name the different types of cells that are responsible for producing acquired immune response in a human body.how do these cells respond when a pathogen enters the body ?
The two types of cell responsible for producing acquired immune response in a human body are Lymphocytes (W.B.C – white blood corpuscles). These are of two types – B-cells and T-cells. Both the cells are originated from the stem cells of bone marrow (adult) and liver (foetus).
B – cells: The cells that develop in the bone marrow are called B- cells. B- Cells produce antibodies. Our body has thousands of antigen specific B- cells which when stimulated produce specific antibodies.
T – cells: The cells that migrate to the thymus and develop there are called T – cells. T- cells are responsible for cellular immunity. T- cells have special receptors on their cell surfaces called T- cell receptors which are absent in B – cells. T – cells can be differentiated according to their functions into three types – killer T – cells (attack directly), helper T – cells (stimulate B – cells) and suppressor T- cells (suppress immune system).
T-cells are responsible for cell-mediated immunity. These cells bears surface receptor known as CD4 or CD8, these CD4 recognise antigens in association with class II MHC proteins on the surface of the other cells. While, B-cells are responsible for antibody mediated immunity. The B-cells behave as antigen presenting cells (APCs) , the antigens of other cells bound to the antibody receptor on the surface of B-cells in association with class II MHC molecule. This activates the B-cells to become Ab secreting plasma cells and memory B-cells.
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