A Level Biology Practice Exam 2025 - Free A Level Biology Practice Questions and Study Guide

The primary role of T helper cells in the immune response is to help stimulate other immune cells. These cells are crucial for orchestrating the immune response by secreting signaling proteins known as cytokines. When T helper cells recognize antigens presented by antigen-presenting cells (APCs), they become activated and proliferate.

Once activated, they play a key role in enhancing the activity of other immune cells, including B cells, which produce antibodies, and cytotoxic T cells, which destroy infected cells. T helper cells also support macrophage activity, improving their ability to phagocytose pathogens.

This coordination is vital for an effective and robust immune response, as it ensures that various components of the immune system are working together efficiently to eliminate pathogens. Thus, their primary role is not to directly destroy infected cells, regulate inflammation, or remember past infections, although they do participate indirectly in these processes through their interactions with other immune cells.