Tumorigenicity of High Five insect cell line / 中国实验动物学报

Objective To observe the tumorigenicity of High Five insect cell line in Balb/c nude mice,and make sure the safety of the cells when used in vaccine production.Methods Balb/c nude mice were randomly divided into 5 groups:the basic cell bank of High Five group,the highest limited passages of High Five group,HEp-2 cell group as positive control,CEF cell group as negative control,and blank control.Except of the blank control,cell suspension was injected subcutaneously into the nude mice in the different groups,respectively.At 3 and 12 weeks after injection,anatomical observation and histopathologic examination were performed to detect the tumor formation.Results At 3 and 12 weeks after injection,the tumorigenicity study results showed that no tumor developed at the transplantation site in the blank control group,negative group,and High Five groups.Histopathological examinations also showed no abnormality in these groups.Otherwise,squamous cell carcinoma was developed in the positive group at 3 weeks after injection.Conclusions High Five cells of basic cell bank and highest limited passages are not tumorigenic,and can be used in vaccine production safely.

Transcription analysis of the porcine alveolar macrophage response to Mycoplasma hyopneumoniae.

Mycoplasma hyopneumoniae is considered the major causative agent of porcine respiratory disease complex, occurs worldwide and causes major economic losses to the pig industry. To gain more insights into the pathogenesis of this organism, the high throughput cDNA microarray assays were employed to evaluate host responses of porcine alveolar macrophages to M. hyopneumoniae infection. A total of 1033 and 1235 differentially expressed genes were identified in porcine alveolar macrophages in responses to exposure to M. hyopneumoniae at 6 and 15 hours post infection, respectively. The differentially expressed genes were involved in many vital functional classes, including inflammatory response, immune response, apoptosis, cell adhesion, defense response, signal transduction, protein folding, protein ubiquitination and so on. The pathway analysis demonstrated that the most significant pathways were the chemokine signaling pathway, Toll-like receptor signaling pathway, RIG-I-like receptor signaling pathway, nucleotide-binding oligomerization domains (Nod)-like receptor signaling pathway and apoptosis signaling pathway. The reliability of the data obtained from the microarray was verified by performing quantitative real-time PCR. The expression kinetics of chemokines was further analyzed. The present study is the first to document the response of porcine alveolar macrophages to M. hyopneumoniae infection. The data further developed our understanding of the molecular pathogenesis of M. hyopneumoniae.

Complete genomic sequence of the coronavirus transmissible gastroenteritis virus SHXB isolated in China.

A strain of transmissible gastroenteritis virus (TGEV), SHXB, was isolated in Shanghai, China. The complete genome of strain SHXB was sequenced, and its sequence was compared those of other TGEV strains in the GenBank database. The comparison showed that there were no insertions or deletions in the 5' and 3'- non-translated regions, in the nonstructural genes ORF1, ORF3, and ORF7, or in the genes encoding the structural proteins envelope (E), membrane (M) and nucleoprotein (N). A phenomenon in common with other strains was that nucleotide (nt) 655 of the spike (S) gene was G, and a common change in nt 1753 of the S gene was a T-to-G mutation that caused a serine-to-alanine mutation at amino acid 585, which is in the region of the main major antigenic sites A and B of the TGEV S protein. A 6-nt deletion was also found at nt 1123-1128 in all Purdue strains except the strain Virulent Purdue. Phylogenetic analysis showed that TGEV SHXB was closely related to the Purdue strains and shared a common ancestor with the Miller strains as well as strain PRCV-ISU-1.