CD5L, also known as CD5 antigen-like, is secreted protein which mainly expressed by macrophages in lymphoid and inflammed tissues and regulates mechanisms in inflammatory responses, such as infection or atherosclerosis. It is able to inhibit lipid droplet size in adipocytes. CD5L acts as a key regulator of metabolic switch in T-helper Th17 cells. It is Participates in obesity-associated autoimmunity via its association with IgM, interfering with the binding of IgM to Fcalpha/mu receptor and enhancing the development of long-lived plasma cells that produce high-affinity IgG autoantibodies. It also acts as an inhibitor of apoptosis in macrophages: promotes macrophage survival from the apoptotic effects of oxidized lipids in case of atherosclerosis. It is involved in early response to microbial infection against various pathogens by acting as a pattern recognition receptor and by promoting autophagy.
The cluster of differentiation (CD) system is commonly used as cell markers in immunophynotyping. Different kinds of cells in the immune system can be identified through the surface CD molecules which associating with the immune function of the cell. There are more than 320 CD unique clusters and subclusters have been identified. Some of the CD molecules serve as receptors or ligands important to the cell through initiating a signal cascade which then alter the behavior of the cell. Some CD proteins do not take part in cell signal process but have other functions such as cell adhesion. CD5 is a member of the CD system. CD5 was found to be widely distributed in T-cells and B1 cells which is a subset of IgM-secreting B cells. CD5 also was found expressed in small lymphocytic lymphoma, hairy cell leukaemia and mantle cell lymphoma cells. CD5 serves to weaken the activating stimulus from the BCR so that the B1 cells can only reflect to the very strong stimuli but not the normal tissue proteins.
CD5 is a transmembrane glycoprotein of the conserved scavenger receptor cysteine-rich (SRCR) superfamily and expressed on thymocytes, peripheral T cells and a subset of B cells (B1-a). Moreover, CD5 also was found expressed in small lymphocytic lymphoma, hairy cell leukaemia and mantle cell lymphoma cells. The long cytoplasmic tail of CD5 has no intrinsic enzymatic activity, but contains four tyrosine phosphorylation sites, including an immunoreceptor tyrosine-based (ITAM)-like motif (pseudo-ITAM) and an immunoreceptor tyrosine-based inhibitory (ITIM)-like motif (pseudo-ITIM), as well as multiple potential serine and threonine phosphorylation sites. It physically associates with the T cell antigen receptor (TCR) and B cell antigen receptor (BCR), where it negatively modulates the activation and differentiation signals transduced by these receptors. CD5 also plays an important role in protection from activation-induced cell death and in the recognition of pathogen associated molecular patterns (PAMPS) present on fungal surfaces.
L-selectin (SELL), also known as CD62L, is a key adhesion molecule that regulates both the migration of leukocytes at sites of inflammation and the recirculation of lymphocytes between blood and lymphoid tissues. It belongs to the selectin family of proteins, and consisting of a large, highly glycosylated, extracellular domain, a single spanning transmembrane domain and a small cytoplasmic tail. L-selectin is the only selectin expressed on leukocytes and mediates a number of leukocyte-endothelial interactions. L-selectin acts as a ",homing receptor", for leukocytes to enter secondary lymphoid tissues via high endothelial venules. Ligands present on endothelial cells will bind to leukocyte expressing L-selectin, slowing leukocyte trafficking through the blood, and facilitating entry into a secondary lymphoid organ at that point. L-selectin-mediated lymphocyte recirculation is required for maintaining the appropriate tissue distribution of lymphocyte subpopulations including naï,ve and effector subsets such as regulatory T cells. In addition, L-selectin-mediated entry into peripheral lymph nodes is required for optimal induction of lymphocyte homeostatic proliferation during lymphopenia. Importantly, L-selectin has been shown to have both adhesive and signaling functions during leukocyte migration. L-selectin has also been shown to mediate leukocyte recruitment during chronic inflammatory and autoimmune diseases and thus is a potential therapeutic target for drug development.
High affinity immunoglobulin gamma Fc receptor I, also known as FCGR1 and CD64, is an integral membraneglycoprotein and a member of the immunoglobulin superfamily. CD64 is a high affinity receptor for the Fc region of IgG gamma and functions in both innate and adaptive immune responses. Receptors that recognize the Fc portion of IgG function in the regulation of immune response and are divided into three classes designated CD64, CD32, and CD16. CD64 is structurally composed of asignal peptidethat allows its transport to the surface of a cell, threeextracellularimmunoglobulin domainsof the C2-type that it uses to bind antibody, a hydrophobictransmembrane domain, and a short cytoplasmic tail. CD64 isconstitutivelyfound on only macrophages and monocytes, but treatment of polymorphonuclear leukocyteswith cytokines likeIFNγandG-CSFcan induce CD64 expression on these cells. The inactivation of the mouse CD64 resulted in a wide range of defects in antibody Fc-dependent functions. Mouse CD64 is an early participant in Fc-dependent cell activation and in the development of immune responses.
CD64, also known as Fc-gamma receptor 1 (FcγRI), is a type of integral membrane glycoprotein that binds monomeric IgG-type antibodies with high affinity. After binding IgG, CD64 interacts with an accessory chain known as the common γ chain (γ chain), which possesses an ITAM motif that is necessary for triggering cellular activation. CD64 is composed of a signal peptide, three extracellular immunoglobulin domains of the C2-type used to bind antibody, a hydrophobic transmembrane domain, and a short cytoplasmic tail. CD64 mediates endocytosis, phagocytosis, antibody-dependent cellular cytotoxicity, cytokine release, and superoxide production. It is normally expressed on the surfaces of monocytes and macrophages.
Inserisci la tua e-mail e seleziona le aree di interesse per ricevere le ultime novità, approfondimenti e promozioni.
Seleziona uno o più ambiti di interesse per ricevere comunicazioni più utili e mirate.
2025 TEMA Ricerca - All Rights Reserved.
