In the first-ever (sanctioned) investigational use of multiple edits to the human genome, a study found that cells edited in three specific ways and then removed from patients and brought back into the lab setting were able to kill cancer months after their original manufacturing and infusion.

This is the first U.S. clinical trial to test the gene editing approach in humans, and the publication of this new data today follows on the initial report last year that researchers were able to use CRISPR/Cas9 technology to successfully edit three cancer patients' immune cells. The ongoing study is a cooperative between Tmunity Therapeutics, the Parker Institute for Cancer Immunotherapy, and the University of Pennsylvania. 

Patients on this trial were treated by Edward A. Stadtmauer, MD, section chief of Hematologic Malignancies at Penn, co-lead author on the study. The approach in this study is closely related to CAR T cell therapy, in which patient immune cells are engineered to fight cancer, but it has some key differences. Just like CAR T, researchers in this study began by collecting a patient's T cells from blood. However, instead of arming these cells with a receptor against a protein such as CD19, the team first used CRISPR/Cas9 editing to remove three genes. The first two edits removed a T cell's natural receptors so they can be reprogrammed to express a synthetic T cell receptor, allowing these cells to seek out and destroy tumors. The third edit removed PD-1, a natural checkpoint that sometimes blocks T cells from doing their job. 

Once the three genes are knocked out, a fourth genetic modification was accomplished using a lentivirus to insert the cancer-specific synthetic T cell receptor, which tells the edited T cells to target an antigen called NY-ESO-1. Previously published data show these cells typically survive for less than a week, but this new analysis shows the edited cells used in this study persisted, with the longest follow up at nine months. 

Several months after the infusion, researchers drew more blood and isolated the CRISPR-edited cells for study. When brought back into the lab setting, the cells were still able to kill tumors. 

The CRISPR-edited T cells used in this study are not active on their own like CAR T cells. Instead, they require the cooperation of a molecule known as HLA-A*02:01, which is only expressed in a subset of patients. This means that patients had to be screened ahead of time to make sure they were a match for the approach. Participants who met the requirements received other clinically-indicated therapy as needed while they waited for their cells to be manufactured. Once that process was completed, all three patients received the gene-edited cells in a single infusion after a short course of chemotherapy. Analysis of blood samples revealed that all three participants had the CRISPR-edited T cells take root and thrive in the patients. While none responded to the therapy, there were no treatment-related serious adverse events. 

CRISPR technology has not previously been tested in humans in the U.S. so the research team had to move through a comprehensive and rigorous series of institutional and federal regulatory approval steps, including approval by the National Institutes of Health's Recombinant DNA Research Advisory Committee and review by the U.S. Food and Drug Administration, as well as Penn's institutional review board and institutional biosafety committee. The entire process required more than two years.

 Researchers say these new data will open the door to later stage studies to investigate and extend this approach to a broader field beyond cancer, several of which are already planned at Penn.

After a newborn (born to a mother infected with the 2019 novel coronavirus disease (COVID-19) testing positive for COVID-19 infection within 36 hours of birth, there were concerns about whether the virus could be contracted in the womb. A new study finds that COVID-19 does not pass to the child while in the womb. The women in the small study were from Wuhan, China, in the third trimester of pregnancy and had pneumonia caused by COVID-19. However, it only included women who were late in their pregnancy and gave birth by caesarean section. 

There were two cases of fetal distress but all nine pregnancies resulted in live births. That symptoms from COVID-19 infection in pregnant women were similar to those reported in non-pregnant adults, and no women in the study developed severe pneumonia or died.

All mothers in the study were aged between 26-40 years. None of them had underlying health conditions, but one developed gestational hypertension from week 27 of her pregnancy, and another developed pre-eclampsia at week 31. Both patients’ conditions were stable during pregnancy. The nine women in the study had typical symptoms of COVID-19 infection, and were given oxygen support and antibiotics. Six of the women were also given antiviral therapy. In the study, the medical records of nine pregnant women who had pneumonia caused by COVID-19 infection were retrospectively reviewed. Infection was lab-confirmed for all women in the study, and the authors studied the nine women’s symptoms.

In addition, samples of amniotic fluid, cord blood, neonatal throat swabs and breast milk were taken for six of the nine cases [2] and tested for severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2). Importantly, the samples of amniotic fluid, cord blood, and neonatal throat swabs were collected in the operating room at the time of birth to guarantee that samples were not contaminated and best represented intrauterine conditions. All nine pregnancies resulted in live births, and there were no cases of neonatal asphyxia. Four women had pregnancy complications (two had fetal distress and two had premature rupture of membrane), and four women had preterm labor which was not related to their infection and occurred after 36 gestational weeks. Two of the prematurely born newborns had a low birth weight.

The authors note that their findings are similar to observations of the severe acute respiratory syndrome (SARS) virus in pregnant women, where there was no evidence of the virus being passed from mother to child during pregnancy or birth. The findings are based on a limited number of cases, over a short period of time, and the effects of mothers being infected with the virus during the first or second trimester of pregnancy and the subsequent outcomes for their offspring are still unclear, as well as whether the virus can be passed from mother to child during vaginal birth.

Dr Jie Qiao (who was not involved in the study) of Peking University Third Hospital, China,compares the effects of the virus to those of SARS, and says: “Previous studies have shown that SARS during pregnancy is associated with a high incidence of adverse maternal and neonatal complications, such as spontaneous miscarriage, preterm delivery, intrauterine growth restriction, application of endotracheal intubation, admission to the intensive care unit, renal failure, and disseminated intravascular coagulopathy. However, pregnant women with COVID-19 infection in the present study had fewer adverse maternal and neonatal complications and outcomes than would be anticipated for those with SARS-CoV-1 infection. Although a small number of cases was analysed and the findings should be interpreted with caution, the findings are mostly consistent with the clinical analysis done by Zhu and colleagues of ten neonates born to mothers with COVID-19 pneumonia."

Imagine trying to cope with a pandemic like COVID-19 in a world where microscopic life was unknown. Prior to the 17th century, people were limited by what they could see with their own two eyes. But then a Dutch cloth merchant changed everything.

His name was Antonie van Leeuwenhoek, and he lived from 1632 to 1723. Although untrained in science, Leeuwenhoek became the greatest lens-maker of his day, discovered microscopic life forms and is known today as the “father of microbiology.”

Visualizing ‘animalcules’ with a ‘small see-er’

Leeuwenhoek opened the door to a vast, previously unseen world. J. Verolje/Wellcome Collection, CC BY

Leeuwenhoek didn’t set out to identify microbes. Instead, he was trying to assess the quality of thread. He developed a method for making lenses by heating thin filaments of glass to make tiny spheres. His lenses were of such high quality he saw things no one else could.

This enabled him to train his microscope – literally, “small see-er” – on a new and largely unexpected realm: objects, including organisms, far too small to be seen by the naked eye. He was the first to visualize red blood cells, blood flow in capillaries and sperm.

Drawings from a Leeuwenhoek letter in 1683 illustrating human mouth bacteria. Huydang2910, CC BY-SA

Leeuwenhoek was also the first human being to see a bacterium – and the importance of this discovery for microbiology and medicine can hardly be overstated. Yet he was reluctant to publish his findings, due to his lack of formal education. Eventually, friends prevailed upon him to do so.

He wrote, “Whenever I found out anything remarkable, I thought it my duty to put down my discovery on paper, so that all ingenious people might be informed thereof.” He was guided by his curiosity and joy in discovery, asserting “I’ve taken no notice of those who have said why take so much trouble and what good is it?”

When he reported visualizing “animalcules” (tiny animals) swimming in a drop of pond water, members of the scientific community questioned his reliability. After his findings were corroborated by reliable religious and scientific authorities, they were published, and in 1680 he was invited to join the Royal Society in London, then the world’s premier scientific body.

Leeuwenhoek was not the world’s only microscopist. In England, his contemporary Robert Hooke coined the term “cell” to describe the basic unit of life and published his “Micrographia,” featuring incredibly detailed images of insects and the like, which became the first scientific best-seller. Hooke, however, did not identify bacteria.

Despite Leuwenhoek’s prowess as a lens-maker, even he could not see viruses. They are about 1/100th the size of bacteria, much too small to be visualized by light microscopes, which because of the physics of light can magnify only thousands of times. Viruses weren’t visualized until 1931 with the invention of electron microscopes, which could magnify by the millions.

An image of the hepatitis virus courtesy of the electron microscope. E.H. Cook, Jr./CDC via Associated Press

A vast, previously unseen world

Leeuwenhoek and his successors opened up, by far, the largest realm of life. For example, all the bacteria on Earth outweigh humans by more than 1,100 times and outnumber us by an unimaginable margin. There is fossil evidence that bacteria were among the first life forms on Earth, dating back over 3 billion years, and today it is thought the planet houses about 5 nonillion (1 followed by 30 zeroes) bacteria.

Some species of bacteria cause diseases, such as cholera, syphilis and strep throat; while others, known as extremophiles, can survive at temperatures beyond the boiling and freezing points of water, from the upper reaches of the atmosphere to the deepest points of the oceans. Also, the number of harmless bacterial cells on and in our bodies likely outnumber the human ones.

Viruses, which include the coronavirus SARS-CoV-2 that causes COVID-19, outnumber bacteria by a factor of 100, meaning there are more of them on Earth than stars in the universe. They, too, are found everywhere, from the upper atmosphere to the ocean depths.

A visualization of the human rhinovirus 14, one of many viruses that cause the common cold. Protein spikes are colored white for clarity. Thomas Splettstoesser, CC BY-SA

Strangely, viruses probably do not qualify as living organisms. They can replicate only by infecting other organisms’ cells, where they hijack cellular systems to make copies of themselves, sometimes causing the death of the infected cell.

It is important to remember that microbes such as bacteria and viruses do far more than cause disease, and many are vital to life. For example, bacteria synthesize vitamin B12, without which most living organisms would not be able to make DNA.

Likewise, viruses cause diseases such as the common cold, influenza and COVID-19, but they also play a vital role in transferring genes between species, which helps to increase genetic diversity and propel evolution. Today researchers use viruses to treat diseases such as cancer.

Scientists’ understanding of microbes has progressed a long way since Leeuwenhoek, including the development of antibiotics against bacteria and vaccines against viruses including SARS-CoV-2.

But it was Leeuwenhoek who first opened people’s eyes to life’s vast microscopic realm, a discovery that continues to transform the world.

By Richard Gunderman, Chancellor's Professor of Medicine, Liberal Arts, and Philanthropy, Indiana University. This article is republished from The Conversation under a Creative Commons license. Read the original article.

Sudden oak death, caused by the pathogen Phythophthora ramorum, is one of the most ecologically devastating forest diseases in North America, responsible for the deaths of millions of oaks and tanoaks along the coast.

Science to the rescue? After the success of genetically modified organisms in things like insulin and food, a recent trend is Genetically Rescued Organisms. These GROs would use science to create natural resistance, like a vaccine for plants, and reduce the impact of altered species composition, released carbon pools, and greater fire risk the deaths bring.

Before that can happen, scientists need to better understand the basic biology of Phythophthora ramorum, including how well it sporulates on common plants.

Image by RegalShave from Pixabay

Scientists at the University of California, Davis, set out to investigate the sporulation potential of this pathogen on common California plant species. They collected leaves from 13 common plant hosts in the Big Sur-region and inoculated them with the causal pathogen. They found that most of the species produced spores, though there was a ride range, with bay laurel and tanoak producing significantly more sporangia than the other species. They also observed an inconsistent relationship between sporulation and lesion size, indicating that visual symptoms are not a reliable metric of sporulation potential.

 “Our study is the first to investigate the sporulation capacity on a wide range of common coastal California native plant species and with a large enough sample size to statistically distinguish between species," explained first author Dr. Lisa Rosenthal. "It largely confirms what was previously reported in observational field studies – that tanoak and bay laurel are the main drivers of sudden oak death infections—but also indicates that many other hosts are capable of producing spores.”

Citation: Lisa M. Rosenthal, Sebastian N. Fajardo, and David M. Rizzo, Sporulation Potential of Phytophthora ramorum Differs Among Common California Plant Species in the Big Sur Region, Plant Disease 17 Aug 2021 https://doi.org/10.1094/PDIS-03-20-0485-RE