Tyvelose

Fig. 6.2. Caco-2 epithelial cell monolayers cultured with T. spiralis L1 larvae in (A) the absence or (B) presence of 1 mg ml 1 rat monoclonal, tyvelose-specific antibody 9D4 (McVay etal., 2000). Monolayers were fixed and stained with trypan blue as described in ManWarren etal. (1997). (A) Serpentine trails of nuclei in dead cells are evident, revealing the paths travelled by larvae. (B) Tyvelose-specific antibody has inhibited the migration of the larva such that it is encumbered in cell debris and has pulled up a large area of the monolayer, creating a plaque (P). Bar = 50 urn. Photomicrograph prepared by C. McVay, TTUHSC, Lubbock, Texas. 

Ellis, L.A., McVay, C.S., Probert, M.A., Zhang, J., Bundle, D.R. and Appleton, J.A. (1997) Terminal [blinked tyvelose creates unique epitopes in Trichinella spiralis glycan antigens. Glycobiology 7, 383-390. 

McVay, C.S., Bracken, P., Gagliardo, L.F. and Appleton, J.A (2000) Antibodies to tyvelose exhibit multiple modes of interference with the epithelial niche of TrichineUa spiralis. Infection and Immunity 68, 1912-1918. 

Reason, A.J., Ellis, L.A., Appleton, J.A., Wisnewski, N., Grieve, R.B., McNeil, M., Wassom, D.L., Morris, H.R. and Dell, A. (1994) Novel tyvelose-containing tri- and tetra-antennary N-glycans in the immunodominant antigens of the intracellular parasite TrichineUa spiralis. Glycobiology 4, 593-603. 

It is important to emphasize that detection of NA has depended on antibody determinants shared by other parasite products, such as the tyvelose containing glycan. The earliest detection of NA is about 9 dpi (Despommier et al., 1990) and persists throughout the chronic infection. Therefore, current evidence supports a potential role for NA only after cell cycle repositioning. 

Fig. 15.5. Structures of A/-linked glycans from several different species of parasitic nematodes, illustrating both similarities with mammalian glycans (compare with Figs 15.1 and 15.2) and features unique to nematodes (e.g. tyvelose and PC capping and novel core fucosylation). The filarial nematode glycans are believed to be substituted with charged residues, which are not yet characterized.

M. A. Probert, J. Zhang, and D. R. Bundle, Synthesis of a- and /blinked tyvelose epitopes of the Trichinella spiralis glycan 2-Acetamido-2-deoxy-3-0-(3, 6-dideoxy-D-arabmo-hexopyninosyl)-/)-D-galactopyranosides. Carbohydr. Res., 296 (1996) 149-170. 

The biologically important sugars paratose (3,6-dideoxy-D-nho-hexose) and tyvelose (3,6-dideoxy-D-arafctno-hexose) have also been conveniently prepared203 by routes involving reductive dechlorination by hydrogenation over Raney nickel catalyst these 3,6-dideoxy-... 

The derivative (9) of 3,6-dideoxy-a-D-xyIo-hexopyranose (abequose) was isolated from a strain of Salmonella typhimurium,16 that (10) of 3,6-dideoxy-a-D-nfco-hexopyranose (paratose) from Salmonella paratyphi,54 and a mixture of 10 and the ester (11) of 3,6-dideoxy-a-D-arabino-hexopyranose (tyvelose) from Salmonella enteritidis.,6 It was shown that these derivatives are formed from cytidine 5 -(a-D-glu-copyranosyl pyrophosphate) by treatment with nicotinamide adenine dinucleotide (NAD+) and reduced nicotinamide adenine dinucleotide phosphate (NADPH) in the presence of cell extracts of the respective bacterial strain. For example, formation of 9 is characteristic of preparations from Salmonella, group B,55,56 or Pasteurella pseudotuberculosis, type II.56 The derivative 10 was obtained with extracts of Salmonella, group A,56 and Pasteurella pseudotuberculosis, type I and III,56 and a mixture of 10 and 11 with those of Salmonella, group D,55-60 or Pasteurella pseudotuberculosis, type IV 56.59,60 Under similar conditions, the ester (12) of cytidine 5 -pyro-... 

E. H. Williams, W. A. Szarek, and J. K. N. Jones, Synthesis of paratose (3,6-dideoxy-D-rifw-hexose) and tyvelose (3,6-dideoxy-D-orahmo-hexose), Can. J. Chem. 49 796 (1971). 

C. Fouquey, J. Polonsky, and E. Lederer, Synthesis of three 3,6-dideoxyhexoses. Determination of the structure of the natural sugars tyvelose, ascarylose, and paratose, Bull. Soc. Chim. Fr. p. 803 (1959). 

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