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 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 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 Distinct Immunoglobulin Fc Glycosylation Patterns Are Associated with Disease Nonprogression and Broadly Neutralizing Antibody Responses in Children with HIV Infection

mSphere ◽  
2020 ◽  
Vol 5 (6) ◽  
pp. e00880-20
Author(s):  
M. Muenchhoff ◽  
A. W. Chung ◽  
J. Roider ◽  
Anne-Sophie Dugast ◽  
Simone Richardson ◽  
...  
Keyword(s):  
Potential Role ◽  
Sexual Debut ◽  
Neutralizing Antibody ◽  
Affinity Maturation ◽  
Hiv Vaccine ◽  
Antibody Responses ◽  
Effector Functions ◽  
Systems Immunology ◽  
Broadly Neutralizing Antibody

ABSTRACTA prophylactic HIV vaccine would ideally induce protective immunity prior to sexual debut. Children develop broadly neutralizing antibody (bnAb) responses faster and at higher frequencies than adults, but little is known about the underlying mechanisms or the potential role of Fc-mediated effector functions in disease progression. We therefore performed systems immunology, with immunoglobulin profiling, on HIV-infected children with progressive and nonprogressive disease. Pediatric nonprogressors (PNPs) showed distinct immunoglobulin profiles with an increased ability to elicit potent Fc-mediated natural killer (NK)-cell effector functions. In contrast to previous reports in adults, both groups of children showed high levels of gp120-specific IgG Fc glycan sialylation compared to bulk IgG. Importantly, higher levels of Fc glycan sialylation were associated with increased bnAb breadth, providing the first evidence that Fc sialylation may drive affinity maturation of HIV-specific antibodies in children, a mechanism that could be exploited for vaccination strategies.IMPORTANCE To protect future generations against HIV, a vaccine will need to induce immunity by the time of sexual debut and hence requires immunization during childhood. Current strategies for a prophylactic HIV vaccine include the induction of a broadly neutralizing antibody response and the recruitment of potent effector functions of immune cells via the constant antibody Fc region. In this study, we show that nonprogressing HIV-infected children mounted antibody responses against HIV that were able to mediate potent Fc effector functions, which may contribute to the control of HIV replication. Children who had specific glycan structures on the Fc portion of antibodies against HIV were able to neutralize a broader range of HIV variants, providing evidence of a potential role of Fc glycovariation in the development of bnAbs against HIV. These findings complement our knowledge of the distinct immune landscape in early life that could be exploited in the development of vaccine strategies.

scholarly journals Contrasting Adult and Infant Immune Responses to HIV Infection and Vaccination

2015 ◽  
Vol 23 (2) ◽  
pp. 84-94 ◽  
Author(s):  
David R. Martinez ◽  
Sallie R. Permar ◽  
Genevieve G. Fouda
Keyword(s):  
Immune Responses ◽  
Hiv Infection ◽  
Vaccine Efficacy ◽  
Neutralizing Antibody ◽  
Hiv Vaccine ◽  
Antibody Responses ◽  
Hiv Vaccines ◽  
Vaccine Candidates ◽  
Protective Antibodies ◽  
Pediatric Populations

ABSTRACTExtensive studies have demonstrated that infant immune responses are distinct from those of adults. Despite these differences, infant immunization can elicit protective immune responses at levels comparable to or, in some cases, higher than adult immune responses to many vaccines. To date, only a few HIV vaccine candidates have been tested in infant populations, and none of them evaluated vaccine efficacy. Recent exciting studies showing that HIV-infected infants can develop broad neutralizing antibody responses and that some HIV vaccine regimens can elicit high levels of potentially protective antibodies in infants provide support for the development and testing of HIV vaccines in pediatric populations. In this review, we discuss the differences in adult and infant immune responses in the setting of HIV infection and vaccination.

DNA KNOT FORMATION IN AQUEOUS SOLUTIONS

1994 ◽  
Vol 03 (03) ◽  
pp. 287-298 ◽  
Author(s):  
STANLEY Y. SHAW ◽  
JAMES C. WANG
Keyword(s):  
Aqueous Solutions ◽  
Experimental Test ◽  
Attractive Potential ◽  
Sodium Ions ◽  
Magnesium Ions ◽  
Close Apposition ◽  
Closed Chain ◽  
Solvent Properties

The knotting probability of a closed chain has been calculated as a function of chain dimensions and solvent properties in a number of studies. We have measured the probability of DNA knot formation upon random cyclization of linear DNA in vitro to provide an experimental test of the various theoretical treatments of the problem; parameters of these models, such as the effective chain diameter of DNA, were calculated in different concentrations of counterions. Our results in the presence of sodium ions agree well with theoretical treatments of DNA as a polyelectrolyte; knotting data in the presence of divalent magnesium ions indicate that moderate concentrations of magnesium ions can induce an attractive potential between DNA segments, resulting in negative values of the calculated effective DNA helix diameter. We discuss structures in which the divalent magnesium counterion facilitates the close apposition of two DNA segments, and review the effect of chemical- and protein-mediated crosslinks between DNA segments on DNA knot formation. Finally, we consider DNA knot formation in vivo.

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.

scholarly journals Anti-DKK1 mAb (BHQ880) as a potential therapeutic agent for multiple myeloma

Blood ◽  
2009 ◽  
Vol 114 (2) ◽  
pp. 371-379 ◽  
Author(s):  
Mariateresa Fulciniti ◽  
Pierfrancesco Tassone ◽  
Teru Hideshima ◽  
Sonia Vallet ◽  
Puru Nanjappa ◽  
...  
Keyword(s):  
Multiple Myeloma ◽  
Cell Growth ◽  
Murine Model ◽  
Severe Combined Immunodeficiency ◽  
Neutralizing Antibody ◽  
Nuclear Factor Κb ◽  
Bone Lesions ◽  
Wnt Inhibitor

Abstract Decreased activity of osteoblasts (OBs) contributes to osteolytic lesions in multiple myeloma (MM). The production of the soluble Wnt inhibitor Dickkopf-1 (DKK1) by MM cells inhibits OB activity, and its serum level correlates with focal bone lesions in MM. Therefore, we have evaluated bone anabolic effects of a DKK1 neutralizing antibody (BHQ880) in MM. In vitro BHQ880 increased OB differentiation, neutralized the negative effect of MM cells on osteoblastogenesis, and reduced IL-6 secretion. In a severe combined immunodeficiency (SCID)–hu murine model of human MM, BHQ880 treatment led to a significant increase in OB number, serum human osteocalcin level, and trabecular bone. Although BHQ880 had no direct effect on MM cell growth, it significantly inhibited growth of MM cells in the presence of bone marrow stromal cells (BMSCs) in vitro. This effect was associated with inhibition of BMSC/MM cell adhesion and production of IL-6. In addition, BHQ880 up-regulated β-catenin level while down-regulating nuclear factor-κB (NF-κB) activity in BMSC. Interestingly, we also observed in vivo inhibition of MM cell growth by BHQ880 treatment in the SCID-hu murine model. These results confirm DKK1 as an important therapeutic target in myeloma and provide the rationale for clinical evaluation of BHQ880 to improve bone disease and to inhibit MM growth.

scholarly journals In vivo and in vitro effects of a novel anti-Dkk1 neutralizing antibody in multiple myeloma

Bone ◽  
2013 ◽  
Vol 53 (2) ◽  
pp. 487-496 ◽  
Author(s):  
Samantha Pozzi ◽  
Mariateresa Fulciniti ◽  
Hua Yan ◽  
Sonia Vallet ◽  
Homare Eda ◽  
...  
Keyword(s):  
Multiple Myeloma ◽  
Neutralizing Antibody ◽  
In Vitro Effects
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