Mycobacterium tuberculosis chaperonin 60.1 is a more potent cytokine stimulator than chaperonin 60.2 (Hsp 65) and contains a CD14-binding domain.

Abstract

Much attention has focused on the Mycobacterium tuberculosis molecular chaperone chaperonin (Cpn) 60.2 (Hsp 65) in the pathology of tuberculosis because of its immunogenicity and ability to directly activate human monocytes and vascular endothelial cells. However, M. tuberculosis is one of a small group of bacteria that contain multiple genes encoding Cpn 60 proteins. We have now cloned and expressed both M. tuberculosis proteins and report that the novel chaperonin 60, Cpn 60.1, is a more potent inducer of cytokine synthesis than is Cpn 60.2. This is in spite of 76% amino acid sequence similarity between the two mycobacterial chaperonins. The M. tuberculosis Cpn 60.2 protein activates human peripheral blood mononuclear cells by a CD14-independent mechanism, whereas Cpn 60.1 is partially CD14 dependent and contains a peptide sequence whose actions are blocked by anti-CD14 monoclonal antibodies. The cytokine-inducing activity of both chaperonins is extremely resistant to heat. Cpn 60.1 may be an important virulence factor in tuberculosis, able to activate cells by diverse receptor-driven mechanisms.

• Authors: J C Lewthwaite, A R Coates, P Tormay, M Singh, P Mascagni, S Poole, M Roberts, L Sharp, B Henderson
• Journal: Infection and immunity (Infect Immun) Vol. 69 Issue 12 Pg. 7349-55 (Dec 2001) ISSN: 0019-9567 [Print] United States
• PMID: 11705907 (Publication Type: Comparative Study, Journal Article, Research Support, Non-U.S. Gov't)

Chemical References

• Bacterial Proteins
• Chaperonin 60
• Cytokines
• Lipopolysaccharide Receptors
• Lipopolysaccharides
• Peptides
• heat-shock protein 65, Mycobacterium
• Chaperonins

Topics

• Amino Acid Sequence
• Bacterial Proteins (chemistry, immunology)
• Binding Sites
• Chaperonin 60 (immunology)
• Chaperonins (chemistry, immunology)
• Cytokines (biosynthesis)
• Humans
• Leukocytes, Mononuclear (immunology)
• Lipopolysaccharide Receptors
• Lipopolysaccharides (immunology)
• Molecular Sequence Data
• Mycobacterium tuberculosis
• Peptides (chemistry, immunology)
• Protein Binding
• Protein Structure, Secondary
• Protein Structure, Tertiary
• Signal Transduction