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CD44 is a cell-surface glycoprotein that plays a role in cell-cell interactions, cell adhesion and migration. CD44 is a receptor for hyaluronic acid and also interacts with other ligands, such as osteopontin, collagens, and matrix metalloproteinases. CD44 participates in a wide variety of cellular functions such as lymphocyte activation, recirculation and homing, hematopoiesis, and tumor metastasis.

Mmitochondrial import receptor subunit TOMM20 homolog (TOMM20) is a member of the Tom20 family. The Tom machinery consists of import receptors for the initial binding of cytosolically synthesized preproteins and a general import pore (GIP) for the membrane translocation of various preproteins into the mitochondria. TOMM20 acts as the transit peptide receptor at the surface of the mitochondrion outer membrane and facilitates the movement of preproteins into the TOM40 translocation pore.

The cytokine Macrophage migration inhibitory factor (MIF) has been identified to be secreted by the pituitary gland and the monocyte/macrophage and to play an important role in endotoxic shock. MIF has the unique property of being released from macrophages and T cells in response to physiological concentrations of glucocorticoids. The secretion of MIF is tightly regulated and decreases at high, anti-inflammatory steroid concentration.

IL3RA, also known as Interleukin 3 Receptor Subunit Alpha, is a single-pass type 1 membrane protein which is a member of the type 1 cytokine receptor family as well as type 5 subfamily. IL3RA is a pleiotropic cytokine which is produced mainly by activated T cells or mast cells. Moreover, the specific alpha subunit of the interleukin 3 receptor is strongly expressed in a variety of leukemic blasts as well as leukemic stem cells and appears to be a great target for the therapy of leukemias.

L-Selectin belongs to a family of divalent cation-dependent carbohydrate-binding glycoproteins or adhesion molecules. The L-Selectin molecule is composed of various domains: one homologous to lectins, one to epidermal growth factor, and two to the consensus repeat units found in C3/C4 binding proteins.
L-selectin is expressed constitutively on lymphocytes, monocytes and granulocytes and interacts specifically with carbohydrate groups on activated endothelial cells. L-Selectin may be shed by proteolytic cleavage and circulating levels in biological fluids may be used as an indicator of various pathological conditions. L-Selectin is cleaved by ADAM17.
L-selectin works as a "homing receptor" for leukocytes to enter secondary lymphoid tissues via the high endothelial venules. Ligands present on endothelial cells will attach to leukocytes expressing L-selectin, which causes the leukocytes to become localized at that juncture. The receptor is also located on the cell surfaces of "naive" T cells, which have not yet encountered their particular antigen. This surface expression is lost following the cells activation.

CD5 antigen-like (CD5L) participates in the regulation of the immune system. CD5L functions as an inhibitor of apoptosis. CD5L is expressed in the spleen, lymph node, thymus and bone marrow.

Sialic acid-binding Ig-like lectin 7 isoform 1, also known as SIGLEC7, is a newly discovered family of sialic acid-binding lectins of the immunoglobulin (Ig) superfamily. The extracellular portion has two Ig-like domains, with the amino-terminal V-set Ig domain containing amino acid residues which known to be implicated in sialic acid recognition by other Siglecs. The combination of an extracellular sialic acid binding site and an intracellular ITIM motif proposes that SIGLEC7 is involved in trans-membrane regulatory signaling reactions. Furthermore, on the cell surface SIGLEC7 exists as a monomer and is expressed on natural killer cells.

LYVE-1 has been identified as a major receptor for HA (extracellular matrix glycosaminoglycan hyaluronan) on the lymph vessel wall. The deduced amino acid sequence of LYVE-1 predicts a 322-residue type I integral membrane polypeptide 41% similar to the CD44 HA receptor with a 212-residue extracellular domain containing a single Link module the prototypic HA binding domain of the Link protein superfamily. Like CD44, the LYVE-1 molecule binds both soluble and immobilized HA. However, unlike CD44, the LYVE-1 molecule colocalizes with HA on the luminal face of the lymph vessel wall and is completely absent from blood vessels. Hence, LYVE-1 is the first lymph-specific HA receptor to be characterized and is a uniquely powerful marker for lymph vessels themselves.

MARCKS-related protein (MARCKSL1) which is a part of MARCKS family of PKC substrate is broadly used in the signal transduction studies as an indicator of PKC activation. MARCKSL1 plays a part in the coordination of membrane-cytoskeletal signaling events, including secretion, migration, phagocytosis and cell adhesion and is expressed in a variety of tissues with highest levels found in testis and uterus. Furthermore, MARCKSL1 serves as a regulator of Integrin activation and is thought to regulate Integrin-dependent signal transduction pathways, particularly those involved in macrophage spreading.

HEPACAM2 is necessary during prometaphase for centrosome maturation. Following poly-ADP-ribosylation (PARsylation) by TNKS, HEPACAM2 translocates from the Golgi apparatus to mitotic centrosomes and takes a significant part in the formation of robust microtubules for quick movement of chromosomes.

Integrins are heterodimeric integral membrane proteins composed of an alpha chain and a beta chain. This I-domain containing alpha integrin combines with the beta 2 chain (ITGB2) to form a leukocyte-specific integrin referred to as macrophage receptor 1 ('Mac-1'), or inactivated-C3b (iC3b) receptor 3 ('CR3'). The alpha M beta 2 integrin is important in the adherence of neutrophils and monocytes to stimulated endothelium, and also in the phagocytosis of complement coated particles. Integrin alpha-m/beta-2 is implicated in various adhesive interactions of monocytes, macrophages and granulocytes as well as in mediating the uptake of complement-coated particles. CD-11b is identical with cr-3, the receptor for the ic3b fragment of the third complement component. CD-11b probably recognizes the r-g-d peptide in c3b. Integrin alpha-m/beta-2 is also a receptor for fibrinogen, factor x and icam1. it recognizes p1 and p2 peptides of fibrinogen gamma chain.

Chemokine (C-C motif) ligand 18 (CCL18 / MIP-4) is a small cytokine belonging to the CC chemokine family that was previously called PARC (pulmonary and activation-regulated chemokine). MIP-4 is approximately 60% identical in amino acid sequence to CCL3. MIP-4 is expressed at high levels in lung and at lower levels in certain lymphoid tissues, such as the lymph nodes, and is chemotactic for activated T cells and non activated lymphocytes. The gene for human CCL18 contains three exons and is located on chromosome 17.

Interleukin-1 ra is a member of the interleukin 1 cytokine family. This protein inhibits the activities of interleukin 1, alpha (IL1A) and interleukin 1, beta (IL1B), and modulates a variety of interleukin 1 related immune and inflammatory responses. This gene and five other closely related cytokine genes form a gene cluster spanning approximately 400 kb on chromosome 2. A polymorphism of this gene is reported to be associated with increased risk of osteoporotic fractures and gastric cancer. Four alternatively spliced transcript variants encoding distinct isoforms have been reported.

Interleukin-1 ra is a member of the interleukin 1 cytokine family. This protein inhibits the activities of interleukin 1, alpha (IL1A) and interleukin 1, beta (IL1B), and modulates a variety of interleukin 1 related immune and inflammatory responses. This gene and five other closely related cytokine genes form a gene cluster spanning approximately 400 kb on chromosome 2. A polymorphism of this gene is reported to be associated with increased risk of osteoporotic fractures and gastric cancer. Four alternatively spliced transcript variants encoding distinct isoforms have been reported.

Low affinity immunoglobulin gamma Fc region receptor III-A (FCGR3A) is a receptor for the Fc portion of immunoglobulin G, and is involved in the elimination of antigen-antibody complexes from the circulation, as well as other antibody-dependent responses. FCGR3A needs to associate with the gamma subunit of Fc epsilon. The FCGR3A receptor is expressed on natural killer (NK) cells as an integral membrane glycoprotein anchored through a transmembrane peptide, while FCGR3B is expressed on polymorphonuclear neutrophils (PMN) where the receptor is anchored through a phosphatidylinositol (PI) linkage. In addition, FCGR3A is expressed on macrophages, subpopulation of T-cells, immature thymocytes and placental trophoblasts. FCGR3A mediates antibody-dependent cellular cytotoxicity (ADCC) and other antibody-dependent responses, such as phagocytosis. FCGR3A gene mutations are linked with susceptibility to recurrent viral infections, susceptibility to systemic lupus erythematosus, and alloimmune neonatal neutropenia.

Mediator of ErbB2-driven cell motility 1 (MEMO1) is a member of the UPF0103 family. MEMO1 regulates cell migration by transmitting extracellular chemotactic signals to the microtubule cytoskeleton. Furthermore, MEMO1 controls the localization of APC and CLASP2 to the cell membrane, using the regulation of GSK3B activity. MEMO1 is essential for breast carcinoma cell migration, suggesting a key role in tumorigenesis. MEMO1 is also a mediator of ERBB2 signaling.

TICAM2 belongs to the Toll/interleukin-1 receptor (TIR) family, a group of proteins which include the Toll-like receptors (TLRs). TICAM2, a cytoplasmic protein, physically bonds TLR4 and TICAM-1 and functionally transfers LPS-TLR4 signaling to TICAM-1, that sequentially activates IRF-3. TICAM2 takes part in IL1-triggered NF-kappa-B activation, operating upstream of IRAK1, IRAK2, TRAF6, and IKBKB.

The bone morphogenetic protein (BMP) receptors are a family of transmembrane serine/threonine kinases that include the type I receptors BMPR1A and BMPR1B and the type II receptor BMPR2. These receptors are also closely related to the activin receptors, ACVR1 and ACVR2. The ligands of these receptors are members of the TGF-beta superfamily. TGF-betas and activins transduce their signals through the formation of heteromeric complexes with 2 different types of serine (threonine) kinase receptors: type I receptors of about 50-55 kD and type II receptors of about 70-80 kD. Type II receptors bind ligands in the absence of type I receptors, but they require their respective type I receptors for signaling, whereas type I receptors require their respective type II receptors for ligand binding.

CD33 is putative adhesion molecule of myelomonocytic-derived cells which mediates sialic-acid dependent binding to cells. CD33 prefers to bind to alpha-2,6-linked sialic acid. The sialic acid recognition site is masked by cis interactions with sialic acids on the same cell surface. In the immune response, CD33 perform as an inhibitory receptor upon ligand induced tyrosine phosphorylation by recruiting cytoplasmic phosphatases through their SH2 domains which block signal transduction through dephosphorylation of signaling molecules. In addition, CD33 induces apoptosis in acute myeloid leukemia.

Macrophage Inflammatory Proteins (MIP) belong to the family of chemotactic cytokines known as chemokines. In humans, there are two major forms, MIP-1a and MIP-1b that are now officially named CCL3 and CCL4 respectively. Both are major factors produced by macrophages after they are stimulated with bacterial endotoxins. They activate human granulocytes (neutrophils, eosinophils and basophils) which can lead to acute neutrophilic inflammation. They also induce the synthesis and release of other pro-inflammatory cytokines such as interleukin 1 (IL-1), IL-6 and TNF-a from fibroblasts and macrophages. The genes for CCL3 and CCL4 are both located on human chromosome 17.

Chemokine (C-C motif) ligand 19 (CCL19) is a small cytokine belonging to the CC chemokine family that is also known as EBI1 ligand chemokine (ELC) and macrophage inflammatory protein-3-beta (MIP-3-beta). CCL19 is expressed abundantly in thymus and lymph nodes, with moderate levels in trachea and colonand low levels in stomach, small intestine, lung, kidney and spleen. The gene for CCL19 is located on human chromosome 9. This chemokine elicits its effects on its target cells by binding to the chemokine receptor chemokine receptor CCR7. It attracts certain cells of the immune system, including dendritic cellsand antigen-engaged B cells.

IFN-alpha is produced by macrophages, IFN-alpha has antiviral activities and stimulates the production of two enzymes: a protein kinase and an oligoadenylate synthetase.

Vimentin expression in human malignant glioma cells depends on cellular density, algorithms of drug delivery and chemo/radio treatment. Vimentin and detyrosinated microtubules provide structural support for the extensive microtentacles observed in detached tumor cells and a mechanism to promote successful metastatic spread. Primary colorectal carcinomas display aberrant expression of vimentin, and have activated Notch and TGFbeta signaling pathways. Vimentin is a strong arterial substrate for transglutaminases. Transglutaminase-mediated vimentin dimerization results in a novel unifying pathway by which vasodilatory and remodeling responses may be regulated. Ablation of vimentin expression inhibits migration and invasion of colon and breast cancer cell lines.

IFNs are cytokines that are widely known to induce potent anti-viral activity. IFN-a exerts a variety of other biological effects, including antitumor and immunomodulatory activities and are increasingly used clinically to treat a range of malignancies, myelodysplasias and autoimmune diseases.