Human genetics of intracellular infectious diseases: molecular and cellular immunity against mycobacteria and salmonellae

Lancet Infect Dis. 2004 Dec;4(12):739-49. doi: 10.1016/S1473-3099(04)01203-4.


The ability to develop adequate immunity to intracellular bacterial pathogens is unequally distributed among human beings. In the case of tuberculosis, for example, infection with Mycobacterium tuberculosis results in disease in 5-10% of exposed individuals, whereas the remainder control infection effectively. Similar interindividual differences in disease susceptibility are characteristic features of leprosy, typhoid fever, leishmaniasis, and other chronic infectious diseases, including viral infections. The outcome of infection is influenced by many factors, such as nutritional status, co-infections, exposure to environmental microbes, and previous vaccinations. It is clear, however, that genetic host factors also play an important part in controlling disease susceptibility to intracellular pathogens. Recently, patients with severe infections due to otherwise poorly pathogenic mycobacteria (non-tuberculous mycobacteria or Mycobacterium bovis BCG) or Salmonella spp have been identified. Many of these patients were unable to produce or respond to interferon gamma, due to deleterious mutations in genes that encode major proteins in the type 1 cytokine (interleukin 12/interleukin 23/interferon gamma) axis (interleukin 12p40/interleukin 23p40, IL12 receptor beta1/IL23 receptor beta1, interferon gamma receptors 1 and 2, or signal transducer and activator of transcription 1). This axis is a major immunoregulatory system that bridges innate and adaptive immunity. Unusual mycobacterial infections were also reported in several patients with genetic defects in inhibitor of NFkappaB kinase gamma, a key regulatory molecule in the nuclear factor kappaB pathway. New findings discussed in this review provide further and sometimes surprising insights into the role of type 1 cytokines, and into the unexpected heterogeneity seen in these syndromes.

Publication types

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

MeSH terms

  • Cytokines / genetics
  • Cytokines / immunology*
  • Genetic Predisposition to Disease
  • Humans
  • Immunity, Cellular / genetics
  • Immunity, Cellular / immunology
  • Interferon-gamma / biosynthesis
  • Interferon-gamma / genetics
  • Interleukin-12 / genetics
  • Interleukin-12 Subunit p40
  • Interleukin-23
  • Interleukin-23 Subunit p19
  • Interleukins / genetics
  • Mycobacterium Infections / genetics
  • Mycobacterium Infections / immunology*
  • Protein Subunits / genetics
  • Receptors, Interferon / genetics
  • Receptors, Interleukin / genetics
  • Receptors, Interleukin-12
  • Salmonella Infections / genetics
  • Salmonella Infections / immunology*


  • Cytokines
  • IL12RB1 protein, human
  • IL23A protein, human
  • Interleukin-12 Subunit p40
  • Interleukin-23
  • Interleukin-23 Subunit p19
  • Interleukins
  • Protein Subunits
  • Receptors, Interferon
  • Receptors, Interleukin
  • Receptors, Interleukin-12
  • interferon gamma receptor
  • Interleukin-12
  • Interferon-gamma