Mycobacterial glycolipids di-O-acylated trehalose and tri-O-acylated trehalose downregulate inducible nitric oxide synthase and nitric oxide production in macrophages.

Background: Tuberculosis (TB) remains a serious human health problem that affects millions of people in the world. Understanding the biology of Mycobacterium tuberculosis (Mtb) is essential for tackling this devastating disease. Mtb possesses a very complex cell envelope containing a variety of lipid components that participate in the establishment of the infection.

Mycobacterium tuberculosis lipids regulate cytokines, TLR-2/4 and MHC class II expression in human macrophages.

The interaction of macrophages with Mycobacterium tuberculosis through Toll-like receptors is critical in defining the cytokine profile that may or may not control disease progression. Cell-wall lipids are the main pathogen-associated molecular ligands of mycobacteria, in this paper, we analysed how lipid fractions of three different strains of the M. tuberculosis complex (genotypes Canetti, Beijing and H37Rv) affected the innate immunity by regulating TNF-alpha and IL-10 secretion, TLR2, TLR4, and MHC class II expression of human monocyte-derived macrophages.

[Human and bovine tuberculosis in Latin America: from the studies about virulence to some tools for its control].

Human and bovine tuberculosis (TB) are currently a serious health problem in Latin America. Although the causal agents were discovered more than one century ago, the control of these illnesses is still beyond our reach: human TB accounts for more than one hundred deaths each day in this region, whereas bovine TB represents a public health risk as well as a major economic problem. We herein analyze the situation of human and bovine TB in Latin America, and present studies from our laboratories on bacterial virulence factors, intrinsic resistance features in the host, and the protective response induced in cattle through vaccination or immunization.

Structure and antigenicity of the major glycolipid from Taenia solium cysticerci.

Lipids were extracted from cysticerci of the human tapeworm Taenia solium isolated from various infected pigs and analysed by two-dimensional thin-layer chromatography. These consisted of both alkali-labile and alkali-stable glycolipids, and phosphorylated non-glycosylated lipids. Because abundant and immunogenic glycolipids of parasites have been implicated in host-parasite interactions, the major lipid, an alkali-stable glycolipid, was purified by chromatography and its structure and antigenicity were determined.

Seroreactive species-specific lipooligosaccharides of Mycobacterium mucogenicum sp. nov. (formerly Mycobacterium chelonae-like organisms): identification and chemical characterization.

Strains of the new species Mycobacterium mucogenicum exhibit physiological and biochemical features very similar to those of the other species of the Mycobacterium fortuitum complex. To define taxonomic criteria for easy identification of M. mucogenicum, the glycolipid patterns of the reference strains and of 32 environmental and clinical isolates were examined by TLC.