What does clonal diversity mean?
Clonal diversity provides information about plant and animal evolutionary history, i.e. how clones spread, or the age of a particular clone. In plants, this could provide valuable information about agrobiodiversity dynamics and more broadly about the evolutionary history of a particular crop.
What is clonal diversity immune system?
Clonal selection theory is a scientific theory in immunology that explains the functions of cells of the immune system (lymphocytes) in response to specific antigens invading the body. In short, the theory is an explanation of the mechanism for the generation of diversity of antibody specificity.
What causes clonal selection?
When an antigen encounters the immune system, its epitopes eventually will react only with B-lymphocytes with B-cell receptors on their surface that more or less fit and this activates those B-lymphocytes. This process is known as clonal selection.
What is meant by the clonal selection hypothesis?
The clonal selection theory proposes that antigen selects lymphocytes for activation from a population of cells precommitted to produce specific antibody. Implicit in this theory is that antibody-forming cells are monospecific and express cell-surface receptors capable of binding foreign antigens.
What is meant by clonal?
1. A group of cells or organisms that are descended from and genetically identical to a single progenitor, such as a bacterial colony whose members arose from a single original cell.
What happens during clonal selection?
During clonal selection, random mutations during clonal expansion cause the production of B cells with increased antibody-binding affinity for their antigens. The clonal selection hypothesis may explain why secondary immune responses are so effective at preventing reinfection by the same pathogen.
What is clonal diversity pathophysiology?
STUDY. clonal diversity. occurs in specialized lymphoid organs (Thymus-T cells, and bone marrow- B cells); 1st phase of immune response; antigen recognition, and lymphocyte specificity. clonal selection.
What is generation of clonal diversity?
Generation of clonal diversity. to produce large numbers of T and B lymphocytes with the maximum diversity of antigen receptors. -occurs primarily in the fetus in the central lymphoid organs: thymus and bone marrow. -foreign antigens are not involved.
What causes clonal expansion?
Clonal selection is the theory that specific antigen receptors exist on lymphocytes before they are presented with an antigen due to random mutations during initial maturation and proliferation. After antigen presentation, selected lymphocytes undergo clonal expansion because they have the needed antigen receptor.
What is clonal lymphoid expansion?
Clonal expansion of lymphocytes is a hallmark of vertebrate adaptive immunity. A small number of precursor cells that recognize a specific antigen proliferate into expanded clones, differentiate and acquire various effector and memory phenotypes, which promote effective immune responses.
What is clonal expansion so important?
What is a clonal mutation?
Mutations that appear clonal across a tumour are those mutations present in all taken samples.
What is the pathophysiology of work-related asthma?
Pathophysiology. Work-related asthma is defined by causation or worsening from exposure to occupational environmental sensitizers, irritants, or physical conditions. Regardless of the asthma trigger type, the response is characterized by inflammation, edema, bronchoconstriction, and buildup of mucus in the airways, leading to coughing, wheezing,…
What is the pathophysiology of non-allergen asthma?
Non-allergen-induced asthma pathophysiology is less understood. Exposure to cold air and physical exertion. Cooling or warming of the airway is thought to lead to bronchoconstriction.
What causes persistent changes in airway structure in asthma?
In some patients, persistent changes in airway structure occur, including sub-basement fibrosis, mucus hypersecretion, injury to epithelial cells, smooth muscle hypertrophy, and angiogenesis. Gene-by-environment interactions are important to the expression of asthma.
What is the role of inhaled antigen in the pathogenesis of asthma?
Inhaled antigen activates mast cells and Th2 cells in the airway. They in turn induce the production of mediators of inflammation (such as histamine and leukotrienes) and cytokines including interleukin-4 and interleukin-5. Interleukin-5 travels to the bone marrow and causes terminal differentiation of eosinophils.