Helper T-cells, also known as CD4+ 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 are activated when they recognize specific antigens presented by antigen-presenting cells. Once activated, Helper T-cells release cytokines, which are signaling molecules that enhance the immune response. This process is essential for developing immunity and ensuring the body can effectively fight off infections.