Genetic Characterization of Norovirus GII.3 Circulating in Korea

Noroviruses (NoV) are the major viral pathogen that causes epidemic acute gastroenteritis and outbreaks of food-borne illness. The major genotypes responsible for the epidemics of NoV are GII.4 and GII.3. However, most studies of NoV have been associated with GII.4 genotype and only few studies have been done with GII.3 genotype. Here, we selected 18 GII.3 strains, which recently circulated in Korea, and determined the partial sequences of the capsid gene. Phylogenetic analysis comparing these sequences with 29 reference strains from the GenBank database was performed using the MEGA program. All NoV GII.3 strains formed 2 distinct genetic lineages and variant groups. Lineage A showed 94.1~97.6%, 90.2~94.6% nucleotide identities from lineage B and variant group, respectively. Lineage B showed 90.2~94.6% nucleotide identities from variant group. These different genetic lineages based on the phylogenetic analysis of capsid sequences imply that the circulating Korean NoV GII.3 strains have potential antigenic variation.

Primary structure of mature SAG1 gene of an Indonesian Toxoplasma gondii and comparison with other strains

Toxoplasma gondii is a persistent protozoan parasite capable of infecting almost any warm-blooded vertebrates. SAG1 (p30) is the prototypic member of a superfamily of surface antigens called SRS (SAG1-related sequence). It constitutes the most abundant and predominant antigen. In this paper the primary structure of mature SAG1 gene of an Indonesian T. gondii isolate is described and sequence comparison is made with published sequence data of 7 other strains or isolates. Sequence comparison indicated that SAG1 is highly conserved through evolution and despite parasite spreading world-wide. Sequences may be divided into two major families, independent of the strain/isolate geographic origin. Variations were mainly localized at the C-terminal half or domain 2 and some clustered in restricted areas. Sequence comparison allowed us to define the Indonesian isolate as genuine virulent RH strain. A phylogenetic tree of Toxoplasma strains/isolates was constructed based on SAG1.

Study on the evolutional reIationship among the member of MAGE-A family / 中国免疫学杂志

Abstract Objective:To explore homology in mage-A family and find some common epitopes recognized by cytotoxic T lymphocyte(CTL) to oppose tumor escape.Methods:The amino acid sequence,differents open reading frame(ORF) and the known CTL epitope of themember of MAGE-A family,were analyzed using DNAstar software, and phylogenetic tree is also constructed. Results: MAGE-A family shareidentity nucleotide 57.6% - 98.0%,the phylogenetic tree showed that they are derived from a common ancestor at different time, as well asfound some CTL epitopes high similarity. Conclusion: MAGE-A family come from common an ancestor, but they bave many differences in thepattern of expression in tumor.This study can help to find the best CTL epitope vaccine to cure tumor.