Featuring Dr. Gautam
In recent times, we have expanded our understanding greatly about the processes that underlie the function of cells within our bodies. New developments have allowed us to explore cellular mechanisms and processes in previously unthinkable ways. Promising research from Dr. Narasimhan Gautam in the Division of Biology and Biomedical Sciences brings us closer to being able to actively manipulate and control the functions of many cells. This ability to manipulate cellular function – ranging from simple movement to the secretion of chemicals – has incredible implications for treatment of a large number of conditions and can be a keystone technology in targeted therapies for cancer.
The coordinated functions of a complex biological organism would be impossible to achieve without a complex network of receptors and cell signalling. For example, the epinephrine receptor binds to epinephrine, a chemical associated with the “fight-or-flight” response, After a multi-step biochemical pathway, large amounts of glucose is released, providing the organism the fuel it needs in this “fight-or-flight” response.
In a similar fashion to the system just described, other receptors (especially those in the eyes) respond to light instead of a chemical signal. This also results in a cellular response (e.g. the sensation of light in the eye). These receptors found in the photoreceptor cells of the retina, called opsins, can be used for the laboratory manipulation of cells that may not ordinarily have receptors that respond to light. By taking these opsins and placing them in other cells throughout the body, cells that usually only respond to very specific stimuli will now readily respond to light. Because the cell in which the opsins have been transplanted can now be controlled using light, scientists are able to activate it with precision by shining light on the receptor. Using specialized lasers that are able to focus light on extremely minute areas, this signal can be made to be even more specific than the signal that usually activates the cell. This allows researchers to probe into previously unexplorable processes by targeting one area of a cell but not others.
The implications of generalizing this cellular response to light to other cells are incredible. Immune cells that normally respond to the establishment of a chemical gradient may now be controlled by light, allowing researchers to use light to target these cells to places in the body that might ordinarily be ignored by the immune system, such as tumors.
As tumors are comprised of cells that have lost the ability to stop dividing but still retain cell surface markers identifying it as as non-foreign, the body’s immune system will often fail to identify them as something to take action against, despite the fact that the cell has a major problem. By shining light on immune cells embedded with the opsin receptor, physicians will theoretically be able to target immune cells to attack the tumor, in spite of the fact that the immune cell would not naturally do so on its own. In this way, addition of the opsin receptor to a cell serves as a form of “manual override”, allowing researchers to guide important cellular processes when the natural response is insufficient. Given how the greatest disadvantage of radiation therapy and chemotherapy is the massive collateral damage they inflict on a person’s health, targeted therapies like the one described above have massive advantages and have the potential to revolutionize cancer treatment.
Ultimately, this new method of controlling cells through use of a light-sensing receptor is a novel technology that will have significant effects on the treatment of disease as well as the future of biological research. By enabling precise control of cells, Dr. Gautam’s research will propel research forward and elucidate functions and pathways that were once hidden to us, potentially unlocking many new cures now and in the future.
For more information about Dr. Gautam :
E-mail : firstname.lastname@example.org
Website : http://elysium.wustl.edu/gautam_lab/lab_overview/
Phone : (314)362-8568
5548 Clinical Sciences Research Building
4939 Children’s Place
St. Louis, MO 63110
Edited by Jeff Bai, Luis Muniz