Human Immunity and Blood

Natural killer cells produce interferon, which is a cytokine that helps to fight viral infections.

T cells produce interleukin-2, which is a cytokine that helps to activate other immune cells.

Macrophages produce tumor necrosis factor, which is a cytokine that helps to kill tumor cells.

T cells are a type of white blood cell that plays a crucial role in the immune system. They are responsible for recognizing and destroying infected cells, as well as helping B cells differentiate into plasma cells, which produce antibodies.

Cytotoxic T cells, also known as killer T cells, are a type of T cell that is responsible for killing infected cells. They recognize and bind to infected cells, releasing toxic substances that destroy the cells.

Cell-mediated immunity is the T cell-mediated immune response. It involves the activation of T cells, which recognize and destroy infected cells, as well as helping B cells differentiate into plasma cells, which produce antibodies.

The complement system is a complex network of proteins that plays a crucial role in the immune system. It is activated by the presence of an antigen and helps in the destruction of infected cells, as well as the activation of other immune cells.

MHC molecules, also known as major histocompatibility complex molecules, are proteins that are expressed on the surface of cells. They play a crucial role in the immune system by presenting antigens to immune cells, such as T cells, which can then recognize and respond to the antigens.

Humoral immunity is the antibody-mediated immune response. It involves the production of antibodies by B cells and plasma cells in response to the presence of an antigen. Antibodies bind to antigens, marking them for destruction by other components of the immune system.

Dendritic cells are a type of antigen-presenting cell that plays a crucial role in the immune system. They capture and process antigens, and then present them to T cells, which can then recognize and respond to the antigens.

Cell-mediated immunity is the T cell-mediated immune response. It involves the activation of T cells, which recognize and destroy infected cells, as well as helping B cells differentiate into plasma cells, which produce antibodies.

Natural killer cells are a type of cytotoxic lymphocyte that plays a crucial role in the immune system. They recognize and destroy infected cells and tumor cells, without the need for prior sensitization to the specific antigen.

Immediate hypersensitivity reactions are mediated by the release of histamine and other mediators from mast cells and basophils upon exposure to an allergen.

Type III hypersensitivity reactions are characterized by the formation of immune complexes, which can activate complement and lead to tissue damage.

Contact dermatitis is the most common type of delayed hypersensitivity reaction. It is caused by direct contact with an allergen, such as poison ivy or nickel.