T cellB cell collaboration in the immune response to infection Essay

T cellB cell collaboration in the immune response to infection - Essay ExampleIt is referred to as non-specific because it broadly attempts to stop the spread of all types of invaders. (Kuby, 1996)The latter type consists of two categories cell-mediated immunity and antibody-mediated (humoral) immunity. It is the stronger one of the two types but takes several hours or even days to travel fully activated. It is referred to as specific because it responds differently to every other foreign pathogen. (Hariharan, 2006)Lymphocytes, a class of White Blood Cells, are a vital discriminate of the acquired immune system, being responsible for the whole reaction. They are produced in the primary lymphoid organs and then migrate to the secondary lymphoid organs where they make do antigens of foreign bodies by the help of membrane receptors specific to the antigens. Two major classes of lymphocytes take part in the acquired immunity B-Cells (B lymphocytes) and T-Cells (T lymphocytes). (Alber ts, Bray, Lewis, Raff, Roberts, Watson, 1994), (Linnemeyer, 1993)Precursors of T-cells originate in the foetal coloured and yolk sac during the embryonic life, and migrate to the bone marrow after birth. The stem cells then enter the thymus by chemo taxis and develop into T-cells which are after specialized into CD4+ (helper) cells or CD8+ (cytotoxic) cells. (UNC-SOM, 2004)MaturationOn entering the thymus, T-cell precursors (prothymocytes) develop into T-cells that indicate both CD4 and CD8 molecules on their membranes and then later continue to indicate either CD4 or CD8 molecules. The cells having antigen receptors for self proteins are destroyed by aptosis (programmed cell death). This prevents autoimmunity. On the other hand, the cells having antigen receptors that do not react with self MHC proteins are also killed as this causes the decisive selection of T-cells that do react with MHC proteins. (Stadnyk, 2007) Functions of the MHC proteins include positive selection of T-ce lls as well as presentation of foreign body antigens to them. (NIAID, 2003)General FunctionThe avail T-cells activate lymphocytes called macrophages and other T-cells involved in the immune response, and aid B-cells in producing antibodies by alerting them and determining the type of antibody to be produced. (NIAID, 2003)2) B-CellsOriginPrecursors of B-cells migrate from the foetal liver to the bone marrow where they remain and undergo maturation throughout the adult life. They do not require thymus for their development. (Levinson, 2004)MaturationDevelopment of B-cells takes personate in two phases antigen-independent phase & antigen-dependent phase. In the 1st phase, stem cells of the marrow differentiate into B-lineage and progenitor B-cells. The progenitor B-cells proliferate into precursor B-cells which requires the microenvironment supplied by the surrounding stroma. Cells of the stroma blowhole numerous cytokines, most importantly IL-7, which help in the maturation process . Further