ICT (Information Communications Technology) is a term widely used in the context of education. Even though there is no universally accepted definition for ICT, it mainly refers to utilizing digital technologies such as computers, television, email, etc to help individuals or organizations to use information.
Type IV (called also delayed hypersensitivity) involves sensitized T lymphocytes that react with cell bound or associated antigen and release lymphokines, causing mononuclear cell accumulation, tissue damage and inflammation, typically manifesting at least 24 hours after exposure to the antigen.
Type 4 hypersensitivity is often called delayed type hypersensitivity as the reaction takes two to three days to develop. Unlike the other types, it is not antibody mediated but rather is a type of cell-mediated response.CD4+ helper T cells recognize antigen in a complex with Class II major histocompatibility complex.ctivated CD8+ T cells destroy target cells on contact, whereas activated macrophages produce hydrolytic enzymes and, on presentation with certain intracellular pathogens, transform into multinucleated giant cells.