Making Sense Of Our Immune System
What is a system? How does it function? Why is it important to us?
We live in an age where there is a pressing concern about a coronavirus that is highly contagious, and which has become a worldwide pandemic. Many people who have been infected by the coronavirus have not lived to tell the story.
There is a concern, therefore, about how our immune systems function defensively against the virus. But yet the immune system is a complex mix of cells and biochemical signalling processes that not many people can wrap their heads around.
In fact, a question that I came across on Quora was worded as such:
Since a significant number of COVID related deaths are due to an overactive immune system causing a cytokine storm, why then are the vitamins and minerals suggested to help ward it off precisely those that bolster the immune system?
The way that the question was worded suggests that the person who posed the question didn’t really understand how the immune system was functioning.
The question I posed back in response to that original question was: In an immune system, does bolstering cause overactivity?
Bearing that in mind, let’s see how we can make sense of the immune system.
What constitutes a system?
Before we go into the immune system proper, we do need to determine what constitutes a system. The definitions of a system on Dictionary.com include:
An assemblage or combination of things or parts forming a complex or unitary whole.
A coordinated body of methods or a scheme or plan of procedure; organizational scheme.
Every healthy organisation is an example of a well-oiled system. In the grand scheme of things, an employee who works in a company is part of that company’s system. Within that system exist many different departments — some departments deal with internal organisational functions, such as Human Resources (HR) or Information Technology (IT). Without those departments, an employee may not be able to work efficiently with current technological tools, or they may not get paid their wages promptly.
There are other departments that deal with the external side of things, such as the sales department, which focuses on providing solutions for clients. A person who is working in HR would not necessarily be suited to work in sales, for instance.
All these individual departments have mid level managers and higher level management tiers, who are present to regulate the workflow and the tasks that are required for each department to function and to improve.
Communication is key for each department to be on the same page — hence emails, messenger apps and phone calls are necessary to get messages sent across effectively. A nastily worded email can create its own issues inasmuch as a vague email can cause confusion.
What’s in our immune system, then?
Our immune systems comprise many different types of cells that do different things. For instance, we have macrophage cells, which are responsible for “detecting, engulfing and destroying pathogens”. We have T cells, dendritic cells and natural killer cells, all of which are responsible for producing biochemical signals in the form of cytokines to communicate messages across to other cells to do something somewhere. Our B cells also produce antibodies that are responsible for tagging and neutralising specific virus or bacterial invaders (also known as the antigens).
These cells, therefore, have to work in sync. The cytokine signals have to be effective in communication. Each different type of cell has to be efficient in responding to certain threats in the body. The overall immune response to any threat has to be balanced. When we want to “bolster” our immune system, therefore, it is a case of wanting to get an immune response to a threat to be as balanced as possible, and not reach a state of overactivity, where the response has overshot the mark.
Because an overshoot brings with it a new set of problems. If there was an internal problem in a department that could not be dealt with by the employees themselves, the problem would be escalated up to higher levels of management in due time. The consequences of escalation would be more severe — especially if the stink is raised all the way to the Chief Executive Officer’s office!
The immune system functions in a similar way
Our macrophages are equipped to handle the digestion of dead cells and other pathogens via the process of phagocytosis. They essentially eat up and digest the cells/pathogens, and whatever nucleic acids that can be obtained from the deoxyribonucleic acid (DNA) material of the digested cells are fed back into a salvage pathway to obtain fresh nucleic acid components that can be used to synthesise new DNA strands for new cells.
These macrophages are also responsible for the digestion of any antigens that have been tagged by antibodies. In a viral infection, for instance, the sequence of events is said to be in this article that:
The virus gains entry into the body.
The virus infects a cell and reprogrammes it to only produce copies of the virus RNA/DNA strands. These virus copies can then proceed to infect other healthy cells and amplify the effects of virus multiplication exponentially.
Infected cells continue producing virus copies, until antibodies tag the infected cells as infected and programme them to commit suicide via apoptosis.
These dead cells send out signals to phagocyte cells so that the phagocytes can find them, engulf them and digest them up. This process is known as phagocytosis. The digested RNA/DNA strands are broken back down into their constituent nucleic acids so that new cells can be synthesised to replace the dead ones.
Signals in the form of pro-inflammatory cytokines can also be sent out to kill these infected cells by force if the rate of phagocytosis is less than the rate of infection. Too many infected or apoptotic cells aren’t good for our health.
With the macrophages as our first line of defence, we do need to keep their defensive efficiency levels high. When they can deal with an infection threat efficiently, the higher levels of defence do not have to be activated.
Of course, when macrophage activity is suboptimal…
The rate of threat elimination is proceeding too slowly. When a problem in a company cannot be rectified on the ground, but is escalated to higher management, the consequences can become more drastic.
As I wrote in 5 Things For Consideration In Addressing Viral Infections,
If phagocytosis cannot eliminate all the virus particles or infected cells efficiently enough, other immune cells such as the natural killer cells (NKCs) or the dendritic cells (DCs) are called on to aid the elimination process. The NKCs and DCs are signalled by the complex pro-inflammatory cytokine signalling cascades that the macrophages can present, and proceed to produce their own cytokine signallers.
Interferon alpha (IFN-α), for instance, is a cytokine that is produced mainly by the DCs. In large amounts, IFN-α is pro-inflammatory and pyrogenic — it can cause body temperatures to rise, as it is in the case of a fever.
When one is experiencing flu-like symptoms that progresses on into a fever, it already is an indicator that their macrophages are unable to handle the extra workload that is brought about by the infection, and therefore has to call upon the higher level cells to do something about it, which results in the development of more drastic symptoms such as a fever.
Why would macrophage activity be suboptimal?
We live in a workaholic and time-poor society these days. Employees know what it is like to be stressed out and pressured by looming deadlines. People end up eating unhealthy meals for convenience or comfort. Some are unable to sleep properly with all that stress, or even have to hold multiple jobs just to pay the bills. With an insufficiency of time, who would even want to be thinking of exercising?
And these are also Four Ways That Our Lifestyle Affects Our Immune System.
The main problem with a suboptimally operating immune system is that…
The inflammation response gets dysregulated.
Inflammation is a key communication mechanism in the immune system that is a mix of multiple different cytokine pathways. Some cytokines are pro-inflammatory and amplify an inflammatory response, while others are anti-inflammatory and dampen an inflammatory response.
We do need a sufficiently amplified inflammatory response for acute injuries and illnesses, but we do need the inflammatory response to be dampened out once the injury or illness has been rectified.
However, a suboptimal lifestyle can promote a pro-inflammatory response.
Even in obesity, for instance, as I do explore in Obesity, And Why It Ain’t Good For One’s Health:
Obesity does present itself in the accumulation of fat cells (scientifically termed as adipocytes). But what we do need to understand here is that our cells are living biological organisms that take in biochemical nutrients and produce biochemical waste. And of course, according to this article,
Adipocytes themselves produce IL-1β. This initial event may then lead to IL-1β-induced chemokines, resulting in the recruitment of macrophages. Subsequently, macrophage influx and activation within fat tissue may act as a prominent source of IL-1β secretion, triggering insulin resistance.
Interleukin 1-beta (IL-1β) is a pro-inflammatory cytokine that is a significant player in various situations. As per the quote above, IL-1β is one of the major contributors to insulin resistance, as I explore in Type 2 Diabetes — A Case of The Immune System Gone Bad, Too?
Of course, a dysregulated inflammation response does come with further issues…
It can disrupt other “normal” biochemical signalling pathways in the body and cause them to be dysregulated too.
For example, I do highlight in The Delicate Balance Of A Steady State To Maintain A Healthy Body that higher levels of IL-1β production in the body can result in problems with bone and joint degeneration, which can proceed further into osteoporosis or osteoarthritis, respectively.
It could also weaken our blood-brain barrier over time, resulting in brain inflammation and premature brain cell death.
People with autoimmune disorders or severe allergic reactions would already be facing problems with the regulation of their inflammatory responses.
In a nutshell…
We do want to achieve a balanced inflammation response, and that is what “bolstering” or “strengthening” the immune system ought to be doing. We want our cell populations to be clicking together as a whole unitary system, and not behaving in a disjointed or over-reliant manner.
An imbalanced immune system response can lead further down the line into the development of further chronic inflammatory conditions. That’s exactly the stage that we don’t want to get to.
But the lack of awareness is apparent. Not many people do know that inflammation is an immune system response, though they do know about eating “anti-inflammatory” foods to “fight inflammation”. The line of thinking has to be more about achieving a proper balanced inflammatory response! Doctors don’t necessarily consider Alzheimer’s to be an immune system problem, but yet they do know that people with dementia are more susceptible to death from a COVID-19 infection.
After all, it isn’t explicitly mentioned that too much IL-1β can lead on into acute lung injury, isn’t it? Even when a research paper published way back in 2008 provided a grim foreshadowing of it?
It’s not easy to do, though — that much I will admit. Do feel free to check out Nutrients That Support A Healthy Immune System to see how our diet can influence the inflammatory response from our immune system!