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Native human C3a is created by cleavage of human C3 protein by a human C3 convertase. C3a is a member of the anaphylatoxin family of three proteins (C3a, C4a and C5a) created by the activation of complement. C3a mediates various inflammatory responses including smooth muscle contraction, increased vascular permeability, vasodilation and release of histamine from mast cells and basophils. C3a (In contrast to C5a) does not exhibit significant neutrophil stimulating activities and does not induce chemotaxis, granule release or superoxide production. C3a acts through the C3a Receptor which is a G-protein coupled receptor found mainly on peripheral tissues, lymphoid cells and in the central nervous system. These activities of C3a are inactivated by removal of the C-terminal arginine which happens rapidly in plasma due to the action of carboxypeptidase N.

C3b is derived from native C3 upon cleavage with the alternative pathway C3 convertase and release of C3a. C3b is essential to the function of all 3complement pathways. Initiation of each pathway generates proteolytic enzyme complexes (C3 convertases) which binds the target surface. These enzymes cleave a peptide bond in C3 releasing the anaphylatoxin C3a and activating C3b. Most of the C3b created during complement activation. Surface-bound C3b is needed in all 3 pathways for effective activation of C5 and formation of C5b-9 complexes which lyse the target cell membrane. Surface-bound C3b and its breakdown products iC3b and C3d are identifyid by various receptors on lymphoid and phagocytic cells which use the C3b ligand to stimulate antigen presentation to cells of the adaptive immune system. It results in an expansion of target-specific B-cell and T-cell populations.

CIB1 (Calcium and integrin binding 1) is regulatory protein with 50% homology to calmodulin and calcineurin B, that encodes a member of the calcium-binding protein family. CIB1 interacts with DNA-dependent protein kinase and may play a role in kinase-phosphatase regulation of DNA end joining. Also CIB1 is widely expressed and binds to a number of effectors, such as integrin αIIb, PAK1, and polo-like kinases, in different tissues.

IL-18 is a proinflammatory cytokine. This cytokine can induce the IFN-gamma production of T cells. The combination of this cytokine and IL12 has been shown to inhibit IL4 dependent IgE and IgG1 production, and enhance IgG2a production of B cells. IL-18 binding protein (IL18BP) can specifically interact with this cytokine, and thus negatively regulate its biological activity.

Cystatins are a superfamily of cysteine proteinase inhibitors found in both plants and animals. They comprise a group of proteinase inhibitors, widely distributed in tissues and body fluids, and form tight complexes with cysteine proteases such as cathepsin B, H, L and S. Cystatin C, a secreted molecule of this family, is of interest from biochemical, medicine and evolutionary points of view. Cystatin C is increased in patients with malignant diseases, and is related to the insufficiency of renal function and appears to be a better marker than creatinine. On the other hand, low levels of cystatin C involve cause the breakdown of the elastic laminae and subsequently, the atherosclerosis and abdominal aortic aneurysm.

Flagellin arranges itself in a hollow cylinder to create the filament in bacterial flagellum. Flagellin is the key substituent of bacterial flagellum, and is found in large quantities on almost all flagellated bacteria.

Cystatin-SN (CST1) belongs to the type 2 salivary cystatin family found in a variety of fluids and secretions, including plasma, tears, and saliva. The cystatin superfamily includes proteins which contain multiple cystatin-like sequences. Some of the members are active cysteine protease inhibitors, whereas others have lost or possibly never developed this inhibitory activity. CST1 is up-regulated in cancerous lesions of gastric cancer tissues compared to noncancerous regions, in addition clinicopathological analysis revealed a significant correlation between high expression of CST1.

Chemokine (C-X-C motif) ligand 9 (CXCL9) is a small cytokine belonging to the CXC chemokine family that is also known as Monokine induced by MIG. CXCL9 is a T-cell chemoattractant. It is closely related to two other CXC chemokines called CXCL10 and CXCL11, whose genes are located near the gene for CXCL9 on human chromosome 4. CXCL9, CXCL10 and CXCL11 all elicit their chemotactic functions by interacting with the chemokine receptor CXCR3.

CTLA-4 is a member of the immunoglobulin superfamily and encodes a protein which transmits an inhibitory signal to T cells. The protein contains a V domain, a transmembrane domain, and a cytoplasmic tail. Alternate transcriptional splice variants, encoding different isoforms, have been characterized. The membrane-bound isoform functions as a homodimer interconnected by a disulfide bond, while the soluble isoform functions as a monomer. Mutations in this gene have been associated with insulin-dependent diabetes mellitus, Graves disease, Hashimoto thyroiditis, celiac disease, systemic lupus erythematosus, thyroid-associated orbitopathy, and other autoimmune diseases.

SCG3 belongs to the chromogranin/secretogranin family of neuroendocrine secretory proteins. Though, the function of SCG3 is unknown, Granins operate as precursors for biologically active peptides. Several granins are known to serve as helper proteins in sorting and proteolytic processing of prohormones.

MAX Dimerization Protein 3 (MXD3) belongs to the Myc superfamily of basic helix-loop-helix leucine zipper transcriptional regulators. MXD3 forms a heterodimer with the cofactor MAX that connects specific E-box DNA motifs in the promoters of target genes and regulates their transcription. Disturbance of the MAX-MXD3 complex is correlated with uncontrolled cell proliferation and tumorigenesis. Transcript variants of MXD3 encoding different isoforms have been described.

Chemokine (C-X-C motif) ligand (CXCL7) is a small cytokine belonging to the CXC chemokine family. It is a protein that is released in large amounts from platelets following their activation. It stimulates various processes including mitogenesis, synthesis of extracellular matrix, glucose metabolism and synthesis of plasminogen activator.

AP-3 complex subunit sigma-1 (AP3S1) belongs to the AP-3 complex, an adapter-related complex which is not clathrin-associated. AP3S1 is linkd with the Golgi region in addition to more peripheral structures. AP3S1 facilitates the budding of vesicles from the Golgi membrane and involved in trafficking to lysosomes.

EFNA3 belongs to the ephrin (EPH) family. The ephrins and EPH-related receptors include thelargest subfamily of receptor protein-tyrosine kinases which have been implicated in mediating developmental events, especially in the nervous system and in erythropoiesis. Ephrins are divided into the ephrin-A (EFNA) class and the ephrin-B (EFNB) class, based on their structures and sequence relationships. The Ephrins from the EFNA class are anchored to the membrane by aglycosylphosphatidylinositol linkage, while the others from the EFNB class are transmembrane proteins.

IFN-gamma produced by lymphocytes activated by specific antigens / mitogens.
IFN-gamma, on top of having antiviral activity, has important immunoregulatory functions, it is a potent activator of macrophages, and has antiproliferative effects on transformed cells and it can potentiate the antiviral and antitumor effects of the type I interferons.

Chemokine (C-C motif) ligand 21 (CCL21) is a small cytokine belonging to the CC chemokine family. This chemokine is also known as 6Ckine (because it has six conserved cysteine residues instead of the four cysteines typical to chemokines), exodus-2, and secondary lymphoid-tissue chemokine (SLC). CCL21 is expressed predominantly in the lymph nodes and, in contrast to other CC chemokines, is chemotactic for lymphocytes. The gene for CCL21 is located on human chromosome 9. CCL21 elicits its effects by binding to a cell surface chemokine receptor known as CCR7.

Synaptotagmin-3 (SYT3) is a member of the synaptotagmin family. SYT3 is involved in Ca(2+)-dependent exocytosis of secretory vesicles through Ca(2+) and phospholipid binding to the C2 domain or may function as Ca(2+) sensors in the process of vesicular trafficking and exocytosis.

Follicular Dendritic Cell Secreted Protein (FDCSP) is a small secreted protein which is found in follicular dendritic cells. The FDCSP protein specifically binds to activated B cells, and serves as a regulator of antibody responses. In addition, FDCSP is assumed to contribute to tumor metastases by promoting cancer cell migration and invasion. FDCSP binds to the surface of B-lymphoma cells, but not T-lymphoma cells, which is consistent with a function as a secreted mediator acting upon B-cells. FDCSP is abundantly expressed in the tonsil, lymph node, and tracheam, having a strong expression in the prostate and a lower expression in the thyroid, stomach and colon.

CBX3 takes part in transcriptional silencing in heterochromatin-like complexes. CBX3 identifies and binds histone H3 tails methylated at 'Lys-9', thereby create an epigenetic repression. Additionally, CBX3 takes part in the formation of functional kinetochore by interacting with MIS12 complex proteins.

Phospholipid Scramblase 3, (PLSCR3) may mediate accelerated ATP-independent bidirectional transbilayer migration of phospholipids upon binding calcium ions which results in a loss of phospholipid asymmetry in the plasma membrane. PLSCR3 may play a key role in the initiation of fibrin clot formation, in the activation of mast cells and in the recognition of apoptotic and injured cells by the reticuloendothelial system. In addition, PLSCR3 seems to play a role in apoptosis, through translocation of cardiolipin from the inner to the outer mitochondrial membrane which promotes BID recruitment and enhances tBid-induced mitochondrial damages. Among the diseases associated with PLSCR3 are brain ischemia, and ischemia.

CDC123 is a member of the CDC123 family. CDC123is required for S phase entry of the cell cycle. It is also broadly expressed in spleen,thymus, prostate, testis, ovary, small intestine, colon and leukocytes with the uppermost expression in testis.

Thymic Stromal Lymphopoietin Receptor (TSLPR) is a member of the type I cytokine receptor family. TSLPR alongside the interleukin 7 receptor (IL7R) activate STAT3, STAT5, and JAK2 pathways, which is regulated processes such as cell proliferation and development of the hematopoietic system. Two transcript variants encoding dissimilar isoforms have been found for this gene. TSLPR is expressed in heart, skeletal muscle, kidney and adult and fetal liver.

C-type Lectin Domain Family 1 Member B, also known as CLEC1B. NK-Natural killer cells express multiple calcium-dependent (C-type) lectin-like receptors, for instance CD94 (KLRD1; MIM 602894) and NKG2D (KLRC4; MIM 602893), which interact with major histocompatibility complex class I molecules and either inhibit or else activate cytotoxicity and cytokine secretion. CLEC1B is a C-type lectin-like receptor which is expressed in myeloid cells as well as in NK cells.

Methylosome subunit pICln (CLNS1A), is a member of the pICln (TC 1.A.47) family. CLNS1A takes part in multiple regulatory pathways. CLNS1A interaction with Sm proteins, inhibits their compilation on U RNA and interferes with snRNP biogenesis. CLNS1A inhibits the binding of survival motor neuron protein (SMN) to Sm proteins. Methylosome subunit pICln is related with the plasma membrane where it functions as a chloride present regulator.