Related Experiment Video
Updated: Jun 21, 2026

Experimental Infection with Listeria monocytogenes as a Model for Studying Host Interferon-γ Responses
Published on: November 16, 2016
Phthiocerol dimycocerosate transport is required for resisting interferon-gamma-independent immunity
Jeffrey P Murry1, Amit K Pandey, Christopher M Sassetti
1Department of Microbiology and Molecular Genetics, Harvard Medical School, Boston, MA 02115, USA.
Abstract:
Nitric oxide (NO), which is an important component of immunity to Mycobacterium tuberculosis, has both cytotoxic and immune regulatory functions. We examined the way that this molecule interacts with M. tuberculosis in vivo by screening for bacterial mutations that alter growth in mice that are unable to produce inducible NO synthase (iNOS), the dominant source of NO during infection. We found that very few bacterial genes appeared to be specifically required for resistance to NO in vivo. Instead, mutations in several virulence factors caused greater attenuation in the absence of iNOS. Among these were mutants incapable of transporting the lipid phthiocerol dimycocerosate (PDIM). Although PDIM has been implicated in NO defense, this result indicates that PDIM has other roles during infection. We additionally found that PDIM transport is required for virulence in mice lacking interferon-gamma . Thus, PDIM is important for resisting an interferon-gamma-independent mechanism of immunity.
More Related Videos
Related Concept Videos
Inhibitors of Viral Protein Synthesis
Inhibitors Of Virion Release
Transcytosis of IgG
IgG molecules from a mother undergo transcytosis starting around 13 weeks of gestation. The amount of IgG transferred and entering the fetal blood circulation increases with...
Cytotoxic T Cells-mediated Immune Response
Immunological surveillance is the ability of immune cells to monitor and eliminate infected cells with intracellular pathogens, neoplastically transformed cells, and cells with non-self antigens. Cytotoxic T cells and NK...
Inhibitors of Virion Maturation and Assembly
Carrier-Mediated Transport
Active transport involves two types of membrane-spanning transporters: uptake and efflux. Uptake transporters are expressed in the small...

