BioQuakes

AP Biology class blog for discussing current research in Biology

Tag: Bioluminescence

Analyzing Viruses in One Step Using LUNAS

In this article from the American Chemical Society, Maarten Merkx and his colleagues research how to use and combine CRISPR-related proteins with a bioluminescence technique whose signal could be detected with a digital camera. This new technique can diagnose illnesses faster while being much more efficient and practical. Bioluminescence is a chemical reaction involving the luciferase protein that causes the luminescent, glow-in-the-dark effect. The luciferase protein has been incorporated into sensors that emit an easily observed light when they find their target, but they lack the incredibly high sensitivity required of a clinical diagnostic test.

Mareel - Bioluminescence in Norra Grundsund harbor 2

CRISPR, a gene-editing technique, has the ability to increase sensitivity, but it requires many steps and additional specialized equipment. With the new technique, called LUNAS (luminescent nucleic acid sensor), two CRISPR/Cas9 proteins specific for different neighboring parts of a viral genome each have a distinct fragment of luciferase attached to them. If a specific viral genome that the researchers were testing for was present, the two CRISPR/Cas9 proteins would bind to the targeted nucleic acid sequences and come close to each other, allowing the complete luciferase protein to form and shine blue light in the presence of a chemical substrate. RPA-LUNAS successfully detected SARS-CoV-2 RNA within 20 minutes, even at concentrations as low as 200 copies per microliter.

This is similar to the process of gene regulation that uses an inducible operon as we learned in class. An inducible operon is a type of negative regulation that turns on when it interacts with an inducer. It is usually off which means there is an active repressor that binds to the operator to block the RNA polymerase from transcribing the DNA. When there is the inducer, such as the virus, the inducer inactivates the repressor by binding to the allosteric site which allows the RNA polymerase, such as the CRISPR/Cas9 proteins, to transcribe and eventually produce the protein, such as the luciferase protein.

As we are recovering from the devastating COVID-19 Pandemic, how can new medical advancements and technology help us prepare for future outbreaks?

Chimeric Antigen Receptor T-Cell Therapy: Successful Research to Improve Cancer Treatments

Cancer is when abnormal cells divide without control and spread to other parts of the body through the bloodstream and lymph systems to cause illnesses. Immunotherapy is a type of treatment that utilizes a person’s immune system to battle diseases like cancer. Under the branch of immunotherapy, there is a specific therapy that has been recently improved upon.

Chimeric antigen receptor (CAR) T-cell therapy is a treatment that stimulates T-cells to fight cancer by editing them in the lab so they can be released into the body to find and destroy cancer cells. This treatment has been successful in treating certain types of hematologic malignancies but unsuccessful on solid tumors. Hematologic malignancies are cancers that begin in blood-forming tissues such as the bone marrow and in the immune system. Examples of cancers that can be treated with the CAR T-cell therapy include leukemia, lymphoma, and multiple myeloma.CAR T-Cell Therapy 

CAR stimulates macrophage phagocytosis function against tumor cells and its immunomodulation capacity. Scientists have already achieved success with this therapy in B cell leukemia/lymphoma but are still caught up on complications with solid tumors. The main challenge about solid tumors arise from its immunosuppressive tumor microenvironment. There is also a limited effect on infiltration into the dense extracellular matrix of the solid tumors.

In this type of therapy, the macrophages are the most important aspect of the success in treatment. Macrophages play a central role in the crosstalk between the adaptive and innate immune system. The immune system defends the body and marks pathogens and cancer cells for macrophages to fight and engulf. The researchers at Zhejiang University partnered with a researcher at the Fujian Medical University and The First Affiliated Hospital and Center for Stem Cell and Regenerative Medicine to study macrophage specific CARs and the development of EGFRvIII (epidermal growth factor receptor variant III) Targeting CAR-iMACs. The chimeric antigen receptors were further genetically engineered into induced pluripotent stem cell (iPSC) derived macrophages (iMACs) so that the CAR treatment was more effective toward solid tumors. The firefly luciferase gene (Ffluc) was discovered to promote the research through the bioluminescence signal response from tumor cells.

Macrophages were equipped with receptors called pattern recognition receptors (PRRs) through the discovery of the importance of bioluminescence cell signaling. The chimeric antigen receptor was then reprogrammed to contain Toll/IL-1R (TIR), a domain containing adapter inducing interferon β. The TIR-containing CAR is a novel engineered PRR that recognizes antigen associated molecular patterns and enables macrophages with antigen dependent polarization to be more pro-inflammatory to aid immune cell therapies in cancer.

Connection to AP Biology:

The chimeric antigen receptor T cell therapy has a great deal of connections to our AP Biology class.

Cancers:

CAR treats certain types of cancers, usually those in the blood-forming tissues. As we learned in AP Bio, cancers form when a cell does not properly divide and bypasses the checkpoints in the mitosis cycle. These abnormal cells don’t always become cancerous but they no longer follow the signals to stop dividing, causing masses that could one day become cancerous. 

Macrophages & Phagocytosis:

Macrophages and phagocytosis was something that we learned about in the first semester. Macrophages are specialized cells that are involved in pathogen detection so that phagocytosis can occur and destroy bacteria and other harmful substances.

Phagocytosis occurs when a cell engulfs solid things into the cell. We learned about phagocytosis along with pinocytosis and receptor-mediated endocytosis. In CAR therapy, phagocytosis occurs to engulf pathogens and cancer cells.

Bioluminescence:PanellusStipticusAug12 2009

In AP Bio, we did not directly learn about bioluminescence but we learned about cell communication and cell signaling. In bacteria, there is quorum sensing and it allows bacteria to share information about cell density and adjust gene expression. In bioluminescence bacteria, the power to produce light is controlled by quorum sensing. One bioluminescent bacteria cannot light up on its own, but when multiple bioluminescent bacteria gather together, quorum sensing signals for the “light” to shine once it senses enough of the bacteria together.

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Leading Science with Light

Emmett Chappelle was a African American Scientist and one who contributed greatly to Medicine, Philanthropy, and Astrochemistry. Chapelle was born on October 24, 1925 in Phoenix, Arizona where he grew up to attend Phoenix College. During his time at Phoenix college, he received an Associate’s Degree in electrical engineering and then a Bachelor’s of Science in biology at the University of California. Following, Emmett Chappelle taught biochemistry at Meharry Medical College. He received many offers for his graduate studies which he completed for his Master’s Degree at the University of Washington. Continuing his studies, Chappelle earned a Ph.D at Stanford University for 4 years before leaving for a research position at the Research Institute for Advanced Studies in Maryland. After years of hard work, he moved on to work at NASA before moving on to work at the Goddard Space Flight.

While at NASA, where Chappelle worked as a Exobiologist and Astrochemist, he made several discoveries. Perhaps the most important aspect of his work in the field of biology was his exploration of how light is given off by different organisms. Chappelle learned that certain chemicals give off light when mixed with living cells as long as adenosine triphosphate is present, and use this finding to detect bacteria in various samples, including bodily fluids, water, and other foods. Chappelle used this knowledge to develop a means to determine the health of plants. By measuring the amount of fluorescents emitted by plants in a forest, he was able to determine the amount of photosynthesis occurring within that forest. Chappelle’s study of the enzymes luciferin and luciferase, used by fireflies, to make their cells glow paved the path for many current scientists who still use these chemicals as florescent tags to see cancer cells.

Chappelle was inducted into the National Inventors Hall of Fame for his discoveries related to bioluminescence and the important roles they have played in many fields of science. Aside from his recognition for his scientific discoveries that earned him 14 US patents, Chappelle was also respected for his service in the United States Army and for the time he spent mentoring minority high school and college students. Although he passed away in October of 2019, Chappelle will long be remembered for his many contributions to science.

 

 

 

 

Inhale RNA, Exhale Your Worries

The focus of a recent study is inhalation genetic therapy to give patients with Cystic Fibrosis relief when they breathe. A defective gene in people with Cystic Fibrosis causes a mucus build-up in specific organs. The respiratory complications due to mucus build-up in the lungs are which infections, clogged airways, inflammation, and respiratory failure.

Recently, scientists developed a study that involves mice inhaling messenger RNA. The messenger ribonucleic acid is genetically manipulated so that it contains an oxidative enzyme called “luciferase”, which is known for causing bioluminescence. Scientists manipulated the mRNA by “packaging” or combining the enzyme with a polymer that would be inhaled into the lungs of the mice. The inhaled polymer would then travel through the respiratory system and be taken in by the lungs, where it would eventually be broken down by cells within the lungs. Scientists were able to distinguish if the experiment was successful as the light from the luciferase combined with the mRNA could be detected from within a lung cell.

Another experiment was conducted with similar circumstances in that it tested genetically modified mice cells that glowed red from the cell’s reception of mRNA. This offered the scientists the opportunity to test a range of mRNA-polymer dosages to quantify or count the resulting “red” mice cells.

As we continue this road down modern medicine, mRNA can be evolutionary for patients with Cystic Fibrosis because the messenger RNA can recreate functional copies of itself to produce CFTR protein (cystic fibrosis transmembrane conductance regulator protein), which is the protein that codes and determines the functionality of the CFTR gene. Could mRNA polymers possibly be a treatment for milder respiratory issues like asthma? This experiment might just be a breakthrough in the world of medicine, as strands of ribonucleic acid could be the answer to ending compromising respiratory complications.

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