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.
CD4 + T cells are generally treated as having a pre-defined role as helper T cells within the immune system. For example, when an antigen-presenting cell displays a peptide antigen on MHC class II proteins, a CD4 + cell will aid those cells through a combination of cell to cell interactions (e.g. CD40 (protein) and CD40L ) and through cytokines .
The role of CD4 + T cells in antitumor immunity is controversial. It was suggested that CD4 + T cells can have a direct role in antitumor immunity through direct recognition of tumor antigens presented on the surface of tumor cells in association with MHC class II molecules. [1]
These lymphocytes may target cancerous cells and therefore slow or terminate tumor development. However, this process is complicated because T reg cells seem to be preferentially trafficked to the TME. While T reg cells normally make up only about 4% of CD4 + T cells, they can make up as much as 20–30% of the CD4 + population around the TME. [72]
T cells are one of the important types of white blood cells of the immune system and play a central role in the adaptive immune response. T cells can be distinguished from other lymphocytes by the presence of a T-cell receptor (TCR) on their cell surface. T cells are born from hematopoietic stem cells, [1] found in the bone marrow.
In immunology, a naive T cell (T h 0 cell) is a T cell that has differentiated in the thymus, and successfully undergone the positive and negative processes of central selection in the thymus.
Priming of antigen-specific naive lymphocytes occurs when antigen is presented to them in immunogenic form (capable of inducing an immune response). Subsequently, the primed cells will differentiate either into effector cells or into memory cells that can mount stronger and faster response to second and upcoming immune challenges. [ 2 ]
A lymphocyte is a type of white blood cell (leukocyte) in the immune system of most vertebrates. [1] Lymphocytes include T cells (for cell-mediated and cytotoxic adaptive immunity), B cells (for humoral, antibody-driven adaptive immunity), [2] [3] and innate lymphoid cells (ILCs; "innate T cell-like" cells involved in mucosal immunity and homeostasis), of which natural killer cells are an ...