The Hierarchical Nature Of The Immune System
How does the immune system really function within our body?
The body’s immune system is responsible for defending the body against any potential threats or infections. The idea being that we will be able to prevent ourselves from getting infected if we have a “strong” immune system.
Unfortunately, the strength of one’s immune system is never properly quantified. It’s not that easy to quantify it. We don’t even have any metrics to gauge its performance.
Even worse still is that not many people have a good idea of what constitutes the immune system, let alone what are the key defensive players behind its “strength”.
But here’s an easie analogy for ruminating upon with regards to the immune system.
The hierarchy of an organisation
Most people would have worked in an organisation before, where there are many different departments, and where there is a positional hierarchy.
We have the CEOs, the SVPs, the mid level managers and the minions at the bottom of the totem pole, for instance.
The CEO is so many levels away from the minions positionally that the CEO wouldn’t necessarily know what the minions are doing - it would be the supervisors of the minions who are more in tune with what the minions are doing.
Over time, the minions come and go. A well run organisation would have processes for renewal in place to maintain its relevance and competitiveness in the market. The survival of the minions, therefore, would be dependent on the organisation’s performance reviews/appraisals of the minions - are the minions meeting their key performance indicators (KPIs), or not?
Also, as the CEO is far removed from the minions, the CEO may not necessarily know what the minion is doing. As far as possible, the minion would not want to involve the CEO in their daily activities - because involving the CEO would mean that there is trouble brewing somewhere.
If the minion has the ability to address their work problems and solve them, everything goes on as per normal without much consequence.
But if the case were more serious, such as in the event of sexual harassment or racial discrimination, the minion might have to escalate the issue to upper levels of management to find a proper resolution to the issue.
An escalation of the problem to one’s superiors could lead to more dire consequences.
The immune system would analogically have a similar hierarchy.
The macrophages (or the white blood cells), for instance, are the first line of defence against any bacterial/viral threats or infections. Here’s a video that shows a macrophage chasing down a random bacterial cell, which can be seen on Youtube:
The macrophage proceeds to chase down and engulf the bacterial cell.
It then proceeds to digest the bacterial cell down into simpler pieces in a process known as phagocytosis.
A completely digested bacterial cell poses no more threat to the body with regards to any possible infection.
Meaning that we have a good first line of defence to protect ourselves from the viral and/or bacterial threats that exist all around us.
We’d need the macrophages to be at the top of their game in hunting down all these foreign particles if we want to maintain a strong, healthy defensive scheme in protecting us from those viral and bacterial threats:
The Importance Of The Macrophage In The Immune System
In fact, these macrophages do make use of the phagocytosis digestion process to eliminate the cells in our body that aren’t functioning as properly as they ought to be - in other words, these cells aren’t hitting their KPI targets at all. We know this to be the body’s self-renewal process of autophagy:
The problem is, what if the macrophages themselves aren’t hitting their KPI targets?
When are macrophages distracted from their defensive activities?
As employees in an organisation face distractions at work, so will the macrophages face distractions too.
For example:
Macrophages are responsible for driving and sustaining the inflammatory response in obese people.
Macrophages are also responsible for promoting the formation of atherosclerotic plaques.
Macrophages can also be sent on misguided missions by misguided signals to eliminate healthy cells within the body via phagocytosis, which is the problem of the autoimmune disease.
So if these macrophages end up doing all the stuff that they don’t necessarily have to be doing, then do they have time to carry out their primary function, which is to protect the body from viral and/or bacterial threats by swiftly digesting and eliminating potential invaders?
What implications would that hold for our immune system?
When one’s macrophages aren’t working to eliminate those threats efficiently enough, we have a problem.
We’d need to call upon other cells in the hierarchy to deal with those threats.
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.
Meaning to say that if our macrophages are functioning effectively enough, we’d be able to deactivate and digest the flu bug swiftly and efficiently enough.
If the deactivation and the digestion isn’t swift enough, the immune system might have to call upon the other immune cells to aid the macrophages, and that can bring about the consequence of a fever, for instance.
We can see how suboptimal macrophage activity is implicated in obesity, heart disease and autoimmune disorders. People facing these health issues also do find it a more arduous task to recover from something as simple as the common cold.
When one’s immune system is extremely “strong”, one can easily weather an infection without any symptoms - the macrophages do the elimination work too quickly for any symptoms to build up. A breach in the defensive walls is quickly covered up and the invaders swiftly dealt with.
But when one’s immune system is “weak”, and possibly weakened by the presence of other underlying health issues too, that person would have to be more careful with how they’re maintaining the functionality of their immune system!
Do feel free to check out Nutrients That Support A Healthy Immune System to see how our diet can influence our immune system’s functions!
Also, feel free to share this article and hit the “subscribe” button to get more updates about the science concepts in nutrition and health, all deconstructed nicely for your convenient perusal!