Molecular cloning, biochemical and structural analysis of elongation factor-1 alpha from Leishmania donovani: comparison with the mammalian homologue.

The Src-homology 2 domain containing protein tyrosine phosphatase-1 (SHP-1) is involved in the pathogenesis of infection with Leishmania. Recently, we identified elongation factor-1 alpha (EF-1 alpha) from Leishmania donovani as a SHP-1 binding and activating protein [J. Biol.

The 19-kDa Mycobacterium tuberculosis protein induces macrophage apoptosis through Toll-like receptor-2.

Macrophages infected with Mycobacterium tuberculosis undergo increased rates of apoptosis. Important objectives are to define the microbial factors that cause apoptosis, the mechanisms involved and the impact on infection. The 19-kDa M.

Leishmania EF-1alpha activates the Src homology 2 domain containing tyrosine phosphatase SHP-1 leading to macrophage deactivation.

The human leishmaniasis are persistent infections of macrophages caused by protozoa of the genus Leishmania. The chronic nature of these infections is in part related to induction of macrophage deactivation, linked to activation of the Src homology 2 domain containing tyrosine phosphatase-1 (SHP-1) in infected cells. To investigate the mechanism of SHP-1 activation, lysates of Leishmania donovani promastigotes were subjected to SHP-1 affinity chromatography and proteins bound to the matrix were sequenced by mass spectrometry.

1alpha,25-Dihydroxyvitamin D3-induced monocyte antimycobacterial activity is regulated by phosphatidylinositol 3-kinase and mediated by the NADPH-dependent phagocyte oxidase.

We investigated the basis for the induction of monocyte antimycobacterial activity by 1alpha,25-dihydroxyvitamin D(3) (D(3)). As expected, incubation of Mycobacterium tuberculosis-infected THP-1 cells or human peripheral blood, monocyte-derived macrophages with hormone resulted in the induction of antimycobacterial activity. This effect was significantly abrogated by pretreatment of cells with either of the phosphatidylinositol 3-kinase (PI 3-K) inhibitors, wortmannin or LY294002, or with antisense oligonucleotides to the p110 subunit of PI 3-Kalpha.

1alpha,25-dihydroxyvitamin D(3)-induced myeloid cell differentiation is regulated by a vitamin D receptor-phosphatidylinositol 3-kinase signaling complex.

1alpha,25-dihydroxyvitamin D(3) (D(3)) promotes the maturation of myeloid cells and surface expressions of CD14 and CD11b, markers of cell differentiation in response to D(3). To examine how these responses are regulated, THP-1 cells were grown in serum-free medium and incubated with D(3). This was associated with rapid and transient increases in phosphatidylinositol 3-kinase (PI 3-kinase) activity.

Monocyte adherence induced by lipopolysaccharide involves CD14, LFA-1, and cytohesin-1. Regulation by Rho and phosphatidylinositol 3-kinase.

Mechanisms regulating lipopolysaccharide (LPS)-induced adherence to intercellular adhesion molecule (ICAM)-1 were examined using THP-1 cells transfected with CD14-cDNA (THP-1wt). THP-1wt adherence to ICAM-1 was LPS dose-related, time-dependent, and inhibited by antibodies to either CD14 or leukocyte function associated antigen (LFA)-1, but was independent of any change in the number of surface expressed LFA-1 molecules. A potential role for phosphatidylinositol (PI) 3-kinase (PI 3-kinase) in LPS-induced adherence was examined using the PI 3-kinase inhibitors LY294002 and Wortmannin.

Phosphatidylinositol 3-kinase-dependent activation of protein kinase C-zeta in bacterial lipopolysaccharide-treated human monocytes.

The isoform identity of activated protein kinase C (PKC) and its regulation were investigated in bacterial lipopolysaccharide (LPS)-treated human monocytes. Resolution of detergent-soluble lysates prepared from LPS-treated, peripheral blood monocytes using Mono Q anion-exchange chromatography revealed two principal peaks of myelin basic protein kinase activity. Immunoblotting and immunoprecipitation with isoform-specific anti-PKC antibodies showed that the major and latest eluting peak is accounted for by PKC-zeta.