Antigens: Antigens are substances that cause an immune response in the body by identifying substances in or markers on cells. Your body produces antibodies to fight antigens, or harmful substances, and tries to eliminate them.
Antibodies: Antibodies are proteins which belong to a class known as immunoglobulins. They are made up of chains of amino acids joined by peptide bonds.
Cellular immunity: Lymphocytes act against target cell,Acts directly by killing infected cells,Acts indirectly by releasing chemicals that enhance inflammatory response; or activating other lymphocytes or macrophages.
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