The human body is built to survive in many conditions. The many systems in the body work to ensure humans are able to live in many kinds of environments and if there are any changes affecting the normal body mechanism, the body will make some changes too to adapt. Have you actually wondered how amazing the body is when you simply scratched your leg after falling on the ground? The body will try to cover the injury and you will feel some degree of pain. It is true that pain can be a nuisance but pain is the signal the body gives to activate the blood clotting system to help heal the bleeding injury. This shows that whenever there is disruption to the normal body system, the body does make changes to help fix the situation. In this DoctorOnCall’s article, we will be learning about cytokine inflammation that is usually associated with signalling pain.
Cytokines are a type of protein that is made by certain immune and non-immune cells. Cytokines do have an effect on the immune system which is triggering the inflammation process in the body. Inflammation is the immune system’s response to harmful stimuli such as pathogens and damaged cells. Hence, cytokine inflammation means cytokines that promote the inflammation process.
Cytokine is a general terms to describe the many types of protein messengers that triggers the immune cells and guide the immune cells to destination it needs to act on, among the common types of cytokines are:
- Chemokine- leads the direction for the immune cells to its target. There are at least 45 different kinds of chemokines that are divided into 4 groups which are CC, CXC, XC and CX3C.
- Interleukins- act as signals between white blood cells. It also helps to control the growth and activation of immune cells. It. There are more than 30 interleukins that play a role in the body. Among these amounts, there are few that play vital roles in the human body such as IL-1 which is a potent inflammatory which promotes the recruitment of inflammatory cells at the site of inflammation as a response to many stimuli such as infection and IL-2 that helps the immune cell to grow and divide.
- Interferons- helps the body to resist viral infections and cancer. There are 3 types of interferons which are alpha, beta and gamma. IFB-alpha is produced in the white blood cells infected by virus, IFN-beta is produced from the fibroblasts (cell of connective tissue) infected by virus and IFN-gamma plays a role in activating the anticancer effects.
- Tumour necrosis factor (TNF)- plays a role in the life cycle of cells that includes cell survival, proliferation, differentiation and death. It also signals immune cells to kill tumour cells.
- Colony-stimulating factors (CSF)- substance that stimulates production of blood cells. It signals the hematopoietic stem cells (mostly in the bone marrow and are precursor cells) to develop into specific cell types such as white blood cells like neutrophils through a process known as haematopoiesis.
Cytokines in the inflammatory response can work as pro-inflammatory cytokines and anti-inflammatory cytokines. Pro-inflammatory cytokines are cytokines that trigger the immune system to increase inflammation whereas anti-inflammatory cytokines are cytokines that lessen the inflammation or halt the process.
Cytokines work in the body when there are possible dangers to the body such as infection or pathogen. When such dangers are introduced to the body, the immune cells will the first to notice this. The immune cells will send out messages to other cells or organs through cytokine signalling. Then, an inflammatory response is initiated. Initiation of cytokine lets the immunes cells and non-immune cells in the body to triggers immune response in order to eliminate the dangers. The cytokines travel through the bloodstream or directly reach the tissue to bind with cytokine receptors. Cytokine acts as a key and cytokine receptor acts as the lock. Hence, when the cytokines are bind to the cytokine receptor, the immune response starts.
Inflammation is the immune response. When inflammation occurs, cytokines will lead to many changes in the cells or organs. Common events in the inflammation process include making the blood vessels become porous and leak the blood to the surrounding tissue, allowing immune cells to travel via the leaked fluid to the damaged area before the healing process takes place. This is when a person starts to feel the inflammation sign. For example, when a person accidentally falls on the ground with injury on the knees, the person will feel pain, the skin around the injury become red, swelling and warm upon touch. The person may also avoid standing on the injured knee or walking since it is painful. Such an event explains the 5 important signs of inflammation which are redness, swelling, heat, pain and loss of function.
Remember the pro-inflammatory cytokines and anti-inflammatory cytokines? The response of these cytokines is important to be on equal length. This is because too much of the pro-inflammatory cytokines can lead to a cytokine storm which can be life-threatening while too much anti-inflammatory response can lead to compromised ability of the body to activate immune cells response.
It can be concluded that cytokine plays an important role in regulating the inflammatory response. The knowledge of cytokines not only makes us understand why inflammation sign actually a good sign that the body is responsive towards possible dangers such as pathogen but also helps to treat certain diseases such as cancer by creating drugs mimicking the cytokine function like interferon and interleukins as anti-cancer drugs.