Dr K. G. D. Mawji BM MSc.
Hello, Immune system.
Updated: May 12, 2020
Who are you?
Cells which are part of the immune system
Recently, the hype surrounding COVID-19 has been all about immunisation and vaccination. The internet and the press have gone all out in an attempt to inform the wider public about immunity. Unfortunately, with it inaccurate information has filtered through to the top.
Let us take a moment to understand, what is an immune system and what triggers it.
Your immune system is like a policeman, always there 24/7 all days of the year.
The immune system is a geek. It’s very clever in distinguishing between which cells are normal and which are abnormal. This it does by checking on clues exhibited on abnormal cell's surface called "danger-associated molecular patterns (DAMPs)".
It’s also smart in knowing which cells have been infected e.g. with a virus from what clues the cell is exhibiting on its surface called pathogen-associated molecular patterns (PAMPs).
These clues, the DAMPs and PAMPs are a signal for the immune system to gear up for a fight, destroy the invader and ingest the damged cells.
Understand that immune system is not an organ like the kidney, heart or liver but it’s made up of cells that roam freely throughout the body getting into every crook and cranny of the body.
The bone marrow contains the stem cells which mature to produce fast-acting immune cells that respond first when the infection strikes. Others that are formed in the bone marrow are the white blood cells called lymphocytes. Together they form a lymphatic system which includes lymph nodes, the spleen, tonsils, adenoids and thymus gland, as well as lymph vessels that carry lymph throughout the body. The lymph nodes are roadblocks for viruses and other infections. Where they get trapped and face the immune response.
How does it do it?
It kicks into gear when it comes across “particles” like a virus which it does not recognise. The catalogue of information (white cell memory) tells it whether it’s a new type or ones it has come across before. If its former, it mounts a precise assault on that foreign particle making it ineffective and detroys it. If laters, it goes on to process it and then send in cells to fight the particle. In the intrem time, the virus particle keeps on infecting the body.
Covid-19's shape with skipes in corno arragment
These “particles” are called antigens which are proteins found on the surfaces of viruses, bacteria and fungi. The antigens attach to receptors on immune cells (see pictorial description of antigen-antibody reaction below) setting off a cascade of reactions. The geeky aspect of this process is that whilst its fighting off the foreign particles it simultaneous cataloes this in its memory for future use.
The above is a slide show, click on the picture to view.
In case of COVID-19, which the immune system has not meet before, does not respond until its mechanism has processed the virus to be recognised by PAMPs. By the time that happens the CVOID-19 has widely spread wide in body and started its damaging journey. This virus very quickly infects every organ of the body through a door called ACE2 receptor, which is found on the cell surface.
The blog on vaccination will apper soon.
The next blog is on, People’s minds are beginning to turn towards the future and what its going to hold for them after lockdown.