A cytotoxic T cell, also known as a killer T cell or CD8+ T cell, is a type of white blood cell that plays a crucial role in the immune response against infected or cancerous cells. Cytotoxic T cells are a subset of T lymphocytes and an essential part of the adaptive immune system.
These specialized cells are responsible for recognizing and destroying target cells that have been infected by a virus or transformed into cancer cells. When an antigen-presenting cell displays specific foreign antigens on its surface, cytotoxic T cells bind to these antigens using their T cell receptor (TCR). This antigen recognition triggers the activation of the cytotoxic T cell.
Once activated, cytotoxic T cells release cytotoxic granules, containing proteins such as perforin and granzymes, towards the target cell. Perforin creates pores in the target cell's membrane, allowing entry of granzymes that induce apoptosis or programmed cell death in the infected or cancerous cell. This process helps prevent the further spread of infection or uncontrolled cell growth.
Furthermore, cytotoxic T cells are capable of producing various cytokines, such as interferon-gamma, which can enhance the immune response, promote inflammation, and support other immune cells in their functions.
The potency of cytotoxic T cells makes them a crucial defense mechanism against pathogens and tumor cells. Understanding their mechanism of action is vital in the development of novel immunotherapies and vaccines, harnessing the power of these cells to combat various diseases.
