Can kill cells directly Natural Killer Cells Non specific effector cells, lack CD 4 or CD 8 receptors . Can kill tumor cells and cells infected with virus. Large cells capable of phagocytosis. Can process antigens for presentation to lymphocytes. Discussion Cells can communicate with each other by means of cytokines.
Cytokines are small hormnone like polypeptides.
Produced by a cell, then secreted by that cell, they can then bind to a receptor on the surface of another cell. The binding of a cytokine to a receptor on the surface of another cell intiates a physiological response. Immune cells make many different kinds of cytokines. Often, cytokines can be categorized according to the type of white blood cell that produces them, For example, cytokines produced by lymphocytes are referred to as lymphokines, cytokines produced by monocytes are called monokines. Interferons protect neighboring cells from invasion by parasites, including viruses.