cd4 molecule การใช้

• HIV can infect a variety of CD4 + helper T-cells and macrophages that express the CD4 molecule on their surface.
• But, if there is a signal interruption, the cell stops downregulating CD8 and switches over to downregulating CD4 molecules, instead, eventually becoming a CD8 +, single positive cell.
• This is because its surface protein, gp120, specifically interacts with the CD4 molecule  a chemokine receptor  which is most commonly found on the surface of CD4 + T-Cells.
• HIV-1 entry to macrophages and T helper cells is mediated not only through interaction of the virion envelope glycoproteins ( gp120 ) with the CD4 molecule on the target cells but also with its chemokine coreceptors.
• T cells expressing CD4 molecules ( and not CD8 ) on their surface, therefore, are specific for antigens presented by MHC II and not by MHC class I ( they are " MHC class II-restricted " ).
• Of the three MHC classes identified, attention commonly focuses on classes I and II . By interacting with CD4 molecules on surfaces of helper T cells, MHC class II mediates establishment of specific immunity ( also called acquired immunity or adaptive immunity ).
• When a naive helper T cell's CD4 molecule docks to an APC's MHC class II molecule, its TCR can meet and be imprinted by the epitope coupled within the MHC class II . This event primes the naive helper T cell.