Page 128 - AWSAR 2.0

104 || AWSAR Awarded Popular Science Stories - 2019
regulation?”
“Exactly, some regulatory cells are there
in our immune system. Cancer cells hijack these cells and make them work for them. These are regulatory T cells (Tregs), myeloid- derived suppressor cells, tumor-associated macrophages, and even some non-immune cells such as mesenchymal stem cells, etc.”
“Hmm, a team of Thanos.”
“Something like that,” I patted on his shoulder.
“Now, I am going to tell you about the ancient Ayurveda of India. In ancient India, there was an ayurvedic doctor Sushruta. In his book Sushruta Samhita, he wrote about so many plants of medicinal importance; one of them was this.”, I told him by pointing out to the neem tree. “He mentioned the neem tree as sarbaroganibarani, meaning medicine for all diseases. Recently, a number of natural anti- cancer compounds have been found in plants from different research groups.
Like curcumin from turmeric,
vinblastine, and vincristine from
periwinkle, etc.”
I drank some water from a bottle and continued, “We found in our preliminary research that an extract from mature neem leaves could restrict tumor growth in mice. But it could not kill cancer cells directly.”
“Wow!” he wondered, “This is astonishing.”
“Yes, later, we found a
protein in this extract held
responsible for this anti-tumor
effect. We named it neem leaf glycoprotein, NLGP, in short. But, outside the host body, in a culture that is called in vitro setup, it could not kill cancer cells. We hypothesized that it might work through our immune system. To validate our hypothesis, we injected NLGP into a group of healthy mice and after that
we isolated immune cells from their spleen. Spleen is an organ, even present in us. It has a large reservoir of immune cells. Then, we injected those isolated immune cells into a group of tumor-bearing mice. This procedure was called adoptive cell transfer. Surprisingly, it worked! Mice that received NLGP-educated immune cells showed restricted tumor growth and survived longer than the mice that did not receive the treatment. Our next goal was to find out which immune cell NLGP worked through. We depleted CD8 T cells by using antibody against them and observed that this time NLGP could not work. Therefore, NLGP worked through CD8 T cells. Now, this CD8 T cell cannot work alone; it requires signals from dendritic cells or macrophages to become cytotoxic. We found that NLGP activated dendritic cells and dendritic cells, in turn, activated CD8 T cells.”
“It seems from your words that cells can talk to each other,” Arko asked. “Of course. They can communicate with each other either through direct contact or through some signaling molecules. These signaling molecules bind to their respective receptors present either on the surface or inside of a cell. After binding, this molecule initiates a signal inside the cell and makes a change. NLGP could even suppress the immune suppressor cells, such as Tregs, myeloid-derived suppressor cells, and tumor- associated macrophages. Very recently, we found that NLGP could rectify the immune- suppressive activity of mesenchymal stem cells, MSCs in short, within the tumor. Within the tumor, which is called tumor microenvironment (TME), these MSCs suppress the export of cysteine from dendritic cells. Cysteine
we found a protein in this extract held responsible for this anti-tumor effect. We named it neem leaf glycoprotein, NLGP, in short. But, outside the host body, in a culture that is called in vitro setup, it could not kill cancer cells.