Half-truths and selective memory: Interferon gamma, CD4(+) T cells and protective memory against tuberculosis

Tuberculosis (Edinb). 2007 Nov;87(6):465-73. doi: 10.1016/j.tube.2007.07.001. Epub 2007 Aug 23.


Efforts to develop a new, more effective vaccine for tuberculosis have been hampered by a lack of understanding of what constitutes a protective memory immune response. While interferon gamma production by CD4(+) T cells after vaccination is commonly used as a surrogate of protective memory immunity, its use in this regard appears to have little predictive value. We argue that this is due to the different requirements for interferon gamma-mediated protection in the primary response versus the memory recall response. In this review, we present evidence that suggests memory CD4(+) T cells can protect against tuberculosis in the absence of interferon gamma, and discuss potential mechanisms that may be involved such as IL-17 and regulatory T cells. A comprehensive understanding of the requirements for protective memory immunity to tuberculosis is essential for the development of an effective vaccine.

Publication types

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

MeSH terms

  • CD4-Positive T-Lymphocytes / immunology*
  • Humans
  • Immunologic Memory*
  • Interferon-gamma / immunology*
  • Interleukin-17 / biosynthesis
  • Th1 Cells / immunology
  • Tuberculosis / immunology
  • Tuberculosis / prevention & control*
  • Tuberculosis Vaccines / immunology
  • Tumor Necrosis Factor-alpha / immunology


  • Interleukin-17
  • Tuberculosis Vaccines
  • Tumor Necrosis Factor-alpha
  • Interferon-gamma