Here's a breakdown of how they work:

* T cell receptors (TCRs): T cells have specialized receptors on their surface called TCRs. These receptors recognize specific antigens, which are molecules on the surface of other cells that can trigger an immune response.

* Antigen presentation: Antigens are presented to T cells by other immune cells, like macrophages and dendritic cells, which have engulfed and processed the antigens.

* Activation: When a T cell's TCR binds to its specific antigen, it becomes activated.

* T cell differentiation: Activated T cells differentiate into different types, each with a specific function:

* Cytotoxic T cells (CD8+ T cells): These cells directly kill infected or cancerous cells by releasing cytotoxic molecules.

* Helper T cells (CD4+ T cells): These cells help activate other immune cells, including B cells, which produce antibodies.

Key point: T cells are a crucial part of the adaptive immune system, which allows the body to recognize and destroy specific pathogens or cancer cells.