Mycobacterium tuberculosis PE31 (Rv3477) Attenuates Host Cell Apoptosis and Promotes Recombinant M. smegmatis Intracellular Survival via Up-regulating GTPase Guanylate Binding Protein-1.

Mycobacterium (M.) tuberculosis acidic (PE) proline-glutamic subfamily proteins associate with virulence, pathogenesis and host-immune modulation. While the function of most of the family members have not been explored. Here, we explore the function of "PE only" subfamily members PE31 (Rv3477) in virulence and host-pathogen interactions. Viral Recombinant Proteins

We have stated M. tuberculosis PE31 in non-pathogenic Mycobacterium smegmatis strain (Ms_PE31) and shows that a significant change aspects of the cell PE31 features including colony morphology and biofilm formation. PE31 expressing M. smegmatis showed more resistant to low pH, diamide, H2O2 and surface stress. In addition, the intracellular survival Ms_PE31 showed higher macrophage THP-1 cells. Ms_PE31 significantly down-regulated the production of IL-12p40 and IL-6, while up-regulate the production of IL-10 in macrophages.

 Ms_PE31 also induced the expression of guanylate-binding protein-1 (GBP-1) in macrophages. Further analysis showed that Ms_PE31 inhibits the activation of caspase-3 and reduced macrophage apoptosis. In addition, the NF-kB signaling pathway involves the interaction between Ms_PE31 and macrophages. Collectively, our findings identify that PE31 acts as a virulence factor of the relevant functional M. tuberculosis.

Compare the efficiency of different strains of Escherichia coli to produce recombinant capsid protein from pigs Circovirus type 2.

This study aimed to compare different strains of E. coli to express the capsid protein of Porcine Circovirus 2 (PCV2). Full-length capsid protein can be expressed only in Rosetta-gami 2 (DE3) pLysS strain using pET32b (+) vector. It asserts Yeast Recombinant Proteins that only those strains that have tRNA for rare codons can express capsid protein full length. 

Full-length capsid protein purification can not be achieved even after several attempts using native and denaturing conditions. Furthermore, the efforts made for the expression of N-terminal truncated capsid protein using the same expression system.

 Cut the capsid protein successfully expressed, purified and characterized by western blotting. capsid protein is cut also proven effective in testing serum samples using an optimized indirect ELISA, in which the diagnostic sensitivity of 88.89% and a specificity of 90.82% was obtained compared with commercially available pig GreenSpring® Circovirus (PCV2) ELISA test kit. Thus, a truncated capsid protein expressed seems to be a promising diagnostic agent for PCV2