scholarly journals Protective Efficacy and Long-Term Immunogenicity in Cynomolgus Macaques by Ebola Virus Glycoprotein Synthetic DNA Vaccines

2018 ◽  
Vol 219 (4) ◽  
pp. 544-555 ◽  
Author(s):  
Ami Patel ◽  
Emma L Reuschel ◽  
Kimberly A Kraynyak ◽  
Trina Racine ◽  
Daniel H Park ◽  
...  
Keyword(s):  
Immune Responses ◽  
Ebola Virus ◽  
Dna Vaccines ◽  
Viral Vector ◽  
Protective Efficacy ◽  
Lethal Challenge ◽  
Virus Glycoprotein ◽  
Cynomolgus Macaques ◽  
The Impact

Abstract Background There remains an important need for prophylactic anti-Ebola virus vaccine candidates that elicit long-lasting immune responses and can be delivered to vulnerable populations that are unable to receive live-attenuated or viral vector vaccines. Methods We designed novel synthetic anti-Ebola virus glycoprotein (EBOV-GP) DNA vaccines as a strategy to expand protective breadth against diverse EBOV strains and evaluated the impact of vaccine dosing and route of administration on protection against lethal EBOV-Makona challenge in cynomolgus macaques. Long-term immunogenicity was monitored in nonhuman primates for >1 year, followed by a 12-month boost. Results Multiple-injection regimens of the EBOV-GP DNA vaccine, delivered by intramuscular administration followed by electroporation, were 100% protective against lethal EBOV-Makona challenge. Impressively, 2 injections of a simple, more tolerable, and dose-sparing intradermal administration followed by electroporation generated strong immunogenicity and was 100% protective against lethal challenge. In parallel, we observed that EBOV-GP DNA vaccination induced long-term immune responses in macaques that were detectable for at least 1 year after final vaccination and generated a strong recall response after the final boost. Conclusions These data support that this simple intradermal-administered, serology-independent approach is likely important for additional study towards the goal of induction of anti-EBOV immunity in multiple at-risk populations.

scholarly journals Fusion Cytokines IL-7-Linker-IL-15 Promote Mycobacterium Tuberculosis Subunit Vaccine to Induce Central Memory like T Cell-Mediated Immunity

Vaccines ◽  
2020 ◽  
Vol 8 (4) ◽  
pp. 715
Author(s):  
Chunxiang Bai ◽  
Lijun Zhou ◽  
Junxia Tang ◽  
Juanjuan He ◽  
Jiangyuan Han ◽  
...  
Keyword(s):  
Mycobacterium Tuberculosis ◽  
Immune Responses ◽  
Protective Efficacy ◽  
Central Memory ◽  
Control Group ◽  
Cell Mediated Immunity ◽  
Protein Subunit ◽  
Subunit Vaccines ◽  
Ifn Γ

Tuberculosis (TB), caused by Mycobacterium tuberculosis (M. tuberculosis), is among the most serious infectious diseases worldwide. Adjuvanted protein subunit vaccines have been demonstrated as a kind of promising novel vaccine. This study proposed to investigate whether cytokines interliukine-7 (IL-7) and interliukine-15 (IL-15) help TB subunit vaccines induce long-term cell-mediated immune responses, which are required for vaccination against TB. In this study, mice were immunized with the M. tuberculosis protein subunit vaccines combined with adnovirus-mediated cytokines IL-7, IL-15, IL-7-IL-15, and IL-7-Linker-IL-15 at 0, 2, and 4 weeks, respectively. Twenty weeks after the last immunization, the long-term immune responses, especially the central memory-like T cells (TCM like cell)-mediated immune responses, were determined with the methods of cultured IFN-γ-ELISPOT, expanded secondary immune responses, cell proliferation, and protective efficacy against Mycobacterium bovis Bacilli Calmette-Guerin (BCG) challenge, etc. The results showed that the group of vaccine + rAd-IL-7-Linker-IL-15 induced a stronger long-term antigen-specific TCM like cells-mediated immune responses and had higher protective efficacy against BCG challenge than the vaccine + rAd-vector control group, the vaccine + rAd-IL-7 and the vaccine + rAd-IL-15 groups. This study indicated that rAd-IL-7-Linker-IL-15 improved the TB subunit vaccine’s efficacy by augmenting TCM like cells and provided long-term protective efficacy against Mycobacteria.

scholarly journals Influences of Glycosylation on Antigenicity, Immunogenicity, and Protective Efficacy of Ebola Virus GP DNA Vaccines

2006 ◽  
Vol 81 (4) ◽  
pp. 1821-1837 ◽  
Author(s):  
William Dowling ◽  
Elizabeth Thompson ◽  
Catherine Badger ◽  
Jenny L. Mellquist ◽  
Aura R. Garrison ◽  
...  
Keyword(s):  
T Cell ◽  
Protective Immunity ◽  
Ebola Virus ◽  
Dna Vaccines ◽  
Protective Efficacy ◽  
T Cell Epitopes ◽  
Glycosylation Sites ◽  
Membrane Bound ◽  
Antibody Epitopes

ABSTRACT The Ebola virus (EBOV) envelope glycoprotein (GP) is the primary target of protective immunity. Mature GP consists of two disulfide-linked subunits, GP1 and membrane-bound GP2. GP is highly glycosylated with both N- and O-linked carbohydrates. We measured the influences of GP glycosylation on antigenicity, immunogenicity, and protection by testing DNA vaccines comprised of GP genes with deleted N-linked glycosylation sites or with deletions in the central hypervariable mucin region. We showed that mutation of one of the two N-linked GP2 glycosylation sites was highly detrimental to the antigenicity and immunogenicity of GP. Our data indicate that this is likely due to the inability of GP2 and GP1 to dimerize at the cell surface and suggest that glycosylation at this site is required for achieving the conformational integrity of GP2 and GP1. In contrast, mutation of two N-linked sites on GP1, which flank previously defined protective antibody epitopes on GP, may enhance immunogenicity, possibly by unmasking epitopes. We further showed that although deleting the mucin region apparently had no effect on antigenicity in vitro, it negatively impacted the elicitation of protective immunity in mice. In addition, we confirmed the presence of previously identified B-cell and T-cell epitopes in GP but show that when analyzed individually none of them were neither absolutely required nor sufficient for protective immunity to EBOV. Finally, we identified other potential regions of GP that may contain relevant antibody or T-cell epitopes.

scholarly journals Induction of Specific T-Cell Responses, Opsonizing Antibodies, and Protection against Plasmodium chabaudi adami Infection in Mice Vaccinated with Genomic Expression Libraries Expressed in Targeted and Secretory DNA Vectors

2003 ◽  
Vol 71 (8) ◽  
pp. 4506-4515 ◽  
Author(s):  
A. Rainczuk ◽  
T. Scorza ◽  
P. M. Smooker ◽  
T. W. Spithill
Keyword(s):  
T Cell ◽  
Immune Responses ◽  
Genomic Library ◽  
Protective Efficacy ◽  
T Cell Responses ◽  
Interleukin 4 ◽  
Plasmodium Chabaudi ◽  
Lethal Challenge ◽  
Cell Responses ◽  
Expression Libraries

ABSTRACT It has been proposed that a multivalent malaria vaccine is necessary to mimic the naturally acquired resistance to this disease observed in humans. A major experimental challenge is to identify the optimal components to be used in such a multivalent vaccine. Expression library immunization (ELI) is a method for screening genomes of a pathogen to identify novel combinations of vaccine sequences. Here we describe immune responses associated with, and the protective efficacy of, genomic Plasmodium chabaudi adami DS expression libraries constructed in VR1020 (secretory), monocyte chemotactic protein-3 (chemoattractant), and cytotoxic T lymphocyte antigen 4 (lymph node-targeting) DNA vaccine vectors. With splenocytes from vaccinated mice, specific T-cell responses, as well as gamma interferon and interleukin-4 production, were observed after stimulation with P. chabaudi adami-infected erythrocytes, demonstrating the specificity of genomic library vaccination for two of the three libraries constructed. Sera obtained from mice vaccinated with genomic libraries promoted the opsonization of P. chabaudi adami-infected erythrocytes by murine macrophages in vitro, further demonstrating the induction of malaria-specific immune responses following ELI. Over three vaccine trials using biolistic delivery of the three libraries, protection after lethal challenge with P. chabaudi adami DS ranged from 33 to 50%. These results show that protective epitopes or antigens are expressed within the libraries and that ELI induces responses specific to P. chabaudi adami malaria. This study further demonstrates that ELI is a suitable approach for screening the malaria genome to identify the components of multivalent vaccines.

A sindbis virus replicon-based DNA vaccine encoding the rabies virus glycoprotein elicits immune responses and complete protection in mice from lethal challenge

Vaccine ◽  
2008 ◽  
Vol 26 (51) ◽  
pp. 6592-6601 ◽  
Author(s):  
Sonal Saxena ◽  
Shyam S. Dahiya ◽  
Arvind A. Sonwane ◽  
Chhabi Lal Patel ◽  
Mohini Saini ◽  
...  
Keyword(s):  
Immune Responses ◽  
Rabies Virus ◽  
Dna Vaccine ◽  
Sindbis Virus ◽  
Complete Protection ◽  
Lethal Challenge ◽  
Rabies Virus Glycoprotein ◽  
Virus Glycoprotein

scholarly journals Overcoming Immunity to a Viral Vaccine by DNA Priming before Vector Boosting

2003 ◽  
Vol 77 (1) ◽  
pp. 799-803 ◽  
Author(s):  
Zhi-yong Yang ◽  
Linda S. Wyatt ◽  
Wing-pui Kong ◽  
Zoe Moodie ◽  
Bernard Moss ◽  
...  
Keyword(s):  
Immune Responses ◽  
Viral Vectors ◽  
Ebola Virus ◽  
Viral Vector ◽  
Hemorrhagic Fever ◽  
Viral Immunity ◽  
Humoral Immune ◽  
Humoral Immune Responses ◽  
Viral Vaccine ◽  
Humoral Responses

ABSTRACT Replication-defective adenovirus (ADV) and poxvirus vectors have shown potential as vaccines for pathogens such as Ebola or human immunodeficiency virus in nonhuman primates, but prior immunity to the viral vector in humans may limit their clinical efficacy. To overcome this limitation, the effect of prior viral exposure on immune responses to Ebola virus glycoprotein (GP), shown previously to protect against lethal hemorrhagic fever in animals, was studied. Prior exposure to ADV substantially reduced the cellular and humoral immune responses to GP expressed by ADV, while exposure to vaccinia inhibited vaccine-induced cellular but not humoral responses to GP expressed by vaccinia. This inhibition was largely overcome by priming with a DNA expression vector before boosting with the viral vector. Though heterologous viral vectors for priming and boosting can also overcome this effect, the paucity of such clinical viral vectors may limit their use. In summary, it is possible to counteract prior viral immunity by priming with a nonviral, DNA vaccine.

scholarly journals Virulence, Inflammatory Potential, and Adaptive Immunity Induced by Shigella flexneri msbB Mutants

2009 ◽  
Vol 78 (1) ◽  
pp. 400-412 ◽  
Author(s):  
Ryan T. Ranallo ◽  
Robert W. Kaminski ◽  
Tonia George ◽  
Alexis A. Kordis ◽  
Qing Chen ◽  
...  
Keyword(s):  
Immune Responses ◽  
Proinflammatory Cytokines ◽  
Protective Efficacy ◽  
Shigella Flexneri ◽  
Lung Model ◽  
Mouse Lung ◽  
Acquired Immunity ◽  
Exact Nature ◽  
Lethal Challenge ◽  
Necrosis Factor Alpha

ABSTRACT The ability of genetically detoxified lipopolysaccharide (LPS) to stimulate adaptive immune responses is an ongoing area of investigation with significant consequences for the development of safe and effective bacterial vaccines and adjuvants. One approach to genetic detoxification is the deletion of genes whose products modify LPS. The msbB1 and msbB2 genes, which encode late acyltransferases, were deleted in the Shigella flexneri 2a human challenge strain 2457T to evaluate the virulence, inflammatory potential, and acquired immunity induced by strains producing underacylated lipid A. Consistent with a reduced endotoxic potential, S. flexneri 2a msbB mutants were attenuated in an acute mouse pulmonary challenge model. Attenuation correlated with decreases in the production of proinflammatory cytokines and in chemokine release without significant changes in lung histopathology. The levels of specific proinflammatory cytokines (interleukin-1β [IL-1β], macrophage inflammatory protein 1α [MIP-1α], and tumor necrosis factor alpha [TNF-α]) were also significantly reduced after infection of mouse macrophages with either single or double msbB mutants. Surprisingly, the msbB double mutant displayed defects in the ability to invade, replicate, and spread within epithelial cells. Complementation restored these phenotypes, but the exact nature of the defects was not determined. Acquired immunity and protective efficacy were also assayed in the mouse lung model, using a vaccination-challenge study. Both humoral and cellular responses were generally robust in msbB-immunized mice and afforded significant protection from lethal challenge. These data suggest that the loss of either msbB gene reduces the endotoxicity of Shigella LPS but does not coincide with a reduction in protective immune responses.

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