Tag: Weiner

Highlighting Vaccine Research at The Wistar Institute Through the Penn-CHOP-Wistar Vaccine Symposium

Written by The Wistar Institute on March 23, 2022. Posted in Featured News.

From HIV to COVID-19, Wistar scientists are at the forefront of vaccine development. Read our recap of the recent Vaccine Symposium and the impactful research in progress at the Institute.

This past Monday, The Wistar Institute, University of Pennsylvania Perelman School of Medicine, and Children’s Hospital of Philadelphia held the Penn-CHOP-Wistar Vaccine Symposium. Hosted both in-person at the Smilow Center for Translational Research and online, the all-day event covered the history of vaccines and current vaccine research from the three sponsoring institutions.

Keynote speaker and Wistar professor emeritus Stanley Plotkin, M.D., is a prominent researcher who is known for the development of the rubella vaccine while he was a virologist at The Wistar Institute. Furthermore, his years of work helping in vaccine efforts for rabies, rotavirus, and cytomegalovirus have stimulated much innovation in the biomedical research community.
After giving a brief history of vaccines, Plotkin proclaimed “Vaccinology has taken off. … We are now in a golden age of vaccinology.”

The Symposium’s research presentations opened with Wistar’s Daniel Kulp, Ph.D., Associate Professor in the Vaccine & Immunotherapy Center, and his work on a novel COVID-19 nanoparticle vaccine. Amelia Escolano, Ph.D., Assistant Professor in the Vaccine & Immunotherapy Center, also spoke about her efforts investigating immunization strategies for HIV. Wistar’s Vaccine & Immunotherapy Center Director David B. Weiner, Ph.D., gave a summary of his research into the genetic delivery of vaccines, calling the innovation of vaccinology in Pennsylvania among these institutions “extraordinary”.

The current global pandemic has reinforced the need for scientific solutions and a deeper understanding of human diseases. It is the studies and ideas from research centers like The Wistar Institute and its colleagues that propel forward biomedicine. As keynote speaker Plotkin stated, “Pandemics have occurred throughout the history of humankind and will continue to do so in the future. Infectious diseases of humans will continue to happen. Therefore, we must act against them.”

Dr. Daniel Kulp works with a fellow scientist in a Wistar lab

Wistar Study Opens the Door to Faster, Cheaper HIV Vaccine Research

Written by The Wistar Institute on February 4, 2022. Posted in Featured News.

For the first time, scientists have developed an DNA-encoded immunogen that produces Tier-2 antibodies—the kind that matter for combatting HIV

Nearly four decades after its discovery, HIV has killed 36.3 million people, with no vaccine in sight. Part of the reason vaccine development has been slow is because trialing candidate vaccines that produce Tier-2 neutralizing antibodies—the kind that matter for combatting HIV—has always required long and expensive experiments in large animal models like rabbits and macaque monkeys.

An effective HIV vaccine needs to produce antibodies that protect against the most common variants of HIV, which are categorized as “Tier 2” viruses based on how quickly and easily they can be neutralized by antibodies (more quickly/easily than Tier 3, less than Tier 1).

A new study by scientists at The Wistar Institute shows a quicker, less expensive path to developing this tier of antibodies. For the first time, these scientists have demonstrated a method for eliciting Tier-2 neutralizing antibodies in mice.

“Mice are the workhorse of vaccine design and development because you can iterate lots of concepts in that model due to cost and time constraints,” said Daniel Kulp, Ph.D., associate professor in the Vaccine & Immunotherapy Center at The Wistar Institute.

The scientists developed an immunogen—a substance that causes an immune response—called a native-like trimer, which they administered to mice. Importantly, they encoded the immunogen in DNA, which turns the host bodies (in this case the mice) into “antigen factories” instead of requiring what would otherwise be a complex and expensive vaccine manufacturing process.

They then compared the results from the mice who received the DNA-encoded native-like trimer to results from mice who received a standard protein immunization. Only those mice that received the DNA-encoded native-like trimer developed Tier-2 neutralizing antibodies.

From there, they were able to isolate and examine the atomic structure of one of the antibodies that their immunogen had produced. “The structure gives us incredible insight into how this antibody is able to neutralize the virus,” said Kulp.

“Our data demonstrates the value of this approach as a tool to create surgically tailored immunity against a difficult pathogen’s vulnerable sites, in this case for HIV,” said coauthor David B. Weiner, Ph.D., executive vice president and director of the Vaccine & Immunotherapy Center and the W.W. Smith Charitable Trust Professor in Cancer Research at The Wistar Institute.

Wistar Scientists Move HIV Vaccine Research Forward by Developing an Immunogen that Produces Tier-2 Antibodies—the Kind That Matter for Combatting HIV

Written by The Wistar Institute on February 4, 2022. Posted in Press Releases.

PHILADELPHIA — (Feb. 4, 2022) — Nearly four decades after its discovery, HIV has killed 36.3 million people, with no vaccine in sight. However, a new study by researchers at The Wistar Institute, an international biomedical research leader in cancer, immunology, infectious disease, and vaccine development, takes a promising step in the direction of developing an HIV vaccine.

The findings, published in Nature Communications, demonstrate the promise of using a unique native-like trimer to develop Tier-2 neutralizing antibodies—the kind that matter for combatting HIV—in mice for the first time.

Previously, eliciting these types of antibodies using candidate vaccines required long and expensive experiments in large animal models creating a significant bottleneck on HIV-1 vaccine development. “With our new finding, we have opened the door to rapid, iterative vaccinology in a model that can produce Tier-2 neutralizing antibodies, enabling development of more advanced HIV vaccine concepts,” said Daniel Kulp, Ph.D., associate professor in the Vaccine & Immunotherapy Center at The Wistar Institute and corresponding author on the paper.

The researchers encoded the native-like trimer into DNA for delivery into the mice. This has the practical advantage of turning the host bodies into “antigen factories” instead of requiring what would otherwise be a complex vaccine manufacturing process. The researchers then compared the results from the mice who received the DNA-encoded native-like trimer to results from mice who received a standard protein immunization. Only those mice that received the DNA-encoded native-like trimer developed Tier-2 neutralizing antibodies.

“We were able to generate strong immune responses with both platforms, but the DNA platform uniquely drove this neutralizing response,” said Kulp.

Once they’d verified their immunization regime was producing Tier-2 antibodies, Kulp and his colleagues isolated monoclonal antibodies from the mice and used cryo-electron microscopy to determine the atomic structure of one Tier-2 neutralizing monoclonal antibody. They found that the antibody binds to an epitope (a segment of a protein that sticks out of the antigen, which prompts an immune response) called C3V5. In the gold standard HIV vaccine model (non-human primates), prior research has shown that antibodies binding to C3V5 protect animals from a SHIV infection, which is a close relative of HIV that infects non-human primates.

“The structure gives us incredible insight into how this antibody is able to neutralize the virus,” said Kulp. “For the first time, we can strategize about how to design new vaccines that can generate broadly neutralizing antibody responses to the C3V5 epitope.”

Coauthor David B. Weiner, Ph.D., executive vice president and director of the Vaccine & Immunotherapy Center and the W.W. Smith Charitable Trust Professor in Cancer Research at The Wistar Institute, emphasized the utility of their findings.

“What we’ve done is enable direct in vivo self-assembly of structurally designed immunogens, which are engineered and delivered using nucleic acid technology, inside the vaccinated animal. Our data demonstrating induction of autologous Tier 2 neutralization illustrate the value of this approach as a tool to create surgically tailored immunity against a difficult pathogen’s vulnerable sites, in this case for HIV.”

Co-authors: Ziyang Xu, Susanne Walker, Neethu Chokkalingam, Mansi Purwar, Edgar Tello-Ruiz, Yuanhan Wu, Sonali Majumdar, Kylie M. Konrath, Abhijeet Kulkarni, Nicholas J. Tursi, Faraz I. Zaidi, Emma L. Reuschel, Ishaan Patel, April Obeirne, David B. Weiner, and Daniel W. Kulp from The Wistar Institute; Megan C. Wise, Katherine Schultheis, Lauren Gites, Trevor Smith, Janess Mendoza, Kate E. Broderick, and Laurent Humeau from Inovio Pharmaceuticals; Alan Moore, Jianqiu Du, and Jesper Pallesen from Indiana University.

Work supported by: National Health Institutes (NIH) IPCAVD Grant U19 Al109646-04; W. W. Smith Charitable Trust; and Wistar Monica H.M. Shander Memorial Fellowship.

Publication information: Induction of Tier-2 Neutralizing Antibodies in Mice with a DNA-encoded HIV Envelope Native Like Trimer, Nature Communications, 2022. Online publication.

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The Wistar Institute is an international leader in biomedical research with special expertise in cancer research and vaccine development. Founded in 1892 as the first independent nonprofit biomedical research institute in the United States, Wistar has held the prestigious Cancer Center designation from the National Cancer Institute since 1972. The Institute works actively to ensure that research advances move from the laboratory to the clinic as quickly as possible. wistar.org.

Novel Nanoparticle SARS-CoV-2 Vaccine Combines Immune Focusing and Self-assembling Nanoparticles to Elicit More Potent Protection

Written by The Wistar Institute on February 1, 2022. Posted in Press Releases.

PHILADELPHIA — (Feb. 1, 2022) — The first generation of COVID-19 vaccines have been highly effective, but also have limitations: their efficacy can wane without a booster shot, and they may be less effective against some variants. Now scientists at The Wistar Institute have developed a more targeted vaccine that, in animal studies, shows stronger, broader, and more durable protection in a single, low dose.

The vaccine combines three technologies – immune focusing, self-assembling nanoparticles, and DNA delivery – into a single platform for the first time. In addition to its other advantages, the vaccine could be stored at room temperature, making it potentially easier to transport to remote or developing locations than existing mRNA vaccines, which require specialized cold storage.

“This is among the first next-generation vaccines that will have more advanced features and broader protection,” said Daniel Kulp, Ph.D., associate professor in the Vaccine & Immunotherapy Center at The Wistar Institute and corresponding author of the study.

The paper, “Nucleic acid delivery of immune-focused SARS-CoV-2 nanoparticles drive rapid and potent immunogenicity capable of single-dose protection,” was published in the journal Cell Reports.

Existing vaccines include an unmodifided receptor binding domain of SARS-CoV-2 spike protein. The new vaccine includes a rationally engineered receptor binding domain using computational and structure-based design methodologies. The engineered receptor binding domain blocks ‘immune distracting’ sites and can therefore elicit stronger levels of protective, neutralizing antibodies.

Researchers then used naturally self-assembling proteins to form nanoparticles which display these highly engineered immunogens. By arranging themselves into structures that resemble an actual virus, the nanoparticles are more easily recognized by the immune system and transported to the germinal centers, where they activate B cells which produce protective antibodies.

Using nucleic acid vaccine delivery technology similar to mRNA, the nanoparticle vaccine is encoded in DNA and delivered into cells thereby giving genetic instructions for the body to build the immunogen internally. This is an advance over traditional vaccines that must be manufactured in specialized factories through complex vaccine production processes. In contrast to other vaccines, Dr. Kulp noted that one advantage of the DNA platform is that it doesn’t require refrigeration and it can also be quickly reformulated to target new variants.

In animal models, researchers found that the DNA delivered immune-focused nanoparticle vaccine produced much higher levels of neutralizing antibodies than the vaccine that wasn’t immune-focused.

“A difficulty with current vaccines is that neutralizing antibodies decline over time,” Kulp said. The nanoparticle vaccine produced durable responses after a single immunization out to six months in mice, unlike what we are seeing with current SARS-CoV-2 vaccines in people.

The ultimate test for SARS-CoV-2 vaccine candidates is protection from death in SARS-CoV-2 challenge experiments. The researchers found that in a lethal challenge model 100% of mice who received the immune-focused nanoparticle vaccine were protected from death with a single low dose. Most mice who received the standard, non-immune focused vaccine died within 10 days of challenge.

The vaccine assessment was conducted in both wild-type mice and mice that were genetically engineered to mimic human immune systems, he noted.

Even without being updated, the immune-focused vaccine showed a comparable level of antibody production to Delta, and other variants, Kulp said. That’s partly because of the immune focusing approach itself, he noted; in blocking parts of the receptive binding domain for the purpose of inhibiting non-neutralizing antibodies, it also blocks many of the areas affected by spike protein mutations. Studies on the Omicron variant are underway.

Researchers are seeking funding to begin human trials of the vaccine.

Co-author David B. Weiner, Ph.D., executive vice president, director of the Vaccine & Immunotherapy Center and the W.W. Smith Charitable Trust Professor in Cancer Research, at The Wistar Institute, said the vaccine could provide a needed step forward to improve protection against COVID-19.

“Current vaccine effects on reducing transmission of SARS-CoV-2 variants of concern including Delta and Omicron could be improved for their breadth of protection as well as their immune potency,” Weiner said. “This study demonstrates that using a nucleic acid approach combined with in vivo structural assembly of a glycan immune-focused nanoparticle drives single protection and neutralization against diverse variants of concern in a dose-sparing formulation. Additional studies of this vaccine approach for SARS-CoV-2 appear timely and important.”

Co-authors: Kylie M. Konrath, Kevin Liaw, Yuanhan Wu, Xizhou Zhu, Susanne N. Walker, Ziyang Xu, Neethu Chokkalingam, Nicholas J. Tursi, Mansi Purwar, Emma Reuschel, Drew Frase, Benjamin Fry, and Ami Patel from Wistar; Katherine Schultheis, Igor Maricic, Viviane M. Andrade, Kate E. Broderick, Laurent M.P.F. Humeau, and Trevor R.F. Smith from Inovio Pharmaceuticals; Himanshi Chawla and Max Crispin from the University of Southhampton; Jianqiu Du and Alan Moore from Indiana University; Jared Adolf-Bryfogle and Jesper Pallesen from the Institute for Protein Innovation; Matthew Sullivan from the University of Pennsylvania; and Christel Iffland from Ligand Pharmaceuticals.

Work supported by: Wistar Coronavirus Discovery Fund, CURE/PA Department of Health grant SAP# 4100083104, COVID/PA Department of Human Services grant SAP# 4100089371, NIH/NIAID CIVICs grant 75N93019C00051, Wistar SRA 16-4 / Inovio Pharmaceuticals, Indiana University.

Publication information: Nucleic acid delivery of immune-focused SARS-CoV-2 nanoparticles drive rapid and potent immunogenicity capable of single-dose protection, Cell Reports, 2022.

Latest Wistar Discoveries: Fine-tuning Vaccine Delivery in Preclinical Models to Advance MERS DNA Vaccine Candidate and Discovering New Targets for Cancer Therapy

Written by The Wistar Institute on April 27, 2021. Posted in Featured News.

A team of Wistar scientists led by Dr. David Weiner, Wistar executive vice president, director of the Vaccine & Immunotherapy Center and W.W. Smith Charitable Trust Professor in Cancer Research, and Dr. Ami Patel, Caspar Wistar Fellow, and collaborators have developed a synthetic DNA vaccine candidate for Middle East respiratory syndrome coronavirus (MERS-CoV).

A vaccine candidate based on their research was shown to be safe and tolerable in a recently completed human phase 1 study with a three-dose intramuscular injection regimen and is currently in phase 1/2a trial.

Our scientists continue to expand the preclinical studies of the vaccine in support of its clinical development. They have now tested intradermal delivery using a shortened two-dose immunization schedule in non-human primates (NHP).

“Low-dose delivery and shortened regimes are crucial to rapidly induce protective immunity, particularly during emerging outbreaks, as the current SARS-CoV-2 pandemic has emphasized,” said Weiner.

In a paper published in the journal JCI Insight, he and colleagues reported that low-dose intradermal administration induces potent immunity and protects from virus challenge. The low-dose regimen with intradermal delivery was more impactful in controlling disease and symptoms than the higher dose given intramuscularly.

“Intradermal delivery of synthetic DNA vaccines has significant advantages for rapid clinical development. It can be dose sparing and has higher tolerability in people compared with intramuscular injection,” said Patel.

Their experience developing this MERS vaccine candidate helped the team advance a COVID-19 vaccine through clinical trials in a short time.

Vaccine candidates that are simple to deliver, well tolerated, and can be readily deployed in resource-limited settings will be important to achieve control of infection for coronaviruses and other emerging infectious diseases.

The lab of Dr. Rugang Zhang, deputy director of The Wistar Institute Cancer Center, Christopher M. Davis Professor and leader of the Immunology, Microenvironment & Metastasis Program, studies the process of cellular senescence and the changes in gene expression that accompany it.

Cellular senescence is a stable state of growth arrest in which cells stop dividing but remain viable and produce an array of inflammatory molecules collectively defined as senescence-associated secretory phenotype (SASP). These molecules account for the complex crosstalk between senescent cells and neighboring cells and the effect of cellular senescence in various physiological processes like aging and diseases like cancer.

Although senescence is regarded as a powerful barrier for tumor development, the SASP plays a role during tumor development promoting the growth of established tumors.

In a new study published in Nature Cell Biology, Zhang and colleagues pointed out a new mechanism that allows cells to turn on a set of genes encoding for the SASP molecules.

“This mechanism may potentially be targeted to stop the tumor-promoting aspect of senescence while preserving its antitumor function,” said Zhang.

The team focused on two proteins called METTL3 and METTL14 that are known for other molecular functions and found that these proteins moonlight as regulators of gene expression that help turn on SASP genes.

“Although we focused on senescence, we envision that this function of METTL3 and METTL14 may be involved in many other biological processes beyond our current study,” said Zhang.

Drs. David Weiner and Ami Patel working at a hood in the lab

Low-dose Administration of MERS DNA Vaccine Candidate Induces Potent Immunity and Protects From Virus Challenge in Preclinical Models

Written by The Wistar Institute on April 22, 2021. Posted in Press Releases.

PHILADELPHIA — (April 22, 2021) — A synthetic DNA vaccine candidate for Middle East respiratory syndrome coronavirus (MERS-CoV) developed at The Wistar Institute induced potent immune responses and afforded protective efficacy in non-human primate (NHP) models when given intradermally in abbreviated, low-dose immunization regimen. A similar vaccine candidate was previously shown to be safe and tolerable with a three-dose intramuscular injection regimen in a recently completed human phase 1 study and is currently in expanded studies of phase 1/2a trial. New results were published today in JCI Insight.

“While several vaccine products are being advanced against MERS and other coronaviruses, low-dose delivery and shortened regimes are crucial to rapidly induce protective immunity, particularly during emerging outbreaks, as the current SARS-CoV-2 pandemic has emphasized,” said David B. Weiner, Ph.D., Wistar executive vice president, director of the Vaccine & Immunotherapy Center (VIC) and W.W. Smith Charitable Trust Professor in Cancer Research, who led the study.

Researchers evaluated the immunogenicity and protective efficacy of their MERS synthetic vaccine when delivered intradermally using a shortened two-dose immunization schedule compared with intramuscular delivery of higher doses in NHP.

“Given that human efficacy trials for MERS vaccines may be challenging due to the low number of yearly cases, animal models such as our NHP model are valuable as a bridge with human data coming from early-phase clinical trials,” said Weiner.

In this study, Weiner and team report robust antibody neutralizing antibodies and cellular immune responses in all conditions tested. A rigorous virus challenge experiment showed that all vaccination groups were protected against MERS-CoV compared to unvaccinated control animals. However, the low-dose regimen with intradermal delivery was more impactful in controlling disease and symptoms than the higher dose delivered intramuscularly in NHP models.

“To our knowledge, this is the first demonstration of protection with an intradermally delivered coronavirus vaccine,” said Ami Patel, Ph.D., Caspar Wistar Fellow at the Vaccine & Immunotherapy Center and one of the lead authors of the paper. “Intradermal delivery of synthetic DNA vaccines has significant advantages for rapid clinical development. It can be dose sparing and has higher tolerability in people compared with intramuscular injection. The positive results of this study are important not only for the advancement of this MERS vaccine but also for development of other vaccines.”

“Our team is also advancing a COVID-19 vaccine through clinical trials, and we were able to do so in a very short time thanks to our previous experience developing the MERS vaccine,” added Weiner.

Importantly, no evidence of adverse effects on the lungs was observed in any of the dosing groups compared to unimmunized control animals. Through the assessment of a large panel of blood cytokines, researchers showed significant decrease in all mediators of inflammation, which further suggests the vaccine prevents the destructive inflammation induced by coronaviruses.

“In the past twenty years, three new coronaviruses have emerged and caused human outbreaks. The current SARS-CoV-2 pandemic has further emphasized the importance of rapid infection control for coronaviruses and other emerging infectious diseases,” said Emma L. Reuschel, Ph.D., a staff scientist in the Weiner lab and co-first author on the study. “Vaccine candidates that are simple to deliver, well tolerated, and can be readily deployed in resource-limited settings will be important to achieve control of infection.”

Co-authors: Ziyang Xu, Faraz I. Zaidi, Kevin Y. Kim, Regina Stoltz, and Kar Muthumani from The Wistar Institute; Dana P. Scott, Friederike Feldmann, Tina Thomas, Rebecca Rosenke, Dan Long, Jamie Lovaglio, Patrick W. Hanley, and Greg Saturday from National Institutes of Allergy and Infectious Diseases, National Institutes of Health, Hamilton, MT; Janess Mendoza, Stephanie Ramos, Laurent Humeau, and Kate E. Broderick from INOVIO Pharmaceuticals, Inc.

Work supported by: Funding from the Intramural Research Program, National Institutes of Allergy and Infectious Diseases, and the Coalition for Epidemic Preparedness Innovations (CEPI).

Publication information: Intradermal delivery of a synthetic DNA vaccine protects macaques from Middle East respiratory syndrome coronavirus, JCI Insight (2021). Online publication.

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