scholarly journals Assessment of Immunogenicity and Efficacy of a Zika Vaccine Using Modified Vaccinia Ankara Virus as Carriers

Pathogens ◽  
2019 ◽  
Vol 8 (4) ◽  
pp. 216 ◽  
Author(s):  
López-Camacho ◽  
Kim ◽  
Abbink ◽  
Larocca ◽  
Huiskonen ◽  
...  
Keyword(s):  
Zika Virus ◽  
Transmembrane Domain ◽  
Brazilian Isolate ◽  
Vaccination Regimen ◽  
Vaccine Candidates ◽  
C Terminus ◽  
Single Vaccination ◽  
Active Research ◽  
Vectored Vaccine ◽  
Modest Level

Zika virus (ZIKV) is an emerging mosquito-borne flavivirus that has spread to more than 70 countries worldwide since 2015. Despite active research, there are currently no licensed vaccines or therapeutics. We have previously reported the development of various adenoviral vectored vaccine candidates (ChAdOx1 ZIKV) with the ability to stimulate effective immunity in mice and provide protection upon a ZIKV challenge model, using a non-adjuvanted single vaccination approach. In this study, we constructed various modified vaccinia Ankara (MVA) viruses to express the ZIKV Envelope (E) with modifications on the precursor membrane (prM) or on the C-terminus envelope transmembrane domain (TM), similar to our ChAdOx1 vaccine candidates. MVA-ZIKV vaccine candidates were evaluated as a non-adjuvanted single vaccination regimen against a ZIKV Brazilian isolate, using viraemia as the correlate of protection. Here, we report the induction of a modest level of anti-ZIKV E antibodies by all MVA vectored vaccines and sub-optimal efficacy in a ZIKV challenge model. Our results indicate the requirement of additional strategies when using MVA-ZIKV vaccines to afford sterile protection upon a non-adjuvanted and single vaccination regime.

scholarly journals Role of Capsid Anchor in the Morphogenesis of Zika Virus

2018 ◽  
Vol 92 (22) ◽  
Author(s):  
Jyoti Rana ◽  
José Luis Slon Campos ◽  
Gabriella Leccese ◽  
Maura Francolini ◽  
Marco Bestagno ◽  
...  
Keyword(s):  
Capsid Protein ◽  
Zika Virus ◽  
Protein C ◽  
Transmembrane Domain ◽  
Viral Envelope ◽  
Signal Peptidase ◽  
C Terminus ◽  
Cytosolic Side ◽  
The One

ABSTRACTThe flavivirus capsid protein (C) is separated from the downstream premembrane (PrM) protein by a hydrophobic sequence named capsid anchor (Ca). During polyprotein processing, Ca is sequentially cleaved by the viral NS2B/NS3 protease on the cytosolic side and by signal peptidase on the luminal side of the endoplasmic reticulum (ER). To date, Ca is considered important mostly for directing translocation of PrM into the ER lumen. In this study, the role of Ca in the assembly and secretion of Zika virus was investigated using a pseudovirus-based approach. Our results show that, while Ca-mediated anchoring of C to the ER membrane is not needed for the production of infective particles, Ca expression inciswith respect to PrM is strictly required to allow proper assembly of infectious particles. Finally, we show that the presence of heterologous, but not homologous, Ca induces degradation of E through the autophagy/lysosomal pathway.IMPORTANCEThe capsid anchor (Ca) is a single-pass transmembrane domain at the C terminus of the capsid protein (C) known to function as a signal for the translocation of PrM into the ER lumen. The objective of this study was to further examine the role of Ca in Zika virus life cycle, whether involved in the formation of nucleocapsid through association with C or in the formation of viral envelope. In this study, we show that Ca has a function beyond the one of translocation signal, controlling protein E stability and therefore its availability for assembly of infectious particles.

scholarly journals In silico characterisation of putative Plasmodium falciparum vaccine candidates in African malaria populations

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
O. Ajibola ◽  
M. F. Diop ◽  
A. Ghansah ◽  
L. Amenga-Etego ◽  
L. Golassa ◽  
...  
Keyword(s):  
Plasmodium Falciparum ◽  
Malaria Vaccine ◽  
Transmembrane Domain ◽  
Vaccine Development ◽  
Balancing Selection ◽  
Immune Recognition ◽  
African Countries ◽  
Vaccine Candidates ◽  
D Values ◽  
Tajima’S D

AbstractGenetic diversity of surface exposed and stage specific Plasmodium falciparum immunogenic proteins pose a major roadblock to developing an effective malaria vaccine with broad and long-lasting immunity. We conducted a prospective genetic analysis of candidate antigens (msp1, ama1, rh5, eba175, glurp, celtos, csp, lsa3, Pfsea, trap, conserved chrom3, hyp9, hyp10, phistb, surfin8.2, and surfin14.1) for malaria vaccine development on 2375 P. falciparum sequences from 16 African countries. We described signatures of balancing selection inferred from positive values of Tajima’s D for all antigens across all populations except for glurp. This could be as a result of immune selection on these antigens as positive Tajima’s D values mapped to regions with putative immune epitopes. A less diverse phistb antigen was characterised with a transmembrane domain, glycophosphatidyl anchors between the N and C- terminals, and surface epitopes that could be targets of immune recognition. This study demonstrates the value of population genetic and immunoinformatic analysis for identifying and characterising new putative vaccine candidates towards improving strain transcending immunity, and vaccine efficacy across all endemic populations.

scholarly journals Current Status of Zika Virus Vaccines: Successes and Challenges

Vaccines ◽  
2020 ◽  
Vol 8 (2) ◽  
pp. 266 ◽  
Author(s):  
Aryamav Pattnaik ◽  
Bikash R. Sahoo ◽  
Asit K. Pattnaik
Keyword(s):  
Zika Virus ◽  
Viral Infections ◽  
Current Status ◽  
Effective Vaccine ◽  
Congenital Diseases ◽  
Vaccine Candidates ◽  
Efficacy Trials ◽  
Nucleic Acid Vaccines ◽  
Funding Agencies ◽  
Inactivated Vaccines

The recently emerged Zika virus (ZIKV) spread to the Americas, causing a spectrum of congenital diseases including microcephaly in newborn and Guillain-Barré syndrome (GBS) in adults. The unprecedented nature of the epidemic and serious diseases associated with the viral infections prompted the global research community to understand the immunopathogenic mechanisms of the virus and rapidly develop safe and efficacious vaccines. This has led to a number of ZIKV vaccine candidates that have shown significant promise in human clinical trials. These candidates include nucleic acid vaccines, inactivated vaccines, viral-vectored vaccines, and attenuated vaccines. Additionally, a number of vaccine candidates have been shown to protect animals in preclinical studies. However, as the epidemic has waned in the last three years, further development of the most promising vaccine candidates faces challenges in clinical efficacy trials, which is needed before a vaccine is brought to licensure. It is important that a coalition of government funding agencies and private sector companies is established to move forward with a safe and effective vaccine ready for deployment when the next ZIKV epidemic occurs.

Molecular cloning of a 47 kDa tissue-specific and differentiation-dependent urothelial cell surface glycoprotein

1993 ◽  
Vol 106 (1) ◽  
pp. 31-43 ◽  
Author(s):  
X.R. Wu ◽  
T.T. Sun
Keyword(s):  
Transmembrane Domain ◽  
Core Protein ◽  
Surface Glycoprotein ◽  
Peptide Sequence ◽  
Type I ◽  
Apical Surface ◽  
Bladder Epithelium ◽  
Cell Surface Glycoprotein ◽  
Signal Peptide Sequence ◽  
C Terminus

Despite the fact that bladder epithelium has many interesting biological features and is a frequent site of carcinoma formation, relatively little is known about its biochemical differentiation. We have shown recently that a 47 kDa glycoprotein, uroplakin III (UPIII), in conjunction with uroplakins I (27 kDa) and II (15 kDa), forms the asymmetric unit membrane (AUM)--a highly specialized biomembrane characteristic of the apical surface of bladder epithelium. Deglycosylation and cDNA sequencing revealed that UPIII contains up to 20 kDa of N-linked sugars attached to a core protein of 28.9 kDa. The presence of an N-terminal signal peptide sequence and a single transmembrane domain located near the C terminus, plus the N-terminal location of all the potential N-glycosylation sites, points to a type I (N-exo/C-cyto) configuration. Thus the mass of the extracellular domain (20 kDa plus up to 20 kDa of sugar) of UPIII greatly exceeds that of its intracellular domain (5 kDa). Such an asymmetrical mass distribution, a feature shared by the other two major uroplakins, provides a molecular explanation as to why the luminal leaflet of AUM is almost twice as thick as the cytoplasmic one. The fact that of the three major proteins of AUM only UPIII has a significant cytoplasmic domain suggests that this molecule may play an important role in AUM-cytoskeleton interaction in terminally differentiated urothelial cells.

Identification of a di-leucine motif within the C terminus domain of the Menkes disease protein that mediates endocytosis from the plasma membrane

1999 ◽  
Vol 112 (11) ◽  
pp. 1721-1732 ◽  
Author(s):  
M.J. Francis ◽  
E.E. Jones ◽  
E.R. Levy ◽  
R.L. Martin ◽  
S. Ponnambalam ◽  
...  
Keyword(s):  
Plasma Membrane ◽  
Golgi Apparatus ◽  
Transmembrane Domain ◽  
Menkes Disease ◽  
Cytoplasmic Domain ◽  
Endocytic Pathway ◽  
Site Directed Mutagenesis ◽  
Trans Golgi Network ◽  
C Terminus ◽  
Golgi Network

The protein encoded by the Menkes disease gene (MNK) is localised to the Golgi apparatus and cycles between the trans-Golgi network and the plasma membrane in cultured cells on addition and removal of copper to the growth medium. This suggests that MNK protein contains active signals that are involved in the retention of the protein to the trans-Golgi network and retrieval of the protein from the plasma membrane. Previous studies have identified a signal involved in Golgi retention within transmembrane domain 3 of MNK. To identify a motif sufficient for retrieval of MNK from the plasma membrane, we analysed the cytoplasmic domain, downstream of transmembrane domain 7 and 8. Chimeric constructs containing this cytoplasmic domain fused to the reporter molecule CD8 localised the retrieval signal(s) to 62 amino acids at the C terminus. Further studies were performed on putative internalisation motifs, using site-directed mutagenesis, protein expression, chemical treatment and immunofluorescence. We observed that a di-leucine motif (L1487L1488) was essential for rapid internalisation of chimeric CD8 proteins and the full-length Menkes cDNA from the plasma membrane. We suggest that this motif mediates the retrieval of MNK from the plasma membrane into the endocytic pathway, via the recycling endosomes, but is not sufficient on its own to return the protein to the Golgi apparatus. These studies provide a basis with which to identify other motifs important in the sorting and delivery of MNK from the plasma membrane to the Golgi apparatus.

scholarly journals Structural and functional aspects of the multiplicity of Neu differentiation factors

1994 ◽  
Vol 14 (3) ◽  
pp. 1909-1919
Author(s):  
D Wen ◽  
S V Suggs ◽  
D Karunagaran ◽  
N Liu ◽  
R L Cupples ◽  
...  
Keyword(s):  
Receptor Binding ◽  
Transmembrane Domain ◽  
Structural Heterogeneity ◽  
Binding Activity ◽  
Biologically Active ◽  
Specific Rate ◽  
C Terminus ◽  
Functional Aspects ◽  
Differentiation Factors ◽  
Variable Domains

We used molecular cloning and functional analyses to extend the family of Neu differentiation factors (NDFs) and to explore the biochemical activity of different NDF isoforms. Exhaustive cloning revealed the existence of six distinct fibroblastic pro-NDFs, whose basic transmembrane structure includes an immunoglobulin-like motif and an epidermal growth factor (EGF)-like domain. Structural variation is confined to three domains: the C-terminal portion of the EGF-like domain (isoforms alpha and beta), the adjacent juxtamembrane stretch (isoforms 1 to 4), and the variable-length cytoplasmic domain (isoforms a, b, and c). Only certain combinations of the variable domains exist, and they display partial tissue specificity in their expression: pro-NDF-alpha 2 is the predominant form in mesenchymal cells, whereas pro-NDF-beta 1 is the major neuronal isoform. Only the transmembrane isoforms were glycosylated and secreted as biologically active 44-kDa glycoproteins, implying that the transmembrane domain functions as an internal signal peptide. Extensive glycosylation precedes proteolytic cleavage of pro-NDF but has no effect on receptor binding. By contrast, the EGF-like domain fully retains receptor binding activity when expressed separately, but its beta-type C terminus displays higher affinity than alpha-type NDFs. Likewise, structural heterogeneity of the cytoplasmic tails may determine isoform-specific rate of pro-NDF processing. Taken together, these results suggest that different NDF isoforms are generated by alternative splicing and perform distinct tissue-specific functions.

scholarly journals Progesterone Receptor Membrane Component-1 (PGRMC1) Is the Mediator of Progesterone’s Antiapoptotic Action in Spontaneously Immortalized Granulosa Cells As Revealed by PGRMC1 Small Interfering Ribonucleic Acid Treatment and Functional Analysis of PGRMC1 Mutations

Endocrinology ◽  
2007 ◽  
Vol 149 (2) ◽  
pp. 534-543 ◽  
Author(s):  
John J. Peluso ◽  
Jonathan Romak ◽  
Xiufang Liu
Keyword(s):  
Binding Site ◽  
Rna Binding ◽  
Transmembrane Domain ◽  
Binding Protein ◽  
Plasminogen Activator Inhibitor ◽  
Membrane Receptor ◽  
Membrane Component ◽  
Plasminogen Activator Inhibitor 1 ◽  
Receptor Membrane ◽  
C Terminus

Progesterone (P4) receptor membrane component-1 (PGRMC1) and its binding partner, plasminogen activator inhibitor 1 RNA binding protein (PAIRBP1) are thought to form a complex that functions as membrane receptor for P4. The present investigations confirm PGRMC1’s role in this membrane receptor complex by demonstrating that depleting PGMRC1 with PGRMC1 small interfering RNA results in a 60% decline in [3H]P4 binding and the loss of P4’s antiapoptotic action. Studies conducted on partially purified GFP-PGRMC1 fusion protein indicate that [3H]P4 specifically binds to PGRMC1 at a single site with an apparent Kd of about 35 nm. In addition, experiments using various deletion mutations reveal that the entire PGRMC1 molecule is required for maximal [3H]P4 binding and P4 responsiveness. Analysis of the binding data also suggests that the P4 binding site is within a segment of PGRMC1 that is composed of the transmembrane domain and the initial segment of the C terminus. Interestingly, PAIRBP1 appears to bind to the C terminus between amino acids 70–130, which is distal to the putative P4 binding site. Taken together, these data provide compelling evidence that PGRMC1 is the P4 binding protein that mediates P4’s antiapoptotic action. Moreover, the deletion mutation studies indicate that each domain of PGRMC1 plays an essential role in modulating PGRMC1’s capacity to both bind and respond to P4. Additional studies are required to more precisely delineate the role of each PGRMC1 domain in transducing P4’s antiapoptotic action.

scholarly journals Regulation of Bestrophin Cl Channels by Calcium: Role of the C Terminus

2008 ◽  
Vol 132 (6) ◽  
pp. 681-692 ◽  
Author(s):  
Qinghuan Xiao ◽  
Andrew Prussia ◽  
Kuai Yu ◽  
Yuan-yuan Cui ◽  
H. Criss Hartzell
Keyword(s):  
Amino Acids ◽  
Density Functional ◽  
Transmembrane Domain ◽  
Channel Gating ◽  
Regulatory Domain ◽  
Acidic Amino Acids ◽  
C Terminus ◽  
Ef Hand ◽  
Cl Channels

Human bestrophin-1 (hBest1), which is genetically linked to several kinds of retinopathy and macular degeneration in both humans and dogs, is the founding member of a family of Cl− ion channels that are activated by intracellular Ca2+. At present, the structures and mechanisms responsible for Ca2+ sensing remain unknown. Here, we have used a combination of molecular modeling, density functional–binding energy calculations, mutagenesis, and patch clamp to identify the regions of hBest1 involved in Ca2+ sensing. We identified a cluster of a five contiguous acidic amino acids in the C terminus immediately after the last transmembrane domain, followed by an EF hand and another regulatory domain that are essential for Ca2+ sensing by hBest1. The cluster of five amino acids (293–308) is crucial for normal channel gating by Ca2+ because all but two of the 35 mutations we made in this region rendered the channel incapable of being activated by Ca2+. Using homology models built on the crystal structure of calmodulin (CaM), an EF hand (EF1) was identified in hBest1. EF1 was predicted to bind Ca2+ with a slightly higher affinity than the third EF hand of CaM and lower affinity than the second EF hand of troponin C. As predicted by the model, the D312G mutation in the putative Ca2+-binding loop (312–323) reduced the apparent Ca2+ affinity by 20-fold. In addition, the D312G and D323N mutations abolished Ca2+-dependent rundown of the current. Furthermore, analysis of truncation mutants of hBest1 identified a domain adjacent to EF1 that is rich in acidic amino acids (350–390) that is required for Ca2+ activation and plays a role in current rundown. These experiments identify a region of hBest1 (312–323) that is involved in the gating of hBest1 by Ca2+ and suggest a model in which Ca2+ binding to EF1 activates the channel in a process that requires the acidic domain (293–308) and another regulatory domain (350–390). Many of the ∼100 disease-causing mutations in hBest1 are located in this region that we have implicated in Ca2+ sensing, suggesting that these mutations disrupt hBest1 channel gating by Ca2+.

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