Action mechanism of corticosteroids to aggravate Guillain-Barré syndrome.

Corticosteroids have been proved to be ineffective for Guillain-Barré syndrome, but the mechanism remains unknown. In a rabbit model of axonal Guillain-Barré syndrome, treatment with corticosteroids significantly reduced macrophage infiltration in the spinal ventral roots and the survival rate as well as clinical improvement. On 30(th) day after onset, there was significantly higher frequency of axonal degeneration in the corticosteroids-treated rabbits than saline-treated rabbits. Corticosteroids may reduce the scavengers that play a crucial role for nerve regeneration, thus delay the recovery of this disease.

Construction of a recombinant-BCG containing the LMP2A and BZLF1 genes and its significance in the Epstein-Barr virus positive gastric carcinoma.

The signal peptide Ag85B of Bacillus Chalmette-Guerin (BCG) was used to construct a recombinant plasmid of BCG. The BCG-Ag85B gene and fused EBV LMP2A and BZLF1 genes were amplified and successively inserted into the Escherichia coli-BCG shuttle-vector pMV261. The recombinant plasmids were then amplified in E. coli DH5α and transformed into competent BCG. The expression of BZLF1 and LMP2A fusion proteins in recombinant-BCG (rBCG) was shown by Western blot. After the injection of recombinant-BCG into mice, antibodies against the fusion protein BZLF1 and LMP2A were measured by ELISA, and the cellular immune effects were determined by the lactate dehydrogenate (LDH) release assays. The results confirmed that the cloned genes of BCG-Ag85B and Z2A were correctly inserted into the vector pMV261. The recombinant plasmid pMVZ2A expressed Z2A in BCG effectively after transformation. The rBCG proteins were recognized by the BZLF1 (LMP2A) antibody. An ELISA demonstrated that rBCG could stimulate the generation of antibody against the fusion protein. The fusion gene was constructed successfully, and the rBCG induced humoral and cellular immune response in mice.

[Cloning and prokaryotic expression of human secreted IL-16 gene].

AIM: To clone human secreted IL-16 cDNA, construct its prokaryotic expression vector and express it in E.coli DH5α. METHODS: The secreted IL-16 gene fragment from the cDNA library of human peripheral blood mononuclear cells (PBMC) was amplified by PCR. After purified, the product was cloned into pUC18 T-vector. The recombinant plasmid was confirmed by PCR, endonuclease digestion and sequencing analysis and then subcloned into prokaryotic expression vector pMAL-C2. Then the recombinant expression plasmid pMAL-IL-16 was transformed into E.coli DH5α. The expression of secreted hIL-16 was induced with IPTG and identified by SDS-PAGE and Western blotting. RESULTS: Using PCR, we obtained the human secreted IL-16 cDNA fragment which was 393 bp and encoded 130 amino acids. The prokaryotic expression vector pMAL-IL-16 we constructed was successfully transformed into E.coli DH5α, and under the induction of IPTG, we found the expression of the recombinant fusion protein with relative molecular weight (M(r);) being 56 000 as expected and confirmed by SDS-PAGE and Western blotting. CONCLUSION: We successfully cloned the human secreted IL-16 cDNA and constructed its prokaryotic expression vector and expressed it in E.coli, which is helpful for further purification of human secreted IL-16 protein.

Loss of nuclear pro-IL-16 facilitates cell cycle progression in human cutaneous T cell lymphoma.

Cutaneous T cell lymphomas (CTCLs) represent a heterogeneous group of non-Hodgkin lymphomas that affect the skin. The pathogenesis of these conditions is poorly understood. For example, the signaling mechanisms contributing to the dysregulated growth of the neoplastic T cells are not well defined. Here, we demonstrate that loss of nuclear localization of pro-IL-16 facilitates CTCL cell proliferation by causing a decrease in expression of the cyclin dependent-kinase inhibitor p27Kip1. The decrease in p27Kip1 expression was directly attributable to an increase in expression of S-phase kinase-associated protein 2 (Skp2). Regulation of Skp2 is in part attributed to the nuclear presence of the scaffold protein pro-IL-16. T cells isolated from 11 patients with advanced CTCL, but not those from healthy controls or patients with T cell acute lymphocytic leukemia (T-ALL), demonstrated reduction in nuclear pro-IL-16 levels. Sequence analysis identified the presence of mutations in the 5' end of the PDZ1 region of pro-IL-16, a domain required for association of pro-IL-16 with the nuclear chaperone HSC70 (also known as HSPA8). HSC70 knockdown led to loss of nuclear translocation by pro-IL-16 and subsequent increases in Skp2 levels and decreases in p27Kip1 levels, which ultimately enhanced T cell proliferation. Thus, our data indicate that advanced CTCL cell growth is facilitated, at least in part, by mutations in the scaffold protein pro-IL-16, which directly regulates Skp2 synthesis.