Immune response lipid-binding proteins

It is also likely that direct cytotoxicity of halothane metabolites is important in the process, causing cellular stress by lipid peroxidation and covalent binding to target proteins (Fig. 7.77). Then the cytokines produced by this stress cause upregulation of costimulatory molecules, which provides the second signal for the immune response to occur. 

Many larger lipid carrier proteins are known. The 476-residue plasma cholesteryl ester transfer protein is discussed briefly in Chapter 22. Plasma phospholipid transfer proteins are of similar size.t/U A 456-residue human phospholipid-binding protein interacts with the lipopolysaccharide of the surfaces of gram-negative bacteria (Fig. 8-30) and participates in the immune response to the bacteria. It has an elongated boomerang shape with two cavities, both of which bind a molecule of phosphatidylcholine. Other plasma lipid transfer proteins may have similar structures/... 

Some cell-surface receptors are attached to the plasma membrane by lipids that penetrate only into the outer leaflet of the bilayer. Posttranslational modification of proteins with GPI-lipids allows proteins such as folate receptor-2 (FOLR2) to attach to the cell surface and promote RME of the vitamin 5-methyltetrahydrofolate. Folate receptors are upregulated in certain cancers, and folate derivatives have been linked to drugs and molecular probes to treat and image certain tumors. The related GPI-linked receptor FcyRIIIB (CD16, 26.2 KDa, Fig. 1) is involved in the immune response. This receptor binds the invariant Fc region of immunoglobulin-G to promote RME of this... 

HIV is a retrovirus in which the virus uses the body s cellular machinery to transform RNA to DNA. The number of helper T cells is dramatically reduced thereby lowering the body s immune response. GP-120 is essential to the virus binding to the cell surface receptor for entry into the cell. 14-3-3-0 is specifically implicated in the G2 checkpoint for cell cycle arrest for the HIV-1 VPR (viral protein R) accessory protein, which is associated with cell death since VPR is necessary for viral infection of helper T cells (Bolton et al. 2008). 14-3-3-0 can bind to several cyclin-dependent kinases that regulate the cell cycle leading to overall neurodegeneration in this immune disorder. Lipid peroxidation of the 14-3-3 family of proteins may cause reduced interaction with protein kinases, which can result in reduced signal transduction by which protein synthesis, cell cycle regulation, and DNA repair may be affected. 

CXCRl is a receptor for the chemokine interleukin-8 (IL-8), a mediator of immune and inflammatory responses. Strategically located in the cell membrane, CXCRl binds to IL-8 with high affinity and subsequently transduces a signal across the membrane bilayer to a G-protein-activated second messenger system. Reserchers describe NMR studies of the interactions between IL-8 and human CXCRl in lipid enviromnents. A combination of solution NMR and solid-state NMR studies of IL-8 in the presence of various constructs of CXCRl enables us to propose a model for the multi-step binding process. ... 

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