, immunogenicity, and protective ability of a further cell-adapted SARS-CoV-2 variant, Ca-DelMut, in in vitro and in vivo systems. Ca-DelMut replicates more efficiently than wild type or parental virus in Vero E6 cells, but causes no apparent disease in hamsters, despite replicating in respiratory tissues. Unlike wild type virus, Ca-DelMut causes no obvious pathological changes and does not induce elevation of proinflammatory cytokines, but still triggers a strong neutralizing antibody and T cell response in hamsters and mice. Ca-DelMut immunized hamsters challenged with wild type SARS-CoV-2 are fully protected, with little sign of virus replication in the upper or lower respiratory tract, demonstrating sterilizing immunity.

scholarly journals Design and crystal structure of a native-like HIV-1 envelope trimer that engages multiple broadly neutralizing antibody precursors in vivo

2017 ◽  
Vol 214 (9) ◽  
pp. 2573-2590 ◽  
Author(s):  
Max Medina-Ramírez ◽  
Fernando Garces ◽  
Amelia Escolano ◽  
Patrick Skog ◽  
Steven W. de Taeye ◽  
...  
Keyword(s):  
Crystal Structure ◽  
B Cells ◽  
Neutralizing Antibodies ◽  
Neutralizing Antibody ◽  
Effective Vaccine ◽  
Major Advance ◽  
Cd4 Binding Site ◽  
Hiv 1

Induction of broadly neutralizing antibodies (bNAbs) by HIV-1 envelope glycoprotein immunogens would be a major advance toward an effective vaccine. A critical step in this process is the activation of naive B cells expressing germline (gl) antibody precursors that have the potential to evolve into bNAbs. Here, we reengineered the BG505 SOSIP.664 glycoprotein to engage gl precursors of bNAbs that target either the trimer apex or the CD4-binding site. The resulting BG505 SOSIP.v4.1-GT1 trimer binds multiple bNAb gl precursors in vitro. Immunization experiments in knock-in mice expressing gl-VRC01 or gl-PGT121 show that this trimer activates B cells in vivo, resulting in the secretion of specific antibodies into the sera. A crystal structure of the gl-targeting trimer at 3.2-Å resolution in complex with neutralizing antibodies 35O22 and 9H+109L reveals a native-like conformation and the successful incorporation of design features associated with binding of multiple gl-bNAb precursors.

scholarly journals Chimpanzee SIV Envelope trimer: structure and deployment as an HIV vaccine template

2018 ◽  
Author(s):  
Raiees Andrabi ◽  
Jesper Pallesen ◽  
Joel Allen ◽  
Ge Song ◽  
Jinsong Zhang ◽  
...  
Keyword(s):  
Neutralizing Antibody ◽  
Hiv Vaccine ◽  
Antibody Responses ◽  
Attractive Potential ◽  
Induced Responses ◽  
Potential Component ◽  
Broadly Neutralizing Antibody ◽  
Cross Neutralization

SummaryEpitope-targeted HIV vaccine design seeks to focus antibody responses to broadly neutralizing antibody (bnAb) sites by sequential immunization. Chimpanzee SIV Envelope (Env) shares a single bnAb site, the V2-apex, with HIV, suggesting its possible utility in an HIV immunization strategy. Accordingly, we generated a chimpanzee SIV Env trimer, MT145K, which displays selective binding to HIV V2-apex bnAbs and precursor versions, but no binding to other HIV specificities. We determined the structure of the MT145K trimer by cryo-EM and showed its architecture was remarkably similar to HIV Env. Immunization of an HIV V2-apex bnAb precursor Ab-expressing knock-in mouse with chimpanzee MT145K trimer induced HIV V2-specific neutralizing responses. Subsequent boosting with an HIV trimer cocktail induced responses exhibiting some virus cross-neutralization. Overall, the chimpanzee MT145K trimer behaves as expected from design both in vitro and in vivo and is an attractive potential component of a sequential immunization regimen to induce V2-apex bnAbs.

scholarly journals Protective humoral responses to severe acute respiratory syndrome-associated coronavirus: implications for the design of an effective protein-based vaccine

2004 ◽  
Vol 85 (10) ◽  
pp. 3109-3113 ◽  
Author(s):  
Hai Pang ◽  
Yinggang Liu ◽  
Xueqing Han ◽  
Yanhui Xu ◽  
Fuguo Jiang ◽  
...  
Keyword(s):  
Severe Acute Respiratory Syndrome ◽  
Neutralizing Antibodies ◽  
Neutralizing Antibody ◽  
Structural Proteins ◽  
Effective Vaccine ◽  
S Protein ◽  
M Proteins ◽  
Humoral Responses

Some of the structural proteins of severe acute respiratory syndrome-associated coronavirus (SARS-CoV) carry major epitopes involved in virus neutralization and are essential for the induction of protective humoral responses and the development of an effective vaccine. Rabbit antisera were prepared using full-length N and M proteins and eight expressed fragments covering the S protein. Antisera to S and M proteins were found to have different neutralizing titres towards SARS-CoV infection in vivo, ranging from 1 : 35 to 1 : 128. Antiserum to the N protein did not contain neutralizing antibodies. Epitopes inducing protective humoral responses to virus infection were located mainly in the M protein and a region spanning residues 13–877 of the S protein. The neutralizing ability of antisera directed against the expressed structural proteins was greater than that of convalescent patient antisera, confirming that, as immunogens, the former induce strong, SARS-CoV-specific neutralizing antibody responses. The in vitro neutralization assay has important implications for the design of an effective, protein-based vaccine preventing SARS-CoV infection.

scholarly journals Induction of Mucosal Protection against Primary, Heterologous Simian Immunodeficiency Virus by a DNA Vaccine

2002 ◽  
Vol 76 (7) ◽  
pp. 3309-3317 ◽  
Author(s):  
Deborah Heydenburg Fuller ◽  
Premeela A. Rajakumar ◽  
Lawrence A. Wilson ◽  
Anita M. Trichel ◽  
James T. Fuller ◽  
...  
Keyword(s):  
Simian Immunodeficiency Virus ◽  
Dna Vaccine ◽  
Dna Sequences ◽  
Serum Antibody ◽  
Antibody Responses ◽  
Effective Vaccine ◽  
Lymphoid Tissues ◽  
Mucosal Protection ◽  
Mucosal Transmission ◽  
Immunodeficiency Virus

ABSTRACT An effective vaccine against human immunodeficiency virus (HIV) should protect against mucosal transmission of genetically divergent isolates. As a safe alternative to live attenuated vaccines, the immunogenicity and protective efficacy of a DNA vaccine containing simian immunodeficiency virus (SIV) strain 17E-Fr (SIV/17E-Fr) gag-pol-env was analyzed in rhesus macaques. Significant levels of cytotoxic T lymphocytes (CTL), but low to undetectable serum antibody responses, were observed following multiple immunizations. SIV-specific mucosal antibodies and CTL were also detected in rectal washes and gut-associated lymphoid tissues, respectively. Vaccinated and naive control monkeys were challenged intrarectally with SIV strain DeltaB670 (SIV/DeltaB670), a primary isolate whose env is 15% dissimilar to that of the vaccine strain. Four of seven vaccinees were protected from infection as determined by the inability to identify viral RNA or DNA sequences in the peripheral blood and the absence of anamnestic antibody responses postchallenge. This is the first report of mucosal protection against a primary pathogenic, heterologous isolate of SIV by using a commercially viable vaccine approach. These results support further development of a DNA vaccine for protection against HIV.

scholarly journals Influenza virus hemagglutinin-specific cytotoxic T cell response induced by polypeptide produced in Escherichia coli.

1985 ◽  
Vol 162 (2) ◽  
pp. 663-674 ◽  
Author(s):  
A Yamada ◽  
M R Ziese ◽  
J F Young ◽  
Y K Yamada ◽  
F A Ennis
Keyword(s):  
Influenza Virus ◽  
Recombinant Dna ◽  
Cytotoxic T Lymphocyte ◽  
Nonstructural Protein ◽  
T Cell Response ◽  
Cytotoxic T Cell ◽  
Protein Immunization ◽  
Recombinant Dna Techniques

We have tested the abilities of various polypeptides of A/PR/8/34 (H1N1) virus, constructed by recombinant DNA techniques, to induce influenza virus-specific secondary cytotoxic T lymphocyte (CTL) responses. A hybrid protein (c13 protein), consisting of the first 81 amino acids of viral nonstructural protein (NS1) and the HA2 subunit of viral hemagglutinin (HA), induced H-2-restricted, influenza virus subtype-specific secondary CTL in vitro, although other peptides did not. Using a recombinant virus, the viral determinant responsible for recognition was mapped to the HA2 portion of c13 protein. Immunization of mice with c13 protein induced the generation of memory CTL in vivo. The CTL precursor frequencies of A/PR/8/34 virus- and c13 protein-immune mice were estimated as one in 8,047 and 50,312, respectively. These results indicate that c13 protein primed recipient mice, even though the level of precursor frequency was below that observed in virus-immune mice.

scholarly journals Development of Stable Chimeric IL-15 for Trans-Presentation by the Antigen Presenting Cells

2021 ◽  
Vol 12 ◽  
Author(s):  
Manoj Patidar ◽  
Naveen Yadav ◽  
Sarat K. Dalai
Keyword(s):  
T Cells ◽  
T Cell ◽  
Half Life ◽  
Therapeutic Potential ◽  
Chimeric Protein ◽  
Antigen Presenting Cells ◽  
T Cell Response ◽  
Antigen Presenting

IL-15 is one of the important biologics considered for vaccine adjuvant and treatment of cancer. However, a short half-life and poor bioavailability limit its therapeutic potential. Herein, we have structured IL-15 into a chimeric protein to improve its half-life enabling greater bioavailability for longer periods. We have covalently linked IL-15 with IgG2 base to make the IL-15 a stable chimeric protein, which also increased its serum half-life by 40 fold. The dimeric structure of this kind of IgG based biologics has greater stability, resistance to proteolytic cleavage, and less frequent dosing schedule with minimum dosage for achieving the desired response compared to that of their monomeric forms. The structured chimeric IL-15 naturally forms a dimer, and retains its affinity for binding to its receptor, IL-15Rβ. Moreover, with the focused action of the structured chimeric IL-15, antigen-presenting cells (APC) would transpresent chimeric IL-15 along with antigen to the T cell, that will help the generation of quantitatively and qualitatively better antigen-specific memory T cells. In vitro and in vivo studies demonstrate the biological activity of chimeric IL-15 with respect to its ability to induce IL-15 signaling and modulating CD8+ T cell response in favor of memory generation. Thus, a longer half-life, dimeric nature, and anticipated focused transpresentation by APCs to the T cells will make chimeric IL-15 a super-agonist for memory CD8+ T cell responses.

scholarly journals Single cell RNA sequencing of calvarial and long bone endocortical cells

2019 ◽  
Author(s):  
Ugur M. Ayturk ◽  
Joseph P. Scollan ◽  
Alexander Vesprey ◽  
Christina M. Jacobsen ◽  
Paola Divieti Pajevic ◽  
...  
Keyword(s):  
Gene Expression ◽  
Single Cell ◽  
Cultured Cells ◽  
Neutralizing Antibody ◽  
Long Bone ◽  
Appendicular Skeleton ◽  
Rna Seq ◽  
Isolated Cells

ABSTRACTSingle cell RNA-seq (scRNA-seq) is emerging as a powerful technology to examine transcriptomes of individual cells. We determined whether scRNA-seq could be used to detect the effect of environmental and pharmacologic perturbations on osteoblasts. We began with a commonly used in vitro system in which freshly isolated neonatal mouse calvarial cells are expanded and induced to produce a mineralized matrix. We used scRNA-seq to compare the relative cell type abundances and the transcriptomes of freshly isolated cells to those that had been cultured for 12 days in vitro. We observed that the percentage of macrophage-like cells increased from 6% in freshly isolated calvarial cells to 34% in cultured cells. We also found that Bglap transcripts were abundant in freshly isolated osteoblasts but nearly undetectable in the cultured calvarial cells. Thus, scRNA-seq revealed significant differences between heterogeneity of cells in vivo and in vitro. We next performed scRNA-seq on freshly recovered long bone endocortical cells from mice that received either vehicle or Sclerostin-neutralizing antibody for 1 week. Bone anabolism-associated transcripts were also not significantly increased in immature and mature osteoblasts recovered from Sclerostin-neutralizing antibody treated mice; this is likely a consequence of being underpowered to detect modest changes in gene expression, since only 7% of the sequenced endocortical cells were osteoblasts, and a limited portion of their transcriptomes were sampled. We conclude that scRNA-seq can detect changes in cell abundance, identity, and gene expression in skeletally derived cells. In order to detect modest changes in osteoblast gene expression at the single cell level in the appendicular skeleton, larger numbers of osteoblasts from endocortical bone are required.

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