Cellular immune activation, neopterin production, tryptophan degradation and the development of immunodeficiency

• Authors: B. Widner , B. Wirleitner , G. Baier-Bitterlich , G. Weiss , W. Fuchs
• Languages of publication: EN

Abstracts

EN

Cellular (Th1-type) immune response is centrally involved in the pathogenesis of various diseases. Within the immunological cascades of Th1-type immunity, interferon (IFN-), among other cytokines, is critically involved. It triggers a series of immune-relevant reactions mostly directed towards forward regulation of the antigen specific immune response. However, in chronic states of immune activation, systemically increased IFN-gamma is no longer antigen specific and is associated with the development of immunodeficiency. IFN-gamma also stimulates the production of neopterin, a low-mass compound, in human monocytes/macrophages. Accordingly, neopterin concentrations in humans reflect the degree of Th1-type immune activation. Since IFN-gamma also stimulates the release of reactive oxygen species (ROS) from immunocompetents cells, the amount of neopterin produced also serves as an indirect estimate of oxidative stress. In parallel, IFN-gamma activates the degradation of tryptophan, which appears to limit the growth of intracellular pathogens and the proliferation of cells, including T lymphocytes. Thus, during persisting states of immune activation, the production of IFN-gamma is not only associated with forward regulation of the immune response, but also with immunosuppressive mechanisms. The increased formation of neopterin and degradation of tryptophan may result in a drecreased T cell responsiveness and development of immunodeficiency.

Keywords

EN

IMMUNE RESPONSE; IMMUNODEFICIENCY; NEOPTERIN; TRYPTOPHAN

Discipline

• IMMUNOLOGY: IMMUNOLOGY

• Publisher: Ludwik Hirszfeld Institute of Immunology and Experimental Therapy, Polish Academy of Sciences
• Journal: Archivum Immunologiae et Therapiae Experimentalis
• Year: 2000
• Volume: 48
• Issue: 4
• Pages: 251-258

Contributors

author

B. Widner

author

B. Wirleitner

author

G. Baier-Bitterlich

author

G. Weiss

author

W. Fuchs

• Document Type: REVIEW
• Publication order reference: B. Widner, Institute of Medical Chemistry and Biochemistry, University of Innsbruck, A-6020 Innsbruck, Austria