As of recent, the whole world is working on how to tackle the corona global pandemic. Now that everyone has gotten a good grasp of the situation—thanks to main stream media—there are a lot of concerned people worldwide who would like to understand the pathophysiology of the infection. Let’s dive in straight on Coronas mission for infection. Let’s call it corona’s battle mission.
For the sake of ease, let’s consider the virus as our antagonist that is in a battle mission to conquer the body, infecting and killing the hero—us! The hero has a lot of entourages to support it in this novel battle. I will introduce these entourage protagonists in their own time and scene in the battle, and tell you their roles, responsibilities and sacrifices they will play along in this grand battle scene.
Basically, Corona virus-the villain, has a super power. It can infect people from normal daily contact. They spread via air-borne droplets from cough or sneeze, or contacting eyes with uncleared hands directly. These villains are capable of penetrating through the mucosal membrane of mouth, nose or eyes and enters our circulatory system. So, you can guess it is going to be a bloody battle!
As it happens, the villain is on its own mission to infect everything on its way. The reason why the viruses are so infectious is because it has a special key- a key that can open any Pandora’s box. This special key is known as angiotensin-converting enzyme 2 (ACE2). Our body has a recognition protein that can detect the villains infiltration, but the villain is so covert that it easily deceives our entourage protein. With its covert mission, the villain thus gets intracellular access by disguising itself as a nutrient substance. This is the scene in the movie where disguised as a friend, the villain infiltrates our shield .
In the next scene, after intracellular entrance, the villain releases its main weapon-it’s RNA, which works as its genetic material. Ribonucleic acid (RNA) is a polymeric molecules that are essential in various biological roles in coding, decoding, regulation and expression of genes. This RNA weapon acts like a boss and commands the ribosomes to start producing an army of virus. Thus, our hero’s cell (whole cell) turns into a virus factory, producing millions of virus villains. These newly produced viruses then transport outside the cell repeatedly infecting other healthy cells. The battle has already begun, yet our hero has no clue about it.
The period of this cellular infection could be different, confusing the hero of the attack because there are no obvious symptoms. This is the scene in the movie where our hero is in the dark-absolutely clueless about what’s happening. Hence, our hero does nothing in this scene to counter attack. This is the so called incubation. During the incubation, the army of viruses grows stronger and stronger. Finally, it declares war against our body. Our villains are as aggressive as Hulk and begin besieging our lungs.
FIRE! SMASH! TRIPLE KILL! DANG! BANG!
Now that a one sided battle has begun, and our hero comes to some senses of the attack, the infected cells immediately calls for a backup. To do that, it send an alarm to the immune
AVENGERS ASSEMBLE! COVER ME! DEFEND OUR LUNGS!
Receiving the battle alarm, the van guard of White Blood Cells (WBC) are our entourage that reacts and fights against viruses. WBC’s AKA Leucocytes are the cells of the immune system that are involved in protecting the body against both infections and foreign invaders. One type of WBC, particularly natural killer cells, organizes an indiscriminate attack toward the infected tissues and causes a lot of death. However, there is a collateral damage as natural killer cells not only kills the viruses but also our own cells.
Another vanguard—the Monocyte (one type of WBC) comes for our aid. It arranges it’s offense toward infected cells. Depending on their bigger volume, monocytes swallow the viruses and infected cells. Some more reinforcements come to the battle field right after the WBC vanguards. Two more allies—the Dendritic cells and Macrophages engage and join the glorious battle in besieging the viruses. As the battle wages on, our battle field such as throat and nasal cavity are filled with the corpses of cells and viruses. The stacks of battle corpses causes nasal obstruction. Hence, coughing starts-to remove these
AHEM! AHEM! AA-CHOO!
As the infected cells are removed with coughing and sneezing, our hero feels pain of throat or other parts. While this is only the beginning of the counter attack. We have yet to summon our main ally. Meanwhile when the WBC’s are fighting, the information of the Corona villain is reported to our main commander in chief—the brain. Like any commander, our brain acts very fast in initiating an emergency alarm and call for a total defense by decreasing activity of all cells. Due to the decreased activity of cells in our body, we feel drowsiness and aches all over the body. The body temperature is increased on purpose to a higher level hoping to kill the invaders. We experience fever, headaches, red swelling on throat and muscular pains. As this is happening, More WBC is produced from the saved energy to invite more fighters to joins the fight. Thus, the battle escalates.
If it were any other casual viruses, they would be annihilated within a few days. However, Corona virus is not a normal virus because they have special protein armor that can mislead our immune system into attacking some of our own cell by error. Therefore, immunocompromised patients with some predicting conditions like heart disease or diabetes end up badly harmed or even be dead because of attack of cells from own immune system.
Some other fatalities are caused due to over reacting of the immune system which is also known as cytokines storm. Simply, cytokines storm is an overproduction or immune cells and their activating compounds( cytokines), which, in a flu infection, is often associated with a surge of activated immune cells into the lungs. Cytokines storm makes the WBC’s over excited, and fiercely attack their own lungs by error made by viruses that leads to Pulmonary fibrosis as a result of which leads to lungs to lose its function of expansion. This leads to suffocation and victims die because of it. If this happens, the hero loses the battle of life.
But then, those who are lucky to get timely help of medical professionals and proper healthcare can gain extra time and energy for their immune system, and help the system keep winning until the end of the battle. In an alternative scenario where our hero survives because of time borrowed by the aid of proper medical treatment and care has to do with Dendritic cells. Dendritic cells are messengers that send information to the special force—Lymph gland base. The lymph base consists of elite immune force of T-cells and B-cells. Receiving the information from Dendritic cells, the lymph base will start to produce a lot of T cells and B cells which helps us reverse the situation. This is also when our lymph glands feel swollen.
T-cells are types of lymphocytes which developed in the thymus gland and plays a central role in the immune response. When they function, or are ready for battling, situation is under control. Infected cells in the body will be eliminated directly and the healthy cells start committing suicide in order to isolate the viruses. Basically, Human cells give their life to save the master. Some supportive T-cells summons more T- cells into the battlefields and send more information to B- cells. B-cells or B-lymphocytes are a type of white blood cells that function in the humoral immunity component of the adaptive immune system by secreting antibodies. Instead of showing up in the battlefield, B-cells begin producing millions of antibodies according to the genes of viruses. These antibodies chase and destroy the viruses automatically just like Ironman’s tracking missile. They auto lock the corona viruses until they are inactive to infect anymore.
Also, antibodies tie up the viruses so that they cannot hide from the neutrophils. Neutrophils are a type of white blood cell that protect us from infection and have other protective functions as well.
All in all, with the hard work done by all the cells, majority of Corona viruses are destroyed. Remaining few of them are driven out of the body. As this happens, regulatory T-cells show up and declare victory of the battle and release the army from state of war. As T-cells complete their job, they slowly begin to disappear. A few of them, however survives and transfers into memory T- cells. Together with the antibodies, they then patrol together to defend the body. Thus keeping a natural captain America’s shield like protection.
Adequate amount of rest and patience is necessary for replacing the dead cells and to replenish with the new ones to recover our health back. Victory is achieved. The corona drama thus ends.
By: Serious李 2020.02.14
