Keywords: Antigen presentation.jpg Antigen presentation stimulates T cells to become either cytotoxic CD8+ cells or helper CD4+ cells Cytotoxic cells directly attack other cells carrying certain foreign or abnormal molecules on their surfaces Helper T cells or Th cells coordinate immune responses by communicating with other cells In most cases T cells only recognize an antigen if it is carried on the surface of a cell by one of the body ™s own MHC or major histocompatibility complex molecules http //www niaid nih gov/publications/immune/the_immune_system pdf The Immune System pdf NIH Publication No 03 “5423 September 2003 modifications September 4 2006 Template drawing from The Immune System any modifications made by myself are released into the public domain Original work of the US Federal Government - public domain Image Antigen presentation-tr jpg Image Antigen presentation-es png PD-USGov DO11 10 Antigen presentation alt svg Antigen presentation svg Cell diagrams Antigen presentation |