Glycogen for lysosome-targeted CpG ODNs delivery and enhanced cancer immunotherapy.

CpG oligodeoxynucleotides (ODNs) strongly activate the immune system after binding to toll-like receptor 9 (TLR9) in lysosome, which demonstrated significant potential in cancer immunotherapy. However, their therapeutic efficacy is limited by drawbacks such as rapid degradation and poor cellular uptake. Although encouraging progress have been made on developing various delivery systems for CpG ODNs, safety risks of the synthetic nanocarriers as well as the deficient CpG ODNs release within lysosome remain big obstacles. Herein, we developed a novel nanovector for lysosome-targeted CpG ODNs delivery and enhanced cancer immunotherapy. Natural glycogen was simply aminated (NH2-Gly) through grafting with diethylenetriamine (DETA), which was spherical in shape with diameter of approximately 40 nm. NH2-Gly possessed good biocompatibility. Cationic NH2-Gly complexed CpG ODNs well and protected them from nuclease digestion. NH2-Gly significantly enhanced the cellular uptake of CpG ODNs. Efficient CpG ODNs release was observed in the presence of α-glucosidase that mimicking the environment of lysosome. Consequently, NH2-Gly/CpG complexes triggered potent antitumor immunity and effectively inhibit the tumor growth without causing any toxic effect or tissue damages. This work highlights the promise of glycogen for lysosome-targeted on-command delivery of CpG ODNs, which brings new hope for precision cancer immunotherapy.

[Analysis on nucleoprotein gene sequence of 25 rabies virus isolates in Guizhou Province, China].

To analyze 25 nucleoprotein gene (N gene) sequences of rabies viruses circulating in Guizhou province during 2005-2010, China, and to explore the epidemic characteristics and the probable mutant of rabies in Guizhou Province. Rabies virus RNA in human brain tissues, human saliva, and domestic dog brain tissues derived from different prefectures of Guizhou Province were detected with RT-nested PCR, and the amplified products were then sequenced. Bioinformatics software was used to determine the genetic characteristics of these rabies viruses. The sequences of N gene of 25 Guizhou provincial isolates were identical with homogeny between 97.5% - 99.3% and 98.4% - 99.8% at nucleotide and deduced amino acid level, respectively, while the identities between them and isolated strains from other province of China were 88% - 99.1% and 88% - 99.7%. There were several amino acid substitutions in the nucleoprotein of 25 Guizhou isolates compared with the known genotype 1 isolates. The analysis of phylogenetic tree of 25 Guizhou isolates was demonstrated to be genetically divided into two groups, indicating that the virus presented a unique characteristics in geographic distribution and in a time dependent-manner. And phylogenetic tree of 25 Guizhou isolates and 7 genotype 1 strains isolated from other Province of China was also divided into two groups, which were further composed of several subgroups, respectively. From these observations, the rabies viruses derived from Guizhou province were still genotype 1. These isolates of rabies virus were diverged from the strains isolated from other provinces in both gene sequences and deduced amino acid sequences, and these divergences were characterized in geographic distribution and in a time-dependent manner.