We found no clear difference between the efficiencies of propagation of each strain in NA cells (Fig. 5a). In addition, the growth curves of the RC-HL and R(G 242/255/268) strains in other neural cell lines, such as human neuroblastoma SYM-I and SK-N-SH cells, were almost identical (data not shown). These results indicate that the propagation efficiency of the RC-HL strain in vitro is almost identical to that of the R(G 242/255/268) strain. On the other hand, inconsistent with these Angiogenesis inhibitor results, it was found that the RC-HL strain grew less efficiently in the mouse brain than did the R(G 242/255/268) strain (18),
suggesting that another factor is involved in their different efficiencies in in vivo propagation. Interestingly, we found that infection with the RC-HL strain induces inflammation in the
infected mouse brain more strongly than does infection with the Nishigahara strain (unpublished data). Therefore, it is possible that infection with the R(G 242/255/268) strain induces host immune responses less efficiently than does infection with the RC-HL strain, resulting in more restricted propagation of the RC-HL strain in the mouse brain. We conclude that amino acid substitutions at 242, 255 and 268 in rabies virus G protein affect the efficiencies of cell-to-cell spread, resulting in different distributions of RC-HL and R(G 242/255/268) strain-infected cells in the mouse brain and, consequently, distinct pathogenicities. Although the molecular mechanisms Fluorouracil cell line Acesulfame Potassium remain to be elucidated, we clarified here important biological characteristics related to the different pathogenicities of the Nishigahara and RC-HL strains. We believe that this study provides basic information for understanding the pathogenicity of rabies virus, and also for establishing
an antiviral therapy for rabies. This study was partially supported by a grant (Project Code No., I-AD14-2009-11-01) from the National Veterinary Research & Quarantine Service, Ministry for Food, Agriculture, Forestry and Fisheries, Korea in 2008 to M.S. “
“To express the 56-kDa protein of O. tsutsugamushi strain Karp, this protein gene was cloned into pET30a(+) before transforming into host bacteria, E. coli Rossetta. Specificity of the recombinant protein was assessed by ELISA using rabbit sera against common members of the order Rickettsiae and 10 other pathogenic bacteria. After IPTG induction, SDS-PAGE analysis of isolated protein demonstrated a band at approximately 46-kDa. Western blot and mass spectrometry analysis proved that the recombinant protein was expressed successfully. Specificity analysis demonstrated that all sera were negative, except sera against O. tsutsugamushi strains TA763, TH1817 and Kato, B. quintana, A. phagocytophilum, E. chaffeensis and B. bacilliformis.