Helper T-cells are a type of white blood cell that play a crucial role in the immune system. They help coordinate the body's response to infections by signaling other immune cells, such as B-cells and cytotoxic T-cells, to take action against pathogens like bacteria and viruses. These cells recognize specific antigens presented by antigen-presenting cells and become activated. Once activated, helper T-cells release signaling molecules called cytokines, which enhance the immune response, ensuring that the body effectively fights off infections and maintains overall health.