EXPRESSION ON B CELLS IN HEALTHY INDIVIDUALS AND IN CHRONIC Literature review

EXPRESSION ON B CELLS IN HEALTHY INDIVIDUALS AND IN CHRONIC LYMPHOCYTIC LEUKIMIA - Literature review Example Components of the immune system such as the white blood cells protect the body through the creation of specific antigens. However, in some cases, the immune system itself can be a source of problems, such as in autoimmune diseases, where the immune system recognizes cells of the host body as invaders and attacks these. The cells that form an important part of the immune system can also function incorrectly. Chronic lymphocytic leukemia (CLL) is one example of a disorder where the cells of the immune system are functioning incorrectly. This is a cancer where the B cells of the immune system are highly activated, show increased levels of proliferation and decreased rates of apoptosis. This results in the accumulation of affected cells, which prevents the immune system functioning normally. This review considers the role that Toll-like receptors (TLRs) have on immune system functioning, with a specific focus on CD180 (also known as RP105) and its role on CLL. Toll-like Receptors The imm une system plays a crucial role in protecting the body against pathogens and allows the body to effectively defend itself. One class of molecules that have been shown to have an important role in the effectiveness of the immune system is Toll-like receptors (TLRs). ... Image from Akira et al. (2001) However, while the TLR pathway has been shown to be crucial for the defense and protection of the body, it also can have a significant role in immune system diseases and allergies. This can be due to high levels of signaling or deficiencies of molecules that are involved in the signaling pathway . Thus, TLRs play a significant role in the immune system and related diseases. Understanding their functions both collectively and individual is important to understand the occurrence and progression of many different diseases, as well as looking for treatment for these. Studies have revealed that one potentially important TLR in many immune system diseases is CD180, also known as RP105. This molecule is expressed on the outer membrane of B cells that is known to be a leucine-rich repeat (LLR). LLRs are known to be important in the way in which pathogens within the immune system are recognized. A homolog of the protein has been found on mouse B cells, and has b een associated with a decreased rate of cell death. Experimental evidence shows that cells that were negative for CD180 were susceptible to apoptosis induced by corticosteroids, while those that expressed CD108 were not . In mice, almost all mature B cells expressed CD180; however, this is not true in humans. For example, in individuals suffering from systemic lupus erythematosus (SLE) almost 16% of patients tested were not expressing CD180 in a significant quantity. Individuals who did not have SLE had a significantly lower average level of CD180 expression than those who were affected with SLE . In humans, CD180 is involved in the recognition of B cells and signaling of lipopolysaccharides. However, little more is known about its function . In mice, almost all