HOW DO STEM CELLS CURE THE DISEASE?

WHY IN THE NEWS?

Recently, in the United States of America, an African woman was cured of HIV after receiving a stem cell transplant from a donor who was naturally resistant to the virus that causes AIDS. She became the first woman and the third person to date to be cured of HIV disease.

STEM CELLS

• Normally, diseases can be prevented by vaccines, medicines, or by surgical treatments. All these elements are made up of chemicals and biochemical elements.
• Stem cells are undifferentiated cells that are able to differentiate and transform into any type of cells of the body when and where needed.
• It means they have the ability to develop into many different cell types, such as muscle cells to brain cells.
• The human journey begins with a single cell inside the womb and it gets divided into multiple cells and generates trillions of cells. The bodily organs start producing with the functioning of genetic codes within the womb of the mother.

DO ALL THE CELLS OF A HUMAN BODY IS SAME?

• A cell is defined as the smallest, basic unit of life that is responsible for all of life’s processes.
• All organisms are made up of cells. Each cell contains a fluid called the cytoplasm, which is enclosed by a membrane.
• Every cell has one nucleus, DNA, mitochondria, and membrane-bound organelles in the cytoplasm.
• Each and every cell of a human body is the same, however, each cell has a specific purpose designed in its DNA structure.

HOW ORGANS ARE FORMED?

• Different organs are existing inside the human body such as eyes, ears, hands, legs, heart, liver, etc.
• It is because of the diversity of the cells that different organs are produced according to the genetic code.
• In a respective DNA, some parts are activated and some parts are not activated.
• DNA in every cell has some sequence, this sequence produces protein and the proteins are responsible for building muscles i.e., the entire body is made up of proteins. Thus, organs will be formed when there is the secretion of proteins and the proteins will be produced by cells based on the code.
• The different organs such as eyes, ears, etc. are secreting different proteins responsible for the formation of that particular organ.
• Though the appearance of cells looks identical, the application of their internal code is different.
• Within the same DNA, half of the parts of DNA will be called as regulatory divisions and in that regulatory divisions, only some parts switch to particular type of cells. Therefore, a different part of cells will be switched to different parts of DNA in different cells. This is the reason why there are different parts and organs in the human body.

GENESIS OF THE ORIGINAL STEM CELL

• The original cell can be called the embryonic cells. These cells are having the property to be turn into any of the specialized cells. The process starts immediately after fertilization; the embryo gets formed during the blastocyst process and can be converted into any of the specialized cells.
• These stem cells are those cells from which all other specialized cells are generated.

• These stem cells are available at the time of the embryonic process or at a later part of the body.
• Even children and adults can have stem cells within their bodies i.e., the human body along with other cells having stem cells.

TYPES OF STEM CELLS

Stem cells are divided into four main forms:

1. Embryonic cells

• Embryonic stem cells are the Stem cells that exist during the earliest stage of development of the embryo.
• It is immediately after the fertilization of egg and sperm; the development of the embryo takes place and it has the capacity to turn into any specialized cells.

2. Adult stem cells

• The adult cells are present in the adult human body but it gives rise to a limited number of specialized cell types.
• It comes from fully developed tissues such as the brain, heart, blood cells, and bone marrow. They are more likely to generate only certain types of cells.
• For example, the adult stem cell of a blood cell can turn itself into a blood cell, a liver stem cell can turn into a liver cell only.
• The normal cell cannot have the capacity to multiply into different cell organs.
• The stem cells are not single cells and the cell division happens when it is placed within an egg or oocyte.
• However, there is a recent report which suggests that adult stem cells have the capacity to turn into different specialized cells with some proper programming.

3. Cord blood stem cells or perinatal stem cells

• These stem cells are available in the placental membrane, placenta, umbilical cord, and the amniotic fluid within the womb of a mother.
• These fluids can be collected when the child is born and they have to be cryogenically preserved.
• In the future, if the child or the relative is affected by any diseases, the stored stem cells can be used for getting a cure.

4. Therapeutic cloning of stem cells

• It is the process of fusing eggs and sperm outside the body called in vitro fertilization and by giving proper signals for the formation. The stem cells that have been obtained from the resulting embryos are used for the generation of specialized cells and further stem cells.
• Sometimes, the procedure requires an embryoand, in some cases, the procedure is different.
• It is possible to program the stem cells in a systematic way to generate particular cells.
• For example, by giving proper signals, it is possible to make heart cells from original cells. i.e., the heart stem cell produces specialized cells of the heart along with further heart stem cells which are again utilized for curing diseases.

WHY DO WE NEED STEM CELLS?

The main idea of stem cells is to cure major diseases that is existing today.

• For instance, assume a blood cancer patient who is undergoing radiation would be lacking blood cells in the body. But it is not possible to inject blood each time in the human body. Moreover, the blood cells existing in the body have no capacity to generate further blood cells. In this situation, injecting blood stem cells with proper programming of embryonic or adult stem cells can generate specialized blood cells and blood stem cells also.
• Once injected inside the born marrow, the cell starts producing the blood and the production goes on.
• The entire process will become sustained inside the human body.
• In another case, considering a part of the liver system which got dysfunctionalised. Compensating that portion of the liver with a different set of protein-made cells will result in the failure of the process and it will not function. Placing the liver stem cells can only make the system function properly.

The entire technology is regenerative curing. For curing disease, there is a need to use stem cells and regenerate the cells required. This is the technology involved in Stem cells.

HOW COMPLEX IS THE STEM CELL TECHNOLOGY?

• The technology is not simple.
• It cannot be used for every individual very easily.

The following are the reasons:

1. Therapeutic cloning of stem cells is theoretically successful, but it is not much practical now.
2. Less awareness among cord blood stem cells and the complexity in collecting and storing the same is another concern.
3. Unethical and criminal activity if obtaining embryos from the womb of the mother involuntary because it is morally wrong to use the embryo that contains the cells, capable to transform to a fully developed human being.
4. Matching issue- Adult stem cells can be taken from the body of adults and no issues are associated with this. However, it requires perfect matching between donor and recipient of the stem cells, otherwise, the body may reject it by considering it as a foreign element.
5. Limited to particular stem cells – Adult stem cells can be easily obtained, but they can only give that particular specialized stem cells. However, embryonic stem cells have no such issues and they have the capacity to turn into any specialized cells.
6. Uncertainty with Recent reports about adult stem cells.

• Research suggests that with proper programming and extra process, adult stem cells can make into pluripotent stem cells i.e., they would get the ability to convert into any specialized stem cells. But the entire stem cell is in its nascent stage and this particular research’s success rate and side effects are yet to be known.

HOW IS IT APPLICABLE TO HIV DISEASE?

• HIV stands for Human Immunodeficiency Virus. It affects CD4, a type of White Blood Cell (T cells)in the body’s immune system. Once the virus enters the body, it multiplies itself and destroys CD4 cells, thus severely damaging the human immune system.
• The resultant weak immune system makes a person prone to multiple infections and cancer.
• The process of finding vaccines or medicines for HIV is quite difficult considering the very dynamic nature of the said virus.
• The available medical treatment is Anti-Retroviral Therapy which itself doesn’t provide the cure, but it manages the chronic damage of HIV to the immune system of the patient. It also reduces the spreading of disease from one person to another.

CASE STUDY

• An African woman in US was diagnosed with HIV in 2013 and started Anti-Retroviral therapy.
• In 2017, she was again diagnosed with Leukemia, and later she was exposed to radiation as part of the treatment. During the therapy, some blood cells got destroyed.
• As part of the treatment, the doctors collected adult stem cells from the bone marrow of her relative.
• At the same time, they also collected cord blood from a baby and combined it together.
• The patient was treated with this procedure and her body was able to generate blood cells and blood stem cells. It resulted in curing her Leukemia and after some time, reports show that she is free from HIV infection too.

DIFFERENCE

• The earlier two patients who got a cure from HIV were treated with adult stem cells only and not Cord blood stem cells.

IS THE CURE FOR HIV SO SIMPLE WITH STEM CELLS?

The process of getting a cure for HIV is extremely difficult with stem cells too. The following are the reasons.

1. Need natural immunity

• It is necessary that stem cells must be taken from people who are having natural immunity against HIV infection.
• There are some people whose genetic sequences are designed in such a way that their stem cells are naturally immune to HIV.
• Such genetic modification is not easily available.

2. Matching issue

• It is not easy to find a matching stem cells unless any relative stem cells are matched. The problem of mismatch would lead to failure and rejection of cells within the body.

WHY THE THREE PATIENTS GOT RECOVERY FROM HIV?

• Inherent capacity – By taking the stem cells from adult stem cells having natural immunity, the generated RBC, WBC, and platelets are having immune capacity inherently that acted against HIV.
• Moreover, it is not the passive immunity generated through vaccines. Vaccines cannot bring the required immunity because the nature of the virus changes very frequently.

COMBINATION OF ADULT STEM CELLS AND CORD BLOOD CELLS IN THIS CASE STUDY

• The given combination is actually a part of the research, they tried and tested and it proved successful.
• The application of already matched adult stem cells helped the chord cells to fully integrate into the person’s immune system. Moreover, it boosted the parent immunity in this treatment.

OTHER APPLICATIONS OF STEM CELLS

Apart from curing diseases, a stem cell has the following application also.

1. Development of Regenerative medicines- It helps in the treatment of diseases by developing medicines.
2. Understand the nature of diseases – It helps to understand the reasons behind the occurrence of diseases such as either through pathogens or sometimes, the reasons are far behind understanding.
3. Experiments- Culturing stem cells outside the body and exposing them to different bodily environments helps in analyzing the reason behind the specific occurrence.
4. Testing new drugs – It can be applied for testing the safety and effectiveness which cannot be tested directly in the human body. In this case, application of testing drugs to the cultured stem cells would help to understand the reaction.

OVERALL UTILITY

• Embryonic stem cells and cord blood stem cells are completely versatile and can be converted into any specialized cells.
• Highly relevant – Around 23.48 lakh people are suffering from HIV infection. Within the age group of 15-49, about 0.24 % constitutes the male population and 0.2 % constitutes the female population.

CONCLUSION

 Stem cell therapy holds vast potential in the present scenario. The immunity gained through the stem cell is different from passive immunity gained through vaccines. Here, the treatment is not using direct regenerative medicine, the regenerated medicine used itself has created some sort of immune system that helped to cure HIV.

PRACTICE QUESTION

What do you understand by Stem cell therapy? Explain the application and the associated challenges of stem cell therapy.(150 Words, 10 Marks)