Mycobacterial 65-kD heat shock protein induces release of proinflammatory cytokines from human monocytic cells

Clin Exp Immunol. 1993 Jan;91(1):58-62. doi: 10.1111/j.1365-2249.1993.tb03354.x.


Monocytes having phagocytosed mycobacteria are known to present the bacterial 65-kD heat shock protein (hsp) on their cell surface to alpha beta and gamma delta T lymphocytes. Cytotoxic CD4+ cells may then lyse monocytes expressing mycobacterial 65-kD hsp. However, it is not known whether 65-kD hsp directly stimulates monocyte functions other than antigen presentation. This study has demonstrated that following extraction of bacterial lipopolysaccharide, purified recombinant mycobacterial 65-kD hsp may directly activate THP-1 cells, a human monocytic line, to accumulate mRNA for and secrete tumour necrosis factor (TNF), a cytokine important in granuloma formation, the characteristic host immune response to mycobacterial infection. TNF gene expression and secretion following stimulation by hsp was dose-dependent and abolished by heat-induced proteolysis. Subsequently, THP-1 cells secreted IL-6 and IL-8, cytokines involved in recruitment and differentiation of T lymphocytes. The data indicate that secretion of proinflammatory cytokines from monocytes activated by mycobacterial 65-kD hsp may be important in the host immune response and in the development of antigen-specific T cell-mediated immunity.

Publication types

  • Research Support, Non-U.S. Gov't
  • Research Support, U.S. Gov't, P.H.S.

MeSH terms

  • Bacterial Proteins / pharmacology*
  • Cell Line
  • Gene Expression / drug effects
  • Heat-Shock Proteins / pharmacology*
  • Humans
  • Interleukin-6 / genetics
  • Interleukin-6 / metabolism*
  • Interleukin-8 / genetics
  • Interleukin-8 / metabolism*
  • Lipopolysaccharides
  • Monocytes / drug effects*
  • Monocytes / immunology
  • Mycobacterium / immunology*
  • Recombinant Proteins / pharmacology
  • Tumor Necrosis Factor-alpha / genetics
  • Tumor Necrosis Factor-alpha / metabolism*


  • Bacterial Proteins
  • Heat-Shock Proteins
  • Interleukin-6
  • Interleukin-8
  • Lipopolysaccharides
  • Recombinant Proteins
  • Tumor Necrosis Factor-alpha