Transforming growth factor beta and immunosuppression in experimental visceral leishmaniasis.

Abstract

Hamsters infected with Leishmania donovani develop a disease similar to human kala-azar. They present hypergammaglobulinemia, and their T cells do not respond to parasite antigens. This unresponsiveness has been primarily ascribed to defects in antigen-presenting cells (APCs), because these cells are unable to stimulate proliferation of parasite-specific T cells from immunized animals. In this study, we show that APCs (adherent spleen cells) from L. donovani-infected hamsters produce high levels of the inhibitory cytokine transforming growth factor beta (TGF-beta). Immunohistochemical studies with an anti-TGF-beta monoclonal antibody (MAb) showed that this cytokine is abundantly produced in vivo by the spleen cells of infected animals. In addition, high levels of TGF-beta are produced in vitro by infected hamster cells, either spontaneously or after stimulation with parasite antigen or lipopolysaccharide. Furthermore, in vivo-infected adherent cells obtained from spleens of L. donovani-infected hamsters caused profound inhibition of the in vitro antigen-induced proliferative response of lymph node cells from hamsters immunized with leishmanial antigens. Moreover, this inhibition was totally abrogated by the anti-TGF-beta MAb. These results suggest that the immunosuppression observed in visceral leishmaniasis is, at least in part, due to the abundant production of TGF-beta during the course of the infection.

• Authors: V Rodrigues Jr, J Santana da Silva, A Campos-Neto
• Journal: Infection and immunity (Infect Immun) Vol. 66 Issue 3 Pg. 1233-6 (Mar 1998) ISSN: 0019-9567 [Print] United States
• PMID: 9488418 (Publication Type: Journal Article, Research Support, Non-U.S. Gov't)

Chemical References

• Transforming Growth Factor beta

Topics

• Animals
• Cricetinae
• Immune Tolerance
• Leishmaniasis, Visceral (immunology)
• Mice
• Transforming Growth Factor beta (biosynthesis)