The Murid Herpesvirus-4 gH/gL Binds to Glycosaminoglycans

The first contact a virus makes with cells is an important determinant of its tropism. Murid Herpesvirus-4 (MuHV-4) is highly dependent on glycosaminoglycans (GAGs) for cell binding. Its first contact is therefore likely to involve a GAG-binding virion glycoprotein. We have previously identified two such proteins, gp70 and gp150. Gp70 binds strongly to GAGs. However, deleting it makes little difference to MuHV-4 cell binding or GAG-dependence. Deleting gp150, by contrast, frees MuHV-4 from GAG dependence. This implies that GAGs normally displace gp150 to allow GAG-independent cell binding. But the gp150 GAG interaction is weak, and so would seem unlikely to make an effective first contact. Since neither gp70 nor gp150 matches the expected profile of a first contact glycoprotein, our understanding of MuHV-4 GAG interactions must be incomplete. Here we relate the seemingly disconnected gp70 and gp150 GAG interactions by showing that the MuHV-4 gH/gL also binds to GAGs. gH/gL-blocking and gp70-blocking antibodies individually had little effect on cell binding, but together were strongly inhibitory. Thus, there was redundancy in GAG binding between gp70 and gH/gL. Gp150-deficient MuHV-4 largely resisted blocks to gp70 and gH/gL binding, consistent with its GAG independence. The failure of wild-type MuHV-4 to do the same argues that gp150 is normally engaged only down-stream of gp70 or gH/gL. MuHV-4 GAG dependence is consequently two-fold: gp70 or gH/gL binding provides virions with a vital first foothold, and gp150 is then engaged to reveal GAG-independent binding

Helicobacter species and common gut bacterial DNA in gallbladder with cholecystitis.

AIM: To analyze the association between Helicobacter spp. and some common gut bacteria in patients with cholecystitis. METHODS: A nested-polymerase chain reaction (PCR), specific to 16S rRNA of Helicobacter spp. was performed on paraffin-embedded gallbladder samples of 100 cholecystitis and 102 control cases. The samples were also analyzed for some common gut bacteria by PCR. Positive samples were sequenced for species identification. RESULTS: Helicobacter DNA was found in seven out of 100 cases of acute and chronic cholecystitis. Sequence analysis displayed Helicobacter pullorum (H. pullorum) in six cases and Helicobacter pylori in one; H. pullorum was only found in cases with metaplasia. Control samples were negative for Helicobacter spp. and some common gut bacteria. There was a significant difference (P = 0.007) between cholecystitis and control samples for Helicobacter DNA. CONCLUSION: A possible relationship was detected between Helicobacter DNA and cholecystitis. Further serological and immunohistochemical studies are needed to support these data

Helicobacter species and gut bacterial DNA in Meckel's diverticulum and the appendix.

AIM: To analyse the possible association of various Helicobacter species and certain common gut bacteria in patients with Meckel's diverticulum and appendicitis. METHODS: A nested-polymerase chain reaction (PCR), specific to 16S rRNA of the Helicobacter genus, was performed on paraffin embedded samples, 50 with acute appendicitis, 50 normal appendixes, and 33 Meckel's diverticulum with gastric heterotopia and/or ulcer. Helicobacter genus positive samples were sequenced for species identification. All samples were also analysed for certain gut bacteria by PCR. RESULTS: Helicobacter pullorum DNA was found in one out of 33 cases and Enterobacteria in two cases of Meckel's diverticulum. Helicobacter pylori (H. pylori) was found in three, Enterobacter in 18, and Bacteroides in 19 out of 100 appendix samples by PCR. Enterococcus was not found in any MD or appendix samples. All H. pylori positive cases were from normal appendixes. CONCLUSION: Helicobacter is not an etiological agent in the pathogenesis of symptomatic Meckel's diverticulum or in acute appendicitis