Artist’s rendering of asymmetrically-branched carbohydrates on cell surface proteins.
Glycobiology is the study of glycans, the carbohydrate molecules that cover the surface of most human cells. Glycans attach to cell surface proteins and lipids, in a process called glycosylation. These cell surface structures are responsible for processes as varied at protein folding, cell signaling and cell-cell recognition, including sperm-egg recognition and immune cell interactions. Glycans play important roles in the red blood cell antigens that distinguish blood types O, A and B.
Opportunities in Glycomics Research
As more is learned about the role of glycans in cell communication, they are becoming important disease research targets, particularly the role of glycans in cancer and inflammatory diseases (2).
Some of the open questions surrounding glycans and glycosylation include glycan structural diversity. While some carbohydrates exist as straight or symmetrically branched chains, those populating the human glycome are asymmetrically branched, making them difficult to create and study in the laboratory (3). Continue reading →
Dennis Dimick has focused his journalism career on the collision between human aspiration and the planet. The son of fisheries biologists, Dimick grew up on a farm in Oregon’s Willamette Valley, and he holds degrees in agriculture and agricultural journalism from Oregon State University and the University of Wisconsin-Madison. In his 35 years at National Geographic, he served for over a decade as the magazine’s environment editor, and guided major projects on climate change, energy, freshwater, population, and food security. Dimick is co-founder of Eyes on Earth, a project meant to inspire a new generation of environmental photographers.
As a young man, Dimick witnessed firsthand the price of progress when his family’s farm was cut in half by the construction of an interstate beltway. This invasion of their farm, in addition to the clear-cut logging of nearby forests where Dimick had spent his youth, combined to sensitize him to the profound impacts of human progress on the Earth. Early photography experience and his personal connection to the effects of human progress led to a life and career spent combining these two dimensions.
Clear-cut timber harvest in Oregon’s Cascade Mountains south of Eugene in 2016, one of a series of images for an ongoing project documenting the Anthropocene landscape across North America as seen from passenger airplanes. Photo: Dennis Dimick
In anticipation of hisparticipation in the 2018 Wisconsin Science Festival, I asked Mr. Dimick some questions about photojournalism, and what it’s like documenting the human impact on the environment. Some of his answers have been slightly edited for clarity.
Getting DNA or RNA into cells can be a tricky business, and a variety of transfection reagents have been developed over the years to make the process easier. Lipid-based reagents are especially popular because they combine efficient transfection with relatively low toxicity.
When it comes to transfection, it pays to think small. Human cells range in volume from 20–40 µm3 (sperm cells) to as large as 4 million µm3 (mature egg cells, or oocytes). For several decades, transfection reagents have targeted this size range. However, breakthrough research involves leaving the “micro” realm and entering a world that was once the domain only of science fiction: nanotechnology. Continue reading →
When someone is admitted to a hospital for an illness, the hope is that medical care and treatment will help them them feel better. However, nosocomial infections—infections acquired in a health-care setting—are becoming more prevalent and are associated with an increased mortality rate worldwide. This is largely due to the misuse of antibiotics, allowing some bacteria to become resistant. Furthermore, when an antibiotic wipes out the “good” bacteria that comprise the human microbiome, it leaves a patient vulnerable to opportunistic infections that take advantage of disruptions to the gut microbiota.
One such bacteria, Clostridium difficile, is of growing concern world-wide since it is resistant to many different antibiotics. When a patient is treated with an antibiotic, C. difficile can thrive in the intestinal tract without other bacteria populating the gut. C. difficile infection is the leading cause of antibiotic-associated diarrhea. While symptoms can be mild, aggressive infection can lead to pseudomembranous colitis—a severe inflammation of the colon which can be life-threatening.
C. difficile causes disease by releasing two large toxins, TcdA and TcdB. Understanding the role these toxins play in colonic disease is important for treatment strategies. However, most published research data only report the effects of the toxins independently. A 2016 study demonstrated a method of comparing the toxins side-by-side using the same time points and cell assays to investigate the role each toxin plays in the cell death that leads to disease of the colon. Continue reading →
The 2018 Nobel Prize in Physiology and Medicine was awarded to James P. Allison of the United States and Tasuku Honjo of Japan for their work to identify pathways in the immune system that can be used to attack cancer cells (1). Although immunotherapy for cancer has been a goal for many decades, Dr. Allison and Dr. Honjo succeeded through their manipulation of “checkpoint inhibitor” pathways to target cancer cells.
Immune checkpoint inhibitor drugs have been effective in cancers such as aggressive metastatic melanoma, some lung cancers, kidney, bladder and head and neck cancers. These therapies have succeeded in pushing many aggressive cancers below detectable limits, though these cases are notably not relapse-free or necessarily “cured” (2,3).
One challenge in implementing immunotherapy in a cancer treatment regime is the need to understand the genetic makeup of the tumor. Certain tumors, with specific genetic features, are far more likely to respond to immune checkpoint therapy than others. For this reason, Microsatellite Instability (MSI) analysis has become an increasingly relevant tool in genetic and immuno-oncology research.
One of the best things about the BTC Institute is that we have programs for all levels of learners. It is as rewarding to introduce the concept of how bioluminescence is used by different organisms in the natural world to middle-school students as it is to have top-level scientists use reporter genes to track their knock-in genome edits.
We spend a lot of time working over our curricula to determine whether the content meets the learner where they are to allow our students to achieve their goals. We develop activities that let students who comes to us —via field trips, high school courses, non-scientist sessions and graduate level programs—to test ideas and evaluate strategies for problem solving as they learn techniques and concepts central to biotechnology. Continue reading →
Fc receptor-mediated antibody-dependent cell-mediated cytotoxicity (ADCC) is an important mechanism of action (MOA) by which antibodies target diseased cells for elimination. Traditional methods for measuring ADCC require primary donor peripheral blood mononuclear cells (PBMCs) or purified natural killer (NK) cells that express Fc receptors on the cell surface. Killing of target cells is an endpoint of this pathway activation and is used in classic ADCC bioassays.
PBMCs and NK cells are notoriously difficult to isolate and culture. Furthermore, cultured cells can be a source of variability.
There is a Better Way
Watch this video to learn why traditional ADCC assays can be problematic. You’ll also learn a solution. Find out how to not only save time but also reduce assay variability.
For more details on the benefits of working with ADCC Reporter Bioassays go to the product page.
There you’ll see how standardized reagents in Promega ADCC Reporter Bioassays ensure better results and better consistency in an ADCC Reporter Bioassay that saves you time.
Cloning is a fickle process that can make even the most seasoned bench scientists scream in frustration. By the time you perform a colony PCR and run the gel to check for your insert, you’ve invested several days in preparing these transformed cells. But then, the unthinkable happens. When you image your gel…the target band is missing.
This can trigger what’s known as “The 5 Stages of Failed Cloning Grief.” As you work through each stage at your own pace, just know that scientists all over the world feel your pain and can empathize with you in this difficult time. Continue reading →
It seemed like the rain was never going to stop. It started in the morning, and when I left work around 5pm, it was still coming down hard. I took my normal route home through a back country road. As I turned right onto Fitchrona Road, a long line of cars came into view. There’s usually some congestion leading to the stop sign ahead. Except today, something was different. About 20 yards of the road ahead was submerged in water. Continue reading →
Have you ever thought about plant viruses? Unless you’re a farmer or avid gardener, probably not. And yet, for many people the battle against agricultural viruses never ends. Plant viruses cause billions of dollars in damage every year and leave millions of people food insecure (1–2), making viruses a major barrier to meeting the United Nations’ global sustainable development goal of Zero Hunger by 2030.
At the University of Western Australia, Senior Research Fellow Dr. Laura Boykin is using genomics and supercomputing to tackle the problem of viral plant diseases. In a recent study, Dr. Boykin and her colleagues used genome sequencing to inform disease management in cassava crops. For this work, they used the MinION, a miniature, portable sequencer made by Oxford Nanopore Technologies, to fully sequence the genomes of viruses infecting cassava plants.
Cassava (Manihot esculenta) is one of the 5 most important calorie sources worldwide (3). Over 800 million people rely on cassava for food and/or income (4). Cassava is susceptible to a group of viruses called begomoviruses, which are transmitted by whiteflies. Resistant cassava varieties are available. However, these resistant plants are usually only protected against a small number of begomoviruses, so proper deployment of these plants means farmers must know both whether their plants are infected and, if so, the strain of virus that’s causing the infection. Continue reading →