scholarly journals Anticytomegalovirus Peptides Point to New Insights for CMV Entry Mechanisms and the Limitations ofIn VitroScreenings

mSphere ◽  
2019 ◽  
Vol 4 (1) ◽  
Author(s):  
Joseph W. Jackson ◽  
Trevor J. Hancock ◽  
Pranay Dogra ◽  
Ravi Patel ◽  
Ravit Arav-Boger ◽  
...  
Keyword(s):  
Heparan Sulfate ◽  
Vaccine Development ◽  
Murine Cytomegalovirus ◽  
Effective Vaccine ◽  
Antiviral Peptides ◽  
Highly Effective ◽  
Binding Peptides ◽  
Cell Spread

ABSTRACTHuman cytomegalovirus (HCMV) is a ubiquitous betaherpesvirus that can cause severe disease followingin uteroexposure, during primary infection, or latent virus reactivation in immunocompromised populations. These complications lead to a 1- to 2-billion-dollar economic burden, making vaccine development and/or alternative treatments a high priority. Current treatments for HCMV include nucleoside analogues such as ganciclovir (GCV), foscarnet, and cidofovir. Recently, letermovir, a terminase complex inhibitor, was approved for prophylaxis after stem cell transplantation. These treatments have unwanted side effects, and HCMV is becoming resistant to them. Therefore, we sought to develop an alternative treatment that targets a different stage in viral infection. Currently, small antiviral peptides are being investigated as anti-influenza and anti-HIV treatments. We have developed heparan sulfate-binding peptides as tools for preventing CMV infections. These peptides are highly effective at stopping infection of fibroblasts within vitro-derived HCMV and murine cytomegalovirus (MCMV). However, they do not prevent MCMV infectionin vivo. Interestingly, these peptides inhibit infectivity ofin vivo-derived CMVs, albeit not as well as tissue culture-grown CMVs. We further demonstrate that this class of heparan sulfate-binding peptides is incapable of inhibiting MCMV cell-to-cell spread, which is independent of heparan sulfate usage. These data indicate that inhibition of CMV infection can be achieved using synthetic polybasic peptides, but cell-to-cell spread andin vivo-grown CMVs require further investigation to design appropriate anti-CMV peptides.IMPORTANCEIn the absence of an effective vaccine to prevent HCMV infections, alternative interventions must be developed. Prevention of viral entry into susceptible cells is an attractive alternative strategy. Here we report that heparan sulfate-binding peptides effectively inhibit entry into fibroblasts ofin vitro-derived CMVs and partially inhibitin vivo-derived CMVs. This includes the inhibition of urine-derived HCMV (uCMV), which is highly resistant to antibody neutralization. While these antiviral peptides are highly effective at inhibiting cell-free virus, they do not inhibit MCMV cell-to-cell spread. This underscores the need to understand the mechanism of cell-to-cell spread and differences betweenin vivo-derived versusin vitro-derived CMV entry to effectively prevent CMV’s spread.

scholarly journals A Combined Adjuvant TF–Al Consisting of TFPR1 and Aluminum Hydroxide Augments Strong Humoral and Cellular Immune Responses in Both C57BL/6 and BALB/c Mice

Vaccines ◽  
2021 ◽  
Vol 9 (12) ◽  
pp. 1408
Author(s):  
Qiao Li ◽  
Zhihua Liu ◽  
Yi Liu ◽  
Chen Liang ◽  
Jiayi Shu ◽  
...  
Keyword(s):  
Immune Responses ◽  
Vaccine Development ◽  
Inbred Mouse ◽  
Effective Vaccine ◽  
Mouse Strains ◽  
Cellular Immune Responses ◽  
Recombinant Hbsag ◽  
Cellular Immune

TFPR1 is a novel adjuvant for protein and peptide antigens, which has been demonstrated in BALB/c mice in our previous studies; however, its adjuvanticity in mice with different genetic backgrounds remains unknown, and its adjuvanticity needs to be improved to fit the requirements for various vaccines. In this study, we first compared the adjuvanticity of TFPR1 in two commonly used inbred mouse strains, BALB/c and C57BL/6 mice, in vitro and in vivo, and demonstrated that TFPR1 activated TLR2 to exert its immune activity in vivo. Next, to prove the feasibility of TFPR1 acting as a major component of combined adjuvants, we prepared a combined adjuvant, TF–Al, by formulating TFPR1 and alum at a certain ratio and compared its adjuvanticity with that of TFPR1 and alum alone using OVA and recombinant HBsAg as model antigens in both BALB/c and C57BL/6 mice. Results showed that TFPR1 acts as an effective vaccine adjuvant in both BALB/c mice and C57BL/6 mice, and further demonstrated the role of TLR2 in the adjuvanticity of TFPR1 in vivo. In addition, we obtained a novel combined adjuvant, TF–Al, based on TFPR1, which can augment antibody and cellular immune responses in mice with different genetic backgrounds, suggesting its promise for vaccine development in the future.

scholarly journals Resolution ofStaphylococcus aureusBiofilm Infection Using Vaccination and Antibiotic Treatment

2011 ◽  
Vol 79 (4) ◽  
pp. 1797-1803 ◽  
Author(s):  
Rebecca A. Brady ◽  
Graeme A. O'May ◽  
Jeff G. Leid ◽  
Megan L. Prior ◽  
J. William Costerton ◽  
...  
Keyword(s):  
Antibiotic Treatment ◽  
Vaccine Development ◽  
Hypothetical Protein ◽  
Quadrivalent Vaccine ◽  
Effective Vaccine ◽  
Vast Number ◽  
Protective Antigens ◽  
Biofilm Model

ABSTRACTStaphylococcus aureusinfections, particularly those from methicillin-resistant strains (i.e., MRSA), are reaching epidemic proportions, with no effective vaccine available. The vast number and transient expression of virulence factors in the infectious course of this pathogen have made the discovery of protective antigens particularly difficult. In addition, the divergent planktonic and biofilm modes of growth with their accompanying proteomic changes also demonstrate significant hindrances to vaccine development. In this study, a multicomponent vaccine was evaluated for its ability to clear a staphylococcal biofilm infection. Antigens (glucosaminidase, an ABC transporter lipoprotein, a conserved hypothetical protein, and a conserved lipoprotein) were chosen since they were found in previous studies to have upregulated and sustained expression in a biofilm, bothin vitroandin vivo. Antibodies against these antigens were first used in microscopy studies to localize their expression inin vitrobiofilms. Each of the four antigens showed heterogeneous production in various locations within the complex biofilm community in the biofilm. Based upon these studies, the four antigens were delivered simultaneously as a quadrivalent vaccine in order to compensate for this varied production. In addition, antibiotic treatment was also administered to clear the remaining nonattached planktonic cells since the vaccine antigens may have been biofilm specific. The results demonstrated that when vaccination was coupled with vancomycin treatment in a biofilm model of chronic osteomyelitis in rabbits, clinical and radiographic signs of infection significantly reduced by 67 and 82%, respectively, compared to infected animals that were either treated with vancomycin or left untreated. In contrast, vaccination alone resulted in a modest, and nonsignificant, decrease in clinical (34% reduction) and radiographic signs (9% reduction) of infection, compared to nonvaccinated animal groups untreated or treated with vancomycin. Lastly, MRSA biofilm infections were significantly cleared in 87.5% of vaccinated and antibiotic-treated animals, while antibiotics or vaccine alone could not significantly clear infection compared to controls (55.6, 22.2, and 33.3% clearance rates, respectively). This approach to vaccine development may lead to the generation of vaccines against other pathogenic biofilm bacteria.

scholarly journals MCMV Centrifugal Enhancement: A New Spin on an Old Topic

Pathogens ◽  
2021 ◽  
Vol 10 (12) ◽  
pp. 1577
Author(s):  
Trevor J. Hancock ◽  
Morgan Lynn Hetzel ◽  
Andrea Ramirez ◽  
Tim E. Sparer
Keyword(s):  
Tissue Culture ◽  
Salivary Gland ◽  
Vaccine Development ◽  
Submicron Particles ◽  
Murine Cytomegalovirus ◽  
Submicron Particle ◽  
Congenital Infections ◽  
Life Threatening

Human cytomegalovirus (HCMV) is a ubiquitous pathogen infecting a majority of people worldwide, with diseases ranging from mild to life-threatening. Its clinical relevance in immunocompromised people and congenital infections have made treatment and vaccine development a top priority. Because of cytomegaloviruses’ species specificity, murine cytomegalovirus (MCMV) models have historically informed and advanced translational CMV therapies. Using the phenomenon of centrifugal enhancement, we explored differences between MCMVs derived in vitro and in vivo. We found centrifugal enhancement on tissue culture-derived virus (TCV) was ~3× greater compared with salivary gland derived virus (SGV). Using novel “flow virometry”, we found that TCV contained a distinct submicron particle composition compared to SGV. Using an inhibitor of exosome production, we show these submicron particles are not extracellular vesicles that contribute to centrifugal enhancement. We examined how these differences in submicron particles potentially contribute to differing centrifugal enhancement phenotypes, as well as broader in vivo vs. in vitro MCMV differences.

scholarly journals Synthetic Peptides Elicit Strong Cellular Immunity in Visceral Leishmaniasis Natural Reservoir and Contribute to Long-Lasting Polyfunctional T-Cells in BALB/c Mice

Vaccines ◽  
2019 ◽  
Vol 7 (4) ◽  
pp. 162 ◽  
Author(s):  
Rory Cristiane Fortes De Brito ◽  
Jamille Mirelle de Oliveira Cardoso ◽  
Levi Eduardo Soares Reis ◽  
Fernando Augusto Siqueira Mathias ◽  
Rodrigo Dian de Oliveira Aguiar-Soares ◽  
...  
Keyword(s):  
T Cells ◽  
Visceral Leishmaniasis ◽  
In Silico ◽  
Vaccine Development ◽  
Subcellular Location ◽  
Effector Memory ◽  
Effective Vaccine ◽  
Polyfunctional T Cells

Reverse vaccinology or immunoinformatics is a computational methodology which integrates data from in silico epitope prediction, associated to other important information as, for example, the predicted subcellular location of the proteins used in the design of the context of vaccine development. This approach has the potential to search for new targets for vaccine development in the predicted proteome of pathogenic organisms. To date, there is no effective vaccine employed in vaccination campaigns against visceral leishmaniasis (VL). For the first time, herein, an in silico, in vitro, and in vivo peptide screening was performed, and immunogenic peptides were selected to constitute VL peptide-based vaccines. Firstly, the screening of in silico potential peptides using dogs naturally infected by L. infantum was conducted and the peptides with the best performance were selected. The mentioned peptides were used to compose Cockt-1 (cocktail 1) and Cockt-2 (cocktail 2) in combination with saponin as the adjuvant. Therefore, tests for immunogenicity, polyfunctional T-cells, and the ability to induce central and effector memory in T-lymphocytes capacity in reducing the parasite load on the spleen for Cockt-1 and Cockt-2 were performed. Among the vaccines under study, Cockt-1 showed the best results, eliciting CD4+ and CD8+ polyfunctional T-cells, with a reduction in spleen parasitism that correlates to the generation of T CD4+ central memory and T CD8+ effector memory cells. In this way, our findings corroborate the use of immunoinformatics as a tool for the development of future vaccines against VL.

scholarly journals Development of an Oral Salmonella-Based Vaccine Platform against SARS-CoV-2

Vaccines ◽  
2022 ◽  
Vol 10 (1) ◽  
pp. 67
Author(s):  
Wonsuck Yoon ◽  
Yongsung Park ◽  
Seunghyun Kim ◽  
Iel Soo Bang
Keyword(s):  
Large Scale ◽  
Vaccine Development ◽  
Oral Vaccine ◽  
Oral Bacteria ◽  
Expression Vectors ◽  
Effective Vaccine ◽  
Vaccine Platform ◽  
In Vivo Experiments

Effective vaccine development for global outbreaks, such as the coronavirus disease 2019 (COVID-19), has been successful in the short run. However, the currently available vaccines have been associated with a higher frequency of adverse effects compared with other general vaccines. In this study, the possibility of an oral bacteria-based vaccine that can be safely used as a platform for large-scale, long-term immunization was evaluated. A well-known Salmonella strain that was previously considered as a vaccine delivery candidate was used. Recombinant Salmonella cells expressing engineered viral proteins related with COVID-19 pathogenesis were engineered, and the formulation of the oral vaccine candidate strain was evaluated by in vitro and in vivo experiments. First, engineered S proteins were synthesized and cloned into expression vectors, which were than transformed into Salmonella cells. In addition, when orally administrated to mice, the vaccine promoted antigen-specific antibody production and cellular immunity was induced with no significant toxicity effects. These results suggest that Salmonella strains may represent a valuable platform for the development of an oral vaccine for COVID-19 as an alternative to tackle the outbreak of various mutated coronavirus strains and new infectious diseases in the future.

scholarly journals A capsular polysaccharide-expressing live vaccine suppresses streptococcal toxic shock-like syndrome and provides sequence type-independent protection during Streptococcus suis infection

2018 ◽  
Author(s):  
Zhiwei Li ◽  
Peixi Chang ◽  
Jiali Xu ◽  
Chen Tan ◽  
Xiaohong Wang ◽  
...  
Keyword(s):  
Gene Deletion ◽  
Capsular Polysaccharide ◽  
Vaccine Development ◽  
Streptococcus Suis ◽  
Sequence Type ◽  
Effective Vaccine ◽  
Toxic Shock ◽  
Proinflammatory Responses

AbstractStreptococcus suis (S. suis) is an encapsulated zoonotic pathogen, which is responsible for bacterial meningitis and streptococcal toxic shock-like syndrome (STSLS). Despite many attempts to develop an effective vaccine, none is currently available. Here, a capsular polysaccharide (CPS)-expressing attenuated mutant 2015033 was constructed by deleting five virulence-associated factors (sly, scpA, ssnA, fhb, and ssads) in an outbreak S. suis strain SC19. Genes mentioned above are associated with either innate immunity-evading or tissue barrier-invading. Deletion of these genes did not impact the growth ability and CPS generation of 2015033, and the mutant exhibited no hemolytic activity to erythrocytes and no cytotoxicity to different epithelial or endothelial cells. In addition, 2015033 was more easily eliminated by whole human blood in vitro and by mouse blood in vivo. In addition, 2015033 showed a diminished invasive ability in different mouse organs (brain, lung, and liver) and avirulent properties in mice associated with weak inflammation-inducing ability. Immunization with 2015033 triggered T cell-dependent immunity and this immunity suppressed STSLS during SC19 infection by inhibiting excessive proinflammatory responses. In addition, immunization with 2015033 successfully conferred sequence type (STs)-independent protection to mice during heterogeneous infections (ST1, ST7, and ST658). This study presents the feasibility of the strategy of multi-gene deletion for the development of promising live vaccines against invasive encapsulated pathogens.IMPORTANCES. suis is a traditional zoonotic agent causing human meningitis and STSLS, which is also a neglected emerging food-borne pathogen. Increasing antimicrobial resistance invokes reduction of preventative use of antibiotics in livestock creating an urgent need for effective vaccines. Given the expression of CPS is the basis for promising vaccines against encapsulated pathogens, and in order to find an effective and economical strategy for CPS-based vaccine development, multi-gene deletion was introduced into the design of a S. suis vaccine for the first time. From our results, CPS-expressing attenuated mutant 2015033 exhibited diminished evasive ability against the innate immune system and reduced invasive properties against different host barriers. To our knowledge, 2015033 is the first STSLS-suppressing S. suis vaccine to provide STs-independent protection during heterogeneous infections.

Novel concatameric heparin-binding peptides reverse heparin and low-molecular-weight heparin anticoagulant activities in patient plasma in vitro and in rats in vivo

Blood ◽  
2004 ◽  
Vol 103 (4) ◽  
pp. 1356-1363 ◽  
Author(s):  
Barbara P. Schick ◽  
David Maslow ◽  
Adrianna Moshinski ◽  
James D. San Antonio
Keyword(s):  
Molecular Weight ◽  
Low Molecular Weight Heparin ◽  
Tandem Repeats ◽  
Factor Xa ◽  
Low Molecular Weight ◽  
Heparin Binding ◽  
High Affinity ◽  
Binding Peptides

Abstract Patients given unfractionated heparin (UFH) or low-molecular-weight heparin (LMWH) for prophylaxis or treatment of thrombosis sometimes suffer serious bleeding. We showed previously that peptides containing 3 or more tandem repeats of heparin-binding consensus sequences have high affinity for LMWH and neutralize LMWH (enoxaparin) in vivo in rats and in vitro in citrate. We have now modified the (ARKKAAKA)n tandem repeat peptides by cyclization or by inclusion of hydrophobic tails or cysteines to promote multimerization. These peptides exhibit high-affinity binding to LMWH (dissociation constant [Kd], ≈ 50 nM), similar potencies in neutralizing anti–Factor Xa activity of UFH and enoxaparin added to normal plasma in vitro, and efficacy equivalent to or greater than protamine. Peptide (ARKKAAKA)3VLVLVLVL was most effective in all plasmas from enoxaparin-treated patients, and was 4- to 20-fold more effective than protamine. Several other peptide structures were effective in some patients' plasmas. All high-affinity peptides reversed inhibition of thrombin-induced clot formation by UFH. These peptides (1 mg/300 g rat) neutralized 1 U/mL anti–Factor Xa activity of enoxaparin in rats within 1 to 2 minutes. Direct blood pressure and heart rate measurements showed little or no hemodynamic effect. These heparin-binding peptides, singly or in combination, are potential candidates for clinical reversal of UFH and LMWH in humans.

scholarly journals Effects of Size and Surface Properties of Nanodiamonds on the Immunogenicity of Plant-Based H5 Protein of A/H5N1 Virus in Mice

Nanomaterials ◽  
2021 ◽  
Vol 11 (6) ◽  
pp. 1597
Author(s):  
Thuong Thi Ho ◽  
Van Thi Pham ◽  
Tra Thi Nguyen ◽  
Vy Thai Trinh ◽  
Tram Vi ◽  
...  
Keyword(s):  
High Pressure ◽  
Neutralizing Antibodies ◽  
H5n1 Virus ◽  
Vaccine Development ◽  
Particle Characterization ◽  
Innovative Strategy ◽  
Specific Igg ◽  
Positively Charged

Nanodiamond (ND) has recently emerged as a potential nanomaterial for nanovaccine development. Here, a plant-based haemagglutinin protein (H5.c2) of A/H5N1 virus was conjugated with detonation NDs (DND) of 3.7 nm in diameter (ND4), and high-pressure and high-temperature (HPHT) oxidative NDs of ~40–70 nm (ND40) and ~100–250 nm (ND100) in diameter. Our results revealed that the surface charge, but not the size of NDs, is crucial to the protein conjugation, as well as the in vitro and in vivo behaviors of H5.c2:ND conjugates. Positively charged ND4 does not effectively form stable conjugates with H5.c2, and has no impact on the immunogenicity of the protein both in vitro and in vivo. In contrast, the negatively oxidized NDs (ND40 and ND100) are excellent protein antigen carriers. When compared to free H5.c2, H5.c2:ND40, and H5.c2:ND100 conjugates are highly immunogenic with hemagglutination titers that are both 16 times higher than that of the free H5.c2 protein. Notably, H5.c2:ND40 and H5.c2:ND100 conjugates induce over 3-folds stronger production of both H5.c2-specific-IgG and neutralizing antibodies against A/H5N1 than free H5.c2 in mice. These findings support the innovative strategy of using negatively oxidized ND particles as novel antigen carriers for vaccine development, while also highlighting the importance of particle characterization before use.

scholarly journals Heparan sulfate and heparin interactions with proteins

2015 ◽  
Vol 12 (110) ◽  
pp. 20150589 ◽  
Author(s):  
Maria C. Z. Meneghetti ◽  
Ashley J. Hughes ◽  
Timothy R. Rudd ◽  
Helena B. Nader ◽  
Andrew K. Powell ◽  
...  
Keyword(s):  
Heparan Sulfate ◽  
Ex Vivo ◽  
Sequence Specificity ◽  
Structure Activity ◽  
Multiple Binding Sites ◽  
Multiple Binding ◽  
Heparin Activity

Heparan sulfate (HS) polysaccharides are ubiquitous components of the cell surface and extracellular matrix of all multicellular animals, whereas heparin is present within mast cells and can be viewed as a more sulfated, tissue-specific, HS variant. HS and heparin regulate biological processes through interactions with a large repertoire of proteins. Owing to these interactions and diverse effects observed during in vitro , ex vivo and in vivo experiments, manifold biological/pharmacological activities have been attributed to them. The properties that have been thought to bestow protein binding and biological activity upon HS and heparin vary from high levels of sequence specificity to a dependence on charge. In contrast to these opposing opinions, we will argue that the evidence supports both a level of redundancy and a degree of selectivity in the structure–activity relationship. The relationship between this apparent redundancy, the multi-dentate nature of heparin and HS polysaccharide chains, their involvement in protein networks and the multiple binding sites on proteins, each possessing different properties, will also be considered. Finally, the role of cations in modulating HS/heparin activity will be reviewed and some of the implications for structure–activity relationships and regulation will be discussed.

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