scholarly journals Heparan Sulfate Mediates Infection of High-Neurovirulence Theiler's Viruses

2003 ◽  
Vol 77 (16) ◽  
pp. 9106-9106
Author(s):  
Honey V. Reddi ◽  
Howard L. Lipton
2002 ◽  
Vol 76 (16) ◽  
pp. 8400-8407 ◽  
Author(s):  
Honey V. Reddi ◽  
Howard L. Lipton

ABSTRACT The mechanisms by which Theiler's murine encephalomyelitis virus (TMEV) binds and enters host cells and the molecules involved are not completely understood. In this study, we demonstrate that the high-neurovirulence TMEV GDVII virus uses the glycosaminoglycan heparan sulfate (HS) as an attachment factor that is required for efficient infection. Studies based on soluble HS-mediated inhibition of attachment and infection, removal of HS with specific enzymes, and blocking with anti-HS antibodies establish that HS mediates GDVII virus entry into mammalian cells. Data from defined proteoglycan-deficient Chinese hamster ovary mutant cells further support the role of HS in GDVII infection and indicate that the extent of sulfation is critical for infection. Neuraminidase treatment of proteoglycan-deficient cells restores permissiveness to GDVII virus, indicating that sialic acid hinders direct access of virus to the protein entry receptor. A model of the potential steps in GDVII virus entry into mammalian cells involving HS is proposed.


Author(s):  
U. Frevert ◽  
S. Sinnis ◽  
C. Cerami ◽  
V. Nussenzweig

Malaria sporozoites, which invade hepatocytes within minutes after transmission by an infected mosquito, are covered with the circumsporozoite (CS) protein, which in all Plasmodium species contains the conserved region II-plus. This region is also found as a cell-adhesive motif in a variety of host proteins like thrombospondin, properdin and the terminal complement components.The CS protein with its region II-plus specifically binds to heparan sulfate proteoglycans (HSPG) on the basolateral surface of hepatocytes in the space of Disse (FIG. 1), to certain basolateral cell membranes and basement membranes of the kidney (FIG. 2) as well as to heparin in the granules of connective tissue mast cells. The distribution of the HSPG receptors for the CS protein was examined by incubation of Lowicryl K4M or LR White sections of liver and kidney tissue with the recombinant CS ligand, whose binding sites were detected with a monoclonal anti-CS antibody and protein A gold.


1996 ◽  
Vol 75 (01) ◽  
pp. 168-174 ◽  
Author(s):  
Shigeru Tokita ◽  
Morio Arai ◽  
Naomasa Yamamoto ◽  
Yasuhiro Katagiri ◽  
Kenjiro Tanoue ◽  
...  

SummaryTo study the pathological functions of anti-phospholipid (anti-PL) antibodies, we have analyzed their effect on platelet function. We identified an IgG anti-PL mAb, designated PSG3, which cross-reacted specifically with glycoprotein (GP) IIIa in human platelets and inhibited platelet aggregation. PSG3 bound also to certain polyanionic substances, such as double-stranded DNA, heparan sulfate, dextran sulfate and acetylated-LDL, but not to other polyanionic substances. The binding of PSG3 to GPIIIa was completely inhibited by heparan sulfate and dextran sulfate, indicating that PSG3 recognizes a particular array of negative charges expressed on both GPIIIa and the specified polyanionic substances. Since neither neuraminidase- nor endoglycopeptidase F-treatment of GPIIIa had any significant effect on the binding of PSG3, this array must be located within the amino acid sequence of GPIIIa but not in the carbohydrate moiety. Reduction of the disulfide bonds in GPIIIa greatly reduced its reactivity, suggesting that the negative charges in the epitope are arranged in a particular conformation. PSG3 inhibited platelet aggregation induced by either ADP or collagen, it also inhibited fibrinogen binding to activated platelets in a dose-dependent fashion. PSG3, however, did not inhibit the binding of GRGDSP peptide to activated platelets. These results suggest that the PSG3 epitope on GPIIIa contains a particular array of negative charges, and possibly affects the fibrinogen binding to GPIIb/IIIa complex necessary for platelet aggregation.


Diabetes ◽  
1982 ◽  
Vol 31 (2) ◽  
pp. 185-188 ◽  
Author(s):  
D. H. Rohrbach ◽  
J. R. Hassell ◽  
H. K. Kleinman ◽  
G. R. Martin

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