scholarly journals Production and Immunogenicity of a Tag-Free Recombinant Chimera Based on PfMSP-1 and PfMSP-3 Using Alhydrogel and Dipeptide-Based Hydrogels

Vaccines ◽  
2021 ◽  
Vol 9 (7) ◽  
pp. 782
Author(s):  
Gaurav Anand ◽  
Saikat Biswas ◽  
Nitin Yadav ◽  
Paushali Mukherjee ◽  
Virander Singh Chauhan
Keyword(s):  
Immune Responses ◽  
Three Dimensional ◽  
Exchange Chromatography ◽  
Antigen Delivery ◽  
Physiological Conditions ◽  
Ammonium Sulphate Precipitation ◽  
Effective Delivery ◽  
Antibody Titers ◽  
Delivery Platform ◽  
Chimeric Vaccine

A fusion chimeric vaccine comprising multiple protective domains of different blood-stage Plasmodium falciparum antigens is perhaps necessary for widening the protective immune responses and reducing the morbidity caused by the disease. Here we continue to build upon the prior work of developing a recombinant fusion chimera protein, His-tagged PfMSP-Fu24, by producing it as a tag-free recombinant protein. In this study, tag-free recombinant PfMSPFu24 (rFu24) was expressed in Escherichia coli, and the soluble protein was purified using a three-step purification involving ammonium sulphate precipitation followed by 2-step ion exchange chromatography procedures and shown that it was highly immunogenic with the human-compatible adjuvant Alhydrogel. We further investigated two dipeptides, phenylalanine-α, β-dehydrophenylalanine (FΔF) and Leucine-α, β-dehydrophenylalanine (LΔF) based hydrogels as effective delivery platforms for rFu24. These dipeptides self-assembled spontaneously to form a highly stable hydrogel under physiological conditions. rFu24 was efficiently entrapped in both the F∆F and L∆F hydrogels, and the three-dimensional (3D) mesh-like structures of the hydrogels remained intact after the entrapment of the antigen. The two hydrogels significantly stimulated rFu24-specific antibody titers, and the sera from the immunized mice showed an invasion inhibitory activity comparable to that of Alhydrogel. Easily synthesized dipeptide hydrogels can be used as an effective antigen delivery platform to induce immune responses.

scholarly journals A Novel Recombinant Fcγ Receptor-Targeted Survivin Combines with Chemotherapy for Efficient Cancer Treatment

Biomedicines ◽  
2021 ◽  
Vol 9 (7) ◽  
pp. 806
Author(s):  
Chiao-Chieh Wu ◽  
Chen-Yi Chiang ◽  
Shih-Jen Liu ◽  
Hsin-Wei Chen
Keyword(s):  
Immune Responses ◽  
Fusion Protein ◽  
Human Cancer ◽  
Formyl Peptide Receptor ◽  
Antigen Delivery ◽  
Potential Candidate ◽  
Fcγ Receptor ◽  
Formyl Peptide ◽  
Efficient Uptake

Formyl peptide receptor-like 1 inhibitor (FLIPr), an Fcγ receptor (FcγR) antagonist, can be used as a carrier to guide antigen-FLIPr fusion protein to FcγR then enhances antigen-specific immune responses. Survivin, a tumor-associated antigen, is over-expressed in various types of human cancer. In this study, we demonstrate that recombinant survivin-FLIPr fusion protein (rSur-FLIPr) binds to FcγRs, and efficient uptake by dendritic cells in vivo. In addition, rSur-FLIPr alone stimulates survivin-specific immune responses, which effectively suppresses the tumor growth. The antitumor immunities are through TAP-mediated and CD8-dependent pathways. Furthermore, preexisting anti-FLIPr antibody does not abolish antitumor responses induced by rSur-FLIPr immunization. These results suggest that FLIPr is an effective antigen delivery vector and can be repeatedly used. Combination of chemotherapy with rSur-FLIPr treatment reveals a great benefit to tumor-bearing mice. Altogether, these findings suggest that rSur-FLIPr is a potential candidate for efficient cancer therapy.

Changes in the Intestinal Microbiota and Systemic Immune Responses by Dietary 1-Kestose Supplementation in Healthy Dogs

2020 ◽  
Vol 16 (1) ◽  
pp. 7-15
Author(s):  
T. Tochio ◽  
Y. Kadota ◽  
Y. Asami ◽  
R. Azuma ◽  
R. Oishi ◽  
...  
Keyword(s):  
Immune Responses ◽  
Intestinal Microbiota ◽  
Serum Antibody ◽  
Flow Cytometric Analysis ◽  
Allergic Diseases ◽  
Food Material ◽  
Quantification Analysis ◽  
Antibody Titers ◽  
Healthy Dogs ◽  
System 1

1-Kestose is a trisaccharide prebiotic that modifies immune responses in humans and rodents with allergic diseases by altering the intestinal microbiota. In the present study, we examined the effects of 1-kestose supplementation on the intestinal microbiota, peripheral lymphocyte subsets, and antibody production in healthy dogs. Fecal IgA levels and serum antibody titers against the rabies vaccine were not significantly affected by 1-kestose supplementation. In a flow cytometric analysis, the percentage of T cells among total lymphocytes decreased, whereas that of B cells increased in supplemented dogs. A metagenomic analysis of the intestinal microbiota showed that the proportion of Bifidobacterium increased, while that of Lactobacillus did not decrease in supplemented dogs. Furthermore, a quantification analysis using real-time polymerase chain reaction showed that the proportion of Bifidobacterium increased in supplemented dogs. These results suggest that 1-kestose supplementation induced modifications in the intestinal microbiota of dogs, which presumably enhanced the immune system. 1-Kestose may be a useful food material as a prebiotic for dogs.

Cell-Penetrating Peptide-Mediated Nanovaccine Delivery

2021 ◽  
Vol 22 ◽  
Author(s):  
Jizong Jiang
Keyword(s):  
Immune System ◽  
Immune Responses ◽  
Cell Penetrating Peptide ◽  
Antigen Delivery ◽  
Efficient Manner ◽  
Antigen Uptake ◽  
Cell Penetrating ◽  
The Stability ◽  
Antigen Presenting

Abstract: Vaccination with small antigens, such as proteins, peptides, or nucleic acids, is used to activate the immune system and trigger the protective immune responses against a pathogen. Currently, nanovaccines are undergoing development instead of conventional vaccines. The size of nanovaccines is in the range of 10–500 nm, which enables them to be readily taken up by cells and exhibit improved safety profiles. However, low-level immune responses, as the removal of redundant pathogens, trigger counter-effective activation of the immune system invalidly and present a challenging obstacle to antigen recognition and its uptake via antigen-presenting cells (APCs). In addition, toxicity can be substantial. To overcome these problems, a variety of cell-penetrating peptide (CPP)-mediated vaccine delivery systems based on nanotechnology have been proposed, most of which are designed to improve the stability of antigens in vivo and their delivery into immune cells. CPPs are particularly attractive components of antigen delivery. Thus, the unique translocation property of CPPs ensures that they remain an attractive carrier with the capacity to deliver cargo in an efficient manner for the application of drugs, gene transfer, protein, and DNA/RNA vaccination delivery. CPP-mediated nanovaccines can enhance antigen uptake, processing, and presentation by APCs, which are the fundamental steps in initiating an immune response. This review describes the different types of CPP-based nanovaccines delivery strategies.

scholarly journals Isolation, purification and structure of exochelin MS, the extracellular siderophore from Mycobacterium smegmatis

1995 ◽  
Vol 305 (1) ◽  
pp. 187-196 ◽  
Author(s):  
G J Sharman ◽  
D H Williams ◽  
D F Ewing ◽  
C Ratledge
Keyword(s):  
Amino Acids ◽  
Mycobacterium Smegmatis ◽  
Methyl Esters ◽  
Three Dimensional ◽  
Iron Chelation ◽  
Peptide Bond ◽  
Exchange Chromatography ◽  
Peptide Bonds ◽  
Hydrolysis Of ◽  
Gallium Complex

The extracellular siderophore from Mycobacterium smegmatis, exochelin MS, was isolated from iron-deficiently grown cultures and purified to > 98% by a combination of ion-exchange chromatography and h.p.l.c. The material is unextractable into organic solvents, is basic (pI = 9.3-9.5), has a lambda max at 420 nm and a probable Ks for Fe3+ of between 10(25) and 10(30). Its structure has been determined by examination of desferri- and ferri-exochelin and its gallium complex. The methods used were electrospray-m.s. and one- and two-dimensional (NOESY, DQF-COSY and TOCSY) 1H n.m.r. The constituent amino acids were examined by chiral g.l.c analysis of N-trifluoroacetyl isopropyl and N-pentafluoropropionyl methyl esters after hydrolysis, and reductive HI hydrolysis, of the siderophore. The exochelin is a formylated pentapeptide: N-(delta-N-formyl,delta N-hydroxy-R-ornithyl) -beta-alaninyl-delta N-hydroxy-R-ornithinyl-R-allo-threoninyl-delta N-hydroxy-S-ornithine. The linkages involving the three ornithine residues are via their delta N(OH) and alpha-CO groups leaving three free alpha-NH2 groups. Although there are two peptide bonds, these involve the three R (D)-amino acids. Thus the molecule has no conventional peptide bond, and this suggests that it will be resistant to peptidase hydrolysis. The co-ordination centre with Fe3+ is hexadenate in an octahedral structure involving the three hydroxamic acid groups. Molecular modelling shows it to have similar features to other ferric trihydroxamate siderophores whose three-dimensional structures have been established. The molecule is shown to have little flexibility around the iron chelation centre, although the terminal (Orn-3) residue, which is not involved in iron binding except at its delta N atom, has more motional freedom.

scholarly journals Evaluation of Feline Monocyte-Derived Dendritic Cells Loaded with Internally Inactivated Virus as a Vaccine against Feline Immunodeficiency Virus

2008 ◽  
Vol 15 (3) ◽  
pp. 452-459 ◽  
Author(s):  
Giulia Freer ◽  
Donatella Matteucci ◽  
Paola Mazzetti ◽  
Francesca Tarabella ◽  
Valentina Catalucci ◽  
...  
Keyword(s):  
T Cells ◽  
Dendritic Cells ◽  
Immune Responses ◽  
Immune Functions ◽  
Peripheral Blood Mononuclear ◽  
Challenge Virus ◽  
Homologous Virus ◽  
Antibody Titers ◽  
Cellular Immune ◽  
Antigen Presenting

ABSTRACT Dendritic cells are the only antigen-presenting cells that can present exogenous antigens to both helper and cytolytic T cells and prime Th1-type or Th2-type cellular immune responses. Given their unique immune functions, dendritic cells are considered attractive “live adjuvants” for vaccination and immunotherapy against cancer and infectious diseases. The present study was carried out to assess whether the reinjection of autologous monocyte-derived dendritic cells loaded with an aldithriol-2-inactivated primary isolate of feline immune deficiency virus (FIV) was able to elicit protective immune responses against the homologous virus in naive cats. Vaccine efficacy was assessed by monitoring immune responses and, finally, by challenge with the homologous virus of vaccinated, mock-vaccinated, and healthy cats. The outcome of challenge was followed by measuring cellular and antibody responses and viral and proviral loads and quantitating FIV by isolation and a count of CD4+/CD8+ T cells in blood. Vaccinated animals exhibited clearly evident FIV-specific peripheral blood mononuclear cell proliferation and antibody titers in response to immunization; however, they became infected with the challenge virus at rates comparable to those of control animals.

scholarly journals Immune responses to SARS-CoV-2 infection in hospitalized pediatric and adult patients

2020 ◽  
Vol 12 (564) ◽  
pp. eabd5487 ◽  
Author(s):  
Carl A. Pierce ◽  
Paula Preston-Hurlburt ◽  
Yile Dai ◽  
Clare Burn Aschner ◽  
Natalia Cheshenko ◽  
...  
Keyword(s):  
T Cells ◽  
Immune Responses ◽  
Pediatric Patients ◽  
Neutralizing Antibody ◽  
Children And Youth ◽  
Spike Protein ◽  
Serum Concentrations ◽  
Antiviral Immune Response ◽  
Antibody Titers ◽  
Ifn Γ

Children and youth infected with severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) have milder disease than do adults, and even among those with the recently described multisystem inflammatory syndrome, mortality is rare. The reasons for the differences in clinical manifestations are unknown but suggest that age-dependent factors may modulate the antiviral immune response. We compared cytokine, humoral, and cellular immune responses in pediatric (children and youth, age <24 years) (n = 65) and adult (n = 60) patients with coronavirus disease 2019 (COVID-19) at a metropolitan hospital system in New York City. The pediatric patients had a shorter length of stay, decreased requirement for mechanical ventilation, and lower mortality compared to adults. The serum concentrations of interleukin-17A (IL-17A) and interferon-γ (IFN-γ), but not tumor necrosis factor–α (TNF-α) or IL-6, were inversely related to age. Adults mounted a more robust T cell response to the viral spike protein compared to pediatric patients as evidenced by increased expression of CD25+ on CD4+ T cells and the frequency of IFN-γ+ CD4+ T cells. Moreover, serum neutralizing antibody titers and antibody-dependent cellular phagocytosis were higher in adults compared to pediatric patients with COVID-19. The neutralizing antibody titer correlated positively with age and negatively with IL-17A and IFN-γ serum concentrations. There were no differences in anti-spike protein antibody titers to other human coronaviruses. Together, these findings demonstrate that the poor outcome in hospitalized adults with COVID-19 compared to children may not be attributable to a failure to generate adaptive immune responses.

scholarly journals Mapping glycan-mediated galectin-3 interactions by live cell proximity labeling

2020 ◽  
Vol 117 (44) ◽  
pp. 27329-27338
Author(s):  
Eugene Joeh ◽  
Timothy O’Leary ◽  
Weichao Li ◽  
Richard Hawkins ◽  
Jonathan R. Hung ◽  
...  
Keyword(s):  
Immune Responses ◽  
Hepatic Stellate Cells ◽  
Mononuclear Cells ◽  
Three Dimensional ◽  
Stellate Cells ◽  
Live Cells ◽  
Quantitative Mass Spectrometry ◽  
Peripheral Blood Mononuclear ◽  
Galectin 3 ◽  
Labeling Method

Galectin-3 is a glycan-binding protein (GBP) that binds β-galactoside glycan structures to orchestrate a variety of important biological events, including the activation of hepatic stellate cells and regulation of immune responses. While the requisite glycan epitopes needed to bind galectin-3 have long been elucidated, the cellular glycoproteins that bear these glycan signatures remain unknown. Given the importance of the three-dimensional (3D) arrangement of glycans in dictating GBP interactions, strategies that allow the identification of GBP receptors in live cells, where the native glycan presentation and glycoprotein expression are preserved, have significant advantages over static and artificial systems. Here we describe the integration of a proximity labeling method and quantitative mass spectrometry to map the glycan and glycoprotein interactors for galectin-3 in live human hepatic stellate cells and peripheral blood mononuclear cells. Understanding the identity of the glycoproteins and defining the structures of the glycans will empower efforts to design and develop selective therapeutics to mitigate galectin-3–mediated biological events.

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