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Proceedings of the National Academy of... May 2024Efforts to develop an HIV-1 vaccine include those focusing on conserved structural elements as the target of broadly neutralizing monoclonal antibodies. MAb D5 binds to...
Efforts to develop an HIV-1 vaccine include those focusing on conserved structural elements as the target of broadly neutralizing monoclonal antibodies. MAb D5 binds to a highly conserved hydrophobic pocket on the gp41 N-heptad repeat (NHR) coiled coil and neutralizes through prevention of viral fusion and entry. Assessment of 17-mer and 36-mer NHR peptides presenting the D5 epitope in rodent immunogenicity studies showed that the longer peptide elicited higher titers of neutralizing antibodies, suggesting that neutralizing epitopes outside of the D5 pocket may exist. Although the magnitude and breadth of neutralization elicited by NHR-targeting antigens are lower than that observed for antibodies directed to other epitopes on the envelope glycoprotein complex, it has been shown that NHR-directed antibodies are potentiated in TZM-bl cells containing the FcγRI receptor. Herein, we report the design and evaluation of covalently stabilized trimeric 51-mer peptides encompassing the complete gp41 NHR. We demonstrate that these peptide trimers function as effective antiviral entry inhibitors and retain the ability to present the D5 epitope. We further demonstrate in rodent and nonhuman primate immunization studies that our 51-mer constructs elicit a broader repertoire of neutralizing antibody and improved cross-clade neutralization of primary HIV-1 isolates relative to 17-mer and 36-mer NHR peptides in A3R5 and FcγR1-enhanced TZM-bl assays. These results demonstrate that sensitive neutralization assays can be used for structural enhancement of moderately potent neutralizing epitopes. Finally, we present expanded trimeric peptide designs which include unique low-molecular-weight scaffolds that provide versatility in our immunogen presentation strategy.
Topics: HIV Envelope Protein gp41; HIV-1; Animals; AIDS Vaccines; Antibodies, Neutralizing; HIV Antibodies; Humans; Mice; Epitopes; HIV Infections; Peptides; Female; Antibodies, Monoclonal
PubMed: 38768344
DOI: 10.1073/pnas.2317230121 -
NPJ Vaccines May 2024
Author Correction: Modulating the immune response to SARS-CoV-2 by different nanocarriers delivering an mRNA expressing trimeric RBD of the spike protein: COVARNA Consortium.
PubMed: 38762608
DOI: 10.1038/s41541-024-00882-4 -
Cell Jun 2024A critical roadblock to HIV vaccine development is the inability to induce B cell lineages of broadly neutralizing antibodies (bnAbs) in humans. In people living with...
A critical roadblock to HIV vaccine development is the inability to induce B cell lineages of broadly neutralizing antibodies (bnAbs) in humans. In people living with HIV-1, bnAbs take years to develop. The HVTN 133 clinical trial studied a peptide/liposome immunogen targeting B cell lineages of HIV-1 envelope (Env) membrane-proximal external region (MPER) bnAbs (NCT03934541). Here, we report MPER peptide-liposome induction of polyclonal HIV-1 B cell lineages of mature bnAbs and their precursors, the most potent of which neutralized 15% of global tier 2 HIV-1 strains and 35% of clade B strains with lineage initiation after the second immunization. Neutralization was enhanced by vaccine selection of improbable mutations that increased antibody binding to gp41 and lipids. This study demonstrates proof of concept for rapid vaccine induction of human B cell lineages with heterologous neutralizing activity and selection of antibody improbable mutations and outlines a path for successful HIV-1 vaccine development.
Topics: Humans; AIDS Vaccines; HIV-1; Antibodies, Neutralizing; B-Lymphocytes; HIV Antibodies; HIV Infections; Cell Lineage; Liposomes; env Gene Products, Human Immunodeficiency Virus; Mutation; HIV Envelope Protein gp41
PubMed: 38761800
DOI: 10.1016/j.cell.2024.04.033 -
Journal of the International AIDS... May 2024
Topics: Humans; HIV Infections; HIV Antibodies; Antibodies, Neutralizing; Broadly Neutralizing Antibodies; AIDS Vaccines; HIV-1
PubMed: 38757844
DOI: 10.1002/jia2.26257 -
Zoological Research May 2024Hepatocellular carcinoma (HCC), a prevalent solid carcinoma of significant concern, is an aggressive and often fatal disease with increasing global incidence rates and...
Hepatocellular carcinoma (HCC), a prevalent solid carcinoma of significant concern, is an aggressive and often fatal disease with increasing global incidence rates and poor therapeutic outcomes. The etiology and pathological progression of non-alcoholic steatohepatitis (NASH)-related HCC is multifactorial and multistage. However, no single animal model can accurately mimic the full NASH-related HCC pathological progression, posing considerable challenges to transition and mechanistic studies. Herein, a novel conditional inducible wild-type human overexpressed mouse model (HRAS-HCC) was established, demonstrating 100% morbidity and mortality within approximately one month under normal dietary and lifestyle conditions. Advanced symptoms of HCC such as ascites, thrombus, internal hemorrhage, jaundice, and lung metastasis were successfully replicated in mice. In-depth pathological features of NASH- related HCC were demonstrated by pathological staining, biochemical analyses, and typical marker gene detections. Combined murine anti-PD-1 and sorafenib treatment effectively prolonged mouse survival, further confirming the accuracy and reliability of the model. Based on protein-protein interaction (PPI) network and RNA sequencing analyses, we speculated that overexpression of HRAS may initiate the THBS1-COL4A3 axis to induce NASH with severe fibrosis, with subsequent progression to HCC. Collectively, our study successfully duplicated natural sequential progression in a single murine model over a very short period, providing an accurate and reliable preclinical tool for therapeutic evaluations targeting the NASH to HCC continuum.
Topics: Animals; Non-alcoholic Fatty Liver Disease; Carcinoma, Hepatocellular; Mice; Liver Neoplasms; Proto-Oncogene Proteins p21(ras); Disease Models, Animal; Mice, Transgenic; Mice, Inbred C57BL; Humans
PubMed: 38757223
DOI: 10.24272/j.issn.2095-8137.2024.002 -
Swiss Medical Weekly May 2024With the emergence of newer SARS-CoV-2 variants and their substantial effects on the levels and duration of protection against infection, an understanding of these... (Review)
Review
INTRODUCTION
With the emergence of newer SARS-CoV-2 variants and their substantial effects on the levels and duration of protection against infection, an understanding of these characteristics of the protection conferred by humoral and cellular immunity can aid in the proper development and implementation of vaccine and safety guidelines.
METHODS
We conducted a rapid literature review and searched five electronic databases weekly from 1 November 2021 to 30 September 2022. Studies that assessed the humoral or cellular immunity conferred by infection, vaccination or a hybrid (combination of both) in adults and risk groups (immunocompromised and older populations) were identified. Studies were eligible when they reported data on immunological assays of COVID-19 (related to vaccination and/or infection) or the effectiveness of protection (related to the effectiveness of vaccination and/or infection).
RESULTS
We screened 5103 studies and included 205 studies, of which 70 provided data on the duration of protection against SARS-CoV-2 infection. The duration of protection of adaptive immunity was greatly impacted by Omicron and its subvariants: levels of protection were low by 3-6 months from exposure to infection/vaccination. Although more durable, cellular immunity also showed signs of waning by 6 months. First and second mRNA vaccine booster doses increased the levels of protection against infection and severe disease from Omicron and its subvariants but continued to demonstrate a high degree of waning over time.
CONCLUSION
All humoral immunities (infection-acquired, vaccine-acquired and hybrid) waned by 3-6 months. Cellular immunity was more durable but showed signs of waning by 6 months. Hybrid immunity had the highest magnitude of protection against SARS-CoV-2 infection. Boosting may be recommended as early as 3-4 months after the last dose, especially in risk groups.
Topics: Humans; COVID-19; SARS-CoV-2; COVID-19 Vaccines; Immunity, Cellular; Immunity, Humoral; Immunization, Secondary; Vaccination
PubMed: 38749028
DOI: 10.57187/s.3732 -
BMC Medical Ethics May 2024A morally sound framework for benefit-sharing is crucial to minimize research exploitation for research conducted in developing countries. However, in practice, it...
BACKGROUND
A morally sound framework for benefit-sharing is crucial to minimize research exploitation for research conducted in developing countries. However, in practice, it remains uncertain which stakeholders should be involved in the decision-making process regarding benefit-sharing and what the implications might be. Therefore the study aimed to empirically propose a framework for benefit-sharing negotiations in research by taking HIV vaccine trials as a case.
METHODS
The study was conducted in Tanzania using a case study design and qualitative approaches. Data were collected using in-depth interviews (IDI) and focus group discussions (FGD). A total of 37 study participants were selected purposively comprising institutional review board (IRB) members, researchers, community advisory board (CAB) members, a policymaker, and HIV/AIDS advocates. Deductive and inductive thematic analysis approaches were deployed to analyze collected data with the aid of MAXQDA version 20.4.0 software.
RESULTS
The findings indicate a triangular relationship between the research community, researched community and intermediaries. However, the relationship ought to take into consideration the timing of negotiations, the level of understanding between parties and the phase of the clinical trial. The proposed framework operationalize partnership interactions in community-based participatory research.
CONCLUSION
In the context of this study, the suggested framework incorporates the research community, the community being researched, and intermediary parties. The framework would guarantee well-informed and inclusive decision-making regarding benefit-sharing in HIV vaccine trials and other health-related research conducted in resource-limited settings.
Topics: Humans; AIDS Vaccines; Negotiating; HIV Infections; Tanzania; Community-Based Participatory Research; Qualitative Research; Clinical Trials as Topic; Focus Groups; Male; Female; Decision Making; Research Personnel; Stakeholder Participation; Developing Countries; Adult
PubMed: 38745276
DOI: 10.1186/s12910-024-01058-4 -
Nature Communications May 2024The rapid global distribution of COVID-19 vaccines, with over a billion doses administered, has been unprecedented. However, in comparison to most identified clinical...
The rapid global distribution of COVID-19 vaccines, with over a billion doses administered, has been unprecedented. However, in comparison to most identified clinical determinants, the implications of individual genetic factors on antibody responses post-COVID-19 vaccination for breakthrough outcomes remain elusive. Here, we conducted a population-based study including 357,806 vaccinated participants with high-resolution HLA genotyping data, and a subset of 175,000 with antibody serology test results. We confirmed prior findings that single nucleotide polymorphisms associated with antibody response are predominantly located in the Major Histocompatibility Complex region, with the expansive HLA-DQB1*06 gene alleles linked to improved antibody responses. However, our results did not support the claim that this mutation alone can significantly reduce COVID-19 risk in the general population. In addition, we discovered and validated six HLA alleles (A*03:01, C*16:01, DQA1*01:02, DQA1*01:01, DRB3*01:01, and DPB1*10:01) that independently influence antibody responses and demonstrated a combined effect across HLA genes on the risk of breakthrough COVID-19 outcomes. Lastly, we estimated that COVID-19 vaccine-induced antibody positivity provides approximately 20% protection against infection and 50% protection against severity. These findings have immediate implications for functional studies on HLA molecules and can inform future personalised vaccination strategies.
Topics: Humans; COVID-19 Vaccines; COVID-19; SARS-CoV-2; Antibodies, Viral; Alleles; HLA Antigens; Polymorphism, Single Nucleotide; Antibody Formation; Male; Female; Genotype; Vaccination; Middle Aged; Adult; Genetic Variation; HLA-DQ beta-Chains; Breakthrough Infections
PubMed: 38740772
DOI: 10.1038/s41467-024-48339-5 -
Chemical Engineering Journal (Lausanne,... May 2023Immune stimulating complexes (ISCOMs) are safe and effective saponin-based adjuvants formed by the self-assembly of saponin, cholesterol, and phospholipids in water to...
Immune stimulating complexes (ISCOMs) are safe and effective saponin-based adjuvants formed by the self-assembly of saponin, cholesterol, and phospholipids in water to form cage-like 30-40 nm diameter particles. Inclusion of the Toll-like receptor 4 agonist monophosphoryl lipid A (MPLA) in ISCOM particles yields a promising next-generation adjuvant termed Saponin-MPLA NanoParticles (SMNP). In this work, we detail protocols to produce ISCOMs or SMNP via a tangential flow filtration (TFF) process suitable for scalable synthesis and Good Manufacturing Practice (GMP) production of clinical-grade adjuvants. SMNP or ISCOM components were solubilized in micelles of the surfactant MEGA-10, then diluted below the critical micelle concentration (CMC) of the surfactant to drive ISCOM self-assembly. Assembly of ISCOM/SMNP particles using the purified saponin QS-21 used in clinical-grade saponin adjuvants was found to require controlled stepwise dilution of the initial micellar solution, to prevent formation of undesirable kinetically-trapped aggregate species. An optimized protocol gave yields of ~77% based on the initial feed of QS-21 and the final SMNP particle composition mirrored the feed ratios of the components. Further, samples were highly homogeneous with comparable quality to that of material prepared at lab scale by dialysis and purified via size-exclusion chromatography. This protocol may be useful for clinical preparation of ISCOM-based vaccine adjuvants and therapeutics.
PubMed: 38737525
DOI: 10.1016/j.cej.2023.142664 -
Veterinary Medicine (Auckland, N.Z.) 2024Newcastle disease (ND) is a highly infectious poultry disease that causes major economic losses worldwide. The disease is caused by Newcastle Disease Virus (NDV) and...
BACKGROUND
Newcastle disease (ND) is a highly infectious poultry disease that causes major economic losses worldwide. The disease is caused by Newcastle Disease Virus (NDV) and early detection and identification of the viral strain is essential. Having knowledge of the NDV strain genotype that circulates in some regions would help in designing an effective vaccine to control the disease. In this regard, there is little information on NDV strain in chickens in mid Rift Valley and the central part of Ethiopia. Therefore, the purpose of this study was to detect and characterize NDV strain genotype from chickens in mid-Rift Valley and the central part of Ethiopia and test whether this NDV strain genotype matches the vaccine strain currently used in the study area.
METHODS
A total of 98 samples: 78 (tracheal and cloacal) swabs from chicken pools of five and 20 tissue samples were collected. To detect NDV strain, conserved region of the virus Matrix (M) gene was amplified by qRT-PCR. To characterize NDV strain genotypes, M-gene positive samples were specifically re-amplified by conventional PCR targeting the Fusion (F) gene region and sequenced by Sanger method.
RESULTS
13.26% of tested samples were positive for NDV strain in the study area with statistically significant difference (P<0.05) among the study sites. Further characterization of the F genes from NDV strain isolates by phylogenetic analysis indicated that one field isolate clustered with genotype VII whereas three of the isolates clustered to genotype I, II, and III. The isolate of the current NDV strain vaccine in use in the study area clustered with genotype II.
CONCLUSION
The current study indicates the existence of different NDV strain genotype from that of the vaccine strain currently used. Even though large-scale characterization of several isolates is required at national level, the current study laid baseline information for the existence of variations between field NDV strain genotype and vaccine strain currently used against ND in the country.
PubMed: 38737422
DOI: 10.2147/VMRR.S442787