Manjunatha M. Venkataswamy

Learn More
The inhibition of apoptosis of infected host cells is a well-known but poorly understood function of pathogenic mycobacteria. We show that inactivation of the secA2 gene in Mycobacterium tuberculosis, which encodes a component of a virulence-associated protein secretion system, enhanced the apoptosis of infected macrophages by diminishing secretion of(More)
CD1d-restricted natural killer T cells (NKT cells) possess a wide range of effector and regulatory activities that are related to their ability to secrete both T helper 1 (Th1) cell- and Th2 cell-type cytokines. We analyzed presentation of NKT cell activating alpha galactosylceramide (alphaGalCer) analogs that give predominantly Th2 cell-type cytokine(More)
We report the involvement of an evolutionarily conserved set of mycobacterial genes, the esx-3 region, in evasion of bacterial killing by innate immunity. Whereas high-dose intravenous infections of mice with the rapidly growing mycobacterial species Mycobacterium smegmatis bearing an intact esx-3 locus were rapidly lethal, infection with an M. smegmatis(More)
In spite of their relatively limited antigen receptor repertoire, CD1d-restricted NKT cells recognize a surprisingly diverse range of lipid and glycolipid antigens. Recent studies of natural and synthetic CD1d-presented antigens provide an increasingly detailed picture of how the specific structural features of these lipids and glycolipids influence their(More)
The attenuated strain of Mycobacterium bovis known as bacille Calmette-Guérin (BCG) has been widely used as a vaccine for prevention of disease by Mycobacterium tuberculosis, but with relatively little evidence of success. Recent studies suggest that the failure of BCG may be due to its retention of immune evasion mechanisms that delay or prevent the(More)
Structural variants of α-galactosylceramide (αGC) that activate invariant natural killer T cells (iNKT cells) are being developed as potential immunomodulatory agents for a variety of applications. Identification of specific forms of these glycolipids that bias responses to favor production of proinflammatory vs anti-inflammatory cytokines is central to(More)
Background:Immune suppression in the tumour microenvironment remains a major limitation to successful immunotherapy of cancer. In the current study, we analysed whether the natural killer T cell-activating glycolipid α-galactosylceramide could overcome immune suppression and improve vaccination against metastatic breast cancer.Methods:Mice with metastatic(More)
CD1d-restricted invariant natural killer T cells (iNKT cells) have been identified as an important type of effector and regulatory T cell, but their roles in the chronic infectious diseases caused by Mycobacterium tuberculosis and Mycobacterium leprae remain poorly defined. Here, we studied circulating human iNKT cells in blood samples from tuberculosis(More)
KRN7000 is an important ligand identified for CD1d protein of APC, and KRN7000/CD1d complex can stimulate NKT cells to release Th1 and Th2 cytokines. In an effort to understand the structure-activity relationships, we have carried out the synthesis of a complete set of the eight KRN7000 stereoisomers, and their biological activities have been examined.
UNLABELLED Pathogenic and nonpathogenic species of bacteria and fungi release membrane vesicles (MV), containing proteins, polysaccharides, and lipids, into the extracellular milieu. Previously, we demonstrated that several mycobacterial species, including bacillus Calmette-Guerin (BCG) and Mycobacterium tuberculosis, release MV containing lipids and(More)