Macrophage and lymphocytes, transmission electron micrograph (TEM). Macrophage surrounded by lymphocytes in a lymph node. This view includes many intercellular contacts. Macrophages are a type of large white blood cell that recognise foreign particles and phagocytose (engulf and digest) them. Lymphocytes are white blood cells. They are essential cells of the immune defence system that either attack foreign antigens directly or indirectly by the production of antibodies. Magnification: x920 at 35mm.