Effects of entrapment of murine interleukin-2 gene with chitosan nanoparticles on expression of mIL-2 gene and on regulation of immune response in mice / 生物医学工程学杂志

The experiment was conducted to prepare chitosan nanoparticles (CNP), to entrap VRMIL-2 with CNP, the eukaryotic VR1020 expression plasmid containing murine IL-2 gene (mlL-2), and to investigate the expression in vivo and the regulatory effect of mIL-2 on immune-response and immuno-protection in mice inoculated muscularly with CNP entrapped VMIL-2 at 21 days old. The results showed that IgG, IgM and IgA contents increased to different degrees in the sera from the inoculated mice, which were remarkably higher than those of the controls inoculated VR1020 packed with CNP (P<0.05); so were the IL-2, IL-4 and IL-6 contents in the sera of the immunized mice. The number of white blood cells and lymphocytes significantly increased respectively in the vaccinated mice, compared with those of controls. These mice were orally challenged with virulent E. coli 35 days post-inoculation, and all the immune responses were significantly higher than those of the control except the number of neutrophils. The mice inoculated with VRMIL-2 survived healthily, while the mice of control group were ill with the evident lesions. Although there are no remarkable differences between the cellular and humoral immune indexes of mice inoculated with CNP-VRMIL-2 and nude VRMIL-2 (P>0.05), the dosage of CNP-VRMIL-2 is only one fifth of the VRMIL-2. These indicated that entrapment of mIL-2 gene with chitosan nanoparticles could remarkably enhance the expression of mIL-2 in vivo, and significantly raise the levels of cellular and humoral immune, and increase the resistance of mice against E. coli infection. The results suggested that chitosan nanoparticles and IL-2 gene could be used as an effective immunoenhancer to increase the immunity of animals against infection.

Construction and expression of somatostatin (S14) and hepatitis B surface antigen gene in yeast Pichia pastoris / 生物医学工程学杂志

To construct the ss/HBsAg protein gene-engineering vaccine for developing the diagnosis and cure tumors in clinical medicine and promoting the growth in animal husbandry production. A pair of primers were designed according separately to the sequence of Somatostatin gene(S14) and HBsAg gene. Their gene fragments were separately amplified by using PCR and cloned, following sequencing, the DNA fragments were inserted into pBluescript vector. Then the ss/HBsAg chimera was constructed and was cloned into pPICZaA plasmid, and transformed into electroporated Pichia pastoris. High yield protein expression was obtained. Expressed protein was proved with high specificity and it's molecular weigh was about 28 KD identified by SDS-PAGE and Western blot.