Glycoproteins interleukins

These proteins are called acute phase proteins (or reactants) and include C-reactive protein (CRP, so-named because it reacts with the C polysaccharide of pneumococci), ai-antitrypsin, haptoglobin, aj-acid glycoprotein, and fibrinogen. The elevations of the levels of these proteins vary from as little as 50% to as much as 1000-fold in the case of CRP. Their levels are also usually elevated during chronic inflammatory states and in patients with cancer. These proteins are believed to play a role in the body s response to inflammation. For example, C-reactive protein can stimulate the classic complement pathway, and ai-antitrypsin can neutralize certain proteases released during the acute inflammatory state. CRP is used as a marker of tissue injury, infection, and inflammation, and there is considerable interest in its use as a predictor of certain types of cardiovascular conditions secondary to atherosclerosis. Interleukin-1 (IL-1), a polypeptide released from mononuclear phagocytic cells, is the principal—but not the sole—stimulator of the synthesis of the majority of acute phase reactants by hepatocytes. Additional molecules such as IL-6 are involved, and they as well as IL-1 appear to work at the level of gene transcription. 

Amino acid receptors Monoamine receptors Lipid receptors Purine receptors Neuropeptide receptors Peptide hormone receptors Chemokine receptors Glycoprotein receptors Protease receptors Metabotropic glutamate and GABAb receptors Adrenoceptors, dopamine and 5-HT receptors, muscarinic and histamine receptors Prostaglandin, thromboxane and PAF receptors Adenosine and ATP (P2Y) receptors Neuropeptide Y, opiate, cholecystokinin VIP, etc. Angiotensin, bradykinin, glucagon, calcitonin, parathyroid, etc. Interleukin-8 TSH, LH/FSH, chorionic gonadotropin, etc. Thrombin... 

It was found that the HIV envelope glycoprotein in vitro increases the production of NO by human monocyte-derived macrophages [114]. NO production is increased in patients who have AIDS [115], and the increased concentrations of nitrite in AIDS patients with opportunistic infections is caused by T gondii, Pneumocystis carinii, Mycobacterium tuberculosis, and Mycobacterium avium, whereas nitrite concentrations are normal in symptom-free patients. It was also confirmed that there was increased production of NO in the sera of children with HIV-1 infection, and of circulating cytokines, such as interleukin lp, tumor necrosis factor a, and interferon y. It is postulated that rises in the concentrations of these cytokines may represent a substantial stimulation of NO production [116]. In contrast, it has been shown that there was no altered endogenous nitrate formation in eight patients with AIDS, most of whom had opportunistic infections [117]. It has also been noted that there were high... 

Interleukin-3 (IL-3), a glycoprotein lympokine from T cells, stimulates the growth of murine mast cells, neutrophils, and macrophages from haemopoietic progenitor cells [71,153]. Thus, cultures of murine bone marrow or spleen cells supplemented with IL-3 have been shown to generate cells that have many of the characteristics of mucosal mast cells [71, 153]. The release of IL-3 in vivo... 

IL-2 is possibly the most-studied interleukin. It is also called T cell growth factor. IL-2 is a ISkDa glycoprotein produced by CD4+ T helper cells. It has 133 amino acids. There are four helical regions and a short )3-sheet section (Fig. 4.7). 

The biological activities of several other interleukins also render them likely candidates for therapeutic application. IL-5 represents one such candidate. IL-5 is a 115 amino acid glycoprotein produced mainly by activated T lymphocytes and also by mast cells. It functions as a homodimer, exhibiting a molecular mass of 45 kDa. The individual polypeptide chains interact non-covalently and the overall dimeric structure is stabilized by two interchain disulphide linkages between cysteines 42 and 84 of each chain. Removal or alterations of the cytokine s carbohydrate side-chain does not appear to affect its biological activity. 

Fig. 8.1 A schematic diagram illustrating the involvement of NF-k I in gpl20, ROS, NO, PG, IL-1/3 and TNF-a-mediated neurotoxicity. NMDA-R, N-Methyl-D-aspartate receptor, cPLA2, cytosolic phospholipase A2 lyso-PtdCho, lysophosphatidylcholine AA, arachidonic acid cAMP, cyclic adenosine monophosphate PKA, protein kinase A TNF-a, tumor necrosis factor-a TNF-a-R, TNF-a-receptor IL-1/8, interleukin-1 /3 IL-l/i-R, IL-1/8-receptor, IL-6, interleukin-6 MARK, mitogen-activated protein kinase NO, nitric oxide PG, prostaglandins EP-R, prostaglandin receptors NF-kB, nuclear factor-icB NF-kB-RE, nuclear factor-/cB-response element I/cB, inhibitory subunit of NF-icB HIV-1, human immunodeficiency virus type 1 gpl20, HIV-1 coat glycoprotein COX-2, cyclooxygenase-2 iNOS, inducible nitric oxide synthase SPLA2, secretory phospholipase A2 SOD, superoxide dismutase MMP, matrix metalloproteinase and VCAM-1, vascular adhesion molecule-1...

Bonhomme-Faivre L, PeUoqnin A, Tardivel S, Urien S, Mathieu MC, Castagne V, Lacour B, Earinotti R (2002) Recombinant interleukin-2 treatment decreases P-glycoprotein activity and paclitaxel metabolism in mice. Anit-Cancer Drugs 13 51-57. 

Drach J, Gsur A, Hamilton G, Zhao S, Angerler J, Fiegl M, Zojer N, Raderer M, Haberl I, Andreeff M, Huber H (1996) Involvement of P-glycoprotein in the transmembrane transport of interleukin-2 (IL-2), IL-4, and interferon-gamma in normal human T lymphocytes. Blood 88 1747-1754. 

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