Publications by authors named "Goran Bajic"
Unlabelled: SARS-CoV-2 mRNA vaccines induce robust and persistent germinal centre (GC) B cell responses in humans. It remains unclear how the continuous evolution of the virus impacts the breadth of the induced GC B cell response. Using ultrasound-guided fine needle aspiration, we examined draining lymph nodes of nine healthy adults following bivalent booster immunization.
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- Recent research indicates that both neutralizing and non-neutralizing antibodies can help protect against severe COVID-19, even when non-neutralizing antibodies don’t directly neutralize the virus.* -
- Non-neutralizing antibodies may recruit immune cells to help clear infected cells and often bind to virus parts that are conserved across different variants.* -
- The study analyzed 42 human monoclonal antibodies from vaccinated individuals, finding that some non-neutralizing antibodies can provide protection in animal models, highlighting their potential role in immunity.*
Article Synopsis
- Researchers isolated various monoclonal antibodies (mAbs) from human B cells that target the hemagglutinin (HA) protein of influenza, focusing on both H1 and H3 subtypes.
- The study improved the effectiveness of H1 mAbs against contemporary strains and identified potential viral escape routes using deep mutational scanning.
- For H3 mAbs, advanced imaging techniques mapped specific epitopes, showing how these antibodies might guide the development of next-generation vaccines that can provide broader protection against influenza.
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- The study explores how vaccines specifically designed for the Omicron XBB.1.5 variant can generate effective B-cell responses, focusing on the antibody responses in individuals who received a monovalent vaccine.
- Researchers analyzed immune responses from 603 plasmablasts, expressing 100 human monoclonal antibodies to assess their effectiveness against various SARS-CoV-2 variants.
- Two specific monoclonal antibodies, M2 and M39, were identified; M2 targeted only XBB.1.5 while M39 could neutralize both XBB.1.5 and JN.1, highlighting the functional potential of variant-specific vaccines.
Article Synopsis
- Therapeutic monoclonal antibodies (mAbs), specifically bamlanivimab targeting the SARS-CoV-2 spike protein, have been shown to alter the memory B cell (MBC) responses in individuals already infected with the virus.
- The treatment skewed MBCs to favor non-receptor binding domain (RBD) epitopes, resulting in a weaker affinity for RBD memory B cells compared to those who received a placebo.
- Even after mRNA COVID-19 vaccination, these changes persisted, indicating that mAb treatment can have lasting effects on immune memory and how the immune system recognizes specific viral epitopes.
Article Synopsis
- - Recent studies reveal that while neutralizing antibodies are important for protection against SARS-CoV-2, binding antibodies without strong neutralizing activity can still help prevent disease progression by potentially recruiting immune cells to clear infected cells.
- - Researchers characterized 42 human monoclonal antibodies (mAbs) from vaccinated individuals, finding that many lacked neutralizing activity but still provided protection in animal models against severe infections.
- - The study's findings support the real-world observation that non-neutralizing antibodies targeting specific regions of the virus can offer protection, emphasizing the importance of both types of antibodies in the immune response to SARS-CoV-2.
Article Synopsis
- The COVID-19 pandemic continues to be a major public health issue, emphasizing the need for effective therapeutics as new SARS-CoV-2 variants arise.
- Neutralizing monoclonal antibodies are an important treatment option, functioning best when they can adapt to recognize and target these variants.
- The research involved analyzing an antibody's effectiveness against various SARS-CoV-2 strains using advanced techniques like cryo-EM, which can help predict how well these therapies will work in the future and guide the development of new treatments and vaccines.
Article Synopsis
- Seasonal influenza viruses infect around 1 billion people globally each year, leading to millions of severe cases and hundreds of thousands of deaths, emphasizing the need for better vaccines.
- Current vaccines focus on the hemagglutinin (HA) protein but have mixed effectiveness against viral variants, highlighting the importance of improving immune responses through innovative vaccine designs like chimeric and mosaic HAs.
- A new bioprocess was developed to create inactivated split vaccines using chimeric and mosaic HAs, successfully maintaining the active viral components and minimizing harmful residues, paving the way for future research and clinical trials on influenza vaccines.
Article Synopsis
- The COVID-19 pandemic, caused by SARS-CoV-2, has resulted in over 760 million infections and 6.8 million deaths globally, prompting the need for effective treatments.
- Researchers developed human neutralizing monoclonal antibodies (mAbs) targeting the Spike protein of SARS-CoV-2, with one mAb, FG-10A3, effectively inhibiting all variants tested, including the Omicron variants.
- The study also detailed the binding characteristics of FG-10A3, identifying key mutations that may affect the efficacy of these antibodies against emerging variants, highlighting the importance of ongoing therapeutic development.
Article Synopsis
- Despite existing vaccines, influenza continues to cause significant illness and death globally due to the virus's ability to mutate and evade immune responses.
- Current vaccines focus on the less stable head domain of the hemagglutinin (HA) protein, while targeting the more conserved stalk domain could provide better protection, though traditional vaccines generate low levels of antistalk antibodies.
- Research shows that using nanoparticles to present HA in an inverted orientation significantly increases antistalk antibody production and broadens the immune response, leading to better outcomes in mice, suggesting a new approach for developing effective vaccines against influenza and other potential pandemics.
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- The study examines how the first encounter with the influenza virus influences future immune responses, particularly focusing on "immune imprinting" through vaccinations in infants.
- Two infants were monitored for their antibody responses after receiving the quadrivalent inactivated influenza vaccine (IIV4) and experiencing an influenza B virus infection, highlighting differences in B cell specificity between them.
- The research found that the immune profiles of the infants evolved to resemble those of adults after vaccination, showcasing the complexities of immune memory and how it affects responses to changing influenza virus variants.
Article Synopsis
- Immunization and microbial infections create long-term B cell memory both systemically and locally, with local memory contributing to faster responses during re-exposure.
- Local boosts with the same antigen are more effective in recruiting B cells for recall germinal centers than boosts given further away, showing that locality matters for their effectiveness.
- Local boosts lead to B cells with more advanced mutations and stronger responses, making them vital for targeted vaccination strategies against changing viruses.
Article Synopsis
- The study investigates how antibodies from infection or vaccination interact with viruses, specifically focusing on a monoclonal antibody (mAb) that was triggered by an mRNA vaccine against SARS-CoV-2.
- Researchers used electron cryomicroscopy to analyze the mAb's structure in conjunction with the virus's spike glycoprotein, revealing a new neutralizing site on the protein's N-terminal domain (NTD).
- The antibody, labeled PVI.V6-14, is noted for being unmutated and able to bind effectively to various viral variants, showing its potential to inform vaccine design by targeting a stable, conserved epitope.
Article Synopsis
- - SARS-CoV-2 has evolved into various "variants of concern" (VOCs), with specific changes to its spike protein that affect how the virus spreads and causes disease.
- - The spike protein substitution S:655Y, found in the gamma and omicron variants, enhances the virus's ability to replicate and be transmitted more efficiently compared to the original S:655H.
- - Overall, the study shows that mutations in the spike protein of these variants are associated with increased processing and transmission of the virus among humans.
Article Synopsis
- The Omicron variant of SARS-CoV-2 was first discovered in November 2021 in South Africa and has quickly spread worldwide, outpacing the Delta variant in many areas.
- Omicron contains a large number of mutations in its spike protein, leading to increased transmissibility and reduced vaccine effectiveness, especially in convalescent or double-vaccinated individuals.
- Research shows that while immune responses (like virus-neutralizing activity) are lower against Omicron compared to the original virus, those who have had multiple exposures through vaccination and infection mostly retain some level of immunity.
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- The study investigates the adaptive immune response by examining the naive B cell repertoire's ability to recognize and target SARS-CoV-2, focusing on the receptor binding domain (RBD).
- Researchers isolated naive B cells from eight human donors and used single-cell B cell receptor sequencing to analyze their diversity and specificity against various SARS-CoV-2 variants and related coronaviruses.
- Structural analysis revealed that certain naive antibodies could effectively signal B cell activation and, after optimization, showed strong neutralization capabilities against SARS-CoV-2, potentially aiding in the development of broad coronavirus vaccines.
Article Synopsis
- * Analysis of monoclonal antibodies from mRNA vaccine-elicited B cells revealed that while most neutralized the original WA1/2020 D614G strain, their effectiveness varied against variants like B.1.617.2 and B.1.351.
- * The monoclonal antibody 2C08 was particularly effective, reducing lung viral loads in hamsters and was found in a significant portion of individuals vaccinated or infected with SARS-CoV-2, indicating potential for wider application in combating variants.
Article Synopsis
- - Despite regular vaccinations, influenza still causes serious health problems and deaths worldwide, indicating the need for a more effective vaccine that stimulates immune responses like antibody-dependent cellular cytotoxicity (ADCC).
- - Researchers developed a protective vaccine, ΔgD-2, against herpes simplex virus (HSV) that also produces a strong antibody response; they then integrated the hemagglutinin (HA) gene from an H1N1 strain into this vaccine to target influenza.
- - The new ΔgD-2::HA vaccine was shown to effectively protect mice from influenza, even with prior HSV exposure, while also maintaining protection against HSV infections and working in mice lacking certain immune receptors.
Article Synopsis
- * Researchers analyzed memory B cell receptors from 19 recovered COVID-19 patients and identified seven main groups of antibodies that target specific regions of the virus.
- * Although some SARS-CoV-2 variants have evaded neutralization by many potent antibodies, certain antibodies still bind effectively, indicating that various components of the immune response contribute to long-term protection against evolving strains.
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- This study analyzed antibody responses from individuals who received a SARS-CoV-2 spike mRNA vaccine, comparing them to those from natural infections.
- The vaccine-induced antibodies were abundant, with a higher binding-to-neutralizing antibody ratio than seen after natural infection, although most did not neutralize the virus.
- The findings highlighted that while neutralizing activity was present in some monoclonal antibodies (mAbs) targeting the NTD, it was lost against variants like E484K, indicating that vaccine-induced RBD-binding antibodies could still offer protection against certain viral mutations.
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- Complement receptor 3 (CR3) is critical for immune response, particularly in the phagocytosis of cells tagged by a complement fragment called iC3b.
- Researchers found that the CR3-iC3b interaction has a high affinity, with iC3b undergoing a structural change when binding to CR3, which enhances this process.
- The findings suggest that targeting this interaction could lead to new treatments for inflammatory and neurodegenerative diseases while preserving the receptor’s role in recognizing other targets.
Article Synopsis
- The emergence of new SARS-CoV-2 variants that spread quickly poses a significant public health risk, especially since some are resistant to vaccines and natural infection antibodies.
- Researchers discovered a human monoclonal antibody, known as 2C08, that is highly effective in neutralizing various SARS-CoV-2 variants and can reduce illness in tested hamsters.
- The presence of similar B cell clones that produce 2C08-like antibodies in vaccinated individuals suggests that effective responses to these variants can be stimulated by existing COVID-19 vaccines.
Article Synopsis
- The study analyzed the immune response of individuals vaccinated with the SARS-CoV-2 spike mRNA vaccine, examining both polyclonal antibodies and monoclonal antibodies (mAbs) from plasmablasts.
- Results showed that vaccinated individuals produced strong polyclonal antibody responses that could equal or surpass those from natural infections, with a higher ratio of binding to neutralizing antibodies in vaccinated individuals.
- Importantly, many vaccine-induced mAbs lacked neutralizing activity, with findings indicating effective neutralization potential primarily coming from certain RBD-binding mAbs, particularly against variants with specific mutations like E484K.
Article Synopsis
- - Memory B cells can produce antibodies that protect against repeated infections of SARS-CoV-2, but their effectiveness against variant strains is not fully understood.
- - Researchers analyzed monoclonal antibodies from 19 recovered COVID-19 patients and identified 7 main groups that target similar parts of the virus's spike protein.
- - The study reveals how different antibodies interact with various SARS-CoV-2 strains and highlights the significance of diverse immune recognition in combating new variants.
Article Synopsis
- * Researchers isolated naive B cells from seronegative donors and analyzed their gene usage, finding a diverse range that could help in targeting the virus effectively.
- * They discovered that both naive and engineered antibodies could neutralize SARS-CoV-2 and suggest that understanding these B cells could aid in creating universal vaccines against coronaviruses.