Interaction between HIV-1 Tat and DNA-PKcs modulates HIV transcription and class switch recombination.

HIV-1 tat targets a variety of host cell proteins to facilitate viral transcription and disrupts host cellular immunity by inducing lymphocyte apoptosis, but whether it influences humoral immunity remains unclear. Previously, our group demonstrated that tat depresses expression of DNA-PKcs, a critical component of the non-homologous end joining pathway (NHEJ) of DNA double-strand breaks repair, immunoglobulin class switch recombination (CSR) and V(D)J recombination, and sensitizes cells to ionizing radiation. In this study, we demonstrated that HIV-1 Tat down-regulates DNA-PKcs expression by directly binding to the core promoter sequence.

Dynamic proteome changes of Shigella flexneri 2a during transition from exponential growth to stationary phase.

Shigella flexneri is an infectious pathogen that causes dysentery to human, which remains a serious threat to public health, particularly in developing countries. In this study, the global protein expression patterns of S. flexneri during transition from exponential growth to stationary phase in vitro were analyzed by using 2-D PAGE combined with MALDI-TOF MS.

[Comparative proteomics research on THP-1 cells infected with Brucella].

Brucella is a facultative intracellular pathogen that survives and multiplies inside host macrophages to cause brucellosis. The response of macrophage plays an essential role in the initiation of immune process following Brucella challenge. Nowadays, proteome approaches have been widely used in many different systems to investigate host-microbe interactions.

[A new purification methods of small DNAs--the purification methods with silica wool].

The principal purpose of this study is to set up efficient purification techniques of small DNAs which are suitable for isolation of from tens to three hundred bases of genes. On the bases of the technique, purification methods for big DNA fragments are established. In the experiment, the DNA bands were cut after agarose gel electrophoresis and put into 0.

Immunoproteomics of membrane proteins of Shigella flexneri 2a 2457T.

Aim: To screen the immunogenic membrane proteins of Shigella flexneri 2a 2457T.

Methods: The routine two-dimensional polyacrylamide gel electrophoresis (2-DE) and Western blotting were combined to screen immunogenic proteins of S. flexneri 2a 2457T.

[Comparative proteomics research on removing of large invasive plasmid pINV of Shigella flexneri 2a strain 2457T].

S. flexneri 2a strain 2457T and its derivative without large invasive plasmid pINV-2457T were cultured to middle logarithm phase. Whole cellular protein extracts of the two strains were examined by two dimensional (2D) electrophoresis using immobilized pH gradient (IPG) technology.

Simultneous Expression of CS3 Colonization Factor Antigen and Cholera Toxin B Subunit in Salmonella typhi.

A host-plasmid balancing system was established based on asd gene in an avirulent strain of Salmonella typhi to express enterotoxigenic E.coli surface antigen CS3 and V.cholerae toxin subunit B(CTB).