Search results
Results from the WOW.Com Content Network
Image of CD4 co-receptor binding to MHC (Major Histocompatibility Complex) non-polymorphic region. In molecular biology, CD4 (cluster of differentiation 4) is a glycoprotein that serves as a co-receptor for the T-cell receptor (TCR). CD4 is found on the surface of immune cells such as helper T cells, monocytes, macrophages, and dendritic cells.
The depletion of CD4 T cells and the development of chronic inflammation are signature processes in HIV pathogenesis that propel progression to acquired immune deficiency syndrome (AIDS). CD4 T cell depleted to the cell count of less than 200cell/μL in blood during AIDS allows various pathogens to escape T cell recognition, thus allowing ...
A congenital disorder of glycosylation (previously called carbohydrate-deficient glycoprotein syndrome) is one of several rare inborn errors of metabolism in which glycosylation of a variety of tissue proteins and/or lipids is deficient or defective. Congenital disorders of glycosylation are sometimes known as CDG syndromes.
A thymocyte becomes a CD4 + cell by down-regulating expression of its CD8 cell surface receptors. If the cell does not lose its signal, it will continue downregulating CD8 and become a CD4 +, both CD8 + and CD4 + cells are now single positive cells. [11] This process does not filter for thymocytes that may cause autoimmunity. The potentially ...
In lymphocyte populations, the co-receptor CD4 is found on helper T cells and the co-receptor CD8 is found on cytotoxic T cells. CD4 has four Ig domains in its extracellular portion and functions as a monomer. CD8, in contrast, functions as a dimer with either two identical alpha chains or, more typically, with an alpha and beta chain.
As well as being involved in forming a complex with MHC-II with TCR to control T-cell fate, the CD4 receptor is infamously the primary receptor that HIV envelope glycoprotein GP120 binds to. [6] In comparison, CD28 acts as a ‘co-coreceptor’ (costimulatory receptor) for the MHC-II binding with TCR and CD4. CD28 increases the IL-2 secretion ...
One type of MHC class II deficiency, also called bare lymphocyte syndrome, is due to mutations in the genes that code for transcription factors that regulate the expression of the MHC class II genes. [16] It results in the depletion of CD4 T cells and some immunoglobulin isotypes even though there are normal levels of both CD8 Cells and B cells ...
Idiopathic CD4+ lymphocytopenia (ICL) is a rare medical syndrome in which the body has too few CD4 + T lymphocytes, which are a kind of white blood cell. [2] ICL is sometimes characterized as "HIV-negative AIDS", though, in fact, its clinical presentation differs somewhat from that seen with HIV/AIDS. [ 3 ]