Scientists Say: Neutrophil | Science News for Students

Scientists Say: Neutrophil

This is a cell in the immune system that traps and destroys invaders
May 27, 2019 — 6:30 am EST
a microscopic image of a neutrophil attacking a bacterium

A neutrophil (right, in yellow) engulfs a bacterium (left, orange).

Volker Brinkmann/Wikipedia (CC-2.5)

Neutrophil (noun, “NEW-troh-fill”)

This is a type of cell in your immune system — the collection of cells in your body that fight off infections. Neutrophils are the most abundant immune cells in the body. They form in the bone marrow and circulate in the blood. Each neutrophil lives only a few days, but while they are alive they are on constant patrol.

Neutrophils are one of the first cell types to arrive when an infection takes hold. When a cell in the body is infected with a harmful microbe, the cell sends out a chemical distress signal. When neutrophils detect this signal, they crawl toward the infected cell. Once they arrive, they release cytokines — chemicals that serve as an additional alarm call. These chemicals summon more immune cells to the scene.

But neutrophils don’t stop there. They can engulf microbes and digest them. Neutrophils can also spew out antimicrobial chemicals to kill bigger invaders. They can even release a web of fibers that trap and kill invading microbes.

In a sentence

Scientists are using computer models to figure out how to make neutrophils into more efficient killers.

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Power Words

(more about Power Words)

antimicrobial     A substance used to kill or inhibit the growth of microbes. This includes naturally derived chemicals, such as many antibiotic medicines. It also includes synthetic chemical products, such as triclosan and triclocarban. Manufacturers have added some antimicrobials — especially triclosan — to a range of sponges, soaps and other household products to deter the growth of germs.

bacteria   (singular: bacterium) Single-celled organisms. These dwell nearly everywhere on Earth, from the bottom of the sea to inside other living organisms (such as plants and animals).

cell     The smallest structural and functional unit of an organism. Typically too small to see with the unaided eye, it consists of a watery fluid surrounded by a membrane or wall. Depending on their size, animals are made of anywhere from thousands to trillions of cells. Most organisms, such as yeasts, molds, bacteria and some algae, are composed of only one cell.

chemical     A substance formed from two or more atoms that unite (bond) in a fixed proportion and structure. For example, water is a chemical made when two hydrogen atoms bond to one oxygen atom. Its chemical formula is H2O. Chemical also can be an adjective to describe properties of materials that are the result of various reactions between different compounds.

computer model     A program that runs on a computer that creates a model, or simulation, of a real-world feature, phenomenon or event.

cytokine     A substance secreted by certain cells of the immune system which the body uses to have some particular controlling effect on other cells. Examples include interferons, interleukins and growth factors.

digest     (noun: digestion) To break down food into simple compounds that the body can absorb and use for growth. Some sewage-treatment plants harness microbes to digest — or degrade — wastes so that the breakdown products can be recycled for use elsewhere in the environment.

immune     (adj.) Having to do with the immunity. (v.) Able to ward off a particular infection. Alternatively, this term can be used to mean an organism shows no impacts from exposure to a particular poison or process. More generally, the term may signal that something cannot be hurt by a particular drug, disease or chemical.

immune system     The collection of cells and their responses that help the body fight off infections and deal with foreign substances that may provoke allergies.

infection     A disease that can spread from one organism to another. It’s usually caused by some type of germ.

marrow     (in physiology and medicine) Spongy tissue that develops inside of bones. Most red blood cells, infection-fighting white blood cells and blood platelets form within the marrow.

microbe     Short for microorganism. A living thing that is too small to see with the unaided eye, including bacteria, some fungi and many other organisms such as amoebas. Most consist of a single cell.

model     A simulation of a real-world event (usually using a computer) that has been developed to predict one or more likely outcomes. Or an individual that is meant to display how something would work in or look on others.

neutrophil     A type of white blood cell released by the immune system. It gobbles up wastes and release chemicals that can digest cells, including germs.

prey     (n.) Animal species eaten by others. (v.) To attack and eat another species.