A way to cure cancer and HIV by modifying genes
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Plasma, Red blood cells (RBC), Platelets and White blood cells (WBC) are the 4 main components of blood. While RBC are responsible for the transportation of substances in the circulatory system, WBC act as the body fighters. There are several types of WBC such as: Neutrophils, basophils, eosinophils, lymphocytes, monocytes.
Neutrophils: Defend bacterial or fungal infections
Eosophils: Defend parasitic infections or allergic infections
Monocytes: Engulf foreign materials and form antigens on the surface of cells for T cells to attack.
Basophils: contain heparin which helps in increasing the time it takes to form a blood clot (blood thinning) and histamine which produces allergic symptoms. Basophils also engulf foreign material non-specifically (they engulf every cell they think that are not supposed to be in the bloodstream)
Lymphocytes: There are two types of lymphocytes, B-cells (so-called because they mature in the bone marrow) and T-cells (so called because they mature in the thymus, an endocrine organ just above the heart). B-cells secrete antibodies (protein molecules that bind with specific antigens on the surface of germs to stop them by creating clumps to alert the body to send phagocytes to engulf the intruders.)
Neutrophils: Defend bacterial or fungal infections
Eosophils: Defend parasitic infections or allergic infections
Monocytes: Engulf foreign materials and form antigens on the surface of cells for T cells to attack.
Basophils: contain heparin which helps in increasing the time it takes to form a blood clot (blood thinning) and histamine which produces allergic symptoms. Basophils also engulf foreign material non-specifically (they engulf every cell they think that are not supposed to be in the bloodstream)
Lymphocytes: There are two types of lymphocytes, B-cells (so-called because they mature in the bone marrow) and T-cells (so called because they mature in the thymus, an endocrine organ just above the heart). B-cells secrete antibodies (protein molecules that bind with specific antigens on the surface of germs to stop them by creating clumps to alert the body to send phagocytes to engulf the intruders.)
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T-cells are like soldiers, they seek out and destroy invaders of the body.
There are 3 types of T cells:
There are 3 types of T cells:
- Helper T cells: Recognise the presence of a foreign antigens and stimulate antibody production and produce substances to activate other T cells.
- Regulatory T cells: Turn of the immune response.
- Killer T cells: Attack and destroy cells bearing the specific antigen.
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There's a receptor called PD-1 (Programmed cell Death -1) , encoded by the PDCD1 gene, which is responsible for the down regulating ( "turning off" )T-cells that they stop attacking a certain cell (for example normal cells of the body). However cancer cells have learned how to make PH-1 to tell T-cells off so that they stop attacking the cancer cells.
Researchers at the University of California, San Francisco have figured out a way to edit the PD-1 gene of the T-cells and be able to turn T-cells back to fighting against cancer cells.
Editing the genes of T-cells would enhance their abilities to attack cancerous cells.
Researchers at the University of California, San Francisco have figured out a way to edit the PD-1 gene of the T-cells and be able to turn T-cells back to fighting against cancer cells.
Editing the genes of T-cells would enhance their abilities to attack cancerous cells.
This program is called CRISPR (pronounced crisper) (clustered regularly interspaced short palindromic repeats). It's a segment of prokaryotic DNA
The machinery is led into a cell, guided by RNA strands to a target stretch of DNA where it edits the gene by adding, cutting, disrupting or changing a sequence of DNA at any desired location. CRISPR was first discovered in bacteria 3 years ago and has been used in edit the DNA of crops to edit the HIV virus out of human DNA. Chinese researchers have attempted to edit the DNA of human embryo but it was considered to be out of bonds and created a controversy of human moral.
How they do this is by filtering T-cells from a person's blood, edit their DNA and return them to the bloodstream. However scientists are having problems delivering the CRISPR machinery into T-cells. It's done by packaging CRISPR into a harmless virus and transport it into cells. CRISPR would then aim for a targeted sequence of DNA and do its job. But so far, this is done with very low efficiency that only a small part of T-cells can be engineered to fight against cancer cells.
Marco Herold, a molecular biologist at Melbourne's Water and Eliza Hall Institute of Medical Research and his team had the idea of zapping T-cells from healthy donors with an electric field. This would result in temporary holes in the cell's membrane, allowing CRISPR to pass through and edit 20% of T-cells. Thanks to this, they've been able to edit every single letter of the cell's DNA. They changed the doorway for the entrance of a HIV virus so that they cannot enter and infect T-cells. And they were also able to edit the genes of PD-1 mentioned above.
However, turning off the PD-1 gene means that T-cells would not be down regulated even when they attack normal cells. "The danger is the create something you can't control." says Herold.
At the moment they're still having to figure out how ensure safety of T-cells but it is worth the hope of curing the once-to-be incurable diseases.
Source: Cosmos Magazine. Modifying human immune cells to fight cancer. 10 AUG 2015 by Vivianne Richter and Elizabeth Finkel.
#Blood #Bloodcomponents #DNAbasic #DNA
Source: https://www.boundless.com/physiology/textbooks/boundless-anatomy-and-physiology-textbook/blood-17/leukocytes-white-blood-cells-166/wbc-function-832-4473/
http://www.nationalmssociety.org/What-is-MS/Definition-of-MS/T-cells
https://www.boundless.com/physiology/textbooks/boundless-anatomy-and-physiology-textbook/blood-17/leukocytes-white-blood-cells-166/wbc-function-832-4473/
http://www.sciencemuseum.org.uk/WhoAmI/FindOutMore/Yourbody/Whatdoesyourimmunesystemdo/Howdoesyourimmunesystemwork/WhatdoT-andB-cellsdo.aspx
https://en.wikipedia.org/wiki/Programmed_cell_death_1
The machinery is led into a cell, guided by RNA strands to a target stretch of DNA where it edits the gene by adding, cutting, disrupting or changing a sequence of DNA at any desired location. CRISPR was first discovered in bacteria 3 years ago and has been used in edit the DNA of crops to edit the HIV virus out of human DNA. Chinese researchers have attempted to edit the DNA of human embryo but it was considered to be out of bonds and created a controversy of human moral.
How they do this is by filtering T-cells from a person's blood, edit their DNA and return them to the bloodstream. However scientists are having problems delivering the CRISPR machinery into T-cells. It's done by packaging CRISPR into a harmless virus and transport it into cells. CRISPR would then aim for a targeted sequence of DNA and do its job. But so far, this is done with very low efficiency that only a small part of T-cells can be engineered to fight against cancer cells.
Marco Herold, a molecular biologist at Melbourne's Water and Eliza Hall Institute of Medical Research and his team had the idea of zapping T-cells from healthy donors with an electric field. This would result in temporary holes in the cell's membrane, allowing CRISPR to pass through and edit 20% of T-cells. Thanks to this, they've been able to edit every single letter of the cell's DNA. They changed the doorway for the entrance of a HIV virus so that they cannot enter and infect T-cells. And they were also able to edit the genes of PD-1 mentioned above.
However, turning off the PD-1 gene means that T-cells would not be down regulated even when they attack normal cells. "The danger is the create something you can't control." says Herold.
At the moment they're still having to figure out how ensure safety of T-cells but it is worth the hope of curing the once-to-be incurable diseases.
Source: Cosmos Magazine. Modifying human immune cells to fight cancer. 10 AUG 2015 by Vivianne Richter and Elizabeth Finkel.
#Blood #Bloodcomponents #DNAbasic #DNA
Source: https://www.boundless.com/physiology/textbooks/boundless-anatomy-and-physiology-textbook/blood-17/leukocytes-white-blood-cells-166/wbc-function-832-4473/
http://www.nationalmssociety.org/What-is-MS/Definition-of-MS/T-cells
https://www.boundless.com/physiology/textbooks/boundless-anatomy-and-physiology-textbook/blood-17/leukocytes-white-blood-cells-166/wbc-function-832-4473/
http://www.sciencemuseum.org.uk/WhoAmI/FindOutMore/Yourbody/Whatdoesyourimmunesystemdo/Howdoesyourimmunesystemwork/WhatdoT-andB-cellsdo.aspx
https://en.wikipedia.org/wiki/Programmed_cell_death_1