White cell (macrophage/neutrophil) detects bacteria antigen by binding to cell surface receptorsWhite cell engulfs bacteria (this is endocytosis), bacteria is held in a phagosome Lysosomes enter phagosome and digest the bacteria via enzymesBreakdown products of bacteria (ANTIGEN) are presented to the cell membrane via exocytosis (movement out of cell)WBC is now an antigen presenting cell.T Helper Cell binds to antigen presenting cell via receptors and is activatedActivated T Helper Cell binds to a specific B cell via CD40 receptorsThe B cell clones and forms plasma cellsThese release antibodies