Be immuned to Immunology

When we usually talk about immunology, most of us think about white blood cells first. Recalling back to my previous post on the innate immune system, I stated that the innate immune cells are the front line of defence. However, let's not forget our epithelia. Skin Your skin is like an armour that protects your whole body from the environmental pathogens. It serves as a physical barrier, which blocks any pathogen from entering your system. The many layers of skin makes it much more difficult for any pathogen invasion. Also, in the epidermal layer, there are Langerhan's cells (epidermal dendritic cells) which will act to capture pathogens, and present it to T cells to activate them. Innate immune cells can be most commonly found in the skin, so that they are able to get rid of pathogen immediately. Now, the skin usually protects the whole body from external pathogens. However, there are 2 openings which can increase the chance of pathogen invasion. The mouth and nosetril...

So, let's branch into a little Haematology in this post. One of the main component of the immune system, are the immune cells (I usually like to imagine them as little troops of soldiers). Most of us know them as white blood cells. The flow chart above shows the different lineages of the various blood cell types, and to the left, we see the erythrocyte and megakaryocyte. Erythrocytes are basically the red blood cells, while megakaryocytes are the cells which produces platelets (thrombocytes), but we aren't going into details about that. So for immunology newbies, it may seem a little overwhelming, but its actually quite simple after going through it a few more times. As we can see, there are 2 main lineages from the multipotent haematopoietic stem cells: myeloid & lymphoid. In adaptive immunity, it is easy to remember that the small lymphocyte lineages (T and B lymphocytes), all belong to adaptive immunity. Apart from erythrocytes, megakaryocytes and small lym...

We are usually informed that, once we have had a certain infection, we are 'immuned' to the disease. But what exactly does it mean? Our bodies are very very smart. Our immune system, over millions of years of evolution, have developed very specialized cells, which can be 'educated' to recognise pathogens that we have encountered before. So with each exposure to a specific pathogen, adaptive immune cells will develop into specialized memory cells, which remembers that specific pathogen. Why is this function so important? With each exposure to a certain pathogen, the adaptive immune cells does not just remember that pathogen, it also develops cells which are very specific towards that pathogen, and it is also more efficient  in eliciting an inflammatory response to get rid of that pathogen.  Let's talk about the controversy of vaccines. It was pointed out that vaccines can cause autism in kids, but that is not the main point of this post. While I have not ...

I'm sure we have all caught a common cold, cough, or a fever before. These minor illnesses usually leave after a few days, but have you ever wondered, exactly what went on in your body? For starters, we have to remember that the immune system is always fighting off pathogens from the external environment, however, it is not always successful, thus we fall sick sometimes. When we get the common cold and/or cough, it is because certain bacteria and viruses managed to invade into the body, and your immune system is unable to kill it off immediately, thus, it elicits an inflammatory response from the whole body immune system to try and kill the pathogen. Now in relation to the post's topic, innate immunity is the front line of your immune system in protecting your body from external environments. When a pathogen invades, the innate immune system's first instinct is to kill, and rid the body of any pathogen. The story does not end there though, but it will be further ela...