Researchers have discovered new ways in which the coronavirus disease (COVID-19) virus causes human immune cells to overreact, a deadly part of the disease.

Led by researchers from NYU Grossman School of Medicine and Perlmutter Cancer Center at NYU Langone, the new study found that SARS-CoV-2, the pandemic virus, interacts with specific proteins on immune cells, causing these cells to release abnormally high levels of immune signaling proteins called cytokines (a “cytokine storm”). These cytokines, in turn, cause fluid buildup in the lungs and make it hard to breathe.

Before the current study, SARS-CoV-2 was thought to interact mostly with a protein called angiotensin converting enzyme 2 (ACE2), which is present on the outer surfaces of lung cells. The virus evolved to have a protein spike that snags ACE2 as the first step in invading human lung cells, where the virus multiplies. Accordingly, all approved COVID-19 antiviral drugs and vaccines work by interfering with, or protecting against, this viral spike/ACE2 interaction.

Mounting evidence, however, suggests that the virus also interacts directly with human immune cells, which have little ACE2 on their surfaces. Published online May 9 in the journal Immunity, the new study identified six surface proteins on immune cells that attach to the viral spike protein, but in different places than ACE2.

The virus does not appear to replicate in immune cells, as it does when it binds with ACE2 on lung cells, but instead, the newfound interactions cause damaging immune responses, say the study authors. Based on their new understanding, the team generated nanobodies, a type of protein-based therapeutic, to block viral attachment to both ACE2 and the newfound immune cell surface proteins (receptors).

“Our results suggest that we can simultaneously keep SARS-CoV-2 from invading lung cells while also blocking the dangerous hyperactivation that the viral spike protein causes in immune cells,” says corresponding study author Jun Wang, PhD, assistant professor in the Department of Pathology at NYU Langone. “Such dual action, if confirmed in human studies, could more fully address a disease that has taken more than 3.3 million lives globally.”

In the study, the authors used a technique called single-cell RNA-sequencing to examine which genes were expressed, and consequently, which proteins were built, in cells present in lung fluid taken from patients with COVID-19, including cells lining the lungs (epithelial cells) and immune cells.

Their high-speed receptor screening approach identified and described the six human immune cell membrane proteins that bound to SARS-CoV-2 spike protein. Five were C-type lectins, carbohydrate-binding protein units with many biological functions, including in immune defenses. The authors also found that SARS-CoV-2 spike attaches to Tweety family member 2, a protein that controls the entry of charged particles (chloride) into cells, and possibly a switch that activates immune cells. Importantly, the team found the virus spike interacts with these activating surface proteins mostly on myeloid cells, a group of vital immune cells that arise in bone marrow and circulate in the blood.

In addition, the study authors generated nanobodies that blocked SARS-CoV-2 spike/ACE2 and myeloid cell interactions. Nanobodies are smaller derivatives of antibodies, immune proteins that form a surveillance system by recognizing invading microbes. Industry designs synthetic antibodies that specifically glom onto targets of their choice, which can change the action of disease-causing proteins. More recently, researchers began fine-tuning just pieces of antibodies, called nanobodies, which are easier to make.

“Our study will change how the field thinks about mechanisms behind COVID-19, demonstrating that viruses can directly reprogram immune cells with potentially deadly consequences,” says co-first study author Qiao Lu, PhD, a postdoctoral scholar in Dr. Wang’s lab.

As a next step, he says, the research team plans to explore their nanobody’s potential in preclinical and clinical studies in patients with severe cases of COVID-19, as well as in those with emerging virus mutants that cause more severe symptoms.

Along with Dr. Wang, co-corresponding authors for the study were Siyuan Ding in the Department of Molecular Microbiology, Washington University School of Medicine in St. Louis, and Qi Xie of the Institute of Basics Medical Sciences, Westlake Institute for Advanced Study in Hangzhou, China. Along with Dr. Lu, co-first authors were Jia Liu of the Department of Pathology at NYU Langone; and Shuai Zhao of Westlake University. Study authors from the Department of Pathology at NYU Langone were Triantafyllia Karakousi, Ze Zhang, Xufeng Chen, Marianna Teplova, Tenny Mudianto, Jasper Du, Alberto Herrera, Sergei Koralov, Iannis Aifantis; and Leopoldo Segal in the Department of Medicine; as well as Payal Damani-Yokota, Maria Kaczmarek, Stephen Yeung, Kamal Khanna, and Kenneth Stapleford in the Department of Microbiology.

Additional study authors were Xiaojuan Ran, Hongzhen Tang, Haijing Deng, Zhilin Long, Shumin Jin, Peng Lin, and Ming Zhou of the Institute of Basics Medical Sciences, Westlake Institute for Advanced Study; Maria Florencia, Gomez Castro, Juhee Son, Ruochen Zang, Broc McCune, Rita Chen, and Michael Diamond of the Washington University School of Medicine, St. Louis; Maudry Laurent-Rolle, Jack Hsu, Tina Tianjiao Su, and Peter Cresswell of the Department of Immunobiology at Yale University School of Medicine; Jianbo Dong, Betty Huang, and Yue Liu of Ab Studio Inc.; Fei Tang, Xianwen Ren, and Zemin Zhang of the Beijing Advanced Innovation Center for Genomics at Peking University; Renhong Yan and Qiang Zhou of the Joint Research Center of Hangzhou First Hospital Group and Westlake University; Jia Cui of Kactus Biosystems in Shanghai; James Zhu and Tao Wang of the Quantitative Biomedical Research Center at University of Texas Southwestern Medical Center; and Jianzhu Ma of the Department of Computer Science at Purdue University.

This work is supported by internal funds provided by the Office of Science and Research at NYU Langone, Westlake Education Foundation, Tencent Foundation grant XHTX202001008, Hangzhou Science and Technology Development Foundation grant 20202013A05, a Cancer Research Institute Irvington Postdoctoral Fellowship, and National Institutes of Health grants P30 DK052574, R00 AI135031, R01 AI150796, R01 AI157155, R01 AI143861, AI143861S1, and R01-AI059167. Dr. Wang, Dr. Lu, and Dr. Liu from NYU Langone; and Dr. Huang, Dr. Dong, and Dr. Yue Liu from Ab Studio Inc., are named as inventors on patent applications that describe the anti-SARS-CoV-2 blocking nanobodies. Dr. Wang is also a paid consultant for Lilly Asia Ventures and Rootpath Genomics (work not related to the current study).

Featured image: GETTY/FOTOGRAZIA

Reference: Qiao Lu, Jia Liu, Shuai Zhao et al., “SARS-CoV-2 exacerbates proinflammatory responses in myeloid cells through C-type lectin receptors and Tweety family member 2”, Immunity, 2021. DOI: https://doi.org/10.1016/j.immuni.2021.05.006

Provided by NYU Langone

First to demonstrate COVID-19 present in penis tissue long after COVID-19 recovery

University of Miami Miller School of Medicine researchers are the first to demonstrate that COVID-19 can be present in the penis tissue long after men recover from the virus.

The widespread blood vessel dysfunction, or endothelial dysfunction, that results from the COVID-19 infection could then contribute to erectile dysfunction, or ED, according to the study recently published in the World Journal of Men’s Health. Endothelial dysfunction is a condition in which the lining of the small blood vessels fails to perform all of its functions normally. As a result, the tissues supplied by those vessels could undergo damage.

“Our research shows that COVID-19 can cause widespread endothelial dysfunction in organ systems beyond the lungs and kidneys. The underlying endothelial dysfunction that happens because of COVID-19 can enter the endothelial cells and affect many organs, including the penis,” said study author Ranjith Ramasamy, M.D., associate professor and director of the Miller School’s Reproductive Urology Program. “In our pilot study, we found that men who previously did not complain of erectile dysfunction developed pretty severe erectile dysfunction after the onset of COVID-19 infection.”

Dr. Ramasamy and colleagues collected penile tissue from two men with a history of COVID-19 infection who underwent penile prosthesis surgery for ED. One of the men was hospitalized for COVID-19, while the other patient only had mild symptoms when he contracted the virus.

The researchers also collected tissue from two additional men with no history of COVID-19 infection undergoing the same surgery for ED. The investigators analyzed all the tissue samples for not only evidence of the virus but also endothelial dysfunction.

They found COVID-19 was present in the penile tissue of both men who had been infected, but not in the men with no history of the virus. The men had been infected six and eight months prior, respectively. These men had evidence of endothelial dysfunction, while the men who had been free of the virus did not.

“This suggests that men who develop COVID-19 infection should be aware that erectile dysfunction could be an adverse effect of the virus, and they should go to a physician if they develop ED symptoms,” Dr. Ramasamy said.

The authors hypothesize that similar to other COVID-19 related complications, widespread infection and subsequent endothelial dysfunction could result in ED, and that worsening of ED could be due to the virus’s presence in the penile tissue, itself.

In a previously published study, Dr. Ramasamy and Miller School colleagues found that COVID-19 can also invade testis tissue in some men who are infected with the virus, which might be the first step in understanding the virus’s potential impact on male fertility and whether COVID-19 can be sexually transmitted.

“These latest findings are yet another reason that we should all do our best to avoid COVID-19,” said first author Eliyahu Kresch, a medical student working with Dr. Ramasamy.

“We recommend vaccination and to try to stay safe in general,” Kresch said.

Miller School coauthors are medical student Justin K. Achua, M.S.; clinical research coordinator Russell Saltzman; clinical research associate Kajal Khodamoradi, Ph.D.; Research Assistant Professor of Urology Himanshu Arora, Ph.D.; Assistant Professor of Urology and Neurological Surgery Emad Ibrahim, M.D., HCLD; Associate Professor of Pathology Oleksandr N. Kryvenko, M.D.; Transmission Electron Microscopy Core Vania Wolff Almeida; Fakiha Firdaus; and Founding Director of the Interdisciplinary Stem Cell Institute Joshua M. Hare, M.D.

Featured image: Ultrastructure features of penile tissue from live seroconverted COVID-19 patients. (A) Coronavirus-like spiked viral particles (arrows) visualized via TEM in the peri-vascular erectile tissue of a live patient who had previously contracted the COVID-19 virus and subsequently seroconverted. Particle diameter measurement indicated on image. (B) Coronavirus-like spiked viral particles (arrows) visualized via TEM in the peri-vascular erectile tissue of a live patient who had previously contracted the Covid-19 virus and subsequently seroconverted. Particle diameter measurement indicated on image. © Dr. Ranjith Ramasamy/University of Miami Health System

Reference: Kresch E, Achua J, Saltzman R, Khodamoradi K, Arora H, Ibrahim E, Kryvenko O, Almeida VW, Firdaus F, Hare JM, Ramasamy R.   COVID-19 Endothelial Dysfunction Can Cause Erectile Dysfunction: Histopathological, Immunohistochemical, and Ultrastructural Study of the Human Penis.   World J Mens Health. 2021;39:e22.   https://doi.org/10.5534/wjmh.210055

Provided by University of Miami School of Medicine

Melbourne researchers have identified predictors of both severe disease and recovery in hospitalised influenza patients, finding that the immune system works in concert to fight influenza.

Published today in Nature Communications, the team from the Peter Doherty Institute for Infection and Immunity (Doherty Institute), Alfred Health and Monash University sought to understand which patients would recover quickly from influenza and which would become severely ill.

The four-year project took samples from patients hospitalised with influenza at up to five time points during their hospital stay, and 30 days after discharge. They analysed the breadth of the immune response, enabling them to describe the specific roles of several different types of immune cells, including killer and helper T cells, B cells and innate cells.

University of Melbourne Dr Oanh Nguyen, Research Fellow at the Doherty Institute, said two significant findings of the research include understanding the biomarkers that drive recovery and identifying four specific cytokines that cause serious inflammation during influenza virus infection.

“Cytokines are key molecules needed for a robust immune response. However, too much of these cytokines can result in inflammation and in the case of influenza, much more serious infection,” Dr Nguyen said.

“We found four specific types of cytokines that would cause severe inflammation, and this provides clinicians the ability to predict whether a patient will become really sick with influenza.”

The team also consistently saw large populations of immune cells called T-follicular helper cells, working in parallel with antibody-secreting cells, in patients at around three days prior to their recovery.

“These findings are the first to report the importance of T-follicular helper cells during acute influenza virus infection, following previous discoveries from our work and others on the key role of these immune cells after influenza vaccination. Signs of these cells could be used as a biomarker for recovery from influenza,” Dr Nguyen said.

Professor Allen Cheng, Director of Infection Prevention and Healthcare Epidemiology at Alfred Health and Professor of Infectious Diseases Epidemiology at Monash University, said this had been a great collaboration between clinicians and world-renowned immunologists, and a good example of ‘bedside to bench’ science.

“The COVID-19 pandemic, and before this, the swine flu pandemic, has highlighted the importance of improving our understanding of respiratory viral infections to improve the identification of patients at risk of severe outcomes and potentially future treatments,” Professor Cheng said.

University of Melbourne Professor Katherine Kedzierska, Laboratory Head at the Doherty Institute and world-leading influenza immunologist, said this research laid the groundwork for her team’s understanding of how the immune system responds to COVID-19.

“Because of our years of experience, experimental set up, knowledge and collaborations with Alfred Health for this and other influenza studies, we had the speed and agility to apply our work to immune studies of COVID-19,” Professor Kedzierska said.

“This influenza study was the blueprint for our COVID-19 research.”

Reference: Nguyen, T.H.O., Koutsakos, M., van de Sandt, C.E. et al. Immune cellular networks underlying recovery from influenza virus infection in acute hospitalized patients. Nat Commun 12, 2691 (2021). https://doi.org/10.1038/s41467-021-23018-x

Provided by Doherty Institute

Study in animals identifies a potential way to build vaccines to fight future pandemics

A potential new vaccine developed by members of the Duke Human Vaccine Institute has proven effective in protecting monkeys and mice from a variety of coronavirus infections — including SARS-CoV-2 as well as the original SARS-CoV-1 and related bat coronaviruses that could potentially cause the next pandemic.

The new vaccine, called a pan-coronavirus vaccine, triggers neutralizing antibodies via a nanoparticle. The nanoparticle is composed of the coronavirus part that allows it to bind to the body’s cell receptors, and is formulated with a chemical booster called an adjuvant. Success in primates is highly relevant to humans.

The findings appear Monday, May 10 in the journal Nature.

“We began this work last spring with the understanding that, like all viruses, mutations would occur in the SARS-CoV-2 virus, which causes COVID-19,” said senior author Barton F. Haynes, M.D., director of the Duke Human Vaccine Institute (DHVI). “The mRNA vaccines were already under development, so we were looking for ways to sustain their efficacy once those variants appeared.

“This approach not only provided protection against SARS-CoV-2, but the antibodies induced by the vaccine also neutralized variants of concern that originated in the United Kingdom, South Africa and Brazil,” Haynes said. “And the induced antibodies reacted with quite a large panel of coronaviruses.”

Haynes and colleagues, including lead author Kevin Saunders, Ph.D., director of research at DHVI, built on earlier studies involving SARS, the respiratory illness caused by a coronavirus called SARS-CoV-1. They found a person who had been infected with SARS developed antibodies capable of neutralizing multiple coronaviruses, suggesting that a pan-coronavirus might be possible.

The Achilles heel for the coronaviruses is their receptor-binding domain, located on the spike that links the viruses to receptors in human cells. While this binding site enables it to enter the body and cause infection, it can also be targeted by antibodies.

The research team identified one particular receptor-binding domain site that is present on SARS-CoV-2, its circulating variants and SARS-related bat viruses that makes them highly vulnerable to cross-neutralizing antibodies.

The team then designed a nanoparticle displaying this vulnerable spot. The nanoparticle is combined with a small molecule adjuvant — specifically, the toll-like receptor 7 and 8 agonist called 3M-052, formulated with Alum, which was developed by 3M and the Infectious Disease Research Institute. The adjuvant boosts the body’s immune response. 

In tests of its effect on monkeys, the nanoparticle vaccine blocked COVID-19 infection by 100%. The new vaccine also elicited significantly higher neutralizing levels in the animals than current vaccine platforms or natural infection in humans. 

“Basically what we’ve done is take multiple copies of a small part of the coronavirus to make the body’s immune system respond to it in a heightened way,” Saunders said. “We found that not only did that increase the body’s ability to inhibit the virus from causing infection, but it also targets this cross-reactive site of vulnerability on the spike protein more frequently. We think that’s why this vaccine is effective against SARS-CoV-1, SARS-CoV-2 and at least four of its common variants, plus additional animal coronaviruses.”

“There have been three coronavirus epidemics in the past 20 years, so there is a need to develop effective vaccines that can target these pathogens prior to the next pandemic,” Haynes said. “This work represents a platform that could prevent, rapidly temper, or extinguish a pandemic.”

In addition to Haynes and Saunders, study authors include Esther Lee, Robert Parks1,5, David R. Martinez, Dapeng, Haiyan Chen, Robert J. Edwards, Sophie Gobeil, Maggie Barr, Katayoun Mansour, S. Munir Alam, Laura L. Sutherland, Fangping Cai, Aja M. Sanzone, Madison Berry, Kartik Manne, Kevin W. Bock, Mahnaz Minai, Bianca M. Nagata, Anyway B. Kapingidza, Mihai Azoitei, Longping V. Tse, Trevor D. Scobey, Rachel L. Spreng, R. Wes Rountree, C. Todd DeMarco, Thomas N. Denny, Christopher W. Woods, Elizabeth W. Petzold, Thomas H. Oguin III, Gregory D. Sempowski, Matthew Gagne, Daniel C. Douek, Mark A. Tomai, Christopher B. Fox, Robert Seder, Kevin Wiehe, Drew Weissman, Norbert Pardi, Hana Golding, Surender Khurana, Priyamvada Acharya, Hanne Andersen, Mark G. Lewis, Ian N. Moore, David C. Montefiori and Ralph S. Baric.

The study received funding from the State of North Carolina with funds from the federal CARES Act; the National Institutes of Health (AI142596, R01AI157155 U54 CA260543, F32 AI152296, T32 AI007151); the North Carolina Policy Collaboratory at the University of North Carolina at Chapel Hill with funding from the North Carolina Coronavirus Relief Fund; and a Burroughs Wellcome Fund Postdoctoral Enrichment Program Award.

Reference: Saunders, K.O., Lee, E., Parks, R. et al. Neutralizing antibody vaccine for pandemic and pre-emergent coronaviruses. Nature (2021). https://doi.org/10.1038/s41586-021-03594-0

Provided by Duke Health