Various animals have differently evolved immune systems that confer different levels of immunity. Each species of animal has an immune system that is best adapted to their survival
With the COVID-19 pandemic sweeping the globe, pushing people to their physical and mental limits, one thing that’s becoming the center of attention is immunity. Everyone is interested in immunity boosters and people are trying to keep their immune systems as strong as they possibly can. Some of the questions that come up in this regard are: what is immunity and how does it differ from animal to animal?
What is immunity?
Immunity is the capacity of an animal to resist toxins and invasive microbes. This is accomplished by the immune systems of animals, which give them their capability to fight against disease-causing microorganisms.
The immune system is a complex network of cells and organs that work together to fight the never-ending battle against germs and toxins until the day the animal dies.
Simply put, the immune system is to an animal’s body what a defense force is to a nation.
Our immune system fights against millions of continuously evolving germs (Photo Credit : peterschreiber.media/Shutterstock)
How does the immune system of animals work?
Animal immune systems offer two kinds of defenses—innate immunity and adaptive immunity. Both defensive systems operate simultaneously, but in somewhat different fashions, to provide an extensive cover from toxins and microbes.
Every microorganism has a distinct PAMP—a chemical structure that can be made up of carbohydrates, lipids and proteins. This signature PAMP is specific to a particular organism, just as a barcode is a unique pattern for a particular product.
Now, these PAMPs are read by Pattern Recognition Receptors (PRRs). These receptors are present in the bodies of all animals, with the sole purpose of scanning the PAMPS, recognizing the organism and identifying it.
The adaptive immune system is a more complex form of immunity, one that is very specific to the type of animal. This adaptive immune response is mediated by our good ol’ pals T and B lymphocytes.
T-cells are one type of immune cell that recognizes potential pathogens and either destroys them or signals another kind of immune cell—the B cells, to produce antibodies against them. These responses are then “remembered” by the immune system of the animal, offering immunity from that particular pathogen.
Why does immunity differ amongst animals?
There are many factors that determine the immunity of a living thing: their genetic makeup; external environmental factors, such as their habitat, the food they eat, the water they consume; their internal physiological conditions, such as their natural body temperature and body pH, among others.
To illustrate with an example, humans, cattle and deer can all succumb to an illness called anthrax. Anthrax is caused by the bacterium Bacillus anthracis. This particular germ affects its host by producing poisonous toxins within all three species.
This disease can be fatal in humans and cattle, but interestingly enough, chickens are entirely immune to it. The high body temperature of a chicken, as compared to humans or cattle, ensures that the bacteria cannot survive inside them.