B cells are responsible for the production of antibodies, which are proteins that recognize and bind to specific antigens.

T cells are responsible for cell-mediated immunity, which involves the direct killing of infected cells and the activation of other immune cells.

Cytotoxic T cells are responsible for killing infected cells by releasing cytotoxic molecules that induce apoptosis.

Macrophages are phagocytic cells that engulf and destroy foreign particles, including bacteria, viruses, and cellular debris.

T cells are responsible for the production of cytokines, which are small proteins that regulate the immune response.

The thymus is a primary lymphoid organ where T cells mature and undergo selection to ensure self-tolerance.

Both B cells and T cells can differentiate into memory cells, which provide long-term immunity to specific pathogens.

The spleen is a secondary lymphoid organ that filters blood, removing pathogens and damaged cells.

Natural killer cells are produced in the bone marrow and are responsible for killing infected cells and tumor cells.

The complement system is a group of proteins that work together to promote inflammation, enhance phagocytosis, and directly kill pathogens.

Macrophages and natural killer cells produce interferon, a cytokine that inhibits viral replication and activates other immune cells.

The lymphatic system is a network of vessels and nodes that transports immune cells and antigens throughout the body.

Mast cells are responsible for the production of histamine, a chemical mediator that promotes inflammation and allergic reactions.

Peyer's patches are lymphoid tissues located in the small intestine that sample intestinal antigens and initiate immune responses.

Epithelial cells, such as those lining the respiratory and gastrointestinal tracts, produce antimicrobial peptides that help to protect against infection.