Purification of the Neisseria meningitidis transferrin binding protein-2 (TBP2) to homogeneity using column chromatography

The interleukin-6 (IL-6) gene is expressed by various stimuli including cytokines or viral infections, such as human T-cell leukemia virus type I (HTLV-1). However, it has not been well established how HTLV-1 induces the expression of the IL-6 gene. In the present study, we demonstrated that HTLV-1-derived transactivator protein, p40tax, could stimulate endogenous IL-6 gene expression. Furthermore, we showed that the NF-kappa B binding site (IL-6 kappa B site) located between -74 and -62 upstream of the cap site of the IL-6 gene was an essential cis-acting element for p40tax-mediated transactivation of the IL-6 gene expression by utilizing a series of 5' deletion mutants of the IL-6 5' flanking region as well as a construct with a mutated IL-6 kappa B site. We identified the presence of two nuclear factor complexes that bound to the IL-6 kappa B site. One was constitutively expressed, and the other was inducible by p40tax. Taken together, HTLV-1 p40tax directly induces IL-6 gene expression through the IL-6 kappa B site, indicating the close association between IL-6 overproduction and HTLV-1 infection.     

Regulation of nuclear factor-kappa B and its inhibitor I kappa B-alpha/MAD-3 in monocytes by Mycobacterium tuberculosis and during human tuberculosis

Blood monocytes from patients with active tuberculosis are activated in vivo, as evidenced by an increase in the stimulated release of proinflammatory cytokines, such as TNF-alpha, and the spontaneous expression of IL-2R. Further, monocytes from patients demonstrate an augmented susceptibility to a productive infection with HIV-1 in vitro. Mycobacterium tuberculosis and its components are strong signals to activate monocytes to production of cytokines. In this study we examined the basis of activation of monocytes during active tuberculosis and by M. tuberculosis. We found a constitutive degradation of I kappa B-alpha, the major cytoplasmic inhibitor of nuclear factor kappa B (NF-kappa B), in freshly isolated PBMC and monocytes from patients with tuberculosis. In contrast, I kappa B-alpha levels in PBMC and monocytes from healthy subjects or from patients with nontuberculous pulmonary conditions were intact. Further, by electrophoretic mobility shift assay, NF-kappa B was activated in monocytes from tuberculous patients. The expression of I kappa B-alpha gene, which is responsive to activation by NF-kappa B, was up-regulated in PBMC and monocytes from patients, but not in mononuclear cells from healthy subjects or those with nontuberculous lung diseases. By contrast, the expression of other adherence-associated early genes, such as IL-8 and IL-1 beta, was not up-regulated in PBMC of tuberculous patients. Further, M. tuberculosis and its tuberculin, purified protein derivative, induced the degradation of I kappa B-alpha and the expression of I kappa B-alpha mRNA, and purified protein derivative induced the activation of NF-kappa B in monocytes.