Immune cells work to fight infection and other diseases. Different subsets work together to elicit a healthy immune response; however, infections and disease can dysregulate cells and prevent effective immunity. Interestingly, cancer can use immune cells to its advantage.
Cancer employs various mechanisms to alter the immune system. Once established, tumor cells secrete proteins and molecules to generate a favorable environment. In this case, the tumor microenvironment (TME) becomes hypoxic due to a lack of oxygen with increased blood vessel growth to bring nutrients to the tumor and altered cell types that promote tumor progression. Specifically, tumor-secreted molecules polarize healthy immune cells, which allow cancer cells to proliferate and travel to distal tissues of the body.
T cells are specific immune cells responsible for identifying and targeting pathogens. Receptors on T cells recognize proteins on the surface of infected cells, which stimulate an immune response that eliminates the disease. These cells are critical for effective health and many immunotherapies aim to amplify or enhance T cell function. In the context of cancer, these T cells lose their function and, in some cases, promote tumor growth by inhibiting other immune cells. Unfortunately, treatment efficacy is limited to specific subsets of patients due to tumor type and stage of disease. Scientists are currently working to understand more about T cell biology and enhance immunotherapy.
