What is the immune response?
The immune response is the mechanism that the body uses to protect against infection and disease. People are surrounded by viruses, bacteria and other pathogens and survival depend on the fact that it will have an infection system. A person with a healthy immune system is protected by several lines of defense, which include physical barriers, cells that eliminate proteins to destroy pathogens, and cells that use pathogens. This defensive line refers to protection provided by physical barriers of skin, mucus membranes and cilia. Voice acid and enzymes present in tears also protect the body from infection. Specialized cells in the body tissues, known as macrophages, are involved in the immune response by absorbing foreign particles such as bacteria.
The acquired immunity is another part of the immune system. This applies to the immunity that a person develops after being exposed to a pathogen. Pathogens or proteins that can cause immune response are called antigens. Antigens can bind to cells in the body known as lymphocytey.
One type of lymphocytes, known as B-lymphocytes, develops and ripens in the bone marrow. When foreign antigen attacks the body, it binds to the surface of B-lymphocytes. The B-cell then starts to divide and exclude other protein, known as an antibody. This excluded antibody can bind to foreign antigens, such as bacteria or viruses, and neutralize them. The secretion of antibody B-lymphocytes is referred to as a humoral immune response.
T-lymphocytes that differ from B-lymphocytes are part of the cellular immune response. These lymphocytes are also produced in the bone marrow and then migrate to the thymus, where they become ripe T-cells. On the surface of T-cells, an antigen-binding molecule is known as the T-cell receptor. T-cell can be bound to antigen, but it must be in the presence of protein complex on the host cells, called the main histocompatible complex. T-lymphocytes are mainly involved in reaction to changed host cells,As with cells infected with virus or cells that develop into cancer cells.
Some T-cells exclude proteins called cytokines that activate B-cells and macrophages, allowing the cooperation of many cells of the immune system. The immune response can be stimulated by vaccines such as measles, mumps or flu. These vaccines consist of weakened or inactivated viral particles that activate the cells of the body and protect the host from the disease.