Molecular sensors enable eukaryotes to recognize microbial pathogens and their products, thus operating as major players in the protective mechanisms of the innate immune response. In addition to microbial pathogens, innate molecular sensors recognize signals from damaged tissues. The response of innate molecular sensors is typically immediate but short-lived. However, excessive activation and/or engagement of […]
A few days ago, results from the landmark NASA’s “Twin Study” were published in the scientific journal Science (April 12, 2019). The study was carried out in 2015/2016 to understand the health impact of long-duration spaceflight, and centered around astronauts Scott and Mark Kelly, who are identical twins. One of the twins, Scott Kelly, was […]
Why does hair turn gray? Laurence Meyer, a dermatologist at the University of Utah, offers this explanation: “The pigment in hair, as well as in the skin, is called melanin. There are two types of melanin: eumelanin, which is dark brown or black, and pheomelanin, which is reddish yellow. Both are made by a type […]
Tissue injury or infection results in the development of a rapid local inflammatory response, a cascade of events necessary for the clearance of invading microbes, the minimization of tissue damage, and finally the restoration of normal tissue function, or resolution. The resolution phase occurs without compromising host defenses. Similarly to other biological cascades, the inflammatory […]
Immune system cells are able to extrude stringy DNA webs as weapons to fight invading microbes. Neutrophils, the most abundant type of white blood cells, use the so-called extracellular traps—a meshwork of DNA, histones, and antimicrobial proteins derived from the neutrophils’ granules—to immobilize and kill bacteria and fungi. This process results also in the death […]
Natural Killer (NK) cells are lymphocytes that were first noticed for their ability to kill cancer cells without any priming by antigen presenting cells and in absence of prior activation—for this reason, they were dubbed “natural”. They derive from a common progenitor shared with B and T cells. However, NK cells are classified as group […]
Leprosy—also known as Hansen’s disease—is a chronic infectious disease caused by Mycobacterium leprae (and, less commonly, Mycobacterium lepromatosis) that results in severe, disfiguring skin sores and peripheral nerve damage in the arms, legs, and skin areas around the body. It’s most prevalent in the developing world, where living conditions are poor and people struggle to access sufficient […]
The cigarettes known by many different names—e-cigarettes, e-cigs, e-hookahs, mods, vape pens, apes, tank systems, electronic nicotine delivery systems (ENDS) and more—may cause harm by suppressing the immune system, as indicated by recent research. Last year, a study published in the American Journal of Physiology suggested that inhaling the vaporized flavored liquids in e-cigarettes is […]
Innate immunity, the first line of defense against infectious pathogens and cancer cells, relies on a variety of cell types to carry out its pathogen-fighting and clean-up functions. Resident cells present in most tissues serve as sentinels, detect danger signals and send for help. Phagocytic cells—such as macrophages and neutrophils—respond to the call, infiltrate the […]
“When a wound swells up, turns red and hurts, it may be a sign of inflammation. Inflammation is—very generally speaking—the body’s immune system’s response to stimulus. This can be bacteria colonizing a wound or a splinter piercing your finger, for example. Inflammation happens when the immune system fights against something that may turn out to […]