Glucan is a component of the Mycobacterium tuberculosis surface that is expressed in vitro and in vivo

J. Reid Schwebach, Aharona Glatman-Freedman, Leslie Gunther-Cummins, Zhongdong Dai, John B. Robbins, Rachel Schneerson, Arturo Casadevall

Research output: Contribution to journalArticlepeer-review

41 Scopus citations


The outermost layer of Mycobacterium tuberculosis is composed primarily of two polysaccharides, glucan (GC) and arabinomannan. To analyze the surface polysaccharide composition of M. tuberculosis, we generated a monoclonal antibody (MAb) that binds M. tuberculosis GC and is known as MAb 24c5. Immunofluorescence and whole-mount immunoelectron microscopy indicated that GC is on the outermost portion of the bacteria. M. tuberculosis strains Erdman and CDC 1551 were analyzed for their ability to bind MAb 24c5 after in vitro growth in media with and without the detergent Tween 80. MAb 24c5 bound to Erdman and CDC 1551 at all culture times with only slightly greater apparent affinity after extended culture in the absence of Tween 80, indicating that a stable amount of GC polysaccharide antigen is associated with the cell surface of M. tuberculosis. An enzyme-linked immunosorbent assay indicated that GC is antigenically similar to glycogen, and the amount of GC antigen increased in the media of M. tuberculosis cultures grown either with or without the detergent Tween 80. Other nontuberculosis mycobacteria have antigenically similar GCs on their surfaces after in vitro growth. Inoculation of mice with live bacilli but not inoculation with dead bacilli elicited a strong antibody response to GC consistent with production of this antigen in vivo. Our results provide a more comprehensive picture of the M. tuberculosis cell envelope and the conditions that allow expression of M. tuberculosis GC.

Original languageEnglish (US)
Pages (from-to)2566-2575
Number of pages10
JournalInfection and immunity
Issue number5
StatePublished - 2002
Externally publishedYes

ASJC Scopus subject areas

  • Parasitology
  • Microbiology
  • Immunology
  • Infectious Diseases


Dive into the research topics of 'Glucan is a component of the Mycobacterium tuberculosis surface that is expressed in vitro and in vivo'. Together they form a unique fingerprint.

Cite this